Effects of altitude and crop cycle on the occurrence of sugarcane smut under the ecological conditions of low-latitude plateau

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The results showed that there were significant differences in smut incidence among different regions, altitudes, and crop cycle in Yunnan. The smut incidence ranged from 4.94% to 16.44% across different regions, indicating that smut has occurred universally and caused severe damage in Yunnan. The incidence varied from 2.89% to 14.71% across different altitudes, exhibiting a decreasing trend with increasing altitude. For different crop cycle, the incidence ranged from 5.81% to 15.31%, showing an increasing trend as the crop cycle extended. Under the ecological conditions of Yunnan's low-latitude plateau, altitude and crop cycle were identified as the main sources of variation in smut incidence. Their interaction effect was not significant, whereas the respective main effects of both factors were statistically significant. Meanwhile, the contribution rate of variation to smut incidence of altitude (63.20%) was higher than that of crop cycle (28.81%). These findings provide a scientific basis for the rational distribution of elite sugarcane varieties and the scientific control of smut in the low-latitude plateau sugarcane regions of Yunnan. sugarcane smut low-latitude plateau altitude crop cycle Figures Figure 1 Figure 2 Figure 3 Introduction Sugarcane smut, caused by Sporisorium scitamineum , is a widespread systemic fungal disease prevalent in sugarcane-growing countries worldwide (Vánky 1990). It is also one of the most economically damaging diseases affecting sugarcane production in China. The disease leads to particularly severe economic losses in dryland and ratoon cane, with the incidence in ratoon cane reaching 80%-90%, and resulting in yield losses of 20%-50% (Shen et al. 2013 ; Su et al. 2016 ; Song et al. 2019 ). It has been reported that the direct economic losses caused by smut in China amount to 5 billion yuan annually (Li et al. 2020 ). Thus, smut has become a major disease constraining the high-quality and sustainable development of China's sugar industry. Yunnan is the second largest sugarcane planting base in China, which is located on a low latitude plateau; sugarcane is planted between 21º8′-29º15′ north latitude and 97º31′-106º11′ east longitude (Zhang et al. 2013 ) (Fig. 1 ). Its diverse low latitude plateau ecological conditions provide varied environmental conditions for the occurrence and prevalence of smut. In recent years, the high yield, extra high sugar variety Yunzhe 081609 (moderately resistant to smut) has been planted across 208,520 hm 2 , accounting for 65.5% of the total sugarcane planting area in Yunnan (data unpublished). However, the continuous large scale cultivation of a single variety, coupled with the fact that the incidence of smut in low to moderate resistant varieties tends to increases with longer ratoon cycles (Putra and Damayanti 2012 ; Jing et al. 2020 ), has led to an increasingly prominent trend of smut outbreaks and epidemics in Yunnan. Therefore, in this study, Yunzhe 081609 was used as the survey variety to analyze its comprehensive performance across different major sugarcane planting areas under Yunnan's low-latitude plateau ecological environment, as well as the effects of altitude and crop cycle on smut occurrence. The aim of study is to provide theoretical basis for optimizing sugarcane variety distribution and formulating regionalized control strategies for smut. Materials and methods Geo-climatic profile of the investigation site A systematic investigation was conducted from May to June 2024 on the occurrence of smut in the main variety Yunzhe 081609 across three sugarcane planting regions in Yunnan, which included southern subtropical humid (SSH), southern subtropical semi-humid (SSS), and northern tropical semi-humid (NTS) sugarcane growing areas of Yunnan (Zhang et al. 2006). The investigation sites in the SSH, SSS and NTS regions were Lincang and Pu’er, Yuxi, Baoshan respectively. Their geo-climatic profile was shown in Fig. 1 and Table 1. Survey methodology A systematic random sampling method (McMaugh 2005) was employed in this study. Classified by altitude and crop cycle, 10-30 fields were randomly selected from each survey site to investigate the occurrence of smut, with a total of 232 fields surveyed. Three point sampling was conducted in each field, where 100 consecutive plants were surveyed at each point, totaling 300 plants per field. The number of diseased plants were recorded, and the disease incidence was calculated using the following formula: The contribution rate of variable factors (altitude and crop cycles) to smut incidence was calculated using a formula suggested by Yang et al. (2024). Data analyses The effects of different planting regions, altitudes, and crop cycle on smut incidence were analyzed using DPS software and Duncan's new multiple range test (DMRT). Box plots were constructed to visualize significant differences among them. Statistical analysis of the frequency of smut incidence across different ecological regions, altitudes, and crop cycle was performed using Minitab (2014) software to clarify the distribution characteristics of the disease. Disease incidence data was classified into distinct groups as Fininsa and Yuen (2001) described. As reported by Magarey et al. (2010) , a disease incidence of 5% was considered a threshold for smut, thus, smut incidence was categorized into two levels: ≤5% and >5%. Subsequently, a chi-square test was applied to examine the correlation between variables by comparing observed frequencies against expected frequencies derived from theoretical models or distribution assumptions at a specific significance level (Wang and Chen 2022). Three hypotheses were formulated based on the survey objectives: i) if the smut incidence was independent of ecological sugarcane planting regions; ii) if the smut incidence was independent of planting altitude; iii) if the smut incidence was independent of crop cycle. Finally, two-way analysis of variance (ANOVA) was used to analyze the effects of altitude and crop cycle on smut occurrence and their interactive relationships. Results Smut incidence in different ecological sugarcane planting regions Sugarcane smut occurred universally in the SSH, SSS and NTS regions in Yunnan (Fig.2), with significant differences among the regions (P < 0.05). The mean smut incidence ranged from 4.94% to 16.44% across the different ecological regions (Table 1). Among them, relatively higher mean incidence were recorded in Junsai, Quannei and Gengma of Lincang in the SSH, as well as in Mangkuan of Baoshan in the NTS, with rate of 16.44%, 15.48%, 12.42% and 12.89% respectively. In contrast, the lowest mean smut incidence was observed in Shuangjiang of Lincang and Weiyuan of Pu’er, both located in the SSH region, with rate of 4.94% and 5.82%, respectively (Table 1). Smut incidence at different altitude and crop cycle Sugarcane smut occurred across all altitudes and crop cycles, with significant differences observed ( P < 0.05) (Table 2). Among the different altitudes, fields at an altitude ≤1200 m.a.s.l. showed the highest mean smut incidence (14.71%). Followed by the 1200-1500 m.a.s.l., with the mean smut incidence of 8.28%. The lowest mean smut incidence (2.89%) was found at >1500 m.a.s.l. (Table 2). These results indicated that smut incidence decreased with increasing planting altitude (Fig. 3). In contrast, among different crop cycles, the lowest mean smut incidence (5.81%) was observed in newly planted cane, followed by the ratoon 1 (11.00%). The highest mean smut incidence (15.31%) was found in the field with crop cycle > ratoon 1 (Table 2). These results suggested that smut incidence increased with prolonged crop cycles (Fig. 2). Overall, fields at an altitude ≤1200 m.a.s.l. and with crop cycle > ratoon 1 exhibited a higher smut incidence compared to fields at altitudes >1200 m.a.s.l. and with crop cycle < ratoon 1. Characteristics of the occurrence and distribution of smut in relation to different ecological regions, altitudes, and crop cycles The chi-square tests of smut incidence in different ecological regions showed that P > 0.05, and X 2 of 3.69, which is lower than threshold of 5.99 (df=2, α=0.05), indicating that smut incidence was independent of ecological sugarcane planting regions (Table 3). Regarding different altitude, P < 0.01 and X 2 was 66.78, which was higher than threshold of 9.21 (df=2, α=0.01). The result was statistically significant at the 99% confidence level, suggesting that smut incidence was significantly correlated with planting altitude (Table 3). With different crop cycle, P < 0.01 and X 2 was 55.01, which was higher than threshold of 9.21 (df=2, α=0.01). The result was statistically significant at the 99% confidence level, suggesting that smut incidence was significantly correlated with crop cycle (Table 3). Effects of altitude and crop cycle on smut incidence and their contribution rate to variation The two-way ANOVA showed that the effects of altitude and crop cycle on smut incidence were highly significant ( P 0.05) (Table 4). Analysis of the contribution rate to variation indicated that the contribution rate of altitude to smut incidence (63.20%) was higher than that of crop cycle (28.81%) (Table 4). Discussion The incidence of sugarcane smut ranged from 4.94% to 16.44% across different ecological planting regions in Yunnan, a low-latitude plateau area. According to Magarey et al. ( 2010 ) reported, these incidence levels have all exceeded the threshold requiring disease control, indicating that smut has occurred extensively and caused severe damage across various ecological sugarcane planting regions in Yunnan. This finding was consistent with relevant studies, which have confirmed that smut is prevalent in sugarcane-growing areas of China, causing annual direct economic loss of