Maize yield performance altered by trinexapac-ethyl rates and plant population

ABSTRACT Increases in plant density associated with the use of plant growth regulators, aside from modifying the plant architecture, can also change the maize yield performance. This study aims to investigate the yield components and grain yield of maize hybrids with contrasting leaf architecture, in response to different plant populations and trinexapac-ethyl rates (TE). Field experiments were conducted in two growing seasons, in a (5 x 5) factorial randomized block design. The treatments consisted of: five plant population (40, 60, 80, 100, and 120 thousand plants ha-1) and five TE rates (0, 100, 200, 300, and 400 g a.i. ha-1), with four replications, using the hybrids 2B710 HX and Status TL. We evaluated the number of rows per ear, ear length, number of grains per row, 1000-grain mass, and yield. An increased plant density reduces ear length, number of grains per row and 1000-grain mass, without changing the number of grain rows per ear. TE rates increases ear length and number of grains per row and reduces 1000-grain mass, mainly under favorable cultivation conditions. TE interacts with the plant density, changing the maize yield components with increases in grain yield, but these gains variy, according to the environment and genotype characteristics.