Evaluation of IDM Components for Management of Tomato Powdery Mildew under Protected Cultivation

Abstract

Powdery mildew caused by Oidium neolycopersici L. Kiss is one of the most important diseases of tomato under polyhouse conditions. During 2014-15, polyhouses of Kangra district (H.P., India) were surveyed and the disease severity was observed between 5.0 to 89.5 per cent affecting both quality and quantity of the harvest. Fourteen hybrids/cultivars of tomato were screened under p house conditions during 2014-15 cropping season, but all were found either susceptible or weakly resistant against powdery mildew. In vivo evaluation of bioagents viz., Trichoderma harzianum-1 (TH-1), T. harzianum-2 (TH-2), T. viride-1 (TV-1), T. viride-2 (TV-2) and Pseudomonas fluorescence-1 (PF-1) @ 10 g/l showed 63.9-75.41 per cent disease control. Among these, both strains of T. harzianum (TH-1 and TH-2) were found highly effective in controlling the disease. In vivo evaluation of three botanicals viz., Eupatorium adenophorum, Melia azedarach and Azadirachta indica showed that aqueous extract at 100 per cent concentration provided more than 50 per cent disease control being maximum i.e. 65.1 per cent was provided by E. adenophorum. Three sprays of eight fungicides at 10 days interval were evaluated and hexaconazole 5EC @ 1 ml/l and difenoconazole 25EC @ 0.05 ml/l were found highly effective with 91.0 and 89.2 per cent disease control and 42.0 and 39.0 per cent increase in yield as compared to check, respectively.