Effect of chitosan foliar spray on the vegetative development of inoculated soybean

Abstract

Chitosan is a linear polymer of glucosamines linked by β 1-4 exoskeleton, which is obtained by alkaline deacetylation of chitin and, has a wide application as an agricultural biostimulant. The objective of this work was to evaluate the effect of different concentrations (1, 10, 50, 100, 500 and 1000 mg L^-1) of chitosan, applied in phases V1 and V2 by foliar spray, in the nodulation, the physiology and vegetative growth indicators of IS-27 inoculated soybean with Azofert-S^®, in controlled conditions. Seeds inoculated with the ICA 8001 strain of Bradyrhizobium elkanii, prior to sowing, were placed in pots and grown in a growth chamber until phase V4. The application of 10 mg L^-1 chitosan stimulated both the number and the dry mass of the nodules formed and the concentrations 500 and 1000 mg L^-1 stimulated plant growth. On the other hand, the inoculation of seeds with Bradyrhizobium increased the levels of the nitrate reductase (NR) enzyme activity in the V1 soybean phase, while in the V2 and V3-V4 phases, the NR activity was increased with the application of the concentrations between 10 and 500 mg L^-1 chitosan. The benefit of the indicators of the metabolism of nitrogen by chitosan in this work could be to the stimulated vegetative development in plants related.