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

Luiz Fernando Pricinotto,Leandro Teodoski Spolaor,Claudemir Zucareli,Inês Cristina De Batista Fonseca,André Sampaio Ferreira

doi:10.1590/0034-737x202168050005

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.

Highlights

Maize grain yield can be increased by maximizing the photosynthetic efficiency, by intensifying the solar radiation interception of the canopy (Marchão et al, 2006)
Cultivar-specific managements tend to be developed, as it is being done, e.g., for trinexapacethyl rates (TE) application to wheat, where the growth regulator rate is adapted to the response of each cultivar (Zagonel & Fernandes, 2007)
Highest yields were obtained at plant densities exceeding the recommended by the holder of this hybrid (65 thousand plants ha-1), in both growing seasons. These results demonstrate that plant densities above the recommended range are possible, as long as the edaphoclimatic conditions are favorable and the cultivation practices are adequate as discussed by Assefa et al (2018)

Summary

Introduction

Maize grain yield can be increased by maximizing the photosynthetic efficiency, by intensifying the solar radiation interception of the canopy (Marchão et al, 2006). One of the ways of improving interception is an elevation of the plant density, augmenting the leaf area of the canopy (Sangoi et al, 2013). The management of plant density in maize cultivation is a practice with a major effect on grain yield. Very high densities can negatively affect the crop, resulting in blanched plants with thinner stems, favoring lodging. Excessively high densities are harmful for causing an increase in intraspecific competition, reducing components such as ear length, the number and/or grain mass per ear and 1000 grain mass (Brachtvogel, et al, 2009; Sangoi et al, 2009)

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