How to Grow Rapeseed Flowers: Planting Methods and Key Technical Points
Every year in March-April, rapeseed flowers bloom all over the hillsides, looking very beautiful, and once the flowers fade, plump seeds will grow, yielding more oil. So how do you grow rapeseed flowers?
1. Seed selection
Based on the local cultivation system and climate conditions, combined with the local soil fertility level and production situation, select varieties with strong stress resistance and good yield performance.
2. Land selection and preparation
The seedbed should be chosen in a ventilated, sunny plot with fertile, loose soil, close to a water source, and the land should be prepared carefully. Seedbed preparation should achieve “level”, “fine”, and “firm” conditions.
3. Sowing
Sow the seeds evenly into the soil, cover with a layer of soil, and water an appropriate amount. Generally, the suitable germination temperature requires a daily average temperature of 16-22°C, and seedling leaf emergence also requires above 10-15°C to proceed smoothly. In addition, it must be ensured that after transplanting there are at least 40-50 days of effective growth period before entering winter.
4. Transplanting
When the seedlings are 30-35 days old, with 5-6 green leaves and roots 5-6 mm thick, they can be transplanted into the field. When transplanting, use a row spacing of 50 cm × 20 cm, planting about 7,000 plants per mu. Transplant while covering with soil, and water promptly with rooting water after transplanting. Three days after transplanting rapeseed, check for gaps and fill in missing seedlings.
5. Post-transplanting management techniques
(1) Fertilizer requirements: Rapeseed plants are tall and have high fertilizer demands. Organic fertilizer should be the main type, with chemical fertilizer as a supplement. Generally, apply 2000 kg of organic fertilizer per mu, 25-30 kg of 45% general-purpose compound fertilizer or 30-40 kg of 36% compound fertilizer (15-10-11), and 0.5-1 kg of boron fertilizer. Application method: Combine deep application of organic fertilizer, compound fertilizer, and boron fertilizer with plowing and land preparation. Never apply fertilizer too shallowly, to avoid fertilizer deficiency in the middle and late stages of rapeseed growth.
(2) Water requirements: In rapeseed production areas, rainfall is generally low in autumn, winter, and spring, and the soil is dry, which is not conducive to sowing, seedling emergence, and cultivating strong seedlings. In northern regions, winter drought often aggravates freezing damage and causes seedling death. In southern regions, excessive rain in the later period causes waterlogging or flooding damage. Therefore, timely irrigation and drainage must be carried out according to local conditions based on the water requirements of rapeseed.
(3) Topping: 45-50 days after transplanting rapeseed, when flower buds appear at the top of the plant, topping should be done at the right time to encourage rapeseed to produce more robust primary branches, form an excellent population structure, and obtain the best yield. The flower buds should be manually removed during the shortened stem growth stage after budding but before bolting. After topping, the plant should retain 8-9 leaves.
(4) Pest and disease control: The main pests and diseases harming rapeseed include cabbage caterpillars, flea beetles, aphids, cotton bollworms, and others. For damage from cabbage caterpillars, flea beetles, and aphids, spray with 25% deltamethrin 3000 times dilution or 40% dimethoate 1000 times dilution. For cotton bollworm damage, at the young larval stage, use 40 g of Baode plus 20 g of Wanling per mu diluted with water and spray, once every 5-7 days, for 2-3 consecutive sprays.