Application of 'planting once and harvesting twice' technique in canola production

摘要

Canola production pattern of "Planting Once and Harvesting Twice" (POHT) is to harvest both the bolt as vegetable at elongation stage and oilseed on ripening. In this study, investigation was carried out for the following factors: cultvars, sowing stage, appropriate bolt length for cutting, yield and profit. Results showed that it was suitable to pick 15- 20cm long stem when the peduncle is 25-30cm high for early-ripen cultivars sowing on Sept.5 in Hubei Province, harvesting 4500kg/ha fresh vegetable valued 4800 CNY and oilseed 2175kg/ha valued 5250 CNY, almost doubled the income of the conventional pattern. The plant height, primary branch and seed number per pod of the pattern were significantly less than that of the conventional by 16.47%,63.49% and 5.33% respectively. However, the secondary branches and pods per plant were significantly more than that of the conventional by 126% and 7.90%. Maintaining a large number of pods is the key point of POHT to increase the oilseed yield.