Corn yield in different population densities

Abstract

Maize (Zea mays L.) is cultivated on 3.6 Brazilian million farms, with great diversity in culture conditions, ranging from subsistence agriculture to farms employing state-of-the-art technology for higher yields. High productivity advance has been due to modern corn hybrids, with better fertilizers, more efficient control of weeds, advances in management culture and increase in plant density per hectare associated with a decrease in row spacing. Current trial, which evaluated the productivity and physiological characteristics of two commercial hybrids of maize at different densities, was undertaken in the municipality of Santa Tereza do Oeste PR Brazil, altitude 760 m, longitude 53o 57’ 121” "W and latitude 25º 06’ 957” 'S. Two hybrids maize plants (Pioneer - 30F36 and 38R48) and six populations: 45, 60, 75, 90, 105 and 120 thousand plants per hectare, were grown in three randomized blocks, arranged in a 2x6 factorial design. Results show that the mass of one thousand grains is inversely proportional to population increase and that the amount of atypical, lying and broken plants increases according to increase in population for both hybrids. The most recommended population would be 75 and 60 thousand plants per hectare for hybrids 32R48 and 30F36, respectively, in which plants’ productivity (14,351 and 12,966 kg ha-1, respectively) is coupled to their physiological adaptability.