Effect of Time of Planting on Cane Yield and Quality Characters in Sweet Sorghum

Abstract

Sweet sorghum unlike grain sorghum has potential to accumulate sugars in stalks similar to sugarcane. Short duration and lower water requirements of sweet sorghum are other advantages over sugarcane. Sorghum is usually grown in kharif and rabi seasons. As an energy crop, industry demands supply of green cane as raw material through out the year. Hence this agronomic study was conducted to determine suitable time of planting of sweet sorghum under the agro climatic conditions prevailing in India, so that continuous supply of raw material is assured for factory operations through out the year, especially during the lean period of sugarcane crushing. Various physical and chemical characters of plant and stem juice were studied by taking up bimonthly plantings at four locations using 12 genotypes of sweet sorghum in the first year and quarterly plantings at four locations using 10 genotypes (8 genotypes common in both years) in the second year. Of the six plantings, planting during August and April were found to be not suitable for good sweet sorghum yields, therefore, in the second year, four plantings were taken up i.e., June, October, December and February at six locations. The various attributes selected for observations include cane yield, percent brix of stem juice, percent juice extractability, percent total soluble sugars and reducing sugars in the stem juice. Highest green cane yield and percent juice extractability was observed in June planting in all genotypes followed by February, and December in both bimonthly and quarterly plantings. Juice extraction percentage was also highest in June plantings followed by October, April and December plantings. June plantings recorded highest percent brix followed by December and February plantings in bimonthly plantings, while in quarterly planting, highest percent brix and total sugars in juice was observed in February planting followed by planting in June.