Planting techniques of rapeseed

1. The habit of rape

Rape is slightly heat-resistant but not heat-resistant, cold-resistant, adaptable, cold-tolerant, moist, pest-resistant, sweet and crisp, less fiber, and the suitable temperature for growth is 20-25 ℃. The nutritional value of rape is slightly higher than that of lettuce and much better than that of lettuce. For example, compared with lettuce, the protein content is 40% higher, carotene 1.4 times higher, calcium 2 times higher, iron 33% higher, and selenium 1.8 times higher.

2. Raising seedlings and planting

1. Sowing and raising seedlings

Proper amount of rotten barnyard manure should be applied to the seedbed and watered thoroughly. Because the seeds are brown and small, they should be mixed with fine soil before sowing and sown. After sowing, a layer of sifted fine soil should be covered. If it is hot, it will be covered with a layer of plastic film. After emergence, the mulch will be removed. When rape is cultivated in summer and autumn, sprouting and sowing must be accelerated, otherwise it is difficult to ensure the success of seedling raising. Because the optimum temperature of rape seed germination is 18 ℃ 20 ℃, it can not germinate when it is more than 25 ℃ or less than 8 ℃. The simple and easy method is to soak the seeds in clean water for 4 to 6 hours, then pick them up and drain them. There are three methods to promote germination in the silk stockings: first, the method of sprouting by river sand, that is, spreading the soaked seeds on the surface of the river sand with 20~30mm thick moist river sand, then spreading the soaked seeds on the surface of the river sand, then covering it with 1~2mm thick wet river sand, and covering it with fresh vegetable leaves. Second, the method of accelerating germination with ice cubes in a thermos flask, hanging the soaked seeds in the bottle, adding clear water and ice cubes, and controlling the temperature at 18 ℃, rinsing once every other day, and insisting on changing water and adding ice; third, the method of low temperature germination in the refrigerator, wrapping the soaked seeds with gauze and putting them into the refrigerator of 15-20 ℃, rinsing l times a day. After about 2-4 days, 60% and 70% of the above budding can be sown. The seedlings can be raised directly in suitable season, the seedlings can be kept in the arch shed in winter and spring, and the sunshade net should be used to cover and cool the seedlings in summer and autumn.

2. Planting density

The seedling age varies greatly with different seasons, which takes 20-30 days in summer and autumn and 50-70 days in winter and spring. 3) it can be planted with 6 true leaves, and the general row spacing is 1 5cm × 20cm. In order to obtain higher yield, the row spacing is l0cm × 15cm in winter and 15cm × 15cm in summer and autumn, and 1.3-15000 plants per mu can be planted.

3. Land preparation and planting

Before planting, about 3 tons of farm manure, 20 kilograms of potassium sulfate, 1-2 kilograms of magnesium fertilizer, 200 kilograms of silicon-calcium fertilizer, 2 kilograms of boron fertilizer and 10 kilograms of ferrous sulfate were applied per mu, and then turned over to a depth of 20-25 centimeters. Make flat beds in winter and high beds in spring, summer and autumn, and plant them when the seedlings grow to 3-4 true leaves. Attention during cultivation: Brassica campestris is of crisp and tender quality and is not suitable for storage, so it is necessary to stagger the sowing period in production to make it appear on the market in batches and avoid a large number of centralized harvesting.

4. Field management

The growing period of rape and wheat is short, and the management is very simple. Watering fixed planting water after transplanting, watering seedlings slowly for 5-7 days, and then ploughing can not only weed, but also promote root growth. Squatting seedlings after mid-tillage, squatting seedlings are conducive to the formation of good roots, thick and green leaves, make the plants strong, and lay a good foundation for later growth and creation of good quality. The squatting seedling stage is about 10 days, and then the soil can be watered and fertilized to keep the soil moist. On the basis of applying organic fertilizer, high-phosphorus and high-potassium water-soluble fertilizer can be applied twice with a small amount of water, 5-10 kg each time, and should no longer be watered and fertilized about 5 days before harvest. Protected cultivation should also be ventilated and dehumidified, so that the plant is not too tender, reduce plant water content and improve quality.

III. Pest control

1. Downy mildew:

Symptoms: the disease can occur in both seedling and adult stage, and the damage is more severe in adult stage. The disease spreads from the lower part to the upper part, and the light yellow near round or polygonal spot is formed in the early stage of the leaf. When the humidity is high, the disease spot on the back of the leaf will grow into a white mildew layer, and the serious condition will cause the whole leaf to dry up. Make oil, wheat and vegetables lose their commercial value.

