Potential of Fusarium spp. for biocontrol of downy mildew of grapes

Five Fusarium species viz. Fusarium delphinoides (MCC 1343), F. brachygibbosum (MCC 1344), F. pseudonygamai (MCC 1345, MCC 1346) and a Fusarium sp.(MCC 1347) isolatedfrom Plasmopara viticola collectedfrom vineyards were used for the studies. In in vitro studies, all Fusarium species coiled around P. viticola sporangiophores and caused distortionof sporangia. Pre-treatment of leaf discswith Fusarium species reduced sporangial production of P. viticola by 60 to 75%. Extracellular lytic enzymes screening showed that all five species produced β– glucanase, chitinase andprotease enzymes. In the small scale field trial the five species significantly reduced downy mildew incidence on leaves and bunch as compare untreated control. The area under disease progress curce (AUDPC) ranged from 199.25 to 212.41 for leaves and 29.69 to 55.79 for bunch in Fusarium treated vines. The AUDPC in untreated control was 331.47 on leaves and 185.32 on bunch. These Fusarium species show potential for biological control of downy mildew of grapes.