Rasputenko A. Yield properties and sowing qualities of winter rape seeds depending on agrotechnical measures of its cultivation under conditions of the Western Forest-Steppe of Ukraine

The object of the research is the process of formation of seed productivity and sowing characteristics of seeds of winter rape varieties of different originators depending on the terms, methods of sowing, seed sowing terms and plant nutrition in the soil-climatic conditions of the Western Forest-Steppe zone of Ukraine. The purpose of the research is theoretical substantiation and development of the methodological provisions for the formation of seed productivity of 4.5-5.0 t/ha, high seed quality of winter rape varieties of various ecological types, depending on the terms, methods of sowing, seed sowing rates and different systems of root and foliar plant nutrition in the soil-climatic conditions of the Western Forest-Steppe. Research methods are general scientific. There were identified the features of formation of seed yield and sowing qualities when using genetic potential of domestic varieties and their reaction on the agricultural measures studied, in particular, dates and methods of sowing, seeding rates, presowing seed treatment with Vympel-K growth stimulator and microfertilizer Orakul seeds, foliar application of the growth regulator Vympel, micronutrients Orakul chelate boron and Orakul sulfur active in the phase of 4–6 leaves, shooting and large bud. It was established that the varieties Smaraht and Pehas have formed the highest seed yield at optimum (August 10–20) and admissible (August 20–30) sowing dates with wide-row sowing method (45 cm) with a seeding rate of 0.6 million of viable seeds per hectare whereas the varieties Solo and Stilutsa have formed it with ordinary rows (30 cm) and seeding rate of 0.8 million of viable seeds per hectare. Pre-sowing seed treatment with the disinfectants Cruiser (3.0 l/t), the growth stimulator Vympel (500 g/t) and the microfertilizer Orakul seeds (1.0 l/t) provides higher yield of seeds by 0.46 t/ha, 1000 seed mass 4.52 g, seed germination energy 90.6 %, laboratory germination 98.3 %. The winter rape fertilizing system has been developed which includes basic application of macro-fertilizers (N150Р135К240) and additional foliar one of the growth regulator Vympel (1000 g/ha) and the microfertilizers Orakul chelate boron (1.5 l/ha) + Orakul sulfur active (2.0 l/ha) in the large bud phase which contributes to seed yield 4.29–4.51 t/ha, its reproduction rate 429–451 units, yield of certified seeds 80.6–86.1 %. It was given the economic assessment of growing pre-basic seed depending on the agricultural measures studied.