up to 5 billion RMB (Shen et al. 2013 ; Wei et al. 2019 ; Wang et al. 2021 ), and has become a major bottleneck restricting the high-quality development of China’s sugar industry. As is widely recognized, the large-scale continuous cultivation of a single variety is one of the contributing factors to the outbreak and spread of the disease. Once epidemic occurs, it poses a significant threat to the security of the sugar industry in China. Yunzhe 081609 is a high yield and super high sugar variety that has been extensively promoted and planted in Yunnan in recent years (Zhang et al. 2024 ). It also exhibits desirable agronomic traits including early maturity, medium to large stalks, moderate tillering ability, compact plant architecture, good leaf senescence, strong drought tolerance, excellent ratoon performance, and high resistance to sugarcane mosaic disease (Xia et al. 2018 ). Its planting area in Yunnan has reached 208,520 hm 2 , accounting for 65.5% of the total sugarcane cultivation area (unpublished data). However, Yunzhe 081609 exhibits only moderate resistance to smut. Compared with highly smut resistant varieties, it is more susceptible to smut in most sugarcane planting regions of Yunnan and Guangxi in China (Huang et al. 2025 ; Nong et al. 2025 ). Relevant studies indicated that the incidence of smut tends to increase gradually with prolonged crop cycle in varieties with low smut resistance (Putra and Damayanti 2012 ; Jing et al. 2020 ). Therefore, the large-scale continuous cultivation of Yunzhe 081609 may be one of key factors contributing to the widespread occurrence and severe damage of smut in Yunnan. The results of statistical analysis on smut incidence across different altitudes and crop cycles showed that smut incidence was significantly negatively correlated with altitude, whereas it was significantly positively correlated with crop cycle. Furthermore, the contribution rate of altitude to smut incidence was higher than that of crop cycle. The influence of altitude on plant diseases is mainly achieved by altering meteorological factors such as temperature, humidity, precipitation, and light intensity, which in turn affects the survival and transmission of pathogen and vector insects, and determines the infection probability, the rate of disease progression, and damage severity of diseases (Nagakura et al. 2006 ; Li et al. 2010 ; Wang et al. 2019 ). The optimal temperature for teliospore germination and mycelial growth of S. scitamineum is 25–30℃. Generally, temperature decreases by approximately 0.6℃ for every 100 m increase in altitude, while relative humidity tends to increase overall with rising altitude. Consequently, in high altitude sugarcane planting regions, the lower temperatures significantly inhibit teliospore germination and infection, resulting in low smut incidence. In contrast, smut incidence is relatively high in low altitude regions with high temperatures and low humidity (Bhuiyan and Croft 2010 ; Sundravadana et al. 2011 ; Mansoor et al. 2016 ; Tegene et al. 2021 ). Rupiah ( 2017 ) also reported that increased temperatures and decreased humidity lead to a significant increase in smut incidence. Among the sugarcane planting regions with high smut incidence in this study, both GM and MK are located in dry-hot valley regions, which are characterized by a climate of high temperature, drought, and low precipitation (Peng et al. 2018 ). Such environmental conditions are conducive to the survival and spread of S. scitamineum , resulting in significantly higher smut incidence in these two regions than in others. The influence of crop cycle on the occurrence of smut is attributed to the characteristics of sugarcane as a perennial gramineous crop. A longer crop cycle leads to the continuous accumulation of S. scitamineum teliospores in soil or plant residues, which gradually intensifies the infection pressure. Ultimately, this results in a significant upward trend in smut incidence with the extension of crop cycle. Similarly, Antony et al. ( 2010 ) and Lilik and Tri ( 2012 ) identified that the cane and sugar losses caused by smut can reach up to 100% with the extension of crop cycle. Based on the results of this study, particularly that the interaction between altitude and crop cycle on sugarcane smut was not significant, whereas the main effects of both factors were significant, and that altitude contributed more to smut incidence than crop cycle, the following control measures for smut are recommended for the low latitude plateau sugarcane region of Yunnan: i) In low-altitude regions (≤ 1200 m.a.s.l.), if the smut incidence ≥ 5%, completely rogue out all the diseased canes and switch over to resistant varieties such as Yuetang 93159, Liucheng 05136, and Yunzhe 0551. If the smut incidence < 5%, for newly planted cane: select healthy seedcane and plant in trenches along the contour lines, adopting an integrated management approach combining pesticide, plastic film, and fertilizer application. For ratoon cane: implement immediate post-harvest management. Within 7–10 days after harvesting, complete field sanitation, pesticide and fertilizer application, ridge breaking and stubble loosening, and soil covering and mulching. These practices promote early and rapid seedling emergence, ensure vigorous growth, and enhance the disease resistance of sugarcane plants. ii) Strengthen field management: for fields where the incidence ≥ 5%, it is recommended to completely remove all above-ground seedlings and exposed stubble. Rational topdressing with nitrogen, phosphorus, and potassium fertilizers should be conducted to improve sugarcane resistance and promote the sprouting of low-position buds in ratoon canes. During harvesting, the cutting depth of the tools should be controlled at 3–5 cm below the soil surface. iii) In severely infected fields, the ratoon cycles should be shortened and crop rotation implemented to interrupt the long-term damage caused by S. scitamineum . Declarations Acknowledgements We are grateful to Pro. Yingkun Huang for his guidance on the survey methodology. This study was supported by the earmarked fund for China Agriculture Research System of MOF and MARA (CARS-17), Key Project of Yunnan Provincial Agricultural Joint Special Fund (202501BD070001-014), Industry-University-Research Cooperation Project with Lincang Nanhua Sugar Industry Co., Ltd. (LCNH2021-12-003), and Yunnan Province Agriculture Research System (YNGZTX-4-92). Authors’ Contribution Xiao-yan Wang executed survey, data analysis and completed the writing of the first draft of the paper; Yu-Long Jiang monitored survey and data analysis; Lin-Xu Li, Yu-Lin Chen, Wen-Gen Lin, Pi-Zhong Huang, Jin-Xue Lei and Ming Gong participated in the survey and collect data; Hong Xu designed the experiment and data analysis and modified the paper; Hong-Li Shan is the initiator and leader of the project, directing experimental design, and paper modification Funding This work is based on the research supported by the earmarked fund for China Agriculture Research System of MOF and MARA (CARS-17), Key Project of Yunnan Provincial Agricultural Joint Special Fund (202501BD070001-014), Industry-University-Research Cooperation Project with Lincang Nanhua Sugar Industry Co., Ltd. (LCNH2021-12-003), and Yunnan Province Agriculture Research System (YNGZTX-4-92). Data availability All data generated from the study and reported in the paper are included in the article. Further data sets are available from the corresponding author upon request. Conflicts of interest The authors declare that they have no conflict of interest. References Antony G, Magarey R, Milford B (2010) Sugarcane smut after three years: A policy retrospective. Proceeding Australia Society of Sugar Cane Technology 32: 38-39 Bhuiyan SA, Croft BJ (2010) Some biological parameters of the sugarcane smut fungus, Ustilago scitaminea. Sugar Cane International 28(1): 22-26, 38 Fininsa C, Yuen J (2001) Association of maize rust and leaf blight epidemics with cropping systems in Hararghe highlands, Eastern Ethiopia. Crop Protection 20: 669-678 Huang SL, Tao ZJ, Guo GH, Li SF, Wei YA, Xia HM, Zhao PF, Li RD (2025) Occurrence of sugarcane smut at seedling stage and control suggestions in different altitudes of southeastern Yunnan. China Plant Protection 45(7): 48-51 Jing Y, Zhou H, Liu XH, Tan F, Zhang XQ, Zhang RH, Song XP, Li YR, Yan MX, Lei JC, Qin ZQ, Luo YW, Li DM, Wei JJ (2020) Smut resistant identification and analysis of new sugarcane clones of Guitang. Chinese Journal of Tropical Crops 41(2): 333-338 Li HB, Xie YT, Cai WJ, Deng QQ, Chen JW, Shen WK (2020) Identification and evaluation of resistance of new sugarcane lines against Sporisorium scitamineum, causing sugarcane smut. Plant Protection 46(5): 167-173 Li GH, Wen GS, Tian HT, Zhang LY, Li Y, Huang H (2010) Gall disease of Cryptomeria fortunei at different altitudes on Mount Tianmu, Zhejiang Province. Journal of Zhejiang Forestry College 27(4): 483-488 Lilik KP, Tri AD (2012) Major Diseases Affecting Sugarcane Production in Indonesia. Functional Plant Science and Biotechnology 6: 124-129 Magarey RC, Denney D, Sheahan T, Bull JI (2010) The Australian sugarcane smut epidemic, epidemiological considerations and predictions for the final stages. Proceeding of Australian Society of Sugarcane Technology 32: 1-40 Mansoor S, Khan MA, Khan NA (2016) Screening of sugarcane varieties/lines against whip smut disease in relation to epidemiological factors. Journal of Plant pathology and Microbiology 7: 1-5 McMaugh T (2005) Guidelines for surveillance for plant pests in Asia and the Pacific. ACIAR Monograph No.119 pp 192 Minitab (2014) Minitab Statistical Software, Release 17 for Windows. State College, Pennsylvania. Minitab® is a registered trademark of Minitab, Inc. Nagakura J, Akama A, Mizoguchi T, Okabe H, Shigenaga H, Yamanaka T (2006) Effects of chronic nitrogen application on the growth and nutrient status of a Japanese cedar ( Cryptomeria