EMERGENCE, GROWTH, AND PRODUCTION OF COLORED COTTON SUBJECTED TO SALT STRESS AND ORGANIC FERTILIZATION

ABSTRACT The semi-arid region of Northeast Brazil is vulnerable to problems of water scarcity and salinity, resulting in low-quality irrigation water and the need to adopt cultivation strategies that make the production system viable. Given the above, this study aimed to evaluate emergence, growth, and production of colored cotton subjected to increasing levels of irrigation water salinity and organic matter doses. The experiment was carried out in a eutrophic Regolithic Neosol with a sandy loam texture in a greenhouse in the municipality of Campina Grande - PB, Brazil. A randomized block design was used in a 4 x 4 factorial scheme with three replicates, and the treatments corresponded to four levels of electrical conductivity of water - ECw (1.7, 3.4, 5.1, and 6.8 dS m-1) and four doses of organic matter - OM (0, 2.5, 3.5, and 4.5% based on soil volume). Increasing irrigation water salinity with ECw values above 1.7 dS m-1 reduced emergence, growth, and production of colored cotton, and the cotton seed weight was the variable most affected by salinity. Organic matter addition led to increased cotton growth and production, especially in terms of seed weight. Increasing doses of organic matter attenuated the effect of irrigation water salinity on the number of bolls in ‘BRS Jady’ cotton.

摘要 巴西东北部半干旱区域易受水资源短缺与盐渍化问题困扰，导致灌溉水质劣化，亟需探索可维持生产系统可持续性的栽培策略。鉴于此背景，本研究旨在评估不同梯度灌溉水盐度与有机质施用量下，彩色棉的出苗、生长及产量表现。
本试验于巴西帕拉伊巴州坎皮纳格兰德市的温室内开展，供试土壤为质地砂壤土的肥沃岩性新成土（eutrophic Regolithic Neosol）。试验采用4×4因子组合的随机区组设计（randomized block design），设置3次重复；处理因素包含4个灌溉水电导率（electrical conductivity of water, ECw）梯度（1.7、3.4、5.1、6.8 dS·m⁻¹），以及4个有机质（organic matter, OM）施用量水平（以土壤体积占比计，分别为0、2.5%、3.5%、4.5%）。
试验结果表明，当灌溉水ECw高于1.7 dS·m⁻¹时，盐度升高会显著降低彩色棉的出苗、生长与产量，其中棉籽重量是受盐度影响最显著的指标。施加有机质可促进棉花生长与产量提升，尤以棉籽重量的提升效果最为突出。随着有机质施用量递增，盐胁迫对‘BRS Jady’棉花棉铃数的负面影响得到有效缓解。