Saline stress and potassium/calcium ratio in fertigated eggplant

ABSTRACT In order to evaluate the effect of irrigation water salinity in interaction with different potassium and calcium ratios applied through fertigation in eggplant, an experiment was carried out at the Department of Environmental and Technological Sciences of the Federal Rural University of the Semi-Arid Region, in Mossoró, RN, Brazil. The experimental design was randomized blocks, in a 5 x 4 factorial scheme, with four replicates. The treatments were obtained by the combination between five ionic ratios of potassium and calcium (F1 = 4.2/1; F2 = 3.5/1; F3 = 2.8/1; F4 = 2.2/1; F5 = 1.8/1) and four levels of irrigation water salinity (S1 – 0.5; S2 – 2.0; S3 – 3.5; and S4 – 5.0 dS m-1). The following variables were evaluated: number of fruits per plant, fruit length, fruit diameter, fruit fresh weight and yield. Yield, fruit length, fruit fresh weight and number of fruits decreased with the increase of salinity in all the treatments. Salinity significantly affected fruit diameter, which increased only under fertigation with potassium-rich solutions.

摘要 为评估灌溉水盐度与滴灌施肥施用的不同钾钙配比之间的交互效应对茄子的影响，本试验于巴西北里约格朗德州莫斯罗尔市半干旱地区联邦农村大学环境与技术科学系开展。试验采用随机区组设计，设置5×4因子组合，共4次重复。试验处理由5种钾钙离子配比（F1=4.2/1；F2=3.5/1；F3=2.8/1；F4=2.2/1；F5=1.8/1）与4个灌溉水盐度梯度（S1=0.5、S2=2.0、S3=3.5、S4=5.0 dS·m⁻¹）组合而成。测定指标包括单株结果数、果实长度、果实横径、果实鲜重及产量。各处理下，产量、果实长度、果实鲜重与单株结果数均随盐度升高而降低。盐度对果实横径具有显著影响，仅在施用富钾滴灌溶液的处理中，果实横径随盐度升高而增大。