japonica ) stand. Journal of Forest Research 11(5): 299-304 Nong B, Liu XY, Huang DY, Xiao LQ, Guo RM, Ou LP, Huang ZX, Huang GN, Zhou L, Wei QQ, Nong ZR, Lu X (2025) Planting performance of sugarcane variety Yunzhe 081609 in Baise, Guangxi Province. Guangxi Sugar Industry 45(3): 189-193 Peng SJ, Zhang YF, Ou XK (2018) Study on vegetation restoration based on phylogenetic structure of plant communities in Jinshajing Dry-hot Valley. Journal of Kunming University 40(6): 72-76 Putra LK, Damayanti TA (2012) Major diseases affecting sugarcane production in Indonesia. Functional Plant Science and Biotechnology 6(2): 124-129 Rupiah MK (2017) Possible effects of climate change in the agronomy of sugarcane in Zimbabwe. Global Journal of Pests, Diseases and Crop Protection 5: 240-244 Shen WK, Jiang ZD, Deng HH, Liu R (2013) Research progress on sugarcane smut disease and Sporisorium scitaminea. Chinese Journal of Tropical Crops 34(10): 2063-2068 Song QQ, Singh P, Singh RK, Song XP, Li HB, Nong YY, Yang LT, Li YR (2019) Proteomic analysis of sugarcane- Sporisorium scitamineum interaction based on iTRAQ technique. Acta Agronomica Sinica 45(1): 55-69 Su YC, Wang ZP, Xu LP, Peng Q, Liu F, Li Z, Que YX (2016) Early selection for smut resistance in sugarcane using pathogen proliferation and changes in physiological and biochemical indices. Frontiers in Plant Science 7: 1133 Sundravadana S, Ragavan T, Thirumurugan A, Sathiya K, Shah E (2011) Influence of climatic parameters and management strategies on sugarcane smut disease. International Journal of Forestry and Crop Improvement 2: 199-204 Tegene S, Terefe H, Dejene M, Tegegn G, Tena E, Ayalew A (2021) Survey of sugarcane smut ( Sporisorium scitamineum ) and association of factors influencing disease epidemics in sugarcane plantations of Ethiopia. Tropical Plant Pathology 46(4): 393-405 Vánky K (1999) The new classificatory system for smut fungi, and two new genera. Mycotaxon 70(3): 35-49 Wang CM, Li J, Zhang RY, Wang XY, Shan HL, Cang XY, Yin J, Luo ZM, Huang YK (2021) Research progress of sugarcane smut disease. Sugar Crops of China 43(2): 65-70 Wang J, Jiang P, Ailixiati M, Li FJ, Aisikeer R (2019) Preliminary study on occurrence dynamics of walnut leaf spot and extension process of pathogenic condition. Forest Pest and Disease 38(1): 19-22 Wang P, Chen YF (2022) The willingness and impact factors of households’ corn and soybean strip compound planting. Journal of Wuhan Polytechnic University 41(5): 81-88 Wei JJ, Song XP, Wei CY, Zhang XQ, Huang WH, Yan MX (2019) Research progress on sugarcane smut and its control. Guangdong Agricultural Sciences 46(4): 81-88 Xia HM, Zhao PF, Liu JY, Zhao J, Zan FG, Chen XK, Yang K, Yang HC, Yao L, Zhao LP, Wu ZD, Qin W, Wu CW (2018) Breeding of new sugarcane variety Yunzhe081609 with early maturing and high sucrose content. Sugar Crops of China 40(5): 6-9 Yang X, Lyu MY, Hu CQ, Yang F, Wang YB, Dai ZM, Yu HT, Zheng AQ, Zhang YR, Tang YS, Wang LP, Li Q, He YH (2024) Effects of environment and genotype on grain yields of faba bean under ecological conditions of low latitude plateau. Soils and Crop 13(4): 479-489 Zhang YB, Liu SC, Huang YK (2006) The natural climate characteristics and ecological regionalization in Yunnan sugarcane area. Sugar Crops of China 4: 38-40 Zhang YB, Deng J, Cheng Y, Long YF (2013) Study on development and technical strategy of plateau characteristic sugarcane industry in Yunnan. Beijing: China Agriculture Press pp, 12-21 Zhang YB, Zhao PF, Hu CH, Que YX (2024) The recent achievements and development trends of sugarcane improvement in China. Sugar Crops of China 46(1): 87-92 Tables Table 1 Geo-climatic profiles of the investigation sites and their smut incidence (mean±SE) in Yunnan Ecological region Investigation site East longitude North latitude climate type Average annual temperature (℃) Average annual precipitation (mm) Smut incidence a (%) Southern subtropical humid region Shuangjiang, Lincang (SJ) 99°81′ 23°48′ Subtropical mountain monsoon 19.5 995.3 4.94±1.28c Nanshan, Lincang (NS) 98°82′ 23°77′ 19.0 1624.0 8.49±2.17abc Mengdui, Lincang (MDui) 98°90′ 23°94′ 19.5 1500.0 6.65±1.64bc Quannei, Lincang (QN) 100°16′ 23°54′ 18.5 1590.7 15.48±4.36ab Mengsheng, Lincang (MS) 99°42′ 23°34′ Subtropical dry-hot valley 23.0 1000.0 8.57±1.60abc Gengma, Lincang (GM) 99°40′ 23°53′ South subtropical dry-hot valley monsoon 19.2 950.0 12.42±4.53abc Sipaishan, Lincang (SPS) 99°44 23°58 19.2 950.0 10.46±2.59abc Mengyong, Lincang (MY) 99°65′ 23°87′ South subtropical monsoon 19.5 1117.6 8.71±1.82abc Mengdin, Lincang (MDin) 98°92′ 23°51′ Subtropical dry-hot valley monsoon 23.0 1200.0 8.10±2.01abc Junsai, Lincang (JS) 99°32′ 23°73′ Subtropical humid 21.6 1888.0 16.44±3.20a Weiyuan, Pu’er (WY) 100°70′ 23°50′ Subtropical monsoon humid 19.5 1338.0 5.82±2.09c Yongping, Pu’er (YP) 100°23′ 23°24′ South subtropical monsoon 19.0 1271.0 9.51±2.66abc Shangyun, Pu’er (SY) 99°59′ 22°55′ Subtropical monsoon 20.0 1450.0 9.82±1.97abc Southern subtropical semi-humid region Xinping, Yuxi (XP) 102º16′ 23º38′ South subtropical dry-hot valley 18.1 869.0 6.71±1.74bc Northern tropical semi-humid region Mangkuan, Baoshan (MK) 98°87′ 25°45′ Subtropical dry-hot Valley 23.0 1200.0 12.89±3.84abc a Different lowercase letters indicate significant differences among disease incidence of different planting regions ( P <0.05). Table 2 Effects of different altitudes and crop cycle on smut incidence (mean±SE) Altitude (m) Smut incidence（%） Crop cycle Smut incidence a （%） ≤1200 14.71±1.88ab Newly planted 5.81±1.32de 1200-1500 8.29±0.93cd Ratoon 1 11.00±0.98bc >1500 2.89±1.03e >ratoon 1 15.31±1.78a a Different lowercase letters indicate significant differences among disease incidence between altitudes and crop cycle (P5 Ecological planting region Southern subtropical humid region 57 155 212 3.69 a 0.1577 Southern subtropical semi-humid region 3 7 10 Northern tropical semi-humid region 0 10 10 Altitude ≤1200 m.a.s.l 16 84 100 66.78 b 0.0000** 1200-1500 m.a.s.l 12 73 85 >1500 m.a.s.l 35 12 47 Crop cycle Newly planted 61 35 96 55.01 b 0.0000** Ratoon 1 12 58 70 >ratoon 1 10 56 66 a The X 2 employed for comparison was 5.99 (5% significance and 2 degree of freedom). b The X 2 employed for comparison was 9.21 (1% significance and 2 degree of freedom). ** indicates p ＜0.01. Table 4 Two-way ANOVA of smut incidence and contribution rate of variable factors Factor Sum of squares (SS) df Mean square F P Contribution rate（%） Altitude 2648.05 2 1324.03 16.44 <0.001 63.20 Crop cycle 1207.14 2 603.57 7.49 <0.001 28.81 Altitude×Crop cycle 334.47 4 83.62 1.04 0.39 Error 8699.35 108 80.55 Total 12889.01 116 Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Major revisions 16 Mar, 2026 Reviewers agreed at journal 04 Feb, 2026 Reviewers invited by journal 04 Feb, 2026 Editor invited by journal 03 Feb, 2026 Editor assigned by journal 03 Feb, 2026 First submitted to journal 19 Jan, 2026 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-8588952","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":585946341,"identity":"ccd8c620-d68a-4138-84b8-e78ef0dfd92a","order_by":0,"name":"Xiao-Yan Wang","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Xiao-Yan","middleName":"","lastName":"Wang","suffix":""},{"id":585946342,"identity":"543098be-8428-49ca-afec-a0229fe6cef9","order_by":1,"name":"Yu-Long 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Lin","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Wen-Gen","middleName":"","lastName":"Lin","suffix":""},{"id":585946347,"identity":"1f4c60e2-c6e0-4942-81b7-a207ae2dc2b9","order_by":6,"name":"Pi-Zhong Huang","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Pi-Zhong","middleName":"","lastName":"Huang","suffix":""},{"id":585946348,"identity":"adcf3521-daa3-4f97-a9dc-1437dc34a058","order_by":7,"name":"Jin-Xue Lei","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Jin-Xue","middleName":"","lastName":"Lei","suffix":""},{"id":585946349,"identity":"dd1d66db-43e1-4375-b4a9-6d337c292049","order_by":8,"name":"Ming Gong","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Ming","middleName":"","lastName":"Gong","suffix":""},{"id":585946350,"identity":"b754258c-402b-400f-bf55-a49e3aeb00f2","order_by":9,"name":"Hongli Shan","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAr0lEQVRIiWNgGAWjYDACCR7GAzwFDHJs7O0HiNbCcIDHgMGYj+dMAmlaEudJOBgQp0N+du+BA28MDqe3STAkMPyo2EZYi8GdcwkH5xgczm2TbjzA2HPmNhFaJHIMDvMY3M5tkzmQwMzYRoQW+RkQLelsEgkGxGlhuAHRkkC8FgOgFqBf/hu2AQP5IFF+ATrM8MGbijR5+fb2gw9+VBDjMGRwgET1o2AUjIJRMApwAQD6wD4VPezVfAAAAABJRU5ErkJggg==","orcid":"","institution":"Yunnan Sugarcane Research Institute","correspondingAuthor":true,"prefix":"","firstName":"Hongli","middleName":"","lastName":"Shan","suffix":""}],"badges":[],"createdAt":"2026-01-13 08:03:15","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8588952/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8588952/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":102196085,"identity":"b107b896-be94-444d-9aae-79f983d97263","added_by":"auto","created_at":"2026-02-09 09:59:14","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":376661,"visible":true,"origin":"","legend":"\u003cp\u003eGeographical locations of 15 sugarcane planting regions used for smut surveys and their districts in Yunnan\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8588952/v1/a34823224f08708f09324cd1.png"},{"id":102196082,"identity":"0967d330-6175-49e0-9bc2-f8db8493daec","added_by":"auto","created_at":"2026-02-09 09:59:13","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":41687,"visible":true,"origin":"","legend":"\u003cp\u003eSmut incidence in different ecological sugarcane planting regions\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-8588952/v1/5dccc3c6fe67d54e640364ce.png"},{"id":102196083,"identity":"321de3b7-fdd1-4b23-99ca-70e45e707ff7","added_by":"auto","created_at":"2026-02-09 09:59:13","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":230754,"visible":true,"origin":"","legend":"\u003cp\u003eSmut