Evaluation of the activity of a plant extract against Plasmopara viticola in grapes

Abstract

Downy mildew, caused by Plasmopara viticola in grapevine, is one of the most devastating and widespread fungal disease on causing serious harm to grape production. The heavy use of chemical pesticides, necessary to control the pests and pathogens, has caused issues with the resistance, resurgence and residues in food, as well as creating diffuse environmental pollution. In the last decade, biological control started to offer an alternative safe(r) and effective method to control diseases. In this paper, we investigate the potential activity of a plant extract to protect grapevine from downy mildew when used in strategy with a reduced dosage of the conventional fungicides (PPP). Four strategies were tested, with two of them giving the best results. Indeed, the use of LL017 increased the tolerance of the vine against P. viticola compared to its control with the same dosage of PPP, and with an efficacy closer to the full dosage of the PPP. In the tests where the yield was evaluated, the treatment with LL017 always resulted in a higher yield than the respective control with the same dosage of PPP and, in some cases, it gave a higher yield than even the positive control.

THE USE OF BIOPREPARATIONS WITH BACTERIA AND FUNGI TO CONTROL DOWNY MILDEW (Plasmopara vitícola) AND REDUCE CHEMICAL TREATMENTS

“…Previous studies demonstrated antifungal activities of methanolic and alcoholic extract containing mainly stilbenes from cane of vine against P viticola, Botritys cinerea and Erysiphe necator (Schnee et al, 2013). Tests with neem azal oil, vitis cane and Inula viscosum extract demonstrated their direct inhibition activity against P. viticola (Sudiro et al, 2022). The authors also tested a new plant extract identify only as LL017 with apparent a very good results, increasing the plant tolerance comparing with plants treated with conventional pesticides.…”