Baranets L. The effect of the weed contamination level on oidium development and yielding capacity of the vine under conditions of the South Coast of the Crimea.

Research objects - weeds, biological effectiveness of herbicides, chemical weeding as a means of weed control, oidium agent Uncinula necator, agrobiological and photosynthetic indices of the grape plant's development. Research objective - to investigate the effectiveness of the chemical method with a view of weed control of Crimean vineyards and to determine the effect of the degree of weed contamination on the distribution and harmfulness of oidium, and on the grape plant's productivity. Methods - a field method to investigate weed resistance to different herbicides; measuring and weighting methods to determine changes in the degree of weed contamination and the biological effectiveness of herbicides; a biometrical method to determine indices of the grape plant's productivity; routefield investigations envisaging the description of agrobiotic communi-ties to determine the specific composition of weeds; a calculation method on a comparative basis to determine the effectiveness of the technology of control developed; a mathematical-statistical method to determine the confidence of the data obtained. Theoretical and practical results - a new technology of weed control of commercial vineyards has been developed envisaging one application of a herbicide preparation in the rows in combination with two summer cultivations of the spacings. Novelty - principles of weed control of vineyards on the South Coast of the Crimea have been developed based on one application of a herbicide preparation in the rows and in combination with a minimum number of cultivations of the spacings instead of cultivations of the spacings and manua weedings in the rows. It has been established that the following herbicides can be applied for the effective weed control of vineyards on the South Coast of Crimea: glyfosate, 48 % a.s., poast plus, 20 % e.c., basagran-M, 37,5 % a.s. The specific composition of weeds on a number of farms of the South Coast of the Crimea has been revised and enlarged. It has first been established that application of herbicides for weed control leads to reduction in the distribution and development of oidium. Another finding has been that application of herbicides for the above purpose improves the grape plant's growth and development. It has been proved that the effective weed control achieved by application of herbi-cides enables high yields of good quality to be obtained. Realization of implementation - the technology has been implemented on the experiment station of the Institute "Magarach" on a total area of 10 ha. The herbicide preparation with the active ingredient glyfosate (manufactured by Company DauAgrosaiensis) was entered in 2001 into the "List of pesticides and agrochemicals to be applied in Ukraine" as a herbicide for grape under the brand "Dominator". Effectiveness - the economic effectiveness of one application of glyfosate poast plus, basagran-M early in the vegetation period in combination with two summer cultivations of the spacings is 570, 310 and 227 hrn/ha relative to the mechanical method ofweed elimination envisaging six cultivations in the spacings and two manual weedings in the rows. Sphere, branch of use - agriculture, viticulture.