EFFECT OF PLANTING DATES AND SOME CULTURAL PRACTICES ON SUDDEN WILT CONTROL IN MELON

Abstract

Two field experiments were conducted in sandy soil during the fall seasons of 2007 and 2008 to study the effect of some cultural treatments, viz., grafting on bottle gourd (Lagenaria sesiraria), grafting on gourd (Cucurbitajicifolia), grafting on pumpkin (Cucurbita maxima), mycorrhiz.a inoculation, covering with agryl, fungicides drenching, water stress treatment and control, three planting dates, viz., I" of July, I" of August and I" of September and three melon cultivars, namely Galia F1 (Galia type), Nader F1 (Ananas type) and Magenta F 1 (Charantais type), on sudden wilt control, some fruit characters, yield and fruit chemical composition. A spilt-split plot design with 3 replicates was adopted, where, planting dates were distributed randomly in the main plots, while melon cultivars were arranged in sub plots and the cultural treatments in sub-sub plots. The results indicated that the lowest percentages of sudden wilt were recorded in July planting in 'Magenta' and in grafted plants on gourd or bottle gourd as well as covering with agryl and water stress treatment. Grafting on bottle gourd or gourd rootstock in both seasons as well as water stress treatment in the second season led to a significant increment in melon yield, while grafting on pumpkin in both seasons as well as mycorrhiza treatment in the first season, significantly, decreased the total yield, as compared with the control. Also, grafting on pumpkin decreased fruit weight, fruit length, fruit diameter, fruit size, TSS percentage, total sugars concentration and the other chemical compositions (N, P and K), whereas water stress treatment significantly increased TSS percentage, as compared with the control. There were significant effects for melon cultivars on yield, TSS% and fruit characters. Generally, the highest total yield was achieved with Galia F 1 in both seasons. Meanwhile, TSS percentage significantly increased in 'Magenta' and 'Nader' as compared to 'Galia'. Moreover, 'Magenta' gave the best fruit characters, viz., fruit weight, fruit diameter, fruit size and fruit firmness. With regard to the effect of planting dates on melon yield, planting in July significantly increased the early and total yield and enhanced all fruit characters as compared with August planting. On the contrary, planting in September did not achieve any yield, due to the high sudden wilt percentage which occurred two months after planting.