Agronomic performance of green corn at different sowing times and nitrogen doses

Abstract

The present study aimed to identify the best sowing time and the best nitrogen dose in topdressing of the corn crop for "green ear" consumption. The experiment was conducted between October 2018 and June 2019 in a commercial crop, in Ipameri, Goiás, Brazil. The soil in the experimental area is classified as dystrophic Red-Yellow Latosol with clayey texture. The experimental design used was the randomized blocks, in a 5 x 5 factorial scheme, with five sowing times [1st (10/19/2018); 2nd (11/29/2018); 3rd (01/08/2019); 4th (02/18/2019) and 5th (03/28/2019)], implemented with 40 days intervals, after the first sowing, and five nitrogen doses (0, 50, 100, 150, and 200 kg ha-1), with four replicates. The following factors were evaluated for each sowing time: relative chlorophyll index, leaf dry mass, leaf nitrogen content, plant height, first ear insertion height, ears diameter and length, the total yield of ears with husks, the yield of commercial ears without husks and grain yield. The data were submitted to the analysis of variance (F-test). The sowing times and nitrogen doses in topdressing influenced the leaf nitrogen content, relative chlorophyll index, leaf dry mass, yield, and most of its components. Thus, it can be indicated that the best time for sowing corn for fresh consumption is in October (1st sowing time), and the estimated nitrogen dose in topdressing to obtain the maximum yield is 160 kg ha-1 of nitrogen.