Yield, boron uptake and canopy sunlight interception of direct-sown winter rapeseed as affected by boron fertilizer levels in China

Yield, boron uptake and canopy sunlight interception of direct-sown winter rapeseed as affected by boron fertilizer levels in China | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Yield, boron uptake and canopy sunlight interception of direct-sown winter rapeseed as affected by boron fertilizer levels in China Rui Wang, Wenli Peng, Hui Teng This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4981549/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 09 Oct, 2025 Read the published version in Scientific Reports → Version 1 posted 10 You are reading this latest preprint version Abstract Boron is a very important micro-element for winter rapeseed, boron deficiency resulted in “flowering without seed setting” for winter rapeseed. Attention should been paid to the effects of boron application levels on yield and its utilization mechanism in main rapeseed production areas of southwestern China. A split-plot field experiment was conducted with five boron application levels (0, 3.75, 7.5, 15, and 30 kg boron ha − 1 ) and two rapeseed cultivars (Huayouza 9 and Zhongshuang 11). When boron was applied comparing with non-boron supply, seed yield of winter rapeseed increased 17.2–38.5% in 2020-21 and 6.2–38.1% in 2021-22, respectively. The boron uptake in the seed initially increased significantly and then nearly kept steadily, but the accumulation of boron continued to increase in the pericarp and stem with the increase of boron application levels from 0 to 30 kg ha − 1 . Boron application level of 7.5–15 kg ha − 1 is important to increase the current direct-sown winter rapeseed yields in field soils with low available boron in Southwest China cropping areas. Seed yield was more significantly affected by boron input than crop canopy sunlight interception for direct-sown winter rapeseed in this region. These results indicated that it is an effective way to maintain soil fertility by returning no-seed rapeseed plant tissues to replenish soil boron in Southwest China and other boron-deficient planting area. Biological sciences/Plant sciences/Plant physiology Biological sciences/Plant sciences/Plant ecology Biological sciences/Plant sciences/Plant stress responses/Light stress Rapeseed Boron Sunlight interception Crop canopy Yield Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Introduction Rapeseed is now the most important source of vegetable oil and also a potential bio-fuel crop in the world 1 . As the largest winter rapeseed planting country, China accounts for more than 19% of world rapeseed production 2 . However, the rapeseed yield was about 1.65 t ha − 1 in China 3 , less than worldwide average yield of 1.8 t ha − 1 . Hence, a further increase rapeseed yield is critical for the national consumption of edible oil. Rational application of fertilizer is an effective approach to promote winter rapeseed yield and secure the supply of edible oil 4 – 5 . However, comparing with N, P, K fertilizer applications, there is relatively little research on boron fertilizer application 6 – 11 . Boron, which is the eighth essential micro-nutrients for the plants normal growth, plays an important role in plant growth and hence the yield formation for rapeseed 1 . Boron played a special role in transporting photosynthate from pericarp to seed and had potential to promote seed yield 12 . Boron application was beneficial to the significant increase of the number of pods per plant and seeds per pod 13 . Yang et al. 13 indicated that boron deficiency hampered crop growth and development and even resulted in a typical symptom named “flowering without seed setting” for winter rapeseed. The symptoms of boron deficiency ultimately reduced rapeseed yield attributed to the inhibitions of meristem activity and flower development 1 . Field soil available boron-deficiency widely exists in rapeseed producing areas in the southwest of China, as well as other 80 countries around the world 7 , 12 . Winter rapeseed is one of crops sensitive to boron nutrition stress, so it is urgent to investigate the effects of boron application level on yield and its utilization mechanism for winter rapeseed plantation in Southwest China. Seed yield could also be affected positively by crop canopy sunlight interception 5 . Canopy sunlight interception and absorbance are of importance for yield formation during reproductive growth period 14 – 15 . The improvement of canopy sunlight interception can increase winter rapeseed yield 16 . More sunlight intercepted by canopy extending period of photosynthetic activity of rapeseed population canopy 17 . Green leaves and pods were major photosynthetic organs in rapeseed plant canopy, which responsible for crop photosynthesis and dry matter accumulation 18 . Masood et al. 7 suggested that boron fertilizer application promoted crop canopy photosynthesis for winter rapeseed. Excessive boron nutrition in rapeseed instead reduced photosynthetic rates, leading to chlorosis and burning of leaf margins 19 , which negatively impacted crop canopy sunlight utilization. Hence, examining the relationship between canopy sunlight interception and boron application levels is conducive to reveal winter rapeseed growth dynamics and yield formation process. Direct sowing can be benefited from labor-saving and advancements in the whole mechanized process of rapeseed production, which has become increasingly popular in major rapeseed planting areas of China 5 . The research indicated that direct-sowing rapeseed could have significantly more demand for the elemental nutrients than transplanting seedlings 11 . Direct-sowing rapeseed was sensitive to nutrient deficiencies, leading to slow development of individual plants and shrinkage of plants population, low efficiency of nutrient transport in the generative growth period 4 . In addition, Zhu et al. 11 reported that direct-sown rapeseed had reduced yield more than transplanting seedlings under the nutrient stress conditions. That is to say, direct-sown rapeseed might differ in boron uptake characteristics and fertilizer management practices comparing with transplanting seedlings. However, the studies are limited for the boron application level response of direct-sown rapeseed performance in the field, and none have explored the effects of boron deficiency on direct-sown rapeseed canopy sunlight interception. This study aimed to evaluate (i) the effect of boron fertilization on yield and boron uptake in various boron application levels, and (ii) the relationship of boron application levels between seed yield and canopy sunlight interception for direct-sown winter rapeseed. Materials and Methods Site description Field experiments were conducted in Bijiang County (109°13′E, 27°47′N, 470m), Guizhou Province of China during 2020-21 and 2021-22. This location has an average annual temperature of 15.6℃,and an precipitation of 1260 mm. During winter rapeseed growing season, the temperature was always lower (averaged 6.3 and 7.4℃in the two wintering periods during 2020-21 and 2021-22, respectively) and less rainfall (31.0 and 36.3 mm, respectively) during the wintering period. Compared to winter rapeseed flowering period, it always occurred from April to May with warmer temperature (averaged 29.1 and 31.6℃in flowering phases in 2020-21 and 2021-22, respectively) and more rainfall (171.0 and 146.6 mm, respectively). Trial field soil in 0–20 cm layer were: alkali hydrolysable nitrogen of 61.45 mg kg − 1 , available phosphorus of 11.76 mg kg − 1 , available potassium of 92.88 mg kg − 1 and available boron of 0.14 mg kg − 1 in 2020, and 66.96, 16.16, 103.83 and 0.16 mg kg − 1 in 2021, correspondingly. Experimental design A split-plot experiment was conducted with three replications in the two seasons. Main plots were the two rapeseed cultivars of Huayouza 9 (HZ9) and Zhongshuang 11 (ZS11), and subplots were five boron application levels which included 0 (B 0 ), 3.75 (B 1 ), 7.5 (B 2 ), 15 (B 3) , and 30 kg boron ha − 1 (B 4 ). Both cultivars are widely planting in most cropping areas of Southwest China. 180 kg N ha − 1 , 90 kg P 2 O 5 ha − 1 and 75 kg K 2 O ha − 1 were mixed into plot topsoil, respectively, to ensure that nutrients except boron did not limit crop growth. The fertilizers used were urea for N, single superphosphate for P 2 O 5 , potassium chlorid for K 2 O, and borax for boron; and P 2 O 5 , K 2 O and boron were all applied as basal fertilizer before sowing. Half of total N was as basal, the half was applied in overwintering period. The planting density was 30 plants m − 2 and row spacing of 20 cm. Each plot was 10 m 2 , with length of 5 m and width of 2 m. Other field management procedures followed the traditional practices of local farmers. Sampling and measurements Ten representative plants were sampled in each plot to measure parameters in plant individual level one day before harvest. The samples were washed with deionized water, blotted dry and divided into plant tissues (seed, pericarp and stem). After drying for 30 minutes at 105 ℃ to deactivate the enzymes and drying to a constant weight at 65 ℃, the dry weight were measured for the plant tissues. The dried seed, pericarp, and stem samples were then pulverized and sieved to determine their boron content. The boron contents of the different tissues from plant were estimated by Azomethine H-colorimetric method 20 . All plants each plot were manually harvested and threshed at maturity to determine the yields of rapeseed seed and aboveground biomass. The SunScan Canopy Analysis System was used to measure sunlight interception of crop canopy (Delta-T Devices Ltd., UK) following the methods of Wang et al. 5 . Parameter calculation The boron uptake, boron use efficiency and boron harvest index (BHI) were calculated referring to the model of Rathke et al. 4 Boron uptake by seed (B up,s , g ha − 1 ) = seed yield × boron content of seed (1) Boron uptake by pericarp (B up,p , g ha − 1 ) = pericarp yield × boron content of pericarp (2) Boron uptake by stem (B up,t , g ha − 1 ) = stem yield × boron content of stem (3) Boron uptake in aboveground (B up , g ha − 1 ) = B up,s + B up,t + B up,p (4) Boron harvest index (BHI, %) = B up,s / B up (5) Reciprocal internal efficiency (RIE, g t − 1 ) = (B up / Y) × 1000 (6) Internal use efficiency (IUE, kg g − 1 ) = Y / B up (7) Agronomic efficiency (AE, kg g − 1 ) = (Y F –Y 0 ) / F (8) Physiological efficiency (PE, kg g − 1 ) = (Y F – Y 0 ) / (B up,F − B up,0 ) (9) Where F denotes the level of boron application