Damage to spring wheat due to harmful organisms in connection with sowing time and growth regulators application in the conditions of Pre-Baikal region

The conditions of South Siberia region are favorable for the propagation of r-strategy harmful organisms. The authors investigated the influence of sowing time (early — April 26, and usual for this region — Mai 19), presowing seed treatment by the Vial preparation and Humate 80 and Krezacin growth regulators on the damage of spring wheat sowings of the Tulunskaya 12, Iren’, Novosibirskaya 29 by the root rot, wheat leaf bloch, cereal leaf beetle (larva phase), wheat thrips (larva phase), grey cereal noctuid (larva phase). The authors estimated the species composition of weeds, their number, an accumulation of green mass and wheat harvest. The investigations were made on experimental field of the Irkutsk State Agricultural Academy and in practical conditions in other zones of Pre-Baikal region. After early sowing without presowing treatment the authors observed the reduction of spreading of root rot (13.84 %) and ear bloch (13.33 %), also observed the decrease of leaves damages by cereal leaf beetle (2.3 times), corn damages by wheat thrips (6.5 times) and grey cereal noctuid (3.8 times). The weed’s biomass was decreased to 6-8 times. The productivity of spring wheat was raised by 15-40 %. The application of growth regulator-adaptogen (instead of seed treatment) permits to obtain the good and early sprouts, that also permit to increase the competitiveness of cultural plants and to weaken the harmful effect of phytopathogens, phytophages and weeds.