Gas exchange and growth of peanut crop subjected to saline and water stress

ABSTRACT Peanut crops are of great economic interest because their seeds are used as an important source of vegetable protein and edible oil. The objective of this study was to evaluate the physiological indices and growth of peanut crops subjected to saline and water stress. The experiment was conducted in Auroras, Redenção, Ceará, Brazil using a completely randomized split plot statistical design. The plots were composed of irrigation water treatments with varying levels of electrical conductivity - ECw (1.0, 2.0, 3.0, 4.0 and 5.0 dS m-1), while the subplots were formed by the water regimes of 50% and 100% crop evapotranspiration. Plant height, leaf number, shoot dry matter, relative chlorophyll level, transpiration, and leaf temperature were affected by salt stress. The water regime of 100% ETc provided better performance for the variables stem diameter, leaf number, and shoot dry mass of peanuts.摘要：花生作物具有极高经济价值，其籽实是植物蛋白与食用植物油的重要来源。本研究旨在评估盐胁迫与水分胁迫下花生的生理指标及生长状况。试验于巴西塞阿拉州雷登新（Redenção）的奥罗拉斯（Auroras）地区开展，采用完全随机裂区统计设计。主区为不同电导率（electrical conductivity, ECw）水平的灌溉水处理，设置梯度为1.0、2.0、3.0、4.0及5.0 dS·m⁻¹；副区采用作物蒸发蒸腾量（crop evapotranspiration, ETc）的50%与100%两种水分制度。研究结果表明，株高、叶片数、地上部干物质重量、相对叶绿素含量、蒸腾速率及叶温均受盐胁迫影响；而100% ETc的水分制度可使花生的茎粗、叶片数及地上部干物质重量等指标表现更优。