Desempenho agronômico do amaranto no semiárido em função do arranjo espacial

Abstract

ABSTRACT The potential effects of climate change on agricultural yields require a greater understanding of cropping systems that include underutilized agricultural crops with greater adaptive capacity to water and thermal stresses, such as grain amaranth (Amaranthus sp.). The aim of this work was to evaluate how the planting arrangement affects the agronomic performance of grain amaranth BRS Alegria (Amaranthus cruentus L.) grown under semi-arid conditions. One experiment was carried out in a complete randomized block design with five repetitions in a 2 x 3 factorial scheme (two row spacings - 30 and 40 cm; three plant spacings - 20; 30 and 40 cm); in two crop years, 2019 and 2020 in the municipality of Pentecoste, CE, Brazil. The evaluated characteristics were plant height, stem diameter, number of leaves, fresh matter yield, aboveground biomass yield (dry weight), grain yield, thousand-grain weight, lipid content, and harvest and lodging indexes. The evaluated planting arrangements did not affect plant height and number of leaves, but did affect stem diameter and lodging index, as the 40 cm plant spacing resulted in greater stem diameter and lower lodging index. Narrow spacing (30 x 20 cm) resulted in a higher lodging index but also resulted in a higher fresh matter yield, aboveground biomass, grain yield, harvest index and lipid content. Thousand-grain weight was greater at 30 x 40 cm spacing. The 30 x 20 cm arrangement can be recommended for the cultivation of grain amaranth in the study area.