Response of some Summer Squash cultivars grown in greenhouses to the addition of cobalt and its effect on growth and yield

Abstract

The experiment was conducted during both seasons 2021-2022 and 2022-2023 in one of the greenhouses affiliated with the Agricultural Research Station, College of Agriculture, Basrah University, in Karmat Ali, in order to study the effect of cobalt addition on the growth and yield of some summer  cultivars. It included 18 factorial treatments consisting of combinations of six varieties: AL nahrain, Alexandria F1, Seminis, Eskandrany2, Khatoon F1, Mullah Ahmed, and three concentrations of cobalt in the form of cobalt sulfate, CoSo4, which are 0, 0.75, and 1.5 mg. L^-1. It was coundected as a one-time split factorial experiment, according to the randomized complete block design and with three replicates. The results showed that the AL nahrain hybrid was significantly superior in increasing plant height, number of leaves and leaf area. The number of female flowers, the sexual ratio, the number of fruits, and the yield of one plant, for both seasons of the experiment, were superior in fruit weight in the first season only, while the cultivar Khatoon F1 was significantly excelled in increasing the number of male flowers for both seasons of the experiment and in fruit weight in the second season.The plants were treated with cobalt at a concentration of 0.75 mg. L^-1 significantly increased plant height and number of leaves Leaf area, number of female flowers, sexual ratio, weight of one fruit, number of fruits, yield of one plant, and significantly reduced the number of male flowers for both seasons.The interaction between the study factors showed a significant effect on most of the traits under study, as the hybrid plants gave AL nahrain and the cobalt treatment at a concentration of 0.75 mg. L^-1 had the highest yield per plant for both seasons of the experiment, which was (1.671 and 1.537) kg, respectively.