Response of some Egyptian sweet melon (Cucumis melo var. Aegyptiacus L.) cultivars to water stress conditions

Abstract: Drought is a wide-spread problem, seriously influencing sweet melon (Cucumis melo var. Aegyptiacus L.) production and quality. Therefore, identification or development of tolerant genotypes is of immense importance for sweet melon production in drought prone areas. Two field experiments were conducted in clay loam soil at Baramoon Experimental Farm, Dakahlia Governorate, Egypt during the two summer seasons of 2008 and 2009, to evaluate five sweet melon cultivars (Shahd El-Dokki, Ananas El-Dokki, Ismaelawi, Kahera-6 Improved, Albasosi) under regular irrigation and stress conditions (drought conditions were imposed after first irrigation and created by reducing the frequency of irrigation by one half to that of irrigated crop, i.e., missing alternate irrigation) using a split plot design with three replicates. Drought susceptibility index, relative yield reduction and relative yield values were used to describe yield stability and yield potential. Results indicated that exposure of sweet melon cultivars to water stress lead to significant decrease in fruit weight, fruit length, fruit width, fruit flesh thickness and total yield per plant. Whereas, water deficit caused significant increase in total soluble solids. The tested cultivars markedly varied among them in all estimated characters. The interaction between irrigation levels and cultivars had significant effects on all traits under study in both seasons. Cultivars with the highest yield and yield components under non-stress conditions had the highest yield and yield components under stress conditions. On the basis of the drought resistance indices, Kahera-6 Improved was relatively stress susceptible, whereas Albasosi was more tolerant and stable cultivar therefore detailed studies are warrented for validating its drought tolerance characterstic.