ABSTRACT

Wheat (Triticum aestivum L.) is an important cereal crop and belongs to the family Poaceae. Fungal foliar diseases such as rust and spot blotch are the major menance in wheat production which causes significant yield loss. Thus, the present investigation “Variability in Bipolaris sorokiniana (Sacc.) Shoem. and management of foliar diseases of wheat” was carried out during rabi 2023-24.
Roving survey conducted during rabi 2023-24, revealed, very low to moderate spot blotch disease severity in surveyed districts. Cultural and morphological variability studies in Bipolaris sorokiniana showed significant variation among nineteen isolates grown on PDA. Molecular variability study using SSR markers revealed high level of polymorphism among the tested isolates.
Under in vitro studies, among non-systemic fungicides mancozeb 75% WP, among systemic fungicides, propiconazole 25 % EC and tebuconazole 25.9 % EC and among combi product fungicides, (hexaconazole 5 % + captan 70 %) 75 % WP, (azoxystrobin 18.2% + difenoconazole 11.4%) 29.6 % SC and (trifloxystrobin 25 % + tebuconazole 50 %) have shown 100 per cent mycelial inhibition of B. sorokiniana. Among the botanicals, margo neem (Azadirachtin 0.15 per cent) recorded maximum mean per cent mycelial inhibition (81.15%). While, Trichoderma harzianum (MH027645.1) showed 100 per cent mycelial inhibition of the test pathogen B. sorokiniana.
Under field evaluation, spray with combi product (hexaconazole 5 % + captan 70 %) 75 % WP @ 0.2 per cent - (hexaconazole 5 % + captan 70 %) 75 % WP @ 0.2 per cent recorded least disease severity, highest grain yield and B: C ratio. Among the genotypes, screened against foliar diseases of wheat, DBW173, GW547 (I) showed 5MR reaction for stem rust and was immune to leaf rust and genotypes HD3386(I)(C), PBW891 was moderately resistant for spot blotch and was immune to leaf rust.