Derivate OJIP Variables in Sugarcane to Predict Cane Weight, Sucrose Content, and Sugar Yield

AbstractCane weight, sucrose content, and sugar yield represent carbohydrate accumulation available for cane throughout its life cycle. The carbohydrate content is the result of photosynthesis; in other words, we can predict cane weight, sucrose content, and sugar yield from the photosynthesis process. Chlorophyll fluorescence or the OJIP test is one of the benchmarks for expressing the amount of photosynthesis. This study aimed to obtain the dominant OJIP variable as a predictor of cane weight, sucrose content, sugar yield, and measurement time. The study was conducted at the Asembagus Experimental Station, Situbondo Regency, East Java, Indonesia, from December 2016 to October 2017. The study used 18 sugarcane clones in a Randomized Block Design with 3 replications. OJIP variables were measured in the stalk elongation phase and the maturity phase. The results showed that OJIP variables other than Fv/Fm, cane weight, sucrose content, and sugar yield were influenced by sugarcane clones. The right time for measuring OJIP variables was during the maturity phase. The dominant OJIP variables as predictors of cane weight and sugar yield were TRo/RC, DIo/CS, ABS/RC, and PI (79.4 and 76.0%). The dominant predictors of yield were RC/CSo, RC/CSm, DIo/CS, PI, ABS/RC, and ETo/RC (92.9%).