incidence at different altitudes and crop cycles\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-8588952/v1/6c87ff440d9acd5c70f15686.png"},{"id":102296812,"identity":"725cf331-b664-43dc-abf1-8453bdefedfc","added_by":"auto","created_at":"2026-02-10 10:21:53","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1253505,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8588952/v1/651ec0c9-9867-4d18-8a2b-b0703d4e43b4.pdf"}],"financialInterests":"","formattedTitle":"Effects of altitude and crop cycle on the occurrence of sugarcane smut under the ecological conditions of low-latitude plateau","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSugarcane smut, caused by \u003cem\u003eSporisorium scitamineum\u003c/em\u003e, is a widespread systemic fungal disease prevalent in sugarcane-growing countries worldwide (V\u0026aacute;nky 1990). It is also one of the most economically damaging diseases affecting sugarcane production in China. The disease leads to particularly severe economic losses in dryland and ratoon cane, with the incidence in ratoon cane reaching 80%-90%, and resulting in yield losses of 20%-50% (Shen et al. \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Su et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Song et al. \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). It has been reported that the direct economic losses caused by smut in China amount to 5\u0026nbsp;billion yuan annually (Li et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Thus, smut has become a major disease constraining the high-quality and sustainable development of China's sugar industry.\u003c/p\u003e \u003cp\u003eYunnan is the second largest sugarcane planting base in China, which is located on a low latitude plateau; sugarcane is planted between 21\u0026ordm;8\u0026prime;-29\u0026ordm;15\u0026prime; north latitude and 97\u0026ordm;31\u0026prime;-106\u0026ordm;11\u0026prime; east longitude (Zhang et al. \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2013\u003c/span\u003e) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Its diverse low latitude plateau ecological conditions provide varied environmental conditions for the occurrence and prevalence of smut. In recent years, the high yield, extra high sugar variety Yunzhe 081609 (moderately resistant to smut) has been planted across 208,520 hm\u003csup\u003e2\u003c/sup\u003e, accounting for 65.5% of the total sugarcane planting area in Yunnan (data unpublished). However, the continuous large scale cultivation of a single variety, coupled with the fact that the incidence of smut in low to moderate resistant varieties tends to increases with longer ratoon cycles (Putra and Damayanti \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Jing et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), has led to an increasingly prominent trend of smut outbreaks and epidemics in Yunnan. Therefore, in this study, Yunzhe 081609 was used as the survey variety to analyze its comprehensive performance across different major sugarcane planting areas under Yunnan's low-latitude plateau ecological environment, as well as the effects of altitude and crop cycle on smut occurrence. The aim of study is to provide theoretical basis for optimizing sugarcane variety distribution and formulating regionalized control strategies for smut.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cp\u003e\u003cstrong\u003eGeo-climatic profile of the investigation site\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA systematic investigation was conducted from May to June 2024 on the occurrence of smut in the main variety Yunzhe 081609 across three sugarcane planting regions in Yunnan, which included southern subtropical humid (SSH), southern subtropical semi-humid (SSS), and northern tropical semi-humid (NTS) sugarcane growing areas of Yunnan (Zhang et al. 2006). The investigation sites in the SSH, SSS and NTS regions were Lincang and Pu\u0026rsquo;er, Yuxi, Baoshan respectively. Their geo-climatic profile was shown in Fig. 1 and Table 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSurvey methodology\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA systematic random sampling method (McMaugh 2005) was employed in this study. Classified by altitude and crop cycle, 10-30 fields were randomly selected from each survey site to investigate the occurrence of smut, with a total of 232 fields surveyed.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThree point sampling was conducted in each field, where 100 consecutive plants were surveyed at each point, totaling 300 plants per field. The number of diseased plants were recorded, and the disease incidence was calculated using the following formula:\u003c/p\u003e\n\u003cp\u003e\u003cimg width=\"397\" height=\"40\" 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\" alt=\"image\"\u003e\u003c/p\u003e\n\u003cp\u003eThe contribution rate of variable factors (altitude and crop cycles) to smut incidence \u0026nbsp; was calculated using a formula suggested by Yang et al. (2024).\u003c/p\u003e\n\u003cp\u003e\u003cimg width=\"284\" height=\"39\" src=\"data:image/png;base64,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\" alt=\"image\"\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData analyses\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe effects of different planting regions, altitudes, and crop cycle on smut incidence were analyzed using DPS software and Duncan\u0026apos;s new multiple range test (DMRT). Box plots were constructed to visualize significant differences among them. Statistical analysis of the frequency of smut incidence across different ecological regions, altitudes, and crop cycle was performed using Minitab (2014) software to clarify the distribution characteristics of the disease. Disease incidence data was classified into distinct groups as Fininsa and Yuen (2001) described. As reported by Magarey et al. (2010) , a disease incidence of 5% was considered a threshold for smut, thus, smut incidence was categorized into two levels:\u0026nbsp;\u0026le;5% and \u0026gt;5%.\u003c/p\u003e\n\u003cp\u003eSubsequently, a chi-square test was applied to examine the correlation between variables by comparing observed frequencies against expected frequencies derived from theoretical models or distribution assumptions at a specific significance level (Wang and Chen 2022). Three hypotheses were formulated based on the survey objectives: i) if the smut incidence was independent of ecological sugarcane planting regions; ii) if the smut incidence was independent of planting altitude; iii) if the smut incidence was independent of crop cycle. Finally, two-way analysis of variance (ANOVA) was used to analyze the effects of altitude and crop cycle on smut occurrence and their interactive relationships.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eSmut incidence in different ecological sugarcane planting regions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSugarcane smut occurred universally in the SSH, SSS and NTS regions in Yunnan (Fig.2), with significant differences among the regions (P \u0026lt; 0.05). The mean smut incidence ranged from 4.94% to 16.44% across the different ecological regions (Table 1). Among them, relatively higher mean incidence were recorded in Junsai, Quannei and Gengma of Lincang in the SSH, as well as in Mangkuan of Baoshan in the NTS, with rate of 16.44%, 15.48%, 12.42% and 12.89% respectively. In contrast, the lowest mean smut incidence was observed in Shuangjiang of Lincang and Weiyuan of Pu\u0026rsquo;er, both located in the SSH region, with rate of 4.94% and 5.82%, respectively (Table 1).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSmut incidence at different altitude and crop cycle\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSugarcane smut occurred across all altitudes and crop cycles, with significant differences observed (\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.05) (Table 2). Among the different altitudes, fields at an altitude \u0026le;1200 m.a.s.l. showed the highest mean smut incidence (14.71%). Followed by the 1200-1500 m.a.s.l., with the mean smut incidence of 8.28%. The lowest mean smut incidence (2.89%) was found at \u0026gt;1500 m.a.s.l. (Table 2). These results indicated that smut incidence decreased with increasing planting altitude (Fig. 3). In contrast, among different crop cycles, the lowest mean smut incidence (5.81%) was observed in newly planted cane, followed by the ratoon 1 (11.00%). The highest mean smut incidence (15.31%) was found in the field with crop cycle \u0026gt; ratoon 1 (Table 2). These results suggested that smut incidence increased with prolonged crop cycles (Fig. 2). Overall, fields at an altitude \u0026le;1200 m.a.s.l. and with crop cycle \u0026gt; ratoon 1 exhibited a higher smut incidence compared to fields at altitudes \u0026gt;1200 m.a.s.l. and with crop cycle \u0026lt; ratoon 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCharacteristics of the occurrence and distribution of smut in relation to different ecological regions, altitudes, and crop cycles\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe chi-square tests of smut incidence in different ecological regions\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eshowed that\u0026nbsp;\u003cem\u003eP\u003c/em\u003e \u0026gt; 0.05, and\u0026nbsp;\u003cem\u003eX\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e of 3.69, which is lower than threshold of 5.99 (df=2, \u0026alpha;=0.05), indicating that smut incidence was independent of ecological sugarcane planting regions (Table 3). Regarding different altitude,\u0026nbsp;\u003cem\u003eP\u003c/em\u003e\u003cem\u003e\u0026lt;\u003c/em\u003e0.01\u0026nbsp;and\u0026nbsp;\u003cem\u003eX\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e was 66.78, which was higher than threshold of 9.21 (df=2, \u0026alpha;=0.01).