to rapeseed (kg ha − 1 ), and Y denotes the seed yield (kg ha − 1 ), Y F and Y 0 represent the seed yield in supplied boron plot and in non-supplied one, respectively. B up,F and B up,0 represent the boron uptake of the aboveground tissues of rapeseed plant each plot with and without boron application, respectively. Statistical analyses Independent ANOVA was conducted to test the main effects of boron application levels, rapeseed cultivars, and their interactions on boron uptake, sunlight interception, yield, and yield components of each growing seasons. Multiple comparisons were performed to analyze significant effects with the least significant difference test at P ≤ 0.05. A Pearson correlation analysis and ANONA was carried out using the SPSS statistics 25.0 (SPSS, Amonk, NY, USA). Figures were generated with SigmaPlot software (SigmaPlot 10.0, United States) Results Seed yield Boron application levels and rapeseed cultivars produced significant difference in seed yield during the two experimental seasons (Table 1 ). The lowest yields were obtained in B 0 for both cultivars, with harvesting of 1567 kg ha − 1 for ZS11 and 1753 kg ha − 1 for HZ9 in 2020-21, and 1621 kg ha − 1 for ZS11 and 2001 kg ha − 1 for HZ9 in 2021-22, respectively (Fig. 1 ). As results showed that boron application level significantly promoted seed output (Fig. 1 ). Seed yields increased 17.2%-38.5% (from 3.75 to 30 kg boron ha − 1 ) in 2020-21 and 6.2%-38.1% (from 3.75 to 30 kg boron ha − 1 ) in 2021-22 when boron application level differed, by comparison with zero boron supply. In addition, seed yield mostly kept an upward tendency with boron application levels improving for both cultivars and experimental seasons. The ZS11 produced an average yield of 1698, 1863, 2204 and 2175 kg ha − 1 at B 1 , B 2 , B 3 and B 4 , (means of 2 seasons) respectively; and HZ9 did 2097, 2127, 2367 and 2513 kg ha − 1 at B 1 , B 2 , B 3 and B 4 , respectively. Table 1 Results of ANOVA on the effects of boron application level (B), cultivar (C), growing season (GS), and their interactions on seed yield (SY), boron uptake in seed (Bup,s), boron uptake in pericarp (Bup,p), boron uptake in stem (Bup,m), boron harvest index (BHI), reciprocal internal efficiency (RIE), internal use efficiency (IUE), agronomic efficiency (AE), and physiological efficiency (PE) for winter rapeseed. Source SY Bup,s Bup,p Bup,m BHI RIE IUE AE PE B ** ** ** ** ** ** ** ** * C ** ** ** ** ** ** ** ns ** GS ns ns ns ns ns ns ns ns ns BམC ns ** ns ** ** ** ** * * BམGS ns ns ns ns ns ns ns ns ns GSམC ns ns ns ns ns ns ns ns ns BམGSམC ns ns ns ns ns ns ns ns ns F values and significance levels; ns: no significant, p > 0.05, * p < 0.05, ** p < 0.01. Boron uptake The boron fertilizer application levels affected significantly boron uptake in the seed, pericarp, and stem (Table 1 ). As the boron supply enhanced, boron accumulation in the seed increased dramatically at first and then steadied in ZS11 and HZ9, but still increased in pericarp and plant stem (Fig. 2 ). Boron uptake in seed of ZS11 and HZ9 rose by 7.2–18.6 and 9.0-19.6 g ha − 1 , respectively, when boron application levels were raised from B 1 to B 4 by comparison with B 0 . Similarly, when compared to B 0 , boron absorption rose by 49.5-118.1 and 47.5-118.5 g ha − 1 in pericarp of ZS11 and HZ9, respectively; and by 5.0-57.2 and 8.5–91.2 g ha − 1 in crop stem of ZS11 and HZ9, respectively. According to Fig. 3 , there was a positive linear association between boron accumulation in aboveground biomass and boron application level, showing that direct-sown rapeseed acquired more biomass as the boron application levels improved. The boron harvest index (BHI) decreased as boron application levels increased in the 2020-21 and 2021-22 (Fig. 4 ). Averagely, BHI of winter rapeseed cultivars ranged between 15.4–19.5% at various boron application levels. There was no significant interaction for growing seasons and cultivars, therefore, the BHI were averaged for presenting the results of different boron levels across seasons and both cultivars. The results showed that the absorbed boron is primarily distributed in the stem (range 27.7–36.7%, average 33.8%) and pericarp (range 34.9–50.5%, average 45.5%). Results indicated that it is a linear relationship between yield and boron intake across the two cultivars (Fig. 5 ). Within the range of 0-400 kg ha − 1 , seed yield rose up linearly with the boron uptake in the aboveground for both rapeseed cultivars in 2020-21 and 2021-22. As results showed, the aboveground biomass yield also remained to increase with a further increase of boron absorption by rapeseed plant, even in the high boron application levels in the experiments. Boron use efficiency Boron application levels had significantly affected the utilization of boron nutrition for HZ9 and ZS11 (Table 1 ). As Table 2 showed, there was a steady increase in reciprocal internal efficiency (RIE) with rising boron application level. Winter rapeseed required 68.7–137.0 g boron to outcome 1 t seed yield (average 104.0 g t − 1 ) for different boron application levels. During both experimental seasons, internal use efficiency (IUE) decreased significantly as boron application levels rose for both cultivars. Across two cultivars and boron application levels, plant absorbed 1 g boron to produce 7.4–15.7 kg seed yield of winter rapeseed. With an increase of applied boron level, agronomic efficiency (AE) always continuously dropped for boron nutrition. Among the four boron application levels, AE of them differed significantly for both cultivars. Table 2 Effect of boron fertilizer application levels on boron use efficiencies of winter rapeseed. Treatments 2020–2021 2021–2022 HZ9 ZS11 Mean HZ9 ZS11 Mean Reciprocal internal efficiency (RIE), g t − 1 B0 82.5 d 55.0 d 68.8 d 82.7 d 54.8 d 68.7 d B1 99.6 c 81.6 c 90.6 c 99.5 c 81.8 c 90.7 c B2 110.3 c 93.3 bc 101.8 c 110.5 c 93.5 bc 102.0 c B3 131.1 b 112.6 ab 121.8 b 131.3 b 112.7 ab 122.0 b B4 150.0 a 124.1 a 137.0 a 149.3 a 124.5 a 136.9 a Mean 114.7 102.9 104.0 122.6 103.1 104.0 Internal use efficiency (IUE), kg g − 1 B0 15.2 a 18.2 a 15.2 a 12.1 a 18.3 a 15.2 a B1 10.1 b 12.5 b 11.3 ab 10.1 b 12.4 b 11.3 ab B2 9.1 b 10.8 bc 10 b 9.1 c 10.8 bc 10.0 b B3 7.6 b 9.0 cd 8.3 b 7.6 d 8.9 cd 8.3 b B4 6.7 b 8.1 d 7.4 b 6.7 e 8 d 7.4 b Mean 9.7 11.7 10.4 9.1 11.7 10.4 Agronomic efficiency(AE), % B0 - - - - - - B1 33.8 a 71.9 a 52.9 a 33.7 a 71.6 a 52.7 a B2 26.0 b 40.2 b 33.1 b 26.8 b 41.2 b 34.0 b B3 20.7 c 19.2 bc 18.5 c 21.1 bc 19.5 bc 19.0 bc B4 17.8 c 14.2 c 17.5 c 18.4 c 13.5 c 17.3 c Mean 24.6 36.4 30.5 25.0 36.4 30.7 Physiological efficiency (PE) B0 - - - - - - B1 2.6 a 4.6 a 3.4 a 2.6 a 4.4 a 3.3 a B2 2.4 a 3.9 ab 3.3 a 2.5 a 3.8 ab 1.8 a B3 2.3 a 3.2 ab 2.8 a 2.2 a 3.1 ab 3.2 a B4 2.2 a 1.6 b 1.9 a 2.1 a 1.5 b 2.8 a Mean 2.4 3.3 2.8 2.3 3.2 2.8 Treatments refer to the boron fertilizer application levels. RIE, IUE, AE and PE refer to the reciprocal internal efficiency, internal use efficiency, agronomic efficiency and physiological efficiency of boron, respectively. B 0 , B 1 , B 2 , B 3 , B 4 refer to the levels of boron fertilizer applied, which were 0, 3.75, 7.5, 15, 30 kg boron ha − 1 , respectively. HZ9 and ZS11 refer to the different winter rapeseed cultivar, respectively. Means with different letters are significantly different in the treatments (p < 0.05). Values are means of three replicates. In Table 2 , physiological efficiency (PE) gradually decreased with an increase of boron application level. The PE of HZ9 increased from 2.2 to 2.6 kg g − 1 at increased boron application levels across both seasons, and that of ZS11 did from 1.5 to 4.5 kg g − 1 . In compared to B 1 , the PE of B 2 , B 3 and B 4 declined by 4.4, 17.6 and 44.1% across both cultivars in 2020-21 season, and by 3.0, 15.2 and 45.5% in 2021-22. Canopy sunlight interception During different growth periods of direct-sown winter rapeseed, canopy intercepted sunlight significantly different in various boron application levels and both cultivars (Fig. 6 ). B 0 intercepted relatively less sunlight than other boron application levels during the seedling stage and podding stage. Canopy intercepted sunlight at B 0 was significantly less than B 1 , B 2 , B 3 and B 4 during rapeseed seedling stage. However, in the budding and flowering periods, the difference of canopy sunlight interception decreased between B 0 and B 1 , even though there was significant difference between B 1 and the other high boron application levels. Moreover, at podding stage, significant differences in sunlight interception were similarly recorded between B 0 and other varied boron application levels. Averagely, for all growing stages, crops intercepted significantly higher sunlight in B 2 , B 3 and B 4 than in B 0 and B 1 (Fig. 6 ). B 4 intercepted the highest one (70.4%), followed by B 3 (69.0%) and B 2 (68.5%), while B 0 recorded the lowest (56.4%). Figure 6 also showed that canopy intercepted sunlight was slightly lower in ZS11 than in HZ9; HZ9 enhanced sunlight interception by more than 2.5% compared with ZS11 across all the boron levels and experimental seasons. As indicated that both cultivars obtained significant different sunlight interception and seed yield during all growing stages (Fig. 7 ). Discussion The experiment substantiated that boron fertilization level had a significant effect on the increase of seed yield (ranging from 6.2–38.5%) for all boron application levels in direct-sown winter rapeseed. The increase in boron supply level led in a significant increase of seed yield when the level of boron application was above 7.5 kg ha − 1 compared to the levels of 0-7.5 kg ha − 1 . Boron application exactly increased seed yield, which was consistent with the previous reports 12 – 13 . Our results also demonstrated that yield responses to boron supply kept an upward tendency with boron application level improving within certain range. Excessive boron concentrations could be toxic to crop growth, and even reduce seed yield for barley that the boron toxicity threshold values occurred in the 10–130 mg boron kg − 1 dry weight 21 . However, seed yield was not adversely affected by the highest boron application level (30 kg ha − 1 ) in the trial field. Direct-sown winter rapeseed should have higher requirement for boron nutrition in comparison with other crops, maybe involving in some different process to utilizing boron in field soil condition, which need more researches to unveil the physiological mechanism of boron nutrition. Boron uptake in rapeseed aboveground increased sharply as boron application