Eco-friendly approaches to manage spot blotch of wheat incited by Bipolaris sorokiniana (Sacc.)

Spot blotch of wheat caused by Bipolaris sorokiniana is a disease of serious concern in wheat crops for ensuring optimal crop yield and economic viability. This study focused on evaluating different eco-friendly approaches such as plant extracts of onion bulbs, black cumin seeds and ginger rhizome extracts along with fungicides in vivo and in vitro conditions for the management of spot blotch. Our study showed promising results in the case of foliar applications with Propiconazole and Hexaconazole at 0.1%. Hexaconazole emerges as superior over Propiconazole. Combination of Difenoconazole + Propiconazole at 250 ppm demonstrated complete inhibition of mycelial growth of B. sorokiniana, making it another potential option for disease management. Carbendazim and Copper oxychloride also showed complete inhibition, at 500 and 1000 ppm, respectively. Various plant extracts such as neem and eucalyptus leaves, onion bulbs, garlic cloves, ginger rhizomes and black cumin have been proved effective in reducing the percent disease index (PDI). Notably, both eucalyptus leaf extracts and garlic cloves, applied at a 5% concentration exhibited equal efficacy in minimizing the disease by 50% and subsequently enhancing grain production. Moreover, it is important to consider the time of sowing, as delayed sowing has shown to increase the incidence of spot blotch, irrespective of nitrogen levels. Surprisingly, higher nitrogen levels exacerbated the disease at all three sowing dates. These findings will be helpful in deciding the management options for the spot blotch disease management in wheat.