الفهرس | Only 14 pages are availabe for public view |
Abstract Two field experiments were conducted during 2013/2014 and 2014/2015 in a private Farm, Ibshway district, Fayoum, Egypt to study possibility of enhancing the morphological characters, tissue health measurements (RWC, MIS and EL), leaf photosynthetic pigments, osmoprotectants, antioxidant activity, NPK nutrients, yield and their components, yield response factor (Ky) and water use efficiency (WUE) of broccoli plants grown under deficit surface irrigation water (60, 80 and 100% ETc) via foliar application of ascorbic acid (0, 200 and 400 mg l-1). The obtained results clarified that, irrigation rate at 80% or 100% ETc, significantly, resulted in higher mean values of stem length and diameter, number of leaves plant-1, leaf MSI, RWC, carotenoids, DPPH-radical-scavenging, total free amino acids and N content and yield and its components (diameter of central head, number and average weight of lateral heads plant-1, lateral heads : branches ratio, and central, lateral and total head yield weight plant-1 and fed-1) than irrigation rate at 60% ETc. While, irrigation water at an rate of 60% or 80% ETc was superior and significantly recorded higher mean values of Ky or WUE than 100% Etc, in two seasons. On other side, irrigation amounts, irrespective the level used, did not reflect any noticeable impact number of branches plant-1, head contents of ascorbic acid and leaf P and K content, in both seasons. Increasing irrigation water from 60% up to 100% ETc decreased the contents of leaf EL, chlorophyll A, B, A + B, anthocyanin, free proline and TSS, in both seasons. Exogenous application of ascorbic acid at concentrations of 200 and 400 mg l-1 significantly improved most studied growth parameters, RWC, MSI, anthocyanin, DPPH, total free amino acids, endogenous head ascorbic acid, leaf N content, and central, lateral and total head yield weight plant-1 and fed-1 as well as WUE and Ky, particularly under 80% ETc. However, leaf EL decreased gradually with increase in ascorbic concentration in both growing seasons. Moreover, the foliar application of ascorbic acid did not reflect any significant influence on A, B and total chlorophylls, total carotenoids, free proline and total soluble sugars, diameter of central head, number and average of lateral heads plant-1 and lateral heads : branches ratio compared to the control treatment, in the two experimental seasons |