ABSTRACT

Lentil (Lens culinaris M.) is one of the important pulse crop threatened by many diseases, Fusarium wilt caused by Fusarium oxysporum f. sp. lentis is one among them causing significant yield loss. Present study aimed to assess the disease incidence across different locations, in-vitro evaluation of fungicides and bioagents, development of integrated disease management strategies and to identify resistant genotypes through screening. A roving survey in two districts of northern Karnataka revealed that highest disease incidence of 20.71 per cent was recorded in MARS, Dharwad and the minimum incidence of 5.31 per cent in Sambra village of Belagavi district. The cultural and morphological studies showed that the colour of the pathogen varied from white to yellow and variation with respect to size of microconidia, macroconidia and chlamydospre formation. Among the bioagents evaluated, Trichoderma harzianum was effective in inhibiting 87.34 per cent of mycelial growth of Fusarium oxysporum f. sp. lentis under in-vitro condition. Among five systemic and five combi product fungicides tested, carbendazim 50% WP and Carboxin 37.5% + Thiram 37.5% (75% WP) completely inhibited mycelial growth at all the concentrations tested.
Field experiment under natural condition for management of wilt in lentil revealed that seed treatment with Carboxin 37.5% + Thiram 37.5% (75% WP) @ 2g/kg of seeds followed by soil application of vermicompost enriched with Trichoderma harzianum (100:1) @ 250 kg/acre resulted in the lowest disease incidence (11.56%) and highest yield (16.86 q/ha) with a B:C ratio of 2.59. Out of 15 lentil genotypes screened, none of them found immune or resistant. However, 11 genotypes recorded moderate resistance (DLL-5, WBL-58, IPL-531, DD-2, Kittur local, WPL-77, Belagavi local, Basapur local, WBL-77, VL-103, DLL-1, IPL-531) and three genotypes (KLS-218, IPL-316, and DLL-3) found moderately susceptible reaction and the genotype Tadkod local recorded susceptible reaction.