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Prevention and control methods:

1. Agricultural control: increase the application of organic fertilizer, reasonable close planting, timely ploughing, and flood irrigation is strictly prohibited in the later stage of growth.

two。 Reasonable control of temperature and humidity: moderate ventilation around noon, the relative humidity in the shed is reduced to less than 80%, and the temperature is controlled at 20 ℃ ~ 25 ℃.

3. Apply nitrogen fertilizer reasonably and increase the application amount of phosphorus and potassium fertilizer.

Chemical control: metalaxyl, metalaxyl, enyl morpholine, flumorph, flunomide, aldicarb hydrochloride, mancozeb, oxalaxyl, cyanoaxazole, oxazolidone and so on.

War Frost 1500 times + Chu Shuangyi / Pu Shuangjiao 750x

Excellent painting 1500 times

750 times of Wanshi + 500 times of Zhong Chunsheng

2. Sclerotinia disease:

Symptoms: Sclerotinia sclerotiorum occurs at the base of the stem of rape. Most of the infected parts rotted in the form of brown water stains, and sclerotia formed after dense cotton-like white mycelia on the surface of the disease when the humidity was high. The sclerotia was white at first, and then gradually turned into black particles in the shape of mouse feces. The leaves of the infected plants withered and the whole plant died.

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The transmission route and disease condition are mainly that the sclerotia overwintered in the soil with the disease residue, survived for about 1 year in moist soil, survived for more than 3 years in dry soil, and decayed and died after 1 month in water. After sclerotia germination, ascomycetes are produced, and then ascospores and ascospores are formed. After the ascospores mature, they spread by airflow. During the initial infection, ascospores germinate and produce germ tubes, which invade from senescent or locally necrotic tissues. When the bacteria acquired stronger infection ability, it directly attacked the healthy stems and leaves. In the field, diseased leaves spread the disease when they touch the hyphae. The temperature is 20 ℃ and the relative humidity is higher than 85%. When the humidity is less than 70%, the disease is obviously alleviated. In addition, the disease is serious in low-lying plots with excessive density, poor ventilation and light transmission, or poor drainage, or partial application of nitrogen fertilizer.

Prevention and treatment methods: (1) timely watering and venting, proper control of watering in the early growth period and after the disease, watering in the morning in sunny days, timely ventilation and dehumidification, and ventilation in cloudy and rainy days. The lowest temperature at night above 8 ℃ can release wind and dampness throughout the night. (2) reasonable close planting. (3) Drug prevention and treatment: Pythalide, isocourea, ethamyl, pyrimidinamide, sclerotiorum, pyrimidine, polyantimycin, nicotinamide, oxazolidone and so on.

3. Brown spot

Symptoms: mainly harmful leaves, leaf spots show two kinds of symptoms: one is the initial appearance of water stains, and then gradually expands into round to irregular, brown to dark gray spots, ranging in diameter from 2mm to 10mm, and the other is dark brown spots with irregular edges. There are water-stained halos on the periphery. When the spot is wet, there is dark gray mildew on the surface, and when the disease spot is serious, the disease spot merges with each other, causing the leaves to become dry and withered. The pathogen overwintered on the diseased remains with mycelium and conidia. When the conditions were suitable, the conidia were infected for the first time and spread by airflow and Rain Water sputtering. Warm and humid is suitable for the disease, and rainy, dewy or foggy in autumn are conducive to the disease. The disease occurred seriously due to plant growth weakness, lack of fertilizer or partial application of nitrogen fertilizer, overgrowth and so on.

Chemical control: 750 times fresh point, carbon spot win a pack, difenoconazole, tebuconazole, prochloraz, prochloraz manganese salt, nitrilazole, flusilazole and so on. Fresh spot (20% prochloraz ·isocarbamide) 500,750x + Xiexi (23% copper oleate) + carbendazim (40% bromofenitrile ·carbendazim); Yuanshengguan (Shitehao) 750x / 1000 times, finals 2000 times; Yuanshengguan 750x / 1000 times + Zhongchunsheng 500times

4. Soft rot

Symptoms: stem infection, newborn water-soaked spots, dark green irregular, then brown, rapid softening and decay. When the rhizome is infected, the base of the rhizome becomes light brown, softens and rotten gradually, and can go deep into the root pulp when the condition is serious. And it stinks.