Yield of pea of madonna variety depending on sowing rates

In the conditions of sufficient moistening of the western forest-steppe, it is important to establish optimal sowing rates for pea seeds, which are fluctuated over a large interval – from 0.6 to 1.8 million/ha. For this purpose, field studies were conducted on the experimental field of Lviv National Agrarian University on dark gray podzolized light loam soil, in which were studied the following sowing rates: 0.9; 1.0; 1.1; 1,2; 1.3; 1.4 million/ha. Field germination was the highest with the lowest sowing rates of 0.9 and 1.0 million/ha, accounting for 81 % and 82 %, respectively. As the sowing rate increased, field germination naturally decreased and was the smallest with the highest sowing rate of 1.4 million/ha – 74 %. The density of the plants in the germination phase was much higher than the higher sowing rates. Thus, in the variant with a sowing rate of 0.9 million/ha, it is the smallest – 73 plants/m2, and the largest at a sowing rate of 1.4 million/ha –103 pieces/m2. The density of pea plants before harvesting also increased on higher sowing variants. During sowing of 0.9 million/ha, it was 70 pieces/m2, and at maximum sowing rate it increased to 90 pieces/m2, or by 20 pieces/m2. Preferably, the plants are preserved until harvest at lower sowing rates. In the variant with sowing of 0.9 million/ha the plant survival was the highest – 95.8 %, and at the highest sowing rate 1.4 million/ha it was 87.4 %, which is 8.4% less than at the sowing rate 0.9 million/ha. Higher yields of the Madonna variety (6.87 t/ha) were obtained in the first year of research due to better hydrothermal conditions. In 2018 it decreased to 6.25 t/ha, or 0.62 t/ha, and in 2019 it was the lowest – 6.00 t/ha, which is lower by 0.87 t/ha compared to 2017. The decrease of yields in 2018 is due to lower rainfall in April (-18mm from the annual average) and May (-18mm) and excess moisture in June (+69mm) and July (+35mm). In 2019, the decrease of yield was caused by a waterlogging in May (+92 mm). The yield of Madonna variety at the sowing rate of 0.9 million/ha was 6.34 t/ha. As the sowing rate increased to 1.0 and 1.1 million/ha, the yield increased and was the highest, 6.52 and 6.55 t/ha, respectively. Further increase in sowing rate to 1.2; 1.3 and 1.4 million/ha resulted in a regular decrease of the yield. Therefore, there is a need for further studies to optimize the sowing rates of new varieties of peas, taking into account their nutritional characteristics in the western forest-steppe.