MANEJO DE ZINCO E IRRIGAÇÃO DE SALVAMENTO EM VARIEDADES DE CANA-DE-AÇÚCAR CULTIVADAS NO CERRADO

Abstract

The fertilization management with the micronutrient zinc in sugarcane has been updated in Brazil, with tendencies to increase the doses that are currently applied. For the Cerrado region there are still no current and official recommendations, which turns necessary to study this fertilization in different environments, varieties and cycles. In this sense, the study aimed to evaluate the sugarcane performance in two varieties, RB92-579 and SP80-1816, both in plant-cane cycle, cultivated under different irrigation management and zinc fertilization. The study was carried out in a commercial area in a Cerrado Oxisol. For each variety, a randomized block design with three replications was used and analyzed in a 2x4 split plot scheme, where the plots comprised two rescue irrigation managements, with split (30 + 30 mm) and no split (60 mm) associated four zinc doses (0, 5, 10 and 15 kg ha-1). Variety RB92-579 responded positively to irrigation splitting with increases in stalk yield of 44 t ha-1, in addition to 42.7% in sugar yield, while SP80-1816 did not respond to irrigation management. Zinc doses had low expression in both varieties possibly due to the high initial contents in the soil, although doses between 5-10 kg ha-1 promoted good results regarding biometric performance and ATR of RB92-579 when associated with the management of irrigation split.