Technical Guidance Opinions on the Autumn and Winter Planting of Rape in the 2015 - 2016 Crop Year

According to the prediction of the meteorological department, there is a relatively high probability of a strong El Niño event occurring this autumn and winter. In the Yangtze River Basin, there may be low temperatures, rainy weather in autumn and a warm winter, which will be unfavorable for the sowing, transplanting and growth of rapeseed. In order to effectively improve the quality of autumn sowing, implement high-yield and high-efficiency technologies as well as disaster prevention and mitigation measures, and lay a solid foundation for a bumper harvest of rapeseed next year, the technical guidance opinions on the autumn and winter planting of rapeseed in the 2015-2016 season are hereby put forward for the reference of all localities.
       I. Exploit and Utilize the Multifunctionality of Rapeseed to Stabilize the Planting Area
      All localities should strengthen the macro guidance of rapeseed production, plan the production layout of autumn and winter rapeseed planting as early as possible, and expand the multifunctionality of rapeseed such as oil use, vegetable use, sightseeing and green manure according to local conditions, so as to strive to improve the comprehensive benefits of rapeseed planting. In combination with the implementation of projects such as the creation of high-yield rapeseed and the research on green production increase models, vigorously promote high-yield, high-oil, high-resistant and double-low rapeseed varieties, and continuously improve the level of mechanization in rapeseed production. Actively cultivate new production and operation entities of rapeseed, promote moderately large-scale planting, facilitate the connection between production and marketing, and achieve premium prices for high-quality products. Increase the utilization of winter fallow fields and tidal flat resources in the Yangtze River Basin, and promote models such as double-cropping rice-green manure, rice-rapeseed, and intercropping and relay cropping of rapeseed and potatoes, so as to strive to stabilize the rapeseed planting area.
         II. Promote High-yield and High-efficiency Technical Models to Boost Production
     Further increase the promotion of seven high-yield and high-efficiency technical models such as direct seeding and mechanical harvesting of rapeseed in the rice-rapeseed rotation area, and summarize and improve the green high-yield and high-efficiency technical model with mechanized production technology as the core. In the areas where the paddy fields are left after the harvesting of middle-season rice and double-cropping rice (including single-season late rice), the technical model of "mechanized ditch digging and broadcasting (or mechanical direct seeding) + mechanical harvesting" can be adopted. Focus on sowing at appropriate soil moisture and uniform sowing in appropriate amounts, improve the quality of sowing and ditch digging, and plant mid-early maturing rapeseed varieties that are tolerant to late sowing, waterlogging, close planting, pod shattering, sclerotinia stem rot and lodging. In the early dry land stubble areas where corn, soybeans, peanuts, sesame, etc. are harvested and removed from the fields from late September to early October, the technical model of "mechanized tillage and broadcasting (or mechanical direct seeding) + mechanical harvesting" can be adopted. Focus on seizing the soil moisture and sowing early to ensure full seedling emergence in one sowing, and plant mid-maturing rapeseed varieties that are tolerant to pod shattering, close planting, sclerotinia stem rot and lodging. In the late stubble areas of cotton and late rice, the technical model of "seedling raising and transplanting (or relay seeding) + mechanical harvesting" can be adopted. The key to transplanting rapeseed is to cultivate strong seedlings, and the key to relay seeding of rapeseed is to sow evenly according to the furrow and appropriately increase the seeding rate, and plant mid-late maturing varieties with great single-plant production potential and super-high yield.
          III. Sow Early at the Appropriate Time to Ensure the Planting Density
      Early sowing of winter rapeseed at the appropriate time and ensuring the planting density are the keys to achieving high yields. Generally, the appropriate sowing period for transplanted (relay planted) rapeseed is around the middle of September, and the ratio of the seedbed to the field is about 1:6. Strengthen the regulation of fertilizer and water in the seedbed to cultivate strong and large seedlings. The appropriate transplanting period is in the middle and late October, with a seedling age of 35-40 days. About 6,000 plants should be transplanted per mu for early dry stubble fields, and about 8,000 plants per mu for late rice stubble fields. When the transplanting density is relatively high, the method of "two plants per hole" can be adopted, and the plant spacing and row spacing should be adjusted appropriately. When transplanting, the seedlings should be graded according to their sizes, transplanted in the sun-facing furrows, and the roots should be in close contact with the soil to shorten the slow seedling stage. The appropriate sowing period for direct-seeded rapeseed is from late September to early October, with 20,000-30,000 seedlings per mu. The seeding rate should be appropriately increased for fields sown in the middle and late October and fields with poor soil moisture. Try to use mechanical direct seeding to ensure uniform sowing and consistent sowing depth. Pay attention to pressing after sowing when the soil moisture is poor. In the areas with three-crop rotation of rice-rice-rapeseed (including rapeseed after single-season late rice), the seeding rate of early-maturing direct-seeded rapeseed should be appropriately increased to ensure that the planting density per mu reaches about 40,000 plants; the seedling raising time of early-maturing varieties of transplanted rapeseed should be postponed by 1-2 weeks compared with that of mid-maturing varieties to reduce the risk of early bolting and flowering.