level increased (Fig. 3 ). Seed yield followed a significant linear relationship (Fig. 5 ), partially agreed to a previous study that boron fertilization promoted seed output due to the higher boron uptake in aboveground biomass 1 . With the increase of boron application levels, boron uptake in the seed increased significantly initially and then stabilized, while boron uptake in pericarp and stem of rapeseed plants continued to increase, indicating that the consumption of boron was mainly stored in the no-seed tissues of plants when boron application level was higher than a certain degree. Notably, an average of 79.1% (ranging 70.5–86.3%) of boron element was taken up, hence stored in the plant stem and pericarp by winter rapeseed. The parameters related boron uptake provide more information on the acquisition and utilization of boron nutrition by direct-sown winter rapeseed. The amount of required boron to generate 1 t of seed rose as the boron application level increased in this study. Boron utilization efficiency fell as the level of boron supply improved. The highest IUE was at the zero boron applied level of B 0 , and the lowest IUE occurred when boron level was at B 4 . These results agreed that the utilization efficiency of boron uptake generally decreased when the amount of boron supply increased 1 , 22 . Therefore, it is relatively appropriate to applying 7.5–15 kg ha − 1 boron level for the current direct-sown rapeseed cultivation in Southwest China cropping areas. When the level of boron application is high, more boron is absorbed and stored in the pericarp and stem tissues, without storing too much boron in the grain, explaining that this may be a special form of luxurious absorption of boron nutrient. It was a common phenomenon of crop plants’ luxurious consumption in such macro-element uptake as N, P and K 8 , 10 – 11 . In this study, the luxurious consumption of boron only occurred in non-seed tissues (developmental organs) and not in reproductive organs, which may also be a stress avoidance mechanism exhibited in its interaction with the environment by rapeseed. Storing redundant boron in non-seeds can reduce the adverse effects of surfeited boron retention in seeds on rapeseed germination, seedling and growth in excessive boron elemental environments. The research has indicated that high boron concentrations can be toxic to crop growth and reduce seed yield 7 . Shi et al. 21 reported that for many varied crops, the boron toxicity threshold values occurred in the 10–130 mg boron kg − 1 dry weight. In this trial, although rapeseed was not adversely and toxic affected by even the highest boron level (30 kg ha − 1 ), the more physiological activities still need to be explored in depth for direct-sown rapeseed in field. For both winter rapeseed cultivars, sunlight interception (SI) improved sharply at first by increasing of applied boron-levels from 0 to 3.75 kg boron ha − 1 , but then it changed slightly with further increasing boron supply. The SI was closely related to the changes of canopy area index during rapeseed’s growing period, which influenced the distribution of SI for direct-sown rapeseed plant population canopy and hence plants canopy population photosynthesis 16 , 23 . For rapeseed population canopy level, the significant difference in SI among varied boron application levels occurred at seedling stage. The effect of boron deficiency limited the crop canopy initial growth rate, which closely related to aboveground biomass accumulation in direct-sown rapeseed vegetative growing period 1 . This study here showed that the boron supply level significantly affected crop canopy SI at direct-sown rapeseed plant population level at earlier growing stages, and hence led to the difference of above-ground biomass. This relationship could be explained by our results that more boron application level produced more dry matter and had more boron uptake. In addition, some researchers found that sufficient boron nutrition could promote leaf appearance rate, leaf number, and photosynthetic rate, and hence the total production of dry matter 12 – 13 . Responses of SI triggered rapeseed canopy photosynthetic area development under different boron application levels during crop early growing periods, which might contribute to the difference in seed yield consequently 4 , 14 . This study demonstrates that boron application as basal fertilizer can not only improve the light conditions of the crop canopy during the early growth stage, but also significantly increase yield of direct-sown rapeseed. Although the more boron applied, the higher boron stored in pericarp and stem at harvest, this results extend us with a method to improve the boron status of soil. So returning no-seed rapeseed plant tissues to replenish soil boron could be an effective way to maintain soil fertility in locations where soil available boron is low, since boron deficiency is widely in soil in over 80 countries around the world 24 – 25 . This measure implementation utilizes boron element to increase seed yield of direct-sown winter rapeseed, and can utilize the luxurious absorption of boron element by rapeseed no-seed tissues to return most of boron to the cropland soil. Conclusions Boron application level of 7.5–15 kg ha − 1 is important to increase the current direct-sown winter rapeseed yields in field soils with low available boron in Southwest China cropping areas. Boron application enhanced direct-sown winter rapeseed output by 6.2–38.5% compared to zero boron supply. With the increase of boron application, the yield of the two rapeseed cultivars increased continuously in the study. The boron uptake in seed increased initially and then stabilized, while the boron uptake by pericarp and stem kept an upwards tendency significantly with the increase of boron application level. About 79.1% boron absorbed by rapeseed plant is distributed in the pericarp and stem (70.5–86.3%). Effectively returning no-seed rapeseed plant tissues to replenish soil boron could maintain soil fertility. Seed yield was more significantly affected by boron application levels than crop canopy sunlight interception for direct-sown winter rapeseed in this region. Declarations Competing interests The authors declare no competing of interests. Funding This study was supported by National Natural Science Foundation of China (31660354), Guizhou High-level Innovative Talents Project (2020-2018-034) and Doctoral Special Project of Kaili University (BS20240222). Author Contribution Author's contribution"R.W.: Conceptualization, Validation, Writing-review & editing, Supervision, Project administration, Funding acquisition; W.L.P.: Methodology, Formal analysis, Validation, Writing-review & editing, Supervision; H.T.: Methodology, Investigation, Formal analysis, Validation, Writing-original draft. All authors reviewed the manuscript." Data Availability The data that support this study will be shared upon reasonable request to the corresponding author. References Dinh, A. Q., Naeem, A., Sagervanshi, A., Wimmer, M. A. & Muhling, K. H. 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Light restriction delays leaf senescence in winter oilseed rape ( Brassica napus L). J. Plant. Growth Regul. 32 (3), 506–518 (2013). Fortescu, J. A. & Turner, D. W. Changes in seed size and oil accumulation in Brassica napus L. by manipulating the source-sink ratio and excluding light from the developing siliques. Aus J. Agri Res. 58 (5), 413–424 (2007). Wang, Z. F., Wang, Z. H., Shi, L., Wang, L. J. & Xu, F. S. Proteomic alterations of Brassica napus root in response to boron deficiency. Plant. Mol. Bio . 74 (3), 265–278 (2010). Gaines, T. P. & Mitchell, G. A. Boron determination in plant-tissue by the azomethine-h method. Commun. Soil. Sci. Plant. Anal. 10 (8), 1099–1108 (1979). Shi, L. et al. Identification of quantitative trait loci associated with low boron stress that regulate root and shoot growth in Brassica napus seedlings. Mol. Breeding . 30 (1), 393–406 (2012). Misra, S. M., Sinha, N. C. & Tomer, P. S. Seed yield of sorghum grown in an alfisol, in relation to boron nutrition at the reproductive phase. Plant. Soil. 132 (2), 293–296 (1991). Behrens, T. & Diepenbrock, W. Using digital image analysis to describe canopies of winter oilseed rape ( Brassica napus L.) during vegetative developmental stages. J. Agro Crop Sci. 192 (4), 295–302 (2006). Wang, K. et al. Low risks of toxicity from boron fertiliser in oilseed rape-rice rotations in southeast China. Nutr. Cycl. Agro-ecosys . 54 , 189–197 (1999). Yang, X., Yu, Y. G., Yang, Y., Bell, R. W. & Ye, Z. Q. Residual effectiveness of boron fertilizer for oilseed rape in intensively cropped rice-based rotations. Nutri Cycl. Agro-ecosys . 57 , 171–181 (2000). Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 09 Oct, 2025 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 23 Dec, 2024 Reviews received at journal 18 Dec, 2024 Reviews received at journal 04 Dec, 2024 Reviewers agreed at journal 27 Nov, 2024 Reviewers agreed at journal 26 Nov, 2024 Reviewers invited by journal 26 Nov, 2024 Editor assigned by journal 19 Nov, 2024 Editor invited by journal 06 Sep, 2024 Submission checks completed at journal 04 Sep, 2024 First submitted to journal 27 Aug, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4981549","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":361229373,"identity":"ec2ca0c7-d78c-48d5-85fb-61bc13b73c91","order_by":0,"name":"Rui Wang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA4ElEQVRIiWNgGAWjYPACCTkJdiCVAGIfIFKLsQQziVoYEmcww5iEtBgcP3v4dWWbRfrMZh6zBw/bGOT4biQwfi7Ap+VMXprl2TaJ3NnMPOYGiW0MxpI3EpilZ+DRYnYgx8ywEahlHjOPmUTCGYbEDTcS2Jh58Gk5/wasJV0OqqWesJYbOcYPgVoSpMFaKhgSDAhpsb/xxoyx4ZyE4cxmtjKgFiDjzMNmaXxaJPtzjD82lNXJSxxv3ib5w8BGnu948sHP+LQAAZsEEgfEZmzAr4GBgfkDIRWjYBSMglEwwgEAaw5FEFzoPNEAAAAASUVORK5CYII=","orcid":"","institution":"Kaili University","correspondingAuthor":true,"prefix":"","firstName":"Rui","middleName":"","lastName":"Wang","suffix":""},{"id":361229374,"identity":"85602a7f-9b61-48a7-9460-854c3047f1e0","order_by":1,"name":"Wenli Peng","email":"","orcid":"","institution":"Tongren University","correspondingAuthor":false,"prefix":"","firstName":"Wenli","middleName":"","lastName":"Peng","suffix":""},{"id":361229375,"identity":"dfda78a9-92d7-453b-b4b5-eed6124b3e34","order_by":2,"name":"Hui Teng","email":"","orcid":"","institution":"Tongren University","correspondingAuthor":false,"prefix":"","firstName":"Hui","middleName":"","lastName":"Teng","suffix":""}],"badges":[],"createdAt":"2024-08-27 05:08:15","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4981549/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4981549/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-025-19306-x","type":"published","date":"2025-10-09T15:57:03+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":66081032,"identity":"46c1993f-4a18-4e92-bd06-5c31e5d5a95e","added_by":"auto","created_at":"2024-10-07 13:56:45","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":7734,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of boron application levels on seed yield (kg ha\u003csup\u003e-1\u003c/sup\u003e) in 2020-2022. B\u003csub\u003e0\u003c/sub\u003e, B\u003csub\u003e1\u003c/sub\u003e, B\u003csub\u003e2\u003c/sub\u003e, B\u003csub\u003e3\u003c/sub\u003e, and B\u003csub\u003e4\u003c/sub\u003e refer to the boron application levels of 0, 3.75, 7.5, 15, and 30 kg ha\u003csup\u003e-1\u003c/sup\u003e, respectively. HZ9 and ZS11 indicate the different winter rapeseed cultivar, respectively. Means with different letters are significantly different among boron application levels (p \u0026lt; 0.05). Values are means of three replicates. The same as below.