Compatibility of <i>Trichoderma asperelloides</i> with Fungicides Controlling Downy Mildew and Powdery Mildew in Grapes

Abstract

The grape (Vitis vinifera) is an important horticultural crop which belongs to the family Vitaceae. Downy mildew (casual organism: Plasmopara viticola) and powdery mildew (casual organism: Uncinula necator) are two major diseases of grapevine which limit the production of grapes significantly. Both fungicides and bio control agents are used to manage diseases, but both have their own limitations. Integration of bio control agents along with fungicides in disease management helps in reduction of fungicide usage. To understand the effect of these fungicides with commonly used bio-control agents, a compatibility study was carried out under in-vitro condition at ICAR-NRC for Grapes, Pune. Registered fungicides against downy mildew and powdery mildew viz., Mancozeb 75% WP, Dimethomorph 50% WP, Fosetyl Al 80% WP, Amisulbrom 17.7% SC w/w (20% SC w/v), Copper oxychloride 50% WP, Kresoxim methyl 44.3% SC, Tetraconazole 3.8% EW, Metrafenone 50% SC, Cyflufenamid 5% EW and Azoxystrobin 11% + Tebuconazole 18.3% w/w were evaluated for compatibility with a potent bio-control agent viz. Trichoderma asperelloides. Trichoderma asperelloides was found to be fully compatible with Fosetyl Al 80% WP, Amisulbrom 17.7% SC w/w (20% SC w/v) and Cyflufenamid 5% EW and to some extent with Mancozeb 75% WP, Dimethomorph 50% WP at their recommended doses. Such compatibility studies help in understanding the gap between the application of synthetic chemicals and bio control agents.