RESPONSE OF SOME EGYPTIANS 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, the identification or development of tolerant genotypes is of high importance for incorporating in sweet melon production. Hence, two field experiments were conducted in a clay loam soil at Baramoon Experimental Farm, Dakahlia Governorate, Egypt during the two summer seasons of 2009 and 2010, to evaluate five sweet melon cultivars (Shahd El-Dokki, Ananas El-Dokki, Ismaelawi, Kahera-6 improved, Albasosi) under regular irrigation and stress conditions using a split plot design with three replicates. Drought conditions were started after first irrigation and created by reducing the frequency of irrigation by one half compared with regularly irrigated plants, i.e., missing alternate irrigation. Results indicated that exposing the sweet melon cultivars to water stress led to significant decreases in fruit weight, fruit length, fruit width, flesh fruit thickness, total yield per plant and Leaf relative water content in both seasons. Whereas, water deficit caused significant increases in total soluble solids in both seasons. The tested cultivars markedly varied among them in all estimated characters in both seasons. The interaction between irrigation levels and cultivars had significant effects on all traits under study. Cultivars with the highest yield and yield components under non-stress conditions had the highest yield and yield components under stress conditions, and this was true in both seasons. On the basis of the drought resistance indices (drought susceptibility index, relative yield reduction and relative yield values), Kahera-6 improved was relatively stress susceptible, whereas Albasosi was more tolerant and stable cultivar so; this cultivar could be further tested for their drought confirming characteristics.