\u003c/p\u003e","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-4981549/v1/ca31f2f802296f91b720f0b0.png"},{"id":66081034,"identity":"73d7caa1-8733-4580-9e80-1ac352b1531f","added_by":"auto","created_at":"2024-10-07 13:56:45","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":11217,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of boron application levels on boron uptake in seed, pericarp and stem (kg ha\u003csup\u003e-1\u003c/sup\u003e) in 2020-2022. HZ9 and ZS11 refer to the different winter rapeseed cultivar, respectively.\u003c/p\u003e","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-4981549/v1/dc3aefa744ecda19d9582d9d.png"},{"id":66081629,"identity":"6a40f2d3-b003-4f50-b09e-6b40ce607c46","added_by":"auto","created_at":"2024-10-07 14:04:45","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":8397,"visible":true,"origin":"","legend":"\u003cp\u003eCorrelation and regression of boron application levels with boron uptake in aboveground biomass at harvest in 2020-21 and 2021-22. X represents the boron application level, y represents boron uptake by aboveground biomass. **Indicates that the equation is extremely significant at p \u0026lt; 0.01.\u003c/p\u003e","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-4981549/v1/52a8055951f6eddab0f445e9.png"},{"id":66079923,"identity":"2ebe8e48-934d-44e5-a32d-e62b396dce3c","added_by":"auto","created_at":"2024-10-07 13:48:45","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":7853,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of boron application levels on boron harvest index (%) in 2020-2022.\u003c/p\u003e","description":"","filename":"Onlinefloatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-4981549/v1/3fa3ca4cba0c1fcf2f47528d.png"},{"id":66081035,"identity":"02702d6c-fcee-4bb8-a3b0-60bd6e6c326b","added_by":"auto","created_at":"2024-10-07 13:56:45","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":7176,"visible":true,"origin":"","legend":"\u003cp\u003eRelationships between boron uptake in aboveground biomass and seed yield at harvest in (a) 2020-21 and (b) 2021-22 in winter rapeseed. X represents boron uptake in aboveground biomass, y represents seed yield. **Indicates that the equation is extremely significant at p \u0026lt; 0.01.\u003c/p\u003e","description":"","filename":"Onlinefloatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-4981549/v1/30dbecd17110b7b411be1405.png"},{"id":66079924,"identity":"1b6ae599-57d1-47e2-b45e-c4475b239079","added_by":"auto","created_at":"2024-10-07 13:48:45","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":6795,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of different boron application levels on canopy sunlight interception at the seedling (S), budding (B), flowering (F) and podding (P) stages (A) and the cultivars of HZ9 and ZS11 (B). Data are averaged across two seasons.\u003c/p\u003e","description":"","filename":"Onlinefloatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-4981549/v1/7f7f69e07f10f989e9618bc4.png"},{"id":66079919,"identity":"86bda08c-312e-4fe0-89e0-648292062fdd","added_by":"auto","created_at":"2024-10-07 13:48:45","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":10201,"visible":true,"origin":"","legend":"\u003cp\u003eRelationships between seed yield and canopy sunlight interception of winter rapeseed different boron application levels at different growing stages in 2020-2022. S, B, F, P refer to seedling, budding, flowering, and podding stages. R\u003csub\u003eS\u003c/sub\u003e, R\u003csub\u003eB\u003c/sub\u003e, R\u003csub\u003eF\u003c/sub\u003e, R\u003csub\u003eP\u003c/sub\u003e represent the regression eco-efficiency between the seed yield and canopy sunlight interception of winter rapeseed at seedling, budding, flowering, and podding stages.\u003c/p\u003e","description":"","filename":"Onlinefloatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-4981549/v1/28c06cec1c797eb59dabdda1.png"},{"id":93420198,"identity":"eecbc6d8-6d5f-4f32-aa01-14420b9f9a29","added_by":"auto","created_at":"2025-10-13 16:09:44","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1014487,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4981549/v1/5f5647a3-5ae8-4be3-90ea-17c8b8adeddd.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Yield, boron uptake and canopy sunlight interception of direct-sown winter rapeseed as affected by boron fertilizer levels in China","fulltext":[{"header":"Introduction","content":"\u003cp\u003eRapeseed is now the most important source of vegetable oil and also a potential bio-fuel crop in the world\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. As the largest winter rapeseed planting country, China accounts for more than 19% of world rapeseed production\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. However, the rapeseed yield was about 1.65 t ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in China\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e, less than worldwide average yield of 1.8 t ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. Hence, a further increase rapeseed yield is critical for the national consumption of edible oil. Rational application of fertilizer is an effective approach to promote winter rapeseed yield and secure the supply of edible oil\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. However, comparing with N, P, K fertilizer applications, there is relatively little research on boron fertilizer application\u003csup\u003e\u003cspan additionalcitationids=\"CR7 CR8 CR9 CR10\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eBoron, which is the eighth essential micro-nutrients for the plants normal growth, plays an important role in plant growth and hence the yield formation for rapeseed\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. Boron played a special role in transporting photosynthate from pericarp to seed and had potential to promote seed yield\u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e. Boron application was beneficial to the significant increase of the number of pods per plant and seeds per pod\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e. Yang et al.\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e indicated that boron deficiency hampered crop growth and development and even resulted in a typical symptom named \u0026ldquo;flowering without seed setting\u0026rdquo; for winter rapeseed. The symptoms of boron deficiency ultimately reduced rapeseed yield attributed to the inhibitions of meristem activity and flower development\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. Field soil available boron-deficiency widely exists in rapeseed producing areas in the southwest of China, as well as other 80 countries around the world\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e,\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e. Winter rapeseed is one of crops sensitive to boron nutrition stress, so it is urgent to investigate the effects of boron application level on yield and its utilization mechanism for winter rapeseed plantation in Southwest China.\u003c/p\u003e \u003cp\u003eSeed yield could also be affected positively by crop canopy sunlight interception\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. Canopy sunlight interception and absorbance are of importance for yield formation during reproductive growth period\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e. The improvement of canopy sunlight interception can increase winter rapeseed yield\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e. More sunlight intercepted by canopy extending period of photosynthetic activity of rapeseed population canopy\u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e. Green leaves and pods were major photosynthetic organs in rapeseed plant canopy, which responsible for crop photosynthesis and dry matter accumulation\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e. Masood et al.\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e suggested that boron fertilizer application promoted crop canopy photosynthesis for winter rapeseed. Excessive boron nutrition in rapeseed instead reduced photosynthetic rates, leading to chlorosis and burning of leaf margins\u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e, which negatively impacted crop canopy sunlight utilization. Hence, examining the relationship between canopy sunlight interception and boron application levels is conducive to reveal winter rapeseed growth dynamics and yield formation process.\u003c/p\u003e \u003cp\u003eDirect sowing can be benefited from labor-saving and advancements in the whole mechanized process of rapeseed production, which has become increasingly popular in major rapeseed planting areas of China\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. The research indicated that direct-sowing rapeseed could have significantly more demand for the elemental nutrients than transplanting seedlings\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. Direct-sowing rapeseed was sensitive to nutrient deficiencies, leading to slow development of individual plants and shrinkage of plants population, low efficiency of nutrient transport in the generative growth period\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. In addition, Zhu et al.