Despite the fact that there are a lot of varieties with potential yield of 8-15 t / ha in Ukraine in recent years, the average productivity in the country does not exceed 2,8-3,5 t / ha. The level of best varieties potential yield of winter wheat has not yet been fully implemented. Therefore , the main task of Ukrainian farmers is to increase the yield and to ensure stability in winter wheat grain production as soon as possible.

To increase the yield of winter wheat with a simultaneous decrease in the level of technogenic and anthropogenic impact on the environment and to improve the efficiency of grain production under changing climate and energy saving, one need to find ways to improve varietal technology and the tactics to use it.

Sowing term is the most efficient element of the technology that does not require any additional material costs, but affects the realization of the wheat potential productivity significantly.

Analysis of the influence of sowing terms with applying " Vermybiomag " and " Vermyyodis "growth regulators  for presowing  seed treatment of Zolotokolosa winter wheat varietiy on the yield showed that the highest yield of winter wheat was in the variants where sowing was carried out in an optimal (second term).

The results of three years of research have shown that growth regulators under single and double spraying Zolotokolosa winter wheat varieties on all the variants under different sowing terms provided, compared with the control, 0,48-1,64 t / ha increase in the crop productivity. The results of the economic evaluation showed that applying crops growth regulators " Vermybiomag " and " Vermyyodis" in growing Zolotokolosa winter wheat variety, under different dates of sowing, in all variants, compared with the control, provided 23,3-43,7 % increase in profitability and production cost reduce by 50,2-63,7 UAH / t.

The largest relatively net income of 9630 hrn./ha (for the cost of wheat in 2012. ) and profitability of 250.1 %  was in the variant with double  spraying of Zolotokolosa winter wheat variety with  growth regulator "Vermyyodis " in a dose of 5 l / ha in the second ( optimal ) sowing term; relatively net income was higher by 1261hrn./ha compared to the control, the profitability was 33.7 % higher. The cost of 1 ton of winter wheat in this variant was 50.2 hrn/ha lower.than in the control, 90.6 hrn/ ha lower than in the first (early) sowing and 47.5 hrn/ ha lower compared to the third (late) sowing.

Thus, applying crops growth regulators "Vermybiomag " and " Vermyyodis " in presowing seed treatment and under single and double spraying of winter wheat during growing season under different sowing terms, contributed to increase in seed germination and energy, plant hardiness, stimulated crops growth and development and provided significant yield increase of  Zolotokolosa .winter wheat varieties in all variants.

The highest increase of winter wheat yield was in the variants with presowing seed treatment  with "Vermybiomag " in the dose of 6 l/t and " Vermyyodis " in the dose of 4 l/t  and double spraying of winter wheat during vegetation with " Vermybiomag " in the dose of 7 l/ha and " Vermyyodis " in the dose of 5 l/ha growth regulators.

Key words: winter wheat, varieties, growth regulators, yield.