Components of winter rapeseed yield structure when pollinated under group mesh isolator and open pollination

The aim of the research was to study how group mesh isolator conditions influence the formation of winter rapeseed yield structure elements, compared to open pollination conditions. The experiment was conducted from 2023 to 2024 in the central zone of the Krasnodar region. To evaluate plant architectonics and productivity under different pollination conditions, we used seed production sowings of the winter rapeseed varieties Elvis, Loris, Sarmat, Selegor, and the paternal parent line ORK10, with plant population of 50 plants/m2. During the flowering stage, 1 m × 1 m × 1.8 m mesh isolators made of polyamide sieve fabric with a mesh size of 0.25 × 1.0 mm were installed. Under group mesh isolators, no significant changes were observed in the studied varieties and a line with regard to a decrease in parameters such as plant height, number of first and secondorder branches, number of pods on the central branch, number of seeds per pod, and thousandseed weight. However, the formation of elements of plant productivity architectonics in varieties and a parent line during flowering and pollination in a group mesh isolator led to decrease in seed weight per plant by an average of 37%. The decrease in plant productivity was primarily due to a decrease in pod setting on first and secondorder branches (by 63.1–92.8 and 14.4–58.5 pieces, respectively). In isolated pollination, the number of pods could decrease due to greater competition among buds for important resources, insufficient movement of nutrients in the terminal part of the inflorescence, poor ventilation, and the absence of pollinating insects.