\u0026nbsp;The result was statistically significant at the 99% confidence level, suggesting that smut incidence was significantly correlated with planting altitude (Table 3). With different crop cycle,\u0026nbsp;\u003cem\u003eP\u003c/em\u003e\u003cem\u003e\u0026lt;\u003c/em\u003e0.01\u0026nbsp;and\u0026nbsp;\u003cem\u003eX\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e was 55.01, which was higher than threshold of 9.21 (df=2, \u0026alpha;=0.01).\u0026nbsp;The result was statistically significant at the 99% confidence level, suggesting that smut incidence was significantly correlated with crop cycle (Table 3).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEffects of altitude and crop cycle on smut incidence and their contribution rate to variation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe two-way ANOVA showed that the effects of altitude and crop cycle on smut incidence were highly significant (\u003cem\u003eP\u003c/em\u003e \u0026lt;0.001). However, the interaction effect of altitude\u0026times;crop cycle on smut incidence was not significant (\u003cem\u003eP\u003c/em\u003e \u0026gt;0.05) (Table 4). Analysis of the contribution rate to variation indicated that the contribution rate of altitude to smut incidence (63.20%) was higher than that of crop cycle (28.81%) (Table 4).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe incidence of sugarcane smut ranged from 4.94% to 16.44% across different ecological planting regions in Yunnan, a low-latitude plateau area. According to Magarey et al. (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2010\u003c/span\u003e) reported, these incidence levels have all exceeded the threshold requiring disease control, indicating that smut has occurred extensively and caused severe damage across various ecological sugarcane planting regions in Yunnan. This finding was consistent with relevant studies, which have confirmed that smut is prevalent in sugarcane-growing areas of China, causing annual direct economic loss of up to 5\u0026nbsp;billion RMB (Shen et al. \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Wei et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Wang et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2021\u003c/span\u003e), and has become a major bottleneck restricting the high-quality development of China\u0026rsquo;s sugar industry.\u003c/p\u003e \u003cp\u003eAs is widely recognized, the large-scale continuous cultivation of a single variety is one of the contributing factors to the outbreak and spread of the disease. Once epidemic occurs, it poses a significant threat to the security of the sugar industry in China. Yunzhe 081609 is a high yield and super high sugar variety that has been extensively promoted and planted in Yunnan in recent years (Zhang et al. \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). It also exhibits desirable agronomic traits including early maturity, medium to large stalks, moderate tillering ability, compact plant architecture, good leaf senescence, strong drought tolerance, excellent ratoon performance, and high resistance to sugarcane mosaic disease (Xia et al. \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Its planting area in Yunnan has reached 208,520 hm\u003csup\u003e2\u003c/sup\u003e, accounting for 65.5% of the total sugarcane cultivation area (unpublished data). However, Yunzhe 081609 exhibits only moderate resistance to smut. Compared with highly smut resistant varieties, it is more susceptible to smut in most sugarcane planting regions of Yunnan and Guangxi in China (Huang et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2025\u003c/span\u003e; Nong et al. \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2025\u003c/span\u003e). Relevant studies indicated that the incidence of smut tends to increase gradually with prolonged crop cycle in varieties with low smut resistance (Putra and Damayanti \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Jing et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Therefore, the large-scale continuous cultivation of Yunzhe 081609 may be one of key factors contributing to the widespread occurrence and severe damage of smut in Yunnan.\u003c/p\u003e \u003cp\u003eThe results of statistical analysis on smut incidence across different altitudes and crop cycles showed that smut incidence was significantly negatively correlated with altitude, whereas it was significantly positively correlated with crop cycle. Furthermore, the contribution rate of altitude to smut incidence was higher than that of crop cycle. The influence of altitude on plant diseases is mainly achieved by altering meteorological factors such as temperature, humidity, precipitation, and light intensity, which in turn affects the survival and transmission of pathogen and vector insects, and determines the infection probability, the rate of disease progression, and damage severity of diseases (Nagakura et al. \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Li et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2010\u003c/span\u003e; Wang et al. \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). The optimal temperature for teliospore germination and mycelial growth of \u003cem\u003eS. scitamineum\u003c/em\u003e is 25\u0026ndash;30℃. Generally, temperature decreases by approximately 0.6℃ for every 100 m increase in altitude, while relative humidity tends to increase overall with rising altitude. Consequently, in high altitude sugarcane planting regions, the lower temperatures significantly inhibit teliospore germination and infection, resulting in low smut incidence. In contrast, smut incidence is relatively high in low altitude regions with high temperatures and low humidity (Bhuiyan and Croft \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2010\u003c/span\u003e; Sundravadana et al. \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2011\u003c/span\u003e; Mansoor et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Tegene et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Rupiah (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2017\u003c/span\u003e) also reported that increased temperatures and decreased humidity lead to a significant increase in smut incidence. Among the sugarcane planting regions with high smut incidence in this study, both GM and MK are located in dry-hot valley regions, which are characterized by a climate of high temperature, drought, and low precipitation (Peng et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Such environmental conditions are conducive to the survival and spread of \u003cem\u003eS. scitamineum\u003c/em\u003e, resulting in significantly higher smut incidence in these two regions than in others. The influence of crop cycle on the occurrence of smut is attributed to the characteristics of sugarcane as a perennial gramineous crop. A longer crop cycle leads to the continuous accumulation of \u003cem\u003eS. scitamineum\u003c/em\u003e teliospores in soil or plant residues, which gradually intensifies the infection pressure. Ultimately, this results in a significant upward trend in smut incidence with the extension of crop cycle. Similarly, Antony et al. (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2010\u003c/span\u003e) and Lilik and Tri (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2012\u003c/span\u003e) identified that the cane and sugar losses caused by smut can reach up to 100% with the extension of crop cycle.\u003c/p\u003e \u003cp\u003eBased on the results of this study, particularly that the interaction between altitude and crop cycle on sugarcane smut was not significant, whereas the main effects of both factors were significant, and that altitude contributed more to smut incidence than crop cycle, the following control measures for smut are recommended for the low latitude plateau sugarcane region of Yunnan: i) In low-altitude regions (\u0026le;\u0026thinsp;1200 m.a.s.l.), if the smut incidence\u0026thinsp;\u0026ge;\u0026thinsp;5%, completely rogue out all the diseased canes and switch over to resistant varieties such as Yuetang 93159, Liucheng 05136, and Yunzhe 0551. If the smut incidence\u0026thinsp;\u0026lt;\u0026thinsp;5%, for newly planted cane: select healthy seedcane and plant in trenches along the contour lines, adopting an integrated management approach combining pesticide, plastic film, and fertilizer application. For ratoon cane: implement immediate post-harvest management. Within 7\u0026ndash;10 days after harvesting, complete field sanitation, pesticide and fertilizer application, ridge breaking and stubble loosening, and soil covering and mulching. These practices promote early and rapid seedling emergence, ensure vigorous growth, and enhance the disease resistance of sugarcane plants. ii) Strengthen field management: for fields where the incidence\u0026thinsp;\u0026ge;\u0026thinsp;5%, it is recommended to completely remove all above-ground seedlings and exposed stubble. Rational topdressing with nitrogen, phosphorus, and potassium fertilizers should be conducted to improve sugarcane resistance and promote the sprouting of low-position buds in ratoon canes. During harvesting, the cutting depth of the tools should be controlled at 3\u0026ndash;5 cm below the soil surface. iii) In severely infected fields, the ratoon cycles should be shortened and crop rotation implemented to interrupt the long-term damage caused by \u003cem\u003eS. scitamineum\u003c/em\u003e.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe are grateful to Pro. Yingkun Huang for his guidance on the survey methodology. This study was supported by the earmarked fund for China Agriculture Research System of MOF and MARA (CARS-17), Key Project of Yunnan Provincial Agricultural Joint Special Fund (202501BD070001-014), Industry-University-Research Cooperation Project with Lincang Nanhua Sugar Industry Co., Ltd. (LCNH2021-12-003), and Yunnan Province Agriculture Research System (YNGZTX-4-92).