PRODUCTIVITY OF STALK AND SUCROSE IN SUGARCANE IN RELATION TO CULTIVAR AND RIPENER INTERACTION

Abstract

The use of plant growth regulators as ripeners applied to anticipate the ripening of sugarcane is a well-known practice in the sugar and ethanol industry, however its consequences on the productivity of different cultivars is little studied. The objective of this work was to evaluate the stalk and sugar productivity in the plant cane and the residual effect on the ratoon in function of several ripeners applied in five cultivars. The experimental design used was the randomized blocks, in a 5 x 6 factorial arrangement, with five cultivars (PO88-62, RB72454, RB845210, SP83-2847 and SP81-3250) and six ripening managements (sulfomethuron-methyl; ethephon; glyphosate; ethephon + glyphosate; compounds of organic carboxylic radicals and control), with three replicates, in Santa Maria da Serra, SP. As on the harvest after the application of the ripeners as on the harvest in the following ratoon were evaluated the attributes: stalk and sugar productivity, average stalk and sugar productivity of two harvests, estimate stalk productivity for five harvests, decline stalk and sugar productivity from first to second harvest, sucrose (pol%) in the cane and average sucrose of two harvests. There was not interaction among cultivars and ripeners for the attributes evaluated. The ripener sulfomethuron-methyl and the control promoted the smallest decline productivity from the first to the second harvest. The largest increase in sucrose after the ripeners application was obtained with sulfomethuron-methyl and ethephon. No ripener tested affected the stalk and sugar productivity.