A 2-year field experiment was conducted in a research farm at Tehran, Iran, to determine the effect of mild and severe drought stress and foliar application of glycine betaine (0, 50, and 100 mM L⁻¹) and gibberellic acid (0, 60, and 120 ppm) on some physiological traits and yield and yield-related traits of cowpea (Vigna unguiculata L. Walp.) genotypes. Drought stress at both mild and severe levels decreased relative water content (RWC), carotenoids, and total chlorophyll contents, while increased ion leakage which finally affected the yield of cowpea plants represented by 100-seed weight, number of pods per plant, and number of seeds per pod. Application of glycine betaine and gibberellic acid at all tested concentrations significantly alleviated the negative effect of drought on cowpea plants. The maximum relative water content, carotenoids, total chlorophyll, and yield were achieved by application of 120 ppm gibberellic acid and 100 mM glycine betaine at the three irrigation regimes. Gibberellic acid and glycine betaine succeeded in increasing cowpea plant tolerance to drought stress by improving vital plant components and preventing ion loss through ion leakage by controlling cell permeability.

在伊朗德黑兰的一个研究农场进行了为期2年的田间试验，以确定轻度和严重干旱胁迫的影响以及叶面施用甘氨酸甜菜碱（0、50和100 mM L ^-1）和赤霉素（0 ，60和120 ppm）对of豆（Vigna unguiculata）的某些生理特性以及产量和与产量相关的特性L. Walp。）基因型。轻度和重度干旱胁迫均降低了相对含水量（RWC），类胡萝卜素和总叶绿素含量，同时增加了离子渗漏，最终影响了pea豆植物的产量，以100粒重，单株荚数和荚数表示每个吊舱种子数。在所有测试浓度下施用甘氨酸甜菜碱和赤霉素可显着减轻干旱对cow豆植物的负面影响。通过在三种灌溉方式下施用120 ppm赤霉素和100 mM甘氨酸甜菜碱，可获得最大相对水含量，类胡萝卜素，总叶绿素和产量。