Effect of Plant Spacing and Foliar Application of Growth Stimulant on Growth and Fruit Quality Traits of Summer Squash (Cucurbita pepo L.)

In the summers of 2022 and 2023, two open-field experiments on summer squash were conducted at South Valley University Farm, Qena Governorate, Egypt. The primary goal was to investigate how summer squash (Cucurbita pepo L. cv. Eskandarani) resistance to extreme environmental stress was affected by foliar application of different treatments, such as licorice root (LR) extracts, seaweed (SW), Moringa leaf (ML), and a control (water spray). Overall, the application of 5% ML foliar treatment applied three times throughout the experiment, specifically at 20, 30, and 40 days post-sowing, in conjunction with a plant spacing of 60 cm, resulted in vigorous plant growth. This was evidenced by enhanced vegetative growth parameters as plant height, number of leaves per plant, fresh weight, and dry weight, when compared to other foliar treatments. This was in contrast to other foliar treatments. Furthermore, using ML foliar spray at a planting distance of 60 cm produced the highest values of fruit yield and quality components, such as fruit length, fruit diameter, average fruit weight, and number of fruits per plant. In conclusion, the results showed that, under the environmental conditions of Qena Governorate and similar regions, planting squash at 60 cm intra-row spacing and applying ML 5% topically could be regarded as the best way to achieve vigorous, high yield, and superior fruit quality.