\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e reported that direct-sown rapeseed had reduced yield more than transplanting seedlings under the nutrient stress conditions. That is to say, direct-sown rapeseed might differ in boron uptake characteristics and fertilizer management practices comparing with transplanting seedlings. However, the studies are limited for the boron application level response of direct-sown rapeseed performance in the field, and none have explored the effects of boron deficiency on direct-sown rapeseed canopy sunlight interception.\u003c/p\u003e \u003cp\u003eThis study aimed to evaluate (i) the effect of boron fertilization on yield and boron uptake in various boron application levels, and (ii) the relationship of boron application levels between seed yield and canopy sunlight interception for direct-sown winter rapeseed.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eSite description\u003c/h2\u003e \u003cp\u003eField experiments were conducted in Bijiang County (109\u0026deg;13\u0026prime;E, 27\u0026deg;47\u0026prime;N, 470m), Guizhou Province of China during 2020-21 and 2021-22. This location has an average annual temperature of 15.6℃,and an precipitation of 1260 mm. During winter rapeseed growing season, the temperature was always lower (averaged 6.3 and 7.4℃in the two wintering periods during 2020-21 and 2021-22, respectively) and less rainfall (31.0 and 36.3 mm, respectively) during the wintering period. Compared to winter rapeseed flowering period, it always occurred from April to May with warmer temperature (averaged 29.1 and 31.6℃in flowering phases in 2020-21 and 2021-22, respectively) and more rainfall (171.0 and 146.6 mm, respectively). Trial field soil in 0\u0026ndash;20 cm layer were: alkali hydrolysable nitrogen of 61.45 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, available phosphorus of 11.76 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, available potassium of 92.88 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and available boron of 0.14 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in 2020, and 66.96, 16.16, 103.83 and 0.16 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in 2021, correspondingly.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eExperimental design\u003c/h2\u003e \u003cp\u003eA split-plot experiment was conducted with three replications in the two seasons. Main plots were the two rapeseed cultivars of Huayouza 9 (HZ9) and Zhongshuang 11 (ZS11), and subplots were five boron application levels which included 0 (B\u003csub\u003e0\u003c/sub\u003e), 3.75 (B\u003csub\u003e1\u003c/sub\u003e), 7.5 (B\u003csub\u003e2\u003c/sub\u003e), 15 (B\u003csub\u003e3)\u003c/sub\u003e, and 30 kg boron ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (B\u003csub\u003e4\u003c/sub\u003e). Both cultivars are widely planting in most cropping areas of Southwest China. 180 kg N ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 90 kg P\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 75 kg K\u003csub\u003e2\u003c/sub\u003eO ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e were mixed into plot topsoil, respectively, to ensure that nutrients except boron did not limit crop growth. The fertilizers used were urea for N, single superphosphate for P\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e, potassium chlorid for K\u003csub\u003e2\u003c/sub\u003eO, and borax for boron; and P\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e, K\u003csub\u003e2\u003c/sub\u003eO and boron were all applied as basal fertilizer before sowing. Half of total N was as basal, the half was applied in overwintering period. The planting density was 30 plants m\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e and row spacing of 20 cm. Each plot was 10 m\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e, with length of 5 m and width of 2 m. Other field management procedures followed the traditional practices of local farmers.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eSampling and measurements\u003c/h2\u003e \u003cp\u003eTen representative plants were sampled in each plot to measure parameters in plant individual level one day before harvest. The samples were washed with deionized water, blotted dry and divided into plant tissues (seed, pericarp and stem). After drying for 30 minutes at 105 ℃ to deactivate the enzymes and drying to a constant weight at 65 ℃, the dry weight were measured for the plant tissues. The dried seed, pericarp, and stem samples were then pulverized and sieved to determine their boron content. The boron contents of the different tissues from plant were estimated by Azomethine H-colorimetric method\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e. All plants each plot were manually harvested and threshed at maturity to determine the yields of rapeseed seed and aboveground biomass. The SunScan Canopy Analysis System was used to measure sunlight interception of crop canopy (Delta-T Devices Ltd., UK) following the methods of Wang et al.\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eParameter calculation\u003c/h2\u003e \u003cp\u003eThe boron uptake, boron use efficiency and boron harvest index (BHI) were calculated referring to the model of Rathke et al.\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eBoron uptake by seed (B\u003csub\u003eup,s\u003c/sub\u003e, g ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e)\u0026thinsp;=\u0026thinsp;seed yield \u0026times; boron content of seed (1)\u003c/p\u003e \u003cp\u003eBoron uptake by pericarp (B\u003csub\u003eup,p\u003c/sub\u003e, g ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e)\u0026thinsp;=\u0026thinsp;pericarp yield \u0026times; boron content of pericarp (2)\u003c/p\u003e \u003cp\u003eBoron uptake by stem (B\u003csub\u003eup,t\u003c/sub\u003e, g ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e)\u0026thinsp;=\u0026thinsp;stem yield \u0026times; boron content of stem (3)\u003c/p\u003e \u003cp\u003eBoron uptake in aboveground (B\u003csub\u003eup\u003c/sub\u003e, g ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e)\u0026thinsp;=\u0026thinsp;B\u003csub\u003eup,s\u003c/sub\u003e + B\u003csub\u003eup,t\u003c/sub\u003e + B\u003csub\u003eup,p\u003c/sub\u003e (4)\u003c/p\u003e \u003cp\u003eBoron harvest index (BHI, %)\u0026thinsp;=\u0026thinsp;B\u003csub\u003eup,s\u003c/sub\u003e / B\u003csub\u003eup\u003c/sub\u003e (5)\u003c/p\u003e \u003cp\u003eReciprocal internal efficiency (RIE, g t\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) = (B\u003csub\u003eup\u003c/sub\u003e / Y) \u0026times; 1000 (6)\u003c/p\u003e \u003cp\u003eInternal use efficiency (IUE, kg g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e)\u0026thinsp;=\u0026thinsp;Y / B\u003csub\u003eup\u003c/sub\u003e (7)\u003c/p\u003e \u003cp\u003eAgronomic efficiency (AE, kg g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) = (Y\u003csub\u003eF\u003c/sub\u003e \u0026ndash;Y\u003csub\u003e0\u003c/sub\u003e) / F (8)\u003c/p\u003e \u003cp\u003ePhysiological efficiency (PE, kg g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) = (Y\u003csub\u003eF\u003c/sub\u003e \u0026ndash; Y\u003csub\u003e0\u003c/sub\u003e) / (B\u003csub\u003eup,F\u003c/sub\u003e \u0026minus; B\u003csub\u003eup,0\u003c/sub\u003e) (9)\u003c/p\u003e \u003cp\u003eWhere F denotes the level of boron application to rapeseed (kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), and Y denotes the seed yield (kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), Y\u003csub\u003eF\u003c/sub\u003e and Y\u003csub\u003e0\u003c/sub\u003e represent the seed yield in supplied boron plot and in non-supplied one, respectively. B\u003csub\u003eup,F\u003c/sub\u003e and B\u003csub\u003eup,0\u003c/sub\u003e represent the boron uptake of the aboveground tissues of rapeseed plant each plot with and without boron application, respectively.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analyses\u003c/h2\u003e \u003cp\u003eIndependent ANOVA was conducted to test the main effects of boron application levels, rapeseed cultivars, and their interactions on boron uptake, sunlight interception, yield, and yield components of each growing seasons. Multiple comparisons were performed to analyze significant effects with the least significant difference test at P\u0026thinsp;\u0026le;\u0026thinsp;0.05. A Pearson correlation analysis and ANONA was carried out using the SPSS statistics 25.0 (SPSS, Amonk, NY, USA). Figures were generated with SigmaPlot software (SigmaPlot 10.0, United States)\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eSeed yield\u003c/h2\u003e \u003cp\u003eBoron application levels and rapeseed cultivars produced significant difference in seed yield during the two experimental seasons (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The lowest yields were obtained in B\u003csub\u003e0\u003c/sub\u003e for both cultivars, with harvesting of 1567 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for ZS11 and 1753 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for HZ9 in 2020-21, and 1621 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for ZS11 and 2001 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for HZ9 in 2021-22, respectively (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). As results showed that boron application level significantly promoted seed output (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Seed yields increased 17.2%-38.5% (from 3.75 to 30 kg boron ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) in 2020-21 and 6.2%-38.1% (from 3.75 to 30 kg boron ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) in 2021-22 when boron application level differed, by comparison with zero boron supply. In addition, seed yield mostly kept an upward tendency with boron application levels improving for both cultivars and experimental seasons. The ZS11 produced an average yield of 1698, 1863, 2204 and 2175 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e at B\u003csub\u003e1\u003c/sub\u003e, B\u003csub\u003e2\u003c/sub\u003e, B\u003csub\u003e3\u003c/sub\u003e and B\u003csub\u003e4\u003c/sub\u003e, (means of 2 seasons) respectively; and HZ9 did 2097, 2127, 2367 and 2513 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e at B\u003csub\u003e1\u003c/sub\u003e, B\u003csub\u003e2\u003c/sub\u003e, B\u003csub\u003e3\u003c/sub\u003e and B\u003csub\u003e4\u003c/sub\u003e, respectively.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResults of ANOVA on the effects of boron application level (B), cultivar (C), growing season (GS), and their interactions on seed yield (SY), boron uptake in seed (Bup,s), boron uptake in pericarp (Bup,p), boron uptake in stem (Bup,m), boron harvest index (BHI), reciprocal internal efficiency (RIE), internal use efficiency (IUE), agronomic efficiency (AE), and physiological efficiency (PE) for winter rapeseed.