Effect of Spraying with Salicylic Acid (SA) on the Yield of Several Cultivars of Cucumber, Cucumis sativus L., under Protected Cultivation Conditions

Abstract This study examined the growth and yield of four cucumber varieties—Marketmore 76, Beit Alpha, Ocucmol (st), and Lahoba361034,—during the 2022 growing season in a greenhouse owned by the Horticulture Department of the College of Agriculture - University of Baghdad. The cultivars were tested under three concentrations of salicylic acid (0, 0.25, 0.5) mg. L -1 . The results showed the superiority of Lahoba361034 cultivar in most traits, as it gave the highest average number of fruits per plant (15 fruits. plant -1 ), fruit weight (90.9 g), and yield per plant (1.354 kg. plant -1 ), while the cultivar Ocucmol (st) was superior in fruit diameter and fruit length gave an average of 33.39 mm and 15.53 cm, respectively. As for the levels of salicylic acid, the results showed the superiority of the high concentration of salicylic acid (0.5 mg.L -1 ) in all the studied traits, as it gave the highest average in the characteristic of fruit diameter (33.36 mm), fruit length (14.93 cm), and number of fruits per plant (15.08 fruits. plant -1 ), fruit weight (94.2 gm) and yield per plant (1.431 kg. plant -1 ), while the comparison treatment (0 mg SA. L -1 ) gave the lowest mean for most traits. The interaction treatment between the cultivar Lahoba361034 and the high concentration (0.5 mg. L -1 ) showed superiority in the average number of fruits per plant (17 fruits. Plant -1 ), fruit weight (100.6 gm), and yield per plant (1.703 kg).