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; Contribution\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eXiao-yan Wang executed survey, data analysis and completed the writing of the first draft of the paper;\u0026nbsp;Yu-Long Jiang\u0026nbsp;monitored\u0026nbsp;survey and data analysis;\u0026nbsp;Lin-Xu Li, Yu-Lin Chen, Wen-Gen Lin, Pi-Zhong Huang, Jin-Xue Lei and Ming Gong\u0026nbsp;participated in the survey and collect data;\u0026nbsp;Hong Xu\u0026nbsp;designed the experiment and data analysis and modified the paper;\u0026nbsp;Hong-Li Shan\u0026nbsp;is the initiator and leader of the project, directing experimental design, and paper modification\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work is based on the research supported by the earmarked fund for China Agriculture Research System of MOF and MARA (CARS-17), Key Project of Yunnan Provincial Agricultural Joint Special Fund (202501BD070001-014), Industry-University-Research Cooperation Project with Lincang Nanhua Sugar Industry Co., Ltd. (LCNH2021-12-003), and Yunnan Province Agriculture Research System (YNGZTX-4-92).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data generated from the study and reported in the paper are included in the article. Further data sets are available from the corresponding author upon request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflicts of interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no conflict of interest.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAntony G, Magarey R, Milford B (2010) Sugarcane smut after three years: A policy retrospective. Proceeding Australia Society of Sugar Cane Technology 32: 38-39\u003c/li\u003e\n\u003cli\u003eBhuiyan SA, Croft BJ (2010) Some biological parameters of the sugarcane smut fungus, Ustilago scitaminea. Sugar Cane International 28(1): 22-26, 38\u003c/li\u003e\n\u003cli\u003eFininsa C, Yuen J (2001) Association of maize rust and leaf blight epidemics with cropping systems in Hararghe highlands, Eastern Ethiopia. Crop Protection 20: 669-678\u003c/li\u003e\n\u003cli\u003eHuang SL, Tao ZJ, Guo GH, Li SF, Wei YA, Xia HM, Zhao PF, Li RD (2025) Occurrence of sugarcane smut at seedling stage and control suggestions in different altitudes of southeastern Yunnan. China Plant Protection 45(7): 48-51 \u003c/li\u003e\n\u003cli\u003eJing Y, Zhou H, Liu XH, Tan F, Zhang XQ, Zhang RH, Song XP, Li YR, Yan MX, Lei JC, Qin ZQ, Luo YW, Li DM, Wei JJ (2020) Smut resistant identification and analysis of new sugarcane clones of Guitang. Chinese Journal of Tropical Crops 41(2): 333-338\u003c/li\u003e\n\u003cli\u003eLi HB, Xie YT, Cai WJ, Deng QQ, Chen JW, Shen WK (2020) Identification and evaluation of resistance of new sugarcane lines against \u003cem\u003eSporisorium scitamineum, \u003c/em\u003ecausing sugarcane smut. Plant Protection 46(5): 167-173\u003c/li\u003e\n\u003cli\u003eLi GH, Wen GS, Tian HT, Zhang LY, Li Y, Huang H (2010) Gall disease of \u003cem\u003eCryptomeria fortunei\u003c/em\u003e at different altitudes on Mount Tianmu, Zhejiang Province. Journal of Zhejiang Forestry College 27(4): 483-488\u003c/li\u003e\n\u003cli\u003eLilik KP, Tri AD (2012) Major Diseases Affecting Sugarcane Production in Indonesia. Functional Plant Science and Biotechnology 6: 124-129\u003c/li\u003e\n\u003cli\u003eMagarey RC, Denney D, Sheahan T, Bull JI (2010) The Australian sugarcane smut epidemic, epidemiological considerations and predictions for the final stages. Proceeding of Australian Society of Sugarcane Technology 32: 1-40\u003c/li\u003e\n\u003cli\u003eMansoor S, Khan MA, Khan NA (2016) Screening of sugarcane varieties/lines against whip smut disease in relation to epidemiological factors. Journal of Plant pathology and Microbiology 7: 1-5\u003c/li\u003e\n\u003cli\u003eMcMaugh T (2005) Guidelines for surveillance for plant pests in Asia and the Pacific. ACIAR Monograph No.119 pp 192\u003c/li\u003e\n\u003cli\u003eMinitab (2014) Minitab Statistical Software, Release 17 for Windows. State College, Pennsylvania. Minitab\u0026reg; is a registered trademark of Minitab, Inc.\u003c/li\u003e\n\u003cli\u003eNagakura J, Akama A, Mizoguchi T, Okabe H, Shigenaga H, Yamanaka T (2006) Effects of chronic nitrogen application on the growth and nutrient status of a Japanese cedar (\u003cem\u003eCryptomeria japonica\u003c/em\u003e) stand. Journal of Forest Research 11(5): 299-304\u003c/li\u003e\n\u003cli\u003eNong B, Liu XY, Huang DY, Xiao LQ, Guo RM, Ou LP, Huang ZX, Huang GN, Zhou L, Wei QQ, Nong ZR, Lu X (2025) Planting performance of sugarcane variety Yunzhe 081609 in Baise, Guangxi Province. Guangxi Sugar Industry 45(3): 189-193\u003c/li\u003e\n\u003cli\u003ePeng SJ, Zhang YF, Ou XK (2018) Study on vegetation restoration based on phylogenetic structure of plant communities in Jinshajing Dry-hot Valley. Journal of Kunming University 40(6): 72-76\u003c/li\u003e\n\u003cli\u003ePutra LK, Damayanti TA (2012) Major diseases affecting sugarcane production in Indonesia. Functional Plant Science and Biotechnology 6(2): 124-129\u003c/li\u003e\n\u003cli\u003eRupiah MK (2017) Possible effects of climate change in the agronomy of sugarcane in Zimbabwe. Global Journal of Pests, Diseases and Crop Protection 5: 240-244\u003c/li\u003e\n\u003cli\u003eShen WK, Jiang ZD, Deng HH, Liu R (2013) Research progress on sugarcane smut disease and Sporisorium scitaminea. Chinese Journal of Tropical Crops 34(10): 2063-2068\u003c/li\u003e\n\u003cli\u003eSong QQ, Singh P, Singh RK, Song XP, Li HB, Nong YY, Yang LT, Li YR (2019) Proteomic analysis of sugarcane-\u003cem\u003eSporisorium scitamineum \u003c/em\u003einteraction based on iTRAQ technique. Acta Agronomica Sinica 45(1): 55-69\u003c/li\u003e\n\u003cli\u003eSu YC, Wang ZP, Xu LP, Peng Q, Liu F, Li Z, Que YX (2016) Early selection for smut resistance in sugarcane using pathogen proliferation and changes in physiological and biochemical indices. Frontiers in Plant Science 7: 1133\u003c/li\u003e\n\u003cli\u003eSundravadana S, Ragavan T, Thirumurugan A, Sathiya K, Shah E (2011) Influence of climatic parameters and management strategies on sugarcane smut disease. International Journal of Forestry and Crop Improvement 2: 199-204\u003c/li\u003e\n\u003cli\u003eTegene S, Terefe H, Dejene M, Tegegn G, Tena E, Ayalew A (2021) Survey of sugarcane smut (\u003cem\u003eSporisorium scitamineum\u003c/em\u003e) and association of factors influencing disease epidemics in sugarcane plantations of Ethiopia. Tropical Plant Pathology 46(4): 393-405\u003c/li\u003e\n\u003cli\u003eV\u0026aacute;nky K (1999) The new classificatory system for smut fungi, and two new genera. Mycotaxon 70(3): 35-49\u003c/li\u003e\n\u003cli\u003eWang CM, Li J, Zhang RY, Wang XY, Shan HL, Cang XY, Yin J, Luo ZM, Huang YK (2021) Research progress of sugarcane smut disease. Sugar Crops of China 43(2): 65-70\u003c/li\u003e\n\u003cli\u003eWang J, Jiang P, Ailixiati M, Li FJ, Aisikeer R (2019) Preliminary study on occurrence dynamics of walnut leaf spot and extension process of pathogenic condition. Forest Pest and Disease 38(1): 19-22\u003c/li\u003e\n\u003cli\u003eWang P, Chen YF (2022) The willingness and impact factors of households\u0026rsquo; corn and soybean strip compound planting. Journal of Wuhan Polytechnic University 41(5): 81-88\u003c/li\u003e\n\u003cli\u003eWei JJ, Song XP, Wei CY, Zhang XQ, Huang WH, Yan MX (2019) Research progress on sugarcane smut and its control. Guangdong Agricultural Sciences 46(4): 81-88\u003c/li\u003e\n\u003cli\u003eXia HM, Zhao PF, Liu JY, Zhao J, Zan FG, Chen XK, Yang K, Yang HC, Yao L, Zhao LP, Wu ZD, Qin W, Wu CW (2018) Breeding of new sugarcane variety Yunzhe081609 with early maturing and high sucrose content. Sugar Crops of China 40(5): 6-9\u003c/li\u003e\n\u003cli\u003eYang X, Lyu MY, Hu CQ, Yang F, Wang YB, Dai ZM, Yu HT, Zheng AQ, Zhang YR, Tang YS, Wang LP, Li Q, He YH (2024) Effects of environment and genotype on grain yields of faba bean under ecological conditions of low latitude plateau. Soils and Crop 13(4): 479-489\u003c/li\u003e\n\u003cli\u003eZhang YB, Liu SC, Huang YK (2006) The natural climate characteristics and ecological regionalization in Yunnan sugarcane area. Sugar Crops of China 4: 38-40\u003c/li\u003e\n\u003cli\u003eZhang YB, Deng J, Cheng Y, Long YF (2013) Study on development and technical strategy of plateau characteristic sugarcane industry in Yunnan. Beijing: China Agriculture Press pp, 12-21\u003c/li\u003e\n\u003cli\u003eZhang YB, Zhao PF, Hu CH, Que YX (2024) The recent achievements and development trends of sugarcane improvement in China. Sugar Crops of China 46(1): 87-92\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 Geo-climatic profiles of the investigation sites and their smut incidence (mean\u0026plusmn;SE) in Yunnan\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"988\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 135px;\"\u003e\n \u003cp\u003eEcological region\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eInvestigation site\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003eEast longitude\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003eNorth latitude\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 165px;\"\u003e\n \u003cp\u003eclimate type\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003eAverage annual temperature (℃)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003eAverage annual precipitation (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003eSmut incidence\u003csup\u003ea\u003c/sup\u003e (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"13\" valign=\"top\" style=\"width: 135px;\"\u003e\n \u003cp\u003eSouthern subtropical humid region\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eShuangjiang, Lincang (SJ)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e99\u0026deg;81\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e23\u0026deg;48\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"4\" style=\"width: 165px;\"\u003e\n \u003cp\u003eSubtropical mountain monsoon\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e19.