Influence of agrotechnical methods of winter rapeseed cultivation on plant density and yield

Abstract

Purpose. Improving certain elements of winter rapeseed cultivation technology is a necessary measure that will contribute to the formation of stable and high seed productivity. The creation of new adaptive hybrids allows for more effective realization of the biological potential of the crop. Sowing rates and timing play an important role in the cultivation system. After all, they create conditions under which young rapeseed plants successfully take root, accumulate plastic substances in the root collar and are able to safely overwinter. Therefore, studying the effect of sowing rates and timing on the formation of yield indicators is of great scientific and practical importance. Methods. In the course of the work, we used generally accepted scientific methods and special research techniques based on the principles and measures of optimising winter rapeseed cultivation technology. Results. It has been established that crops with reduced sowing rates ensure better survival of winter rapeseed plants in the community during the growing season. Thus, when growing the Pancher hybrid with a sowing rate of 500 thousand pieces/ha of viable seeds, the survival rate of plants was 75.7–80.9 %, while for the Fencer hybrid it was 79.3–83.7 %. When the sowing rate was reduced to 200 thousand seeds/ha of viable seeds, the survival rate of rapeseed plants increased to 82.9–89.5 % for the Pancher hybrid and to 82.4–86.5 % for the Fencer hybrid. The optimal sowing dates (15 August) in the Vinnytsia region contributed to higher rapeseed yields compared to later dates (30 August). Thus, when growing winter rapeseed with a sowing rate of 200,000 thousand pieces/ha of viable seeds, the seed yield was 3.62 t/ha for the Pancher hybrid and 3.87 t/ha for the Fencer hybrid, while in the experimental variants with late sowing dates, it was only 2.94 t/ha and 3.27 t/ha, respectively. Conclusions. The use of such technological methods in the cultivation of winter rapeseed hybrids, such as sowing at the optimal time with a rate of 500 thousand pieces/ha of viable seeds, allowed for the highest seed yields. The yield of the Pancher hybrid was 4.37 t/ha, and that of the Fencer hybrid was 4.55 t/ha. Compared to the least productive variant of the experiment, namely sowing rapeseed late at a rate of 200 thousand seeds per hectare, an increase in yield of 48.6 % and 39.1 %, respectively, was noted.