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"10\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSource\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSY\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eBup,s\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eBup,p\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eBup,m\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eBHI\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eRIE\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eIUE\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eAE\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003ePE\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBམC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBམGS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGSམC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBམGSམC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003ens\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"10\"\u003e\u003cem\u003eF\u003c/em\u003e values and significance levels; ns: no significant, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05, \u003csup\u003e*\u003c/sup\u003e\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003csup\u003e**\u003c/sup\u003e\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eBoron uptake\u003c/h2\u003e \u003cp\u003eThe boron fertilizer application levels affected significantly boron uptake in the seed, pericarp, and stem (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). As the boron supply enhanced, boron accumulation in the seed increased dramatically at first and then steadied in ZS11 and HZ9, but still increased in pericarp and plant stem (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Boron uptake in seed of ZS11 and HZ9 rose by 7.2\u0026ndash;18.6 and 9.0-19.6 g ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, respectively, when boron application levels were raised from B\u003csub\u003e1\u003c/sub\u003e to B\u003csub\u003e4\u003c/sub\u003e by comparison with B\u003csub\u003e0\u003c/sub\u003e. Similarly, when compared to B\u003csub\u003e0\u003c/sub\u003e, boron absorption rose by 49.5-118.1 and 47.5-118.5 g ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in pericarp of ZS11 and HZ9, respectively; and by 5.0-57.2 and 8.5\u0026ndash;91.2 g ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in crop stem of ZS11 and HZ9, respectively. According to Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, there was a positive linear association between boron accumulation in aboveground biomass and boron application level, showing that direct-sown rapeseed acquired more biomass as the boron application levels improved. The boron harvest index (BHI) decreased as boron application levels increased in the 2020-21 and 2021-22 (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Averagely, BHI of winter rapeseed cultivars ranged between 15.4\u0026ndash;19.5% at various boron application levels. There was no significant interaction for growing seasons and cultivars, therefore, the BHI were averaged for presenting the results of different boron levels across seasons and both cultivars. The results showed that the absorbed boron is primarily distributed in the stem (range 27.7\u0026ndash;36.7%, average 33.8%) and pericarp (range 34.9\u0026ndash;50.5%, average 45.5%).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eResults indicated that it is a linear relationship between yield and boron intake across the two cultivars (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). Within the range of 0-400 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, seed yield rose up linearly with the boron uptake in the aboveground for both rapeseed cultivars in 2020-21 and 2021-22. As results showed, the aboveground biomass yield also remained to increase with a further increase of boron absorption by rapeseed plant, even in the high boron application levels in the experiments.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eBoron use efficiency\u003c/h2\u003e \u003cp\u003eBoron application levels had significantly affected the utilization of boron nutrition for HZ9 and ZS11 (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). As Table \u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e showed, there was a steady increase in reciprocal internal efficiency (RIE) with rising boron application level. Winter rapeseed required 68.7\u0026ndash;137.0 g boron to outcome 1 t seed yield (average 104.0 g t\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) for different boron application levels. During both experimental seasons, internal use efficiency (IUE) decreased significantly as boron application levels rose for both cultivars. Across two cultivars and boron application levels, plant absorbed 1 g boron to produce 7.4\u0026ndash;15.7 kg seed yield of winter rapeseed. With an increase of applied boron level, agronomic efficiency (AE) always continuously dropped for boron nutrition. Among the four boron application levels, AE of them differed significantly for both cultivars.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eEffect of boron fertilizer application levels on boron use efficiencies of winter rapeseed.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"13\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c13\" colnum=\"13\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTreatments\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2020\u0026ndash;2021\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2021\u0026ndash;2022\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHZ9\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eZS11\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eMean\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eHZ9\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003eZS11\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c12\"\u003e \u003cp\u003eMean\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"4\" nameend=\"c4\" namest=\"c1\"\u003e \u003cp\u003eReciprocal internal efficiency (RIE), g t\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e82.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e55.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e68.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e82.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e54.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e68.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003ed\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e99.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e81.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e90.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e99.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e81.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e90.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e110.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e93.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ebc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e101.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e110.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e93.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ebc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e102.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e131.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e112.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e121.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e131.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e112.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e122.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e150.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e124.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e137.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e149.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e124.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e136.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e114.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e102.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e104.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e122.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e103.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e104.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"7\" nameend=\"c7\" namest=\"c1\"\u003e \u003cp\u003eInternal use efficiency (IUE), kg g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e18.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e15.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e12.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e18.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e15.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e11.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e10.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e12.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e11.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eab\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ebc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e9.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e10.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ebc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e10.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ecd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e8.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e7.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e8.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ecd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e8.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e6.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ee\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e7.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e10.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e9.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e11.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e10.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eAgronomic efficiency(AE), %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e71.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e52.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e33.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e71.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e52.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e26.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e40.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e33.