Analysis of appearance and nutritional quality of three summer sowing rape varieties for flowering stalks in the Erhai Lake Basin

Objective This study aimed to analyze the appearance and nutritional quality of three summer sowing rape varieties specifically for flowering stalks in the Erhai Lake Basin， so as to provide a reference for the variety selection and cultivation of rape varieties specifically for flowering stalks in the Erhai Lake Basin.Method Three rape varie-ties specifically for flowering stalks （Xiziyuan No. 1， Xiziyuan No. 2， and Dadi 95） were planted for trial in Dali Bai Autonomous Prefecture， Yunnan Province. The applicability of different rape varieties in the Erhai Lake Basin was analyzed from the perspectives of growth periods， agronomic traits， economic benefits， appearance quality， and nutritional quality characteristics.Result The bolting stage of Xiziyuan No. 2 came 16 d and 19 d earlier compared with Xiziyuan No. 1 and Dadi 95. The single stalk weight and stalk diameter of Dadi 95 were significantly higher than those of the other two varieties in the three harvesting times of harvesting（P<0.05，the same below）. The single stalk weight， stalk length， stalk thickness， and leaf number of Xiziyuan No. 1 and Xiziyuan No. 2 were similar. The yield and output value of stalks of Xiziyuan No. 2 were the highest， with increases of yield by 31.9% and 37.6%， and increases of output value by 30.4% and 39.4% compared to those of Xiziyuan No. 1 and Dadi 95， respectively. Among them， the stalk yield in the second harvesting time of Xiziyuan No. 2 increased by 87.8% and 84.9% compared to those of Xiziyuan No. 1 and Dadi 95， respectively， which was the main reason for the increase in total stalk yield. In the grading process， as the number of harvesting time increases， the appearance quality of stalks of Xiziyuan No. 1 and Xiziyuan No. 2 gradually decreases， and Xiziyuan No. 2 had the highest proportion of grade 1 stalks during the second harvesting. For Xiziyuan No. 2， its accumulation of nitrogen， phosphorus， and potassium were the highest in the whole growth period； its nitrogen accumulation significantly increased by 24.5% and 31.8% compared to Xiziyuan No. 1 and Dadi 95； its phosphorus accumulation significantly increased by 23.3% and 52.7% compared to Xiziyuan No. 1 and Dadi 95， respectively； its accumulation of selenium， calcium， zinc， magnesium， and cellulose in Xiziyuan No. 2 were also the highest. There was no significant difference in soluble sugar accumulation between Xiziyuan No. 1 and Dadi 95 （P>0.05）， indicating that Xiziyuan No. 2 had a better nutritional quality.Conclusion Under the same planting conditions， the rape variety Xiziyuan No. 2 shows the best stalk characteristics and nutritional quality， making it suitable for promotion plantation in the Erhai Lake Basin， Dali， Yunnan， thereby providing a solution for low rape plantation efficiency in the Erhai Lake Basin.