Abstract

Productivity and longevity of sugarcane plantations may currently be affected by the expanded cultivation activities in low fertility areas, which can result in micronutrient deficiencies. Zinc is important in this regard because its deficiency in sugarcane can cause reduced tillering, shorter internodes and thinner stalks. Therefore, the agronomic performance of sugarcane was evaluated (plant-sugarcane and first-ratoon-sugarcane), grown on a sandy soil with low zinc content, in response to rates and sources of zinc applications in the planting grooves. The experiment was conducted in an eutrophic Alfisol in Suzanápolis, São Paulo State, Brazil. A randomized blocks design in a factorial scheme (5x3), with five zinc rates (0, 2.5, 5.0, 7.5 and 10.0 kg ha^-1) and three sources of zinc (sulfate, FTE (Zn silicate powder) and EDTA chelated Zinc) applied only in the planting furrow of the plant-sugarcane, with four replications, was used. The zinc sources had a similar effect on the Zn foliar and stalk contents, number of internodes per stalk, number of stalks per meter and sugarcane stalk productivity (cultivar RB867515), in two crops. Increasing zinc rates afforded a linear increase in the levels of foliar Zn and Zn in the stalks of the plant-sugarcane and first-ratoon-sugarcane, independent of the Zn source used. The zinc rates did not affect the production components and productivity of the plant-sugarcane stalks and first-ratoon sugarcane, grown on a sandy and acid soil with low zinc content.

Key words: Saccharum spp., fertilization with zinc, micronutrient, stalk productivity.