Doses de cinetina em cultivares de soja

Abstract

The soybean crop is one of the most important to the agribusinees in the world, and the search for new technologies and methods that drive productivity levels and reduce costs is the target of research to achieve the maximum income at the fields level. In this context, exist the phytoregulators study to understand the morphological and physiological implications of the aplications in crops yield. One of that is the kinetin, a synthetical substance similar to the cytokinin hormonal class. The objective of this study was evaluate the effects of different kinetin doses applied in different soybean cultivars. The experiment was carried out under field conditions, at the Milanez Farm, in the city of Itutinga-MG, and the experimental design was randomized block, sub-divided plots with three replications. Were sprayed at the vegetative stage V6, five kinetin concentrations (0, 500, 1000, 1500, 2000 mg ha-1), that formed the plots, and used four comercial cultivars (FPS URANO RR, 5D690 RR, RK5813 RR, and RK6313 IPRO) in subplots, two with determinate growth habit and two with indeterminate habit. Plant height at harvest, first legume insertion, days to maturity, number of legumes per plant, number of seeds per plant, nitrogen leaf content, chlorophyll content, mass of one hundred grains, grain yield were evaluetad. The statistical analyzes were performed with the SISVAR software (Ferreira, 2011). The kinetin sprayed doses have altered the days to maturity, chlorophyll content, and yield. The plant height, first legume insertion, days to maturity, number of legumes per plant, number of seeds per plant, nitrogen content, chlorophyll content, mass of one hundred grains were altered in all cultivars tested. The FPS URANO RR reached the maturity in 116 days which makes it a usable material for the off-season maize crop. The 1000 mg ha-1 dose is the most efficient for days to maturity, nitrogen and chlorophyll content, mass of one hundred grains, and grain yield. The 1500 mg ha-1 dose represent the highest profit margin for the kinetin application.