The effectiveness of Architect, SE growth regulator (mepiquat chloride, 150 g/l + pyraclostrobin, 100 prohexadione-calcium, 25 g/l) in winter rapeseed var. Vitovt and Mazari Mercedes hybrids is shown. application the preparation phase 4–5 leaves at rate 1,5 l/ha reduces height growing point by 47,7–55,2 %, increases diameter root crown on average 13,5–22,8 crop overwinter survival 3,7–12,3 % oi...