Results of using bactericides in the control of phytoplasmosis Bois Noir (pathogen <i>Candidatus</i> Ph. solani) to preserve grape yield

For finding effective means of controlling phytoplasmosis Bois Noir (BN) in 2020-2022, the effect of bactericides on the intensity of Candidatus Ph. Solani infection and quantitative yield indicators were studied in the vineyards of 2 soil-climatic Crimean regions. Behind the moderate and epiphytotic phytoplasmosis development (15-31% and 56- 76% symptomatic plants, respectively), when using Pharmayod, GS (0.06- 0.1%), Phytolavin, SC (0.2%), Phytoplasmin, SC (0.2-0.3%) preparations, a tendency to a decrease in the intensity of symptoms to 24% and 39% in the 2nd and 3d research years was established, followed by a decrease in the number of plants, completely affected by BN, by 5.3-11 times. A steady tendency to an increase in the “yield per bush” indicator was shown: on symptomatic plants within 11-39%, on asymptomatic - within 12-25%; and to a larger bunch weight: within 12-28% for plants with BN symptoms. The obtained results indicate good prospects for using the studied bactericides.