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e26.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e41.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e34.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e20.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e19.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ebc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e18.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e21.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ebc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e19.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ebc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e19.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003ebc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e17.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e18.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e13.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e17.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003ec\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e36.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e30.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e25.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e36.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e30.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003ePhysiological efficiency (PE)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e4.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e3.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e3.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e1.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e3.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e3.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e2.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003ea\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e3.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e2.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"13\"\u003eTreatments refer to the boron fertilizer application levels. RIE, IUE, AE and PE refer to the reciprocal internal efficiency, internal use efficiency, agronomic efficiency and physiological efficiency of boron, respectively. B\u003csub\u003e0\u003c/sub\u003e, B\u003csub\u003e1\u003c/sub\u003e, B\u003csub\u003e2\u003c/sub\u003e, B\u003csub\u003e3\u003c/sub\u003e, B\u003csub\u003e4\u003c/sub\u003e refer to the levels of boron fertilizer applied, which were 0, 3.75, 7.5, 15, 30 kg boron ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, respectively. HZ9 and ZS11 refer to the different winter rapeseed cultivar, respectively.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"13\"\u003eMeans with different letters are significantly different in the treatments (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Values are means of three replicates.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eIn Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, physiological efficiency (PE) gradually decreased with an increase of boron application level. The PE of HZ9 increased from 2.2 to 2.6 kg g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e at increased boron application levels across both seasons, and that of ZS11 did from 1.5 to 4.5 kg g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. In compared to B\u003csub\u003e1\u003c/sub\u003e, the PE of B\u003csub\u003e2\u003c/sub\u003e, B\u003csub\u003e3\u003c/sub\u003e and B\u003csub\u003e4\u003c/sub\u003e declined by 4.4, 17.6 and 44.1% across both cultivars in 2020-21 season, and by 3.0, 15.2 and 45.5% in 2021-22.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eCanopy sunlight interception\u003c/h2\u003e \u003cp\u003eDuring different growth periods of direct-sown winter rapeseed, canopy intercepted sunlight significantly different in various boron application levels and both cultivars (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). B\u003csub\u003e0\u003c/sub\u003e intercepted relatively less sunlight than other boron application levels during the seedling stage and podding stage. Canopy intercepted sunlight at B\u003csub\u003e0\u003c/sub\u003e was significantly less than B\u003csub\u003e1\u003c/sub\u003e, B\u003csub\u003e2\u003c/sub\u003e, B\u003csub\u003e3\u003c/sub\u003e and B\u003csub\u003e4\u003c/sub\u003e during rapeseed seedling stage. However, in the budding and flowering periods, the difference of canopy sunlight interception decreased between B\u003csub\u003e0\u003c/sub\u003e and B\u003csub\u003e1\u003c/sub\u003e, even though there was significant difference between B\u003csub\u003e1\u003c/sub\u003e and the other high boron application levels. Moreover, at podding stage, significant differences in sunlight interception were similarly recorded between B\u003csub\u003e0\u003c/sub\u003e and other varied boron application levels. Averagely, for all growing stages, crops intercepted significantly higher sunlight in B\u003csub\u003e2\u003c/sub\u003e, B\u003csub\u003e3\u003c/sub\u003e and B\u003csub\u003e4\u003c/sub\u003e than in B\u003csub\u003e0\u003c/sub\u003e and B\u003csub\u003e1\u003c/sub\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). B\u003csub\u003e4\u003c/sub\u003e intercepted the highest one (70.4%), followed by B\u003csub\u003e3\u003c/sub\u003e (69.0%) and B\u003csub\u003e2\u003c/sub\u003e (68.5%), while B\u003csub\u003e0\u003c/sub\u003e recorded the lowest (56.4%). Figure\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e also showed that canopy intercepted sunlight was slightly lower in ZS11 than in HZ9; HZ9 enhanced sunlight interception by more than 2.5% compared with ZS11 across all the boron levels and experimental seasons. As indicated that both cultivars obtained significant different sunlight interception and seed yield during all growing stages (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe experiment substantiated that boron fertilization level had a significant effect on the increase of seed yield (ranging from 6.2\u0026ndash;38.5%) for all boron application levels in direct-sown winter rapeseed. The increase in boron supply level led in a significant increase of seed yield when the level of boron application was above 7.5 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e compared to the levels of 0-7.5 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. Boron application exactly increased seed yield, which was consistent with the previous reports\u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e. Our results also demonstrated that yield responses to boron supply kept an upward tendency with boron application level improving within certain range. Excessive boron concentrations could be toxic to crop growth, and even reduce seed yield for barley that the boron toxicity threshold values occurred in the 10\u0026ndash;130 mg boron kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e dry weight\u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e. However, seed yield was not adversely affected by the highest boron application level (30 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) in the trial field. Direct-sown winter rapeseed should have higher requirement for boron nutrition in comparison with other crops, maybe involving in some different process to utilizing boron in field soil condition, which need more researches to unveil the physiological mechanism of boron nutrition.\u003c/p\u003e \u003cp\u003eBoron uptake in rapeseed aboveground increased sharply as boron application level increased (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Seed yield followed a significant linear relationship (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e), partially agreed to a previous study that boron fertilization promoted seed output due to the higher boron uptake in aboveground biomass\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. With the increase of boron application levels, boron uptake in the seed increased significantly initially and then stabilized, while boron uptake in pericarp and stem of rapeseed plants continued to increase, indicating that the consumption of boron was mainly stored in the no-seed tissues of plants when boron application level was higher than a certain degree. Notably, an average of 79.1% (ranging 70.5\u0026ndash;86.3%) of boron element was taken up, hence stored in the plant stem and pericarp by winter rapeseed.\u003c/p\u003e \u003cp\u003eThe parameters related boron uptake provide more information on the acquisition and utilization of boron nutrition by direct-sown winter rapeseed. The amount of required boron to generate 1 t of seed rose as the boron application level increased in this study. Boron utilization efficiency fell as the level of boron supply improved. The highest IUE was at the zero boron applied level of B\u003csub\u003e0\u003c/sub\u003e, and the lowest IUE occurred when boron level was at B\u003csub\u003e4\u003c/sub\u003e. These results agreed that the utilization efficiency of boron uptake generally decreased when the amount of boron supply increased\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u003c/sup\u003e. Therefore, it is relatively appropriate to applying 7.5\u0026ndash;15 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e boron level for the current direct-sown rapeseed cultivation in Southwest China cropping areas. When the level of boron application is high, more boron is absorbed and stored in the pericarp and stem tissues, without storing too much boron in the grain, explaining that this may be a special form of luxurious absorption of boron nutrient. It was a common phenomenon of crop plants\u0026rsquo; luxurious consumption in such macro-element uptake as N, P and K\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e,\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. In this study, the luxurious consumption of boron only occurred in non-seed tissues (developmental organs) and not in reproductive organs, which may also be a stress avoidance mechanism exhibited in its interaction with the environment by rapeseed. Storing redundant boron in non-seeds can reduce the adverse effects of surfeited boron retention in seeds on rapeseed germination, seedling and growth in excessive boron elemental environments. The research has indicated that high boron concentrations can be toxic to crop growth and reduce seed yield\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e. Shi et al.