THE PHYTO SANITARY SITUATION OF SPRING WHEAT SOWINGS IN THE NORTH-WEST OF NON BLACK EARTH (NECHERNOZEMIE) AREA

The conducted researches estimated a present phyto sanitary situation of spring wheat sowings in the north-west of Non Black earth area. A phyto sanitary situation is usually characterized with an average level of weediness, moderate infection with leaf diseases, and slight damage with pests. The varietal composition of harmful organisms and the species of economic value for spring wheat cultivation have been clarified for the region. They are 7 kinds of weeds, larvae of click beetles, Swedish oats fly and cereal aphids, powdery mildew, septoriosis, brown leaf rust. The article considers the change of the phyto sanitary situation under the influence of a variety, a forecrop, sowing terms and seeding rates, fertilizing. The varieties of foreign breeding are more susceptible to the local infectants that results in their strong infection with leaf diseases. The choice of a forecrop effects on a weediness of spring wheat and a damage of its sprouts with wireworms. The most favorable and popular forecrop for spring wheat is potatoes, the most unfavorable forecrop are perennial grasses. The late sowing terms of the crop worsen the situation with phyto pathogens. The grain infection with funguses increases that result in a black head, mold and root rot. The reduced sowing rates of spring wheat increase the weediness of spring wheat. Fertilizing promotes the formation of large phyto mass of weeds, increases the infection of plants with leaf diseases. The fields surrounded with forests are more resistant to pests, but less resistant to leaf diseases.