Comparative study on the characteristics of rapeseed yield under the rapeseed- oil dual-purpose mode in the middle and lower reaches of the Yangtze River

To evaluate the production potential and regional applicability of the rapeseed-oil dual-purpose mode in the winter rapeseed-producing areas of the middle and lower Yangtze River Basin, a field experiment was conducted in Suzhou, Jiangsu Province, from 2024 to 2025. Using the conventional single-purpose oil production mode as a control, this study systematically compared differences in yield components and agronomic traits between the two modes. Additionally, by integrating and analyzing 265 sets of yield data from 27 published studies (2001-2025) in the China National Knowledge Infrastructure (CNKI), the effects of stalk removal on rapeseed yield across different regions were assessed through variance and correlation analyze. Field experiment results showed that, compared with the conventional mode, the dual-purpose mode increased the number of total branches by 26.95% and prolonged the growth period by 3.5 days, while significantly reducing plant height, branch height, 1000-seed weight, and flowering duration by 6.35%, 54.56%, 4.70%, and 12.19%, respectively (<italic>P</italic> &lt; 0.05). No significant overall difference in rapeseed yield was observed between the two modes (<italic>P</italic> &gt; 0.05). However, under the stalk removal mode without nitrogen topdressing, yield decreased significantly by 36.26% (<italic>P</italic> &lt; 0.05), accompanied by notable reductions in the number of primary branches, siliques per plant, branch height, and 1000-seed weight (<italic>P</italic> &lt; 0.05). Regional comparisons revealed that the yield remained stable after stalk removal in mid-Yangtze regions such as Hubei and Jiangxi, while more pronounced yield sensitivity was observed in Jiangsu, Zhejiang, and Anhui. Therefore, the rapeseed-oil dual-purpose mode should be adapted to local conditions, incorporating supportive practices such as optimized variety selection and fertilization strategies. Refining nitrogen management and stalk removal criteria can enhance branch compensation and extend the flowering period, thereby improving overall cultivation efficiency and stabilizing rapeseed yield.