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e995.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e4.94\u0026plusmn;1.28c\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eNanshan, Lincang (NS)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e98\u0026deg;82\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e23\u0026deg;77\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e19.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1624.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e8.49\u0026plusmn;2.17abc\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eMengdui, Lincang (MDui)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e98\u0026deg;90\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e23\u0026deg;94\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e19.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1500.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e6.65\u0026plusmn;1.64bc\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eQuannei, Lincang (QN)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e100\u0026deg;16\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e23\u0026deg;54\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e18.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1590.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e15.48\u0026plusmn;4.36ab\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eMengsheng, Lincang (MS)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e99\u0026deg;42\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e23\u0026deg;34\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 165px;\"\u003e\n \u003cp\u003eSubtropical dry-hot valley\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e23.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1000.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e8.57\u0026plusmn;1.60abc\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eGengma, Lincang (GM)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e99\u0026deg;40\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e23\u0026deg;53\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 165px;\"\u003e\n \u003cp\u003eSouth subtropical dry-hot valley monsoon\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e19.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e950.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e12.42\u0026plusmn;4.53abc\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eSipaishan, Lincang (SPS)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e99\u0026deg;44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e23\u0026deg;58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e19.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e950.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e10.46\u0026plusmn;2.59abc\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eMengyong, Lincang (MY)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e99\u0026deg;65\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e23\u0026deg;87\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 165px;\"\u003e\n \u003cp\u003eSouth subtropical monsoon\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e19.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1117.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e8.71\u0026plusmn;1.82abc\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eMengdin, Lincang (MDin)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e98\u0026deg;92\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e23\u0026deg;51\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 165px;\"\u003e\n \u003cp\u003eSubtropical dry-hot valley monsoon\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e23.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1200.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e8.10\u0026plusmn;2.01abc\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eJunsai, Lincang (JS)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e99\u0026deg;32\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e23\u0026deg;73\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 165px;\"\u003e\n \u003cp\u003eSubtropical humid\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e21.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1888.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e16.44\u0026plusmn;3.20a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eWeiyuan, Pu\u0026rsquo;er (WY)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e100\u0026deg;70\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e23\u0026deg;50\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 165px;\"\u003e\n \u003cp\u003eSubtropical monsoon humid\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e19.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1338.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e5.82\u0026plusmn;2.09c\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eYongping, Pu\u0026rsquo;er (YP)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e100\u0026deg;23\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e23\u0026deg;24\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 165px;\"\u003e\n \u003cp\u003eSouth subtropical monsoon\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e19.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1271.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e9.51\u0026plusmn;2.66abc\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eShangyun, Pu\u0026rsquo;er (SY)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e99\u0026deg;59\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e22\u0026deg;55\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 165px;\"\u003e\n \u003cp\u003eSubtropical monsoon\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e20.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1450.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e9.82\u0026plusmn;1.97abc\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 135px;\"\u003e\n \u003cp\u003eSouthern subtropical semi-humid region\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eXinping, Yuxi (XP)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e102\u0026ordm;16\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e23\u0026ordm;38\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 165px;\"\u003e\n \u003cp\u003eSouth subtropical dry-hot valley\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e18.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e869.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e6.71\u0026plusmn;1.74bc\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 135px;\"\u003e\n \u003cp\u003eNorthern tropical semi-humid region\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eMangkuan, Baoshan (MK)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e98\u0026deg;87\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e25\u0026deg;45\u0026prime;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 165px;\"\u003e\n \u003cp\u003eSubtropical dry-hot Valley\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e23.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 129px;\"\u003e\n \u003cp\u003e1200.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e12.89\u0026plusmn;3.84abc\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003csup\u003ea\u0026nbsp;\u003c/sup\u003eDifferent lowercase letters indicate significant differences among disease incidence of different planting regions\u0026nbsp;(\u003cem\u003eP\u003c/em\u003e\u0026lt;0.05).\u003c/p\u003e\n\u003cp\u003eTable 2 Effects of different altitudes and crop cycle on smut incidence (mean\u0026plusmn;SE)\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"598\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 166px;\"\u003e\n \u003cp\u003e\u0026nbsp;Altitude (m)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 164px;\"\u003e\n \u003cp\u003eSmut incidence（%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 105px;\"\u003e\n \u003cp\u003eCrop cycle\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 164px;\"\u003e\n \u003cp\u003eSmut incidence\u003csup\u003ea\u003c/sup\u003e（%）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 166px;\"\u003e\n \u003cp\u003e\u0026le;1200\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 164px;\"\u003e\n \u003cp\u003e14.71\u0026plusmn;1.88ab\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 105px;\"\u003e\n \u003cp\u003eNewly planted\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 164px;\"\u003e\n \u003cp\u003e5.81\u0026plusmn;1.32de\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 166px;\"\u003e\n \u003cp\u003e1200-1500\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 164px;\"\u003e\n \u003cp\u003e8.29\u0026plusmn;0.93cd\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 105px;\"\u003e\n \u003cp\u003eRatoon 1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 164px;\"\u003e\n \u003cp\u003e11.00\u0026plusmn;0.98bc\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 166px;\"\u003e\n \u003cp\u003e\u0026gt;1500\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 164px;\"\u003e\n \u003cp\u003e2.89\u0026plusmn;1.03e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 105px;\"\u003e\n \u003cp\u003e\u0026gt;ratoon 1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 164px;\"\u003e\n \u003cp\u003e15.31\u0026plusmn;1.78a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003csup\u003ea\u0026nbsp;\u003c/sup\u003eDifferent lowercase letters indicate significant differences among disease incidence between altitudes and crop cycle (P\u0026lt;0.05).