Study The Applications of Water Deficiency Levels and Ascorbic Acid Foliar on Growth Parameters and Yield of Summer Squash Plant (Cucurbita pepo L.)

Abstract

Two field experiments study during 2015 and 2016 summer seasons on sandy loam soil under drip irrigation system by Nile river water, at the Agricultural Research and Production Station National Research Centre, El- Nubaria region, EL- Beheira Governorate,  Egypt. This study focused on the applications of different water deficiency levels (100, 80 and 60% of F.C. i.e. field capacity) and ascorbic acid (AsA) spraying foliar application with different concentrations (0, 50 and 100 ppm) as antioxidant on growth parameters and yield as well as photosynthetic pigments content of summer squash plants (Cucurbitapepo L.cv. Eskandrani). Results indicated that, decreasing water levels caused a significant reduction in the all tested growth and yield parameters, i.e., canopy weight, root weight, number of leaves, leaves fresh weight and leaf area as well as photosynthetic pigments content (total chl., and carotenoids), total yield, fruit weight and length. While increasing ascorbic acid spraying foliar application levels as antioxidant significantly increased the aforementioned parameters in the two seasons as compared with control. On the other hand, decreasing water levels caused a significant increasing in leaf proline content, leaf cell sap osmotic pressure, dry matter % and fruit TSS in the two growing seasons as compared with control.

Keywords: water stress, water deficiency, ascorbic acid, antioxidant, growth, yield, summer squash plant and Cucurbita pepo.