\u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e reported that for many varied crops, the boron toxicity threshold values occurred in the 10\u0026ndash;130 mg boron kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e dry weight. In this trial, although rapeseed was not adversely and toxic affected by even the highest boron level (30 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), the more physiological activities still need to be explored in depth for direct-sown rapeseed in field.\u003c/p\u003e \u003cp\u003eFor both winter rapeseed cultivars, sunlight interception (SI) improved sharply at first by increasing of applied boron-levels from 0 to 3.75 kg boron ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, but then it changed slightly with further increasing boron supply. The SI was closely related to the changes of canopy area index during rapeseed\u0026rsquo;s growing period, which influenced the distribution of SI for direct-sown rapeseed plant population canopy and hence plants canopy population photosynthesis\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e,\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e. For rapeseed population canopy level, the significant difference in SI among varied boron application levels occurred at seedling stage. The effect of boron deficiency limited the crop canopy initial growth rate, which closely related to aboveground biomass accumulation in direct-sown rapeseed vegetative growing period\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. This study here showed that the boron supply level significantly affected crop canopy SI at direct-sown rapeseed plant population level at earlier growing stages, and hence led to the difference of above-ground biomass. This relationship could be explained by our results that more boron application level produced more dry matter and had more boron uptake. In addition, some researchers found that sufficient boron nutrition could promote leaf appearance rate, leaf number, and photosynthetic rate, and hence the total production of dry matter\u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e. Responses of SI triggered rapeseed canopy photosynthetic area development under different boron application levels during crop early growing periods, which might contribute to the difference in seed yield consequently\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e,\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThis study demonstrates that boron application as basal fertilizer can not only improve the light conditions of the crop canopy during the early growth stage, but also significantly increase yield of direct-sown rapeseed. Although the more boron applied, the higher boron stored in pericarp and stem at harvest, this results extend us with a method to improve the boron status of soil. So returning no-seed rapeseed plant tissues to replenish soil boron could be an effective way to maintain soil fertility in locations where soil available boron is low, since boron deficiency is widely in soil in over 80 countries around the world\u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e. This measure implementation utilizes boron element to increase seed yield of direct-sown winter rapeseed, and can utilize the luxurious absorption of boron element by rapeseed no-seed tissues to return most of boron to the cropland soil.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eBoron application level of 7.5\u0026ndash;15 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e is important to increase the current direct-sown winter rapeseed yields in field soils with low available boron in Southwest China cropping areas. Boron application enhanced direct-sown winter rapeseed output by 6.2\u0026ndash;38.5% compared to zero boron supply. With the increase of boron application, the yield of the two rapeseed cultivars increased continuously in the study. The boron uptake in seed increased initially and then stabilized, while the boron uptake by pericarp and stem kept an upwards tendency significantly with the increase of boron application level. About 79.1% boron absorbed by rapeseed plant is distributed in the pericarp and stem (70.5\u0026ndash;86.3%). Effectively returning no-seed rapeseed plant tissues to replenish soil boron could maintain soil fertility. Seed yield was more significantly affected by boron application levels than crop canopy sunlight interception for direct-sown winter rapeseed in this region.\u003c/p\u003e"},{"header":"Declarations","content":" \u003ch2\u003eCompeting interests\u003c/h2\u003e \u003cp\u003eThe authors declare no competing of interests.\u003c/p\u003e \u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eThis study was supported by National Natural Science Foundation of China (31660354), Guizhou High-level Innovative Talents Project (2020-2018-034) and Doctoral Special Project of Kaili University (BS20240222).\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAuthor's contribution\"R.W.: Conceptualization, Validation, Writing-review \u0026amp; editing, Supervision, Project administration, Funding acquisition; W.L.P.: Methodology, Formal analysis, Validation, Writing-review \u0026amp; editing, Supervision; H.T.: Methodology, Investigation, Formal analysis, Validation, Writing-original draft. All authors reviewed the manuscript.\"\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe data that support this study will be shared upon reasonable request to the corresponding author.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eDinh, A. Q., Naeem, A., Sagervanshi, A., Wimmer, M. A. \u0026amp; Muhling, K. H. Boron uptake and distribution by oilseed rape (\u003cem\u003eBrassica napus\u003c/em\u003e L.) as affected by different nitrogen forms under low and high boron supply. \u003cem\u003ePlant. 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Using digital image analysis to describe canopies of winter oilseed rape (\u003cem\u003eBrassica napus\u003c/em\u003e L.) during vegetative developmental stages. \u003cem\u003eJ. Agro Crop Sci.\u003c/em\u003e \u003cb\u003e192\u003c/b\u003e (4), 295\u0026ndash;302 (2006).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang, K. et al. Low risks of toxicity from boron fertiliser in oilseed rape-rice rotations in southeast China. \u003cem\u003eNutr. Cycl. Agro-ecosys\u003c/em\u003e. \u003cb\u003e54\u003c/b\u003e, 189\u0026ndash;197 (1999).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYang, X., Yu, Y. G., Yang, Y., Bell, R. W. \u0026amp; Ye, Z. Q. Residual effectiveness of boron fertilizer for oilseed rape in intensively cropped rice-based rotations. \u003cem\u003eNutri Cycl. Agro-ecosys\u003c/em\u003e. \u003cb\u003e57\u003c/b\u003e, 171\u0026ndash;181 (2000).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Rapeseed, Boron, Sunlight interception, Crop canopy, Yield","lastPublishedDoi":"10.21203/rs.3.rs-4981549/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4981549/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBoron is a very important micro-element for winter rapeseed, boron deficiency resulted in \u0026ldquo;flowering without seed setting\u0026rdquo; for winter rapeseed. Attention should been paid to the effects of boron application levels on yield and its utilization mechanism in main rapeseed production areas of southwestern China. A split-plot field experiment was conducted with five boron application levels (0, 3.75, 7.5, 15, and 30 kg boron ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) and two rapeseed cultivars (Huayouza 9 and Zhongshuang 11). When boron was applied comparing with non-boron supply, seed yield of winter rapeseed increased 17.2\u0026ndash;38.5% in 2020-21 and 6.2\u0026ndash;38.1% in 2021-22, respectively. The boron uptake in the seed initially increased significantly and then nearly kept steadily, but the accumulation of boron continued to increase in the pericarp and stem with the increase of boron application levels from 0 to 30 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. Boron application level of 7.5\u0026ndash;15 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e is important to increase the current direct-sown winter rapeseed yields in field soils with low available boron in Southwest China cropping areas. Seed yield was more significantly affected by boron input than crop canopy sunlight interception for direct-sown winter rapeseed in this region. These results indicated that it is an effective way to maintain soil fertility by returning no-seed rapeseed plant tissues to replenish soil boron in Southwest China and other boron-deficient planting area.\u003c/p\u003e","manuscriptTitle":"Yield, boron uptake and canopy sunlight interception of direct-sown winter rapeseed as affected by boron fertilizer levels in China","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-10-07 13:48:40","doi":"10.21203/rs.3.rs-4981549/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-12-23T07:37:15+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-12-18T20:34:46+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-12-04T11:46:03+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"328145450665338244113439542234903546105","date":"2024-11-27T08:04:05+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"84343556055324128326198084651262818958","date":"2024-11-27T03:08:24+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-11-26T16:24:32+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-11-19T13:38:52+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2024-09-06T17:35:02+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-09-04T15:19:46+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2024-08-27T05:05:16+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"e24b235e-080a-46aa-8ee1-ac9978bd7079","owner":[],"postedDate":"October 7th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":38432837,"name":"Biological sciences/Plant sciences/Plant physiology"},{"id":38432838,"name":"Biological sciences/Plant sciences/Plant ecology"},{"id":38432839,"name":"Biological sciences/Plant sciences/Plant stress responses/Light stress"}],"tags":[],"updatedAt":"2025-10-13T16:08:07+00:00","versionOfRecord":{"articleIdentity":"rs-4981549","link":"https://doi.org/10.1038/s41598-025-19306-x","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2025-10-09 15:57:03","publishedOnDateReadable":"October 9th, 2025"},"versionCreatedAt":"2024-10-07 13:48:40","video":"","vorDoi":"10.1038/s41598-025-19306-x","vorDoiUrl":"https://doi.org/10.1038/s41598-025-19306-x","workflowStages":[]},"version":"v1","identity":"rs-4981549","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4981549","identity":"rs-4981549","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}