Chemical weed control in winter wheat (Triticum aestivum L.) crop of early stages of development: I. Crop weediness

Field trials were carried out at Jonas Aliukonis farm in Prienai district Strielciai village during 2005-2006. Influence of 5 herbicides applied in autumn on crop of winter wheat was investigated. Winter wheat (Triticum aestivum L.) is sensitive to weed competition in early stages of growth and development. Conventionally herbicides are used in spring for weed control in winter cereals, therefore, perennial and winter annual weeds have favorable conditions to grow and compete with cereals when vegetation in spring is renewing. The work hypothesis is that application of herbicides in autumn will control weeds that survive during winter time and winter wheat will not be damaged and better conditions for crop competition in spring after renewing of vegetation will be created. Weediness of winter wheat crop did not have any essential differences before herbicide application in autumn. After herbicide spraying in autumn weediness of winter wheat crop decreased till 15.4-28.4% and the air-dry biomass decreased even till 56.8%. Weeds were most efficiently controlled with Monitor in autumn comparing with non-treated control and other herbicides applied. Crop weediness decreased by 18 weeds m-2 and 9.5 g m-2 of air-dry biomass, it covered 28.4% and 56.8%, respectivelyVytauto Didžiojo universitetasŽemės ūkio akademij