DAMP WATER STEAM INFLUENCE ON WEEDS AND FOLIAR FUNGAL DISEASES IN SUGAR BEET CROP

Field experiments on the influence of damp water steam as a thermal control for weeds and foliar fungal diseases of sugar beet crop were carried out in the Rumokai experimental station of Lithuanian Research Center for Agriculture and Forestry in 2012-2013. The investigation followed the scheme: 1) sugar beets were sprayed with herbicides Betanal Expert 1,0 1 ha(-1) + Goltix 1,0 1 ha(-1), Betanal Expert 1,25 1 ha(-1), Betanal Expert 1,25 1 ha(-1) + Nortron 0,3 1 ha(-1) for three times during vegetation; 2) weed control was carried out for 2 times during sugar beets vegetation using damp water steam; 3) weed control was carried out for 3 times during sugar beets vegetation using damp water steam, the remaining weeds among the plants were removed manually; 4) weed control was carried out for three times during sugar beet vegetation applying damp water steam. The best result was obtained combining damp water steam application for three times and manual weed removal during sugar beets vegetation. This method was the most effective in reducing air-dry mass of weeds as well. In the case when water steam was applied for 2 times the amount of weeds and air-dry mass was almost the same as using chemical weed control, thus, seeking to reduce environmental pollution, herbicides in sugar beet crop protection can be replaced by damp water steam using protection means such as covers or soil beds in order to prevent the crop from the steam. Dump water steam reduced the development of fungal diseases in sugar beet crop. After the treatment of sugar beet crop with wet water steam for 3 times the severity of Cercospora and Ramularia leaf spots as well as powdery mildew in the end of September were 58.8 - 78.9 %, 51.7 - 52.0 % and 70.8 - 77.6 % less than in the chemically treated plots.