AGRONOMIC PERFORMANCE OF GRAIN SORGHUM CULTIVATED IN DOUBLE ROWS SPACE ON BRAZILIAN CERRADO

ABSTRACT The spatial arrangement of plants in the cultivation area is a factor that directly influences grain yield, since the best arrangement can result in the greater use of water, light and nutrients. The aim of the study was to evaluate the agronomic performance of sorghum sown in double row spacing in the Brazilian Cerrado. For this purpose, field experiments were conducted in the 2018 and 2019 seasons in a complete block design with a factorial scheme of 2 x 5. There were four replications, using two row spacing: traditional (0.50 m) and double rows (0.25 m/0.75 m) and five plant populations: 120, 180 (recommended), 240, 300 and 360 thousand, plants ha-1. Morphological characteristics, yield components and grain yield were evaluated using joint data analysis for the two years of study. In 2018, due to lower rainfall during the crop season, the use of a double row arrangement presented grain yield lower than traditional spacing. On the other hand, in 2019, the year with the best water distribution, the yield was superior to that of 2018. The increase in plant population per hectare increased the yield of sorghum grains, with gains of up to 24% in relation to the recommended population of 180 thousand plants ha-1, demonstrated that the densification in this crop can be a promising technique as long as its cost/benefit is considered.

摘要：作物种植区内的植株空间排布直接影响籽粒产量，最优排布可实现对水分、光照与养分的更高效利用。本研究旨在评估巴西塞拉多（Cerrado）地区采用双行行距播种的高粱农艺表现。试验于2018和2019季采用完全区组设计，设置2×5因子试验方案，共设4次重复。供试因子包含2种行距配置：传统行距（0.50 m）与双行行距（0.25 m/0.75 m），以及5个种植密度：120、180（推荐密度）、240、300与360万株·hm⁻²。研究采用两年联合数据分析方法，对植株形态特征、产量构成因素与籽粒产量进行评估。2018年作物季降雨偏少，双行排布处理的籽粒产量低于传统行距处理；而2019年水分分布更均匀，籽粒产量较2018年更高。每公顷种植密度提升可提高高粱籽粒产量，相较于推荐密度180万株·hm⁻²，最高可实现24%的产量增益，表明只要兼顾成本效益，该作物的密植技术具备良好应用前景。