Effect of Pre-Planting Land Flooding Durations on Growth, Yield and Anatomical Parameters of Three Watermelon [Citrullus lanatus (Thunb.) Matsum.] Cultivars

Abstract

Three watermelon cultivars were grown on land flooded with an irrigation depth 10 cm which was sustained for 1, 2, and 3 week periods before planting date besides, unflooded control land. The obtained results revealed that growing watermelon on land flooded with 2 weeks period was the best, as compared to other flooding treatments. This treatment was exceeded that of unflooded in plant length (47.3%), plant stem diameter (26.9%), leaf area (43.7%), leaf area index (82.8%), fruit number per plant (30%), yield (48.8%), number of stomata in 1 mm2 (18.3%), number of cells per 1 mm2 (24.3%) and width of second trichome cell (64.4%), narrowest vessel diameter (28.75%). Moreover, this treatment revealed superiority over 1week flooding period in stem dry matter percentage (26.9%), narrowest width of vessel (27.84%), highest vessel width (12.12%). Two week flooding period also overwhelmed that of 3 week period in fruit number per plant (26.2%), width of narrowest vessel (12.84%) and width of hair second cell (43.7%). Subsequently, this treatment can be categorized as the first treatment in the sequence order. One week flooding period treatment comes next in the order. This treatment preponderated that of unflooded treatment in branches number per plant (19.8%), leaf fresh weight (47.1%) and number of cells at 1 mm2 in upper leaf surface (15.3%). Furthermore, this treatment was exceeded that of 3weeks period in number of branches per plant (24.8%). controls and 3 weeks flooding treatments were the worst and they inferior to others. Noura appeared to be the best positively responded cultivar to dry land cultivation as compared to other evaluated cultivars. This cultivar substantially exceeded Charlee cultivar in term of fruit individual (22.2%), rind weight (31.5%), rind thickness (9.2%), number of stomata in 1 mm2 (9.8%) the widest vessel diameter (20.5%) and number of xylem vassels (9.9%). Additionally, it profoundly surpassed Glorry cultivar in fruit flesh weight (29.1%), fruit diameter (12.3%), rind weight (22.4%), number of stomata in 1 mm2 (10.2%) and widest vessel diameter (15.19%) and number of xylem vassels (7.9%). Glorry water melon comes next in the category order. This cultivar was paramount to Charlee in term of plant stem diameter (19.1%). Therefore, Charlee was the worst responded cultivar and the order according to cultivar capabilities in drought resistance are as the following. Noura > Glory > Charlee. The best dual interaction treatment was growing Noura cultivar on land flooded for 2 week with water height of 10cm which manifested superiority over other treatments. Since it gave the highest (plant length (215cm), leaf dry matter percentage (22.13), fruit length (26 cm), yield (0.87 kgm-2), number of stomata in 1 mm2 (220), number of cells in 1 mm2 (819.5) and widest diameter of xylem vessels (11micron).