Management of spot blotch of barley: an eco-friendly approach

Spot blotch disease caused by the fungus Bipolaris sorokiniana (teleomorph Cochliobolus sativus) is one of the most important fungal diseases of barley. Considering the hazardous effects of fungicidal sprays, an eco-friendly approach was adopted to manage this disease by using botanicals, biocontrol agents and systemic acquired resistance (SAR) chemicals on two barley cultivars, PL426 and PL807. Under in vitro conditions, a 15% solution of neem (Azadirachta indica) and tulsi (Ocimum tenuiflorum) inhibited the growth of B. sorokiniana by 65.48% and 45.37%, respectively. For the bio-agents, Trichoderma harzianum proved to be the best with 60.82% growth inhibition of the pathogen followed by T. viride. The SAR chemicals, maximum disease control was observed when the potted plants were sprayed with salicylic acid (SA) at 0.03% concentration and s-amino-n-butyric acid (BABA) at 0.3% concentration. Similar results were observed for botanicals, bio-control agents and SAR chemicals when tested under field conditions. Considering the economics of these environmentally safe options, it is concluded that the bio-control agent (T. harzianum), plant extracts (neem and tulsi) and SAR chemical (SA) can be used as foliar spray treatments for eco-friendly management of spot blotch of barley in integrated disease management programmes.