População de plantas e níveis de nitrogênio para produção de silagem de milho na segunda safra

Abstract

The objective of this work was to evaluate the corn silage production through different populations of plants (69.000, 79.000 and 93.000 plants/ha) when submitted to different doses of nitrogen (150 and 250 kg/ha) in the second harvest. The experimental design used was randomized blocks (DBA) with treatments in a 2x3 factorial arrangement (two nitrogen doses and three plant populations), using 24 area replications. Sowing took place on February 17, 2022. The experimental area had an area of 968 m², in which the plots were 5 meters long by 3.15 meters wide, totaling 15.75 m² each. Forage production, plant stand, biometric measurements, morphological components and plant yield components were evaluated. The plants were harvested in the transition from the milky grain stage to the hard mealy grain stage (30 to 35% of dry matter). Plant density did not influence (P>0.05) biometric measurements, yield components and morphological components of corn plants. Forage production was higher (P<0.05) for the plant population of 93.000 plants/ha. Nitrogen doses did not influence (P>0.05) the evaluated variables, except for the proportion of leaves that excelled at the dose of 250 Kg of N/ha. An interaction between plant population and nitrogen doses was verified for the proportion of plants with stunting complex symptoms, which was lower in the combination between higher plant population and nitrogen dose in relation to the combination with lower population and nitrogen dose. The increase in the population of corn plants can be a viable strategy to increase the production of corn silage in the second harvest in the Southwest of Paraná.