IMPROVEMENT OF OILSEED CROPS SOWING QUALITIES AT THE EFFECT OF PHYSIOLOGICALLY ACTIVE ANTISTRESS SUBSTANCES

The field of plant growing depends on the weather conditions during the entire production cycle, starting with sowing and ending with harvesting. The factor of weather risk, which significantly affects the yield of crops, is objective and one of the least predictable. Climate of the Steppe zone of Ukraine is recently characterized by substantial temperature increase, decrease of rainfalls, and their irregularity. This led to the decrease of the stock of productive moisture in the arable and meter layers of the soil, occurrence of prolonged hydrothermal stresses during critical phases of plant development. Stimulation of plant growth and development, increase of plant resistance to stress factors by differentiated use of plant growth regulators in various stages of development is an effective way to increase the yield of plants. The results of the research carried out by the method of setting up laboratory experiments, are presented. For presowing seed treatment, plant growth regulators Vympel, Emistim C, AKM were used. It is shown that the use of plant growth regulators of antioxidant action for presowing treatment of oilseed crops can both oppress and stimulate germination processes. It is determined that studied factors affect the main indices that characterize the seed quality: germination energy, laboratory germination, the length of seedlings, the content of solids. Thus, the best values of those indicators were shownd by the variant of presowing seed treatment AKM PGR with the optimum concentration for sunflower – 0,015 g/l, for safflower and oilseed flax – 0,0015 g/l. Vympel and Emistim C PGRs also had a positive effect: they increased germination energy and laboratory germination of sunflower seeds by 14,7 and 24,4%, respectively, compared with the control variant.