Desempenho agronômico do milho em função de arranjos populacionais em diferentes zonas de manejo definidas pela agricultura de precisão

Abstract

The use of precision agriculture (PA) tools, such as the variable rate seeding, is an alternative to adapt the population of corn plants in management zones according to the temporal and spatial variability present in the crops, which affect productivity of grain. The objective of this study was to evaluate the agronomic performance of the corn hybrid P3016VYHR, as a function of plant population and management zones. For this, an experiment was carried out in the municipality of Faxinal dos Guedes - SC, in the 2021/22 harvest. The management zones were delimited through a map of corn production and through knowledge of the production history observed by the rural producer, separating the plot into high (ZA), medium (ZM) and low (ZB) zones, defined from the productivity of previous crops. The experiment was bifactorial with four seeding rates, 55,000, 70,000, 85,000 and 100,000 plants ha-1 in three management zones (ZA, ZM and ZB) under Oxisol. Biometric variables (stem diameter, plant height and ear insertion height), yield components (number of grain rows, number of grains per row, number of grains per ear and weight of 1,000 grains) and grain yield were evaluated. With the productivity results, a projection of sowing in a variable rate was carried out and the calculations of economic return were carried out comparing the variable rate with the fixed rate. Grain yield was influenced by plant population and management zones, in the ZA, the population of 85,000 pl ha-1 showed higher productivity (14,915.76 kg ha-1), in the ZM and ZB, the population of 55,000 pl ha-1 had the highest grain yield. The variable rate can increase the average grain yield by 23%, decreasing seed cost and increasing profitability per hectare.