       IV. Apply Fertilizers Scientifically and Control Growth in a Timely Manner
      For rapeseed fields with general medium yields, apply 10-12 kg of nitrogen fertilizer (N), 3-4 kg of phosphate fertilizer (P₂O₅), 3-5 kg of potassium fertilizer (K₂O) and 0.75 kg of borax per mu. Among them, 60% of the nitrogen fertilizer, 60% of the potassium fertilizer and all of the phosphate fertilizer and borax are used as base fertilizers, 20%-30% of the nitrogen fertilizer is used as winter seedling fertilizer, and 10%-20% of the nitrogen fertilizer and 40% of the potassium fertilizer are used as bolting fertilizer. For fields with strong growth before winter, the winter fertilizer can be omitted and transferred to be used as bolting fertilizer. In order to improve the fertilizer utilization rate, it is recommended to apply 50 kg of rapeseed-specific slow-release fertilizers such as Yishizhuang per mu. Spraying growth regulators is an effective measure for the stable growth of rapeseed. For fields with excessive growth, 25-30 grams of 15% paclobutrazol mixed with 40 kg of water can be sprayed per mu in the early bolting stage to control excessive growth and promote strong growth. Spraying growth regulators such as Bi Hu and Painuoke on rapeseed before winter can effectively improve the frost resistance and stress resistance of the plants.
       V. Strengthen Field Management and Prevent Disasters
      First, dig three types of ditches. During the growth period of rapeseed in the Yangtze River Basin, there is a lot of rain, and waterlogging is likely to occur. Before sowing and transplanting, waist ditches, compartment ditches and surrounding ditches should be dug. The depth of the ditches is generally about 30 cm, and the ditches should be connected to each other so that the fields can dry out after the rain stops. Also, pay attention to regular cleaning to keep the three types of ditches unobstructed. Second, control weeds. For transplanted rapeseed, 50-75 grams of 50% acetochlor EC mixed with 50 kg of water per mu can be sprayed for weed control before transplanting. For direct-seeded rapeseed, the same amount of the herbicide can be sprayed for weed control before the seedlings emerge after sowing. For fields where the effect of closed weed control is not ideal and there are many weeds, the herbicide should be selected and sprayed in a timely manner when the daily average temperature is above 5°C during the wintering period. Pay attention to avoid spraying the herbicide when cold air is coming to prevent the superposition of herbicide damage and freezing damage. Third, prevent and control diseases and pests. Aphids are the main pests in the seedling stage of rapeseed. They can be controlled by spraying with 2,500 times diluted liquid of 10% imidacloprid wettable powder or 3,000-5,000 times diluted liquid of 50% pirimicarb wettable powder. For fields where the damage of cabbage caterpillars and diamondback moths is relatively serious in the seedling stage, pyrethroid pesticides can be selected for control. For damping-off of rapeseed, 1,000 times diluted liquid of 75% chlorothalonil can be sprayed on the seedlings and the soil. In recent years, the clubroot disease of rapeseed in the upper reaches of the Yangtze River has been spreading continuously. Great importance should be attached to comprehensive prevention and control work. In addition to selecting disease-resistant varieties, measures such as crop rotation, deep burial of diseased plants, applying 75 kg of lime powder per mu, covering the seeds with soil mixed with plant ash, and applying calcium cyanamide should be adopted, combined with pouring and applying 600 times diluted liquid of 50% carbendazim or 500 times diluted liquid of dexon for control. Fourth, do a good job in "one promotion and four preventions". In the early flowering stage, mix 100 grams of 40% sclerotiniacide wettable powder or prochloraz + 100 grams of potassium dihydrogen phosphate + 50 grams of quick-acting boron per mu. Use a power sprayer with 15 kg of water or a manual sprayer with 30 kg of water to prevent sclerotinia stem rot.

Source: This article comes from the official website of the Ministry of Agriculture of China.