Abstract:
Objective To evaluate and select the early-maturing, high-yield and high-quality rapeseed varieties suitable for the three-cropping mode of “rice-rice-oil” in Guangdong Province, solve the outstanding problem of crop rotation, and promote the improvement of grain and oil production capacity in Guangdong Province.
Method The experiment was carried out in the idle winter field of double-cropping rice. The 25 early-maturing rapeseed varieties were selected as evaluation materials, their growth duration time, yield and quality were assessed, and their correlations with meteorological factors were analyzed as well.
Result The whole growth duration of 25 winter rapeseed varieties ranged from 136 to 151 d. The days from sowing to initial flowering, from initial flowering to full flowering, from full flowering to flowering end, and from flowering end to maturity were on average 88.0, 7.2, 21.1 and 30.0 d, respectively. The accumulative effective temperatures above 0 ℃ was 1 648.4, 98.3, 360.3 and 525.3 ℃. Their average yield was 1 832.1 kg·hm−2, ranging from 1 279.0 to 2 288.1 kg·hm−2. The average daily yield was 12.5 kg·hm−2, ranging from 8.6 to 15.5 kg·hm−2. The seed yield was positively and significantly correlated with seeds per siliques (P<0.01). The seed oil content averaged at 44.5%, varying from 40.4% to 48.4%. The protein content was 22.4% on average, with a range between 19.2% and 25.4%. Additionally, the average oleic acid content was 58.5%, with a range between 19.6% and 73.3%. Correlation analysis indicated that both yield and oil contents have a significant or extremely significant positive correlation with the average temperature and photosynthetically active radiation from the sowing to initial flowering periods. Cluster analysis discoverd 11 high-yield-type varieties with various growth durations, and their daily yield, seeds per siliques, number of primary branches and total number of siliques per plant were higher or greater.
Conclusion Early-maturing rapeseed varieties displays significantly different adaptability in the winter production of Guangdong. High-yielding varieties can fully utilize the light and temperature resources in the early growth stages, leading to the formation of high-yield and high-oil traits. They are suitable for “rice-rice-rapeseed” production in some rice-growing areas in central Guangdong.