Tsiboulniak Y. Substantiation of Methods to Control Black Spot (Phomopsis viticola Sacc.) on Grapevine.

It has been established that development of black spot on grapevine in the Nikolaev region may be low, medium and high as affected by meteorological conditions. By the harvesting date, the infection intensity was 9.4%, 55% and 100% in years where the progression of the disease was low, medium and high, respectively. Scarce amounts of rainfall in May till July and relatively low temperatures over that period have been found to act as important limiting factors in relation to the progression of the disease. The infection intensity has been shown to correlate positively with the amount of rainfall and the average daily temperature. The substantiated system of black spot control envisages application of two to three specialized sprayings at the stage of three to five leaves on the vine and at the stage of small pea-size berries with any of the following fungicide preparations: Shavit F WP, Folpan, 80 WP or Efal SL at doses as indicated in the List of pesticides and agricultural chemicals to be used in Ukraine. The system is recommended for commercial introduction into the country's current grape-growing practice. Terms of applying protection measures to achieve the highest effectiveness of the preparations have been established: - one spraying at the stage of three to five leaves on the vine; - two sprayings at budbreak and at the stage of three to five leaves on the vine; - three sprayings at budbreak, at the stage of three to five leaves on the vine and at the stage of small pea-size berries. The improved system of black spot control will promote a longer lifetime of vineyards and conservation of yields. The size ratio of yields grown with the use of the improved system of black spot control to those without protection against that disease varies from 108,1% to 110,9%.