ÍNDICES DE VEGETAÇÃO OBTIDOS COM CÂMERA MULTIESPECTRAL COM ADUBAÇÃO NITROGEMADA E PRODUTIVIDADE NO MILHO

Abstract

The objective was to verify vegetation indexes obtained by images performed with Vant, can detect changes in N status in corn plants, as well as correlate with productivity. The experimental design was of blocks to the case being 5 doses (0, 75, 150, 225 and 300 kg ha-1) of N (urea treated with ureaase inhibitor) applied in cover and 4 repetitions. For the evaluations, collections of the plant part of the plant were carried out, where the leaves stood out in the middle third of the corn plant in stages V3, V6 and V9, a flight was also carried out with the drone model DJI Insprire 2, equipped with a multispectral camera (Sentera) in the three phenological stages of collection. At harvest, ears of corn from 4 rows of 2 meters (center of plot) were harvested. Then the number of rows and numbers of grains per row of ears harvested were counted, in addition to being traced and the grains weighed and corrected to 13% humidity, calculating productivity in kg.ha-1. Plants grown on a higher nitrogen supply consequently accumulated higher amounts of N content in the leaf, at stages V6 and V9 the greatest accumulation is at doses of 225 kg.ha-1 (52.09 g.kg of N) and 300 kg.ha-1 (37.48 g.kg of N), respectively. The modified DI1 index was the one that stood out the most in the two phenological stages evaluated, due to working with narrow bands in the infrared (825nm) and in the green (586nm). As for the safrinha corn productivity, no calculated vegetative index was significant. It is concluded that the modified DI1 index was the one that most collaborated in predicting the quantification of nitrogen fertilization in off-season corn.