Productivity of main stem and tillers of rice as a function of nitrogen fertilization fractionation

Abstract

The objective of this work was to evaluate the contribution of the main stem and tillers on the grain yield of irrigated rice, and on the physiological quality of the seeds as a function of fractionation of topdressing nitrogen fertilization. The experiment was performed in the field, at the 2016-2017 and 2017-2018 growing seasons. The treatments consisted of five nitrogen (N) topdress fractionations 50% of the rate at V3, and 50% at R0; 67% at V3, and 33% at R0; 60% at V3, 20% at V6, and 20% at R0, 100% at V3, and a control without N topdress application. The main stem panicle, and each tiller class were harvested, and grain yield (GY), yield components and physiological seed quality were evaluated. Grain yield and physiological seed quality are influenced by the panicle classes, being higher in the main stem panicle. The N fractionations of 67% at V3 and 33% at R0; 60% at V3, 20% at V6 and 20% at R0 and 100% at V3, promote higher GY and number of grains per panicle. The thousand grains mass, spikelet sterility, the physiological quality of seeds are not influenced by the topdressing nitrogen fertilization fractionation.