Correlation between grain yield in maize plant densities

Resumo

When assessing genotypes in different environments, the result depends on the genotype-environment interac­tion. Among the environmental factors, the spatial arrangement of plants is among the most important manage­ment practices to achieve higher grain yield. This arrangement involves changes in the spacing between rows and between plants. The present study evaluates the correlation between the grain yield of maize genotypes and different plant populations. We conducted the experiments in the 2012/2013 harvest season and in the 2012/13 off-seasons at UNESP - Jaboticabal Campus, in Jaboticabal county, São Paulo State, Brazil, and in the 2013 off-season at Cambuhy Farm, in Matão county, São Paulo State, Brazil. The experimental design was in randomized blocks, with three replicates. For the 0.50 m spacing between rows, the spacing between plants was 0.25 m (80,000 pl ha^-1), 0.30 m (66,667 pl ha^-1), and 0.40 m (50,000 pl ha^-1). For the 0.90 m spacing between rows, the spacing between plants was 0.20 m (55,556 pl ha^-1). We assessed the treatments for grain yield (six genotypes), analyzing the correlations between grain yield averages and plant population densities for each environment using the Pearson correlation coefficient. The 2012/2013 harvest season in Jaboticabal county provided the highest average yield, regardless of population density. The 2012 off-season in Jaboticabal county provided the lowest average yield. As for population densities, the one that provided the highest yield was 80,000 plants ha^-1. The present study found several types of correlation, which allows us to say that population density recommendations must be specific.