TECHNOLOGICAL EVALUATION OF SOYBEAN SEED QUALITY DEPENDING ON THE VARIETY

The biochemical component (protein content and fat content) of soybean seed, yield and fat and protein yield significantly depends on weather conditions and variety. It was found that the protein content in soybean seed, on average over two years of research on new varieties can vary from 36.1 to 44.4 %. Khana, Lenka and Alaska varieties have the highest proteincontent in soybean seed – 43.4–44.4 %. Protein content significantly depends on the weather conditions of the study year. Thus, soybean varieties of Kofu, Siberia, Volta, Asuka, Arisa, Khana, Lenka and Alaska, grown in 2020, have this figure 10–19 % higher than in 2019. In the seeds of Nordica, Carra, Kyoto, Ezra, Amadeus and Taurus soybean varieties, the protein content is 4–10 % lower. On average, over two years of research, the fat content in soybean seeds varies from 18.9 to 21.7 % depending on the variety. Only three out of 14 soybean varieties have the fat content ≤ 20.0 % – Khana, Alaska, Arisa. In seeds of other varieties, this figure is ≥ 20 %. Weather conditions reduce the fat content in the seeds by 7–20 % depending on the variety. Studies have shown that soybean seed yields vary significantly depending on the soybean variety. Thus, on average over two years of research, this figure varies from 1.30 t/ha in Amadeus variety to 1.88 t/ha in Siberia one. The highest yields (≥ 1.70 t/ha) were formed by Arisa, Volta and Siberia varieties. However, this figure varies greatly depending on the weather conditions of the study year. Thus, in a more favourable 2019, the yield is from 1.65 to 2.41 t/ ha, depending on the soybean variety. Moisture deficiency and small reserves of moisture in the deeper layers of the soil reduce seed yield from 0.95 to 1.35 t/ha or by 1.7–3.7 times, depending on the soybean variety. Two soybean varieties (Arisa, Siberia) have the highest protein yield at the level of 706–721 kg/ha. The highest fat yield was obtained by Siberia growing – 415 kg/ha. Under the conditions of the Right Bank forest-steppe, for stable formation of high protein yield in different weather conditions, it is necessary to grow Arisa soybean variety which has high protein content and high seed yield, and Alaska variety which has high protein content in seeds. In addition, in the best hydration years it is able to form a high fat yield. Volta, Asuka, Khana and Lenka varieties should be grown in years with sufficient moisture, as they provide the highest protein yield. These varieties should also be grown to obtain a high fat yield under the best moisture conditions. Siberia soybean should be used to produce fat in different weather conditions.