Sugarcane Yield and Yield Components as Affected by Harvest Time

Brazil is the largest sugarcane producing country in the world. Mills usually operate nine months to process the sugarcane produced in the country. Here we investigated the effect of harvest time on the on-farm sugarcane yield and yield components (stalk fresh yield [SFY], sucrose yield [SY], and sucrose concentration [POL%]). We used a large database collected from commercial sugarcane blocks to assess the effect of harvest time on SY and yield components. Blocks were first clustered based on similarity of climate and soil, referred as environments, and the effect of harvest season on SY, SFY, and POL%, as influenced by the environment and the number of harvests, was evaluated using analysis of variance. Harvest season strongly influenced POL% and SY but had a comparably smaller effect on SFY. Although relatively smaller compared with other sources of variation, there was a statistically significant interactive effect of harvest number and harvest season on SY, with highest SY when harvest occurred during the mid-season or late season in old ratoons and during the mid-season in the case of young ratoons. Closing the yield gap due to sub-optimal harvest time by concentrating the harvest around the productivity peak would increase national sucrose production by 8%, but this is not possible due to logistic and milling constrains. In contrast, our findings suggested room to extend the harvest period to 10 months, which will free up milling capacity by 8% with no yield penalty. The extra milling capacity could serve as a motivation to increase productivity via agronomic practices to fully exploit the milling processing capacity.