Response of newly developed sunflower hybrids and varieties to downy mildew disease

Abstract

Amongst the diseases on the cultivated sunflower (Helianthus annuus L.) in India, the downy mildew disease caused by the fungus Plasmopara halstedii (Farl.) Berl. & De Toni is counted as important one. The disease is quite destructive as it is seed-borne and there are large chances for its fast spread to other sunflower growing localities. Use of resistant hybrids/varieties appears to be the only way to combat the disease. During the kharif season of 2005-2006, 21 newly developed hybrids and 10 varieties were included in Initial Hybrid Trial (IHT), Advanced Hybrid Trial (AHT) and Initial/Advanced Variety Trial (I/AVT) within the framework of All- India Coordinated Program and were screened for downy mildew disease reaction. The hybrids/varieties were tested under high disease pressure in downy mildew infected plots at Oilseeds Research Station, Latur (M.S.), India. The data revealed that almost all newly developed varieties were susceptible to the disease. However, five hybrids, NSH-23, Sunbred-2077, NSSH-303, K-678 and MLSFH-93, were totally free from downy mildew incidence. Such hybrids can be exploited for commercial use.