\u003c/p\u003e\n\u003cp\u003eTable 3 Chi-square Analysis of smut incidence in different ecological planting regions, altitudes and crop cycles\u0026nbsp;\u003c/p\u003e\n\u003cdiv align=\"center\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"568\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 88px;\"\u003e\n \u003cp\u003eIndependent Variables\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 173px;\"\u003e\n \u003cp\u003eVariable class\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 119px;\"\u003e\n \u003cp\u003eSmut incidence（%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 54px;\"\u003e\n \u003cp\u003eTotal fields\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 58px;\"\u003e\n \u003cp\u003e\u003cem\u003eX\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 75px;\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e\u0026le;5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e\u0026gt;5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" style=\"width: 88px;\"\u003e\n \u003cp\u003eEcological planting region\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 173px;\"\u003e\n \u003cp\u003eSouthern subtropical humid region\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e155\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e212\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" style=\"width: 58px;\"\u003e\n \u003cp\u003e3.69\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" style=\"width: 75px;\"\u003e\n \u003cp\u003e0.1577\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 173px;\"\u003e\n \u003cp\u003eSouthern subtropical semi-humid region\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 173px;\"\u003e\n \u003cp\u003eNorthern tropical semi-humid region\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" style=\"width: 88px;\"\u003e\n \u003cp\u003eAltitude\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 173px;\"\u003e\n \u003cp\u003e\u0026le;1200 m.a.s.l\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e84\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" style=\"width: 58px;\"\u003e\n \u003cp\u003e66.78\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" style=\"width: 75px;\"\u003e\n \u003cp\u003e0.0000**\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 173px;\"\u003e\n \u003cp\u003e1200-1500 m.a.s.l\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e73\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e85\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 173px;\"\u003e\n \u003cp\u003e\u0026gt;1500 m.a.s.l\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e47\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" style=\"width: 88px;\"\u003e\n \u003cp\u003eCrop cycle\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 173px;\"\u003e\n \u003cp\u003eNewly planted\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" style=\"width: 58px;\"\u003e\n \u003cp\u003e55.01\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" style=\"width: 75px;\"\u003e\n \u003cp\u003e0.0000**\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 173px;\"\u003e\n \u003cp\u003eRatoon 1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e70\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 173px;\"\u003e\n \u003cp\u003e\u0026gt;ratoon 1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 54px;\"\u003e\n \u003cp\u003e66\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003csup\u003ea\u0026nbsp;\u003c/sup\u003eThe\u003cem\u003e\u0026nbsp;X\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e employed for comparison was 5.99 (5% significance and 2 degree of freedom). \u003csup\u003eb\u003c/sup\u003e The\u003cem\u003e\u0026nbsp;X\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e employed for comparison was 9.21 (1% significance and 2 degree of freedom). ** indicates \u003cem\u003ep\u003c/em\u003e＜0.01.\u003c/p\u003e\n\u003cp\u003eTable 4 Two-way ANOVA of smut incidence and contribution rate of variable factors\u003c/p\u003e\n\u003cdiv align=\"center\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"568\" class=\"fr-table-selection-hover\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 122px;\"\u003e\n \u003cp\u003eFactor\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003eSum of squares (SS)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003edf\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003eMean square\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57px;\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 64px;\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 111px;\"\u003e\n \u003cp\u003eContribution rate（%）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 122px;\"\u003e\n \u003cp\u003eAltitude\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e2648.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e1324.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57px;\"\u003e\n \u003cp\u003e16.44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 64px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 111px;\"\u003e\n \u003cp\u003e63.20\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 122px;\"\u003e\n \u003cp\u003eCrop cycle\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e1207.14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e603.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57px;\"\u003e\n \u003cp\u003e7.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 64px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 111px;\"\u003e\n \u003cp\u003e28.81\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 122px;\"\u003e\n \u003cp\u003eAltitude\u0026times;Crop cycle\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e334.47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e83.62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57px;\"\u003e\n \u003cp\u003e1.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 64px;\"\u003e\n \u003cp\u003e0.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 111px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 122px;\"\u003e\n \u003cp\u003eError\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e8699.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e108\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e80.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 64px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 111px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 122px;\"\u003e\n \u003cp\u003eTotal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e12889.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e116\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 64px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 111px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"tropical-plant-pathology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"tppa","sideBox":"Learn more about [Tropical Plant Pathology](https://www.springer.com/journal/40858)","snPcode":"40858","submissionUrl":"https://www.editorialmanager.com/tppa","title":"Tropical Plant Pathology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"sugarcane smut, low-latitude plateau, altitude, crop cycle","lastPublishedDoi":"10.21203/rs.3.rs-8588952/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8588952/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eTo explore the effects of different altitudes and crop cycle on the occurrence of sugarcane smut in the low-latitude plateau region of Yunnan, this study conducted a systematic investigation of smut incidence in the southern subtropical humid, southern subtropical semi-humid, and northern tropical semi-humid sugarcane growing areas of Yunnan. The results showed that there were significant differences in smut incidence among different regions, altitudes, and crop cycle in Yunnan. The smut incidence ranged from 4.94% to 16.44% across different regions, indicating that smut has occurred universally and caused severe damage in Yunnan. The incidence varied from 2.89% to 14.71% across different altitudes, exhibiting a decreasing trend with increasing altitude. For different crop cycle, the incidence ranged from 5.81% to 15.31%, showing an increasing trend as the crop cycle extended. Under the ecological conditions of Yunnan's low-latitude plateau, altitude and crop cycle were identified as the main sources of variation in smut incidence. Their interaction effect was not significant, whereas the respective main effects of both factors were statistically significant. Meanwhile, the contribution rate of variation to smut incidence of altitude (63.20%) was higher than that of crop cycle (28.81%). These findings provide a scientific basis for the rational distribution of elite sugarcane varieties and the scientific control of smut in the low-latitude plateau sugarcane regions of Yunnan.\u003c/p\u003e","manuscriptTitle":"Effects of altitude and crop cycle on the occurrence of sugarcane smut under the ecological conditions of low-latitude plateau","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-09 09:59:09","doi":"10.21203/rs.3.rs-8588952/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revisions","date":"2026-03-16T21:35:16+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2026-02-04T22:29:54+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-02-04T21:21:17+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"Tropical Plant Pathology","date":"2026-02-03T11:30:49+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-03T06:02:07+00:00","index":"","fulltext":""},{"type":"submitted","content":"Tropical Plant Pathology","date":"2026-01-19T20:07:11+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"tropical-plant-pathology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"tppa","sideBox":"Learn more about [Tropical Plant Pathology](https://www.springer.com/journal/40858)","snPcode":"40858","submissionUrl":"https://www.editorialmanager.com/tppa","title":"Tropical Plant Pathology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"cf9d3635-2bff-4a64-b515-d33e03b5b409","owner":[],"postedDate":"February 9th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-20T10:12:32+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-09 09:59:09","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8588952","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8588952","identity":"rs-8588952","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}