It is very important to plant the rapeseed in the early spring in the early stage. The sowing is too early, and it is easy to cause cold damage, roots, rotten roots and convulsions due to the influence of low temperature conditions. Late planting will delay the listing, poor product quality (mainly because the temperature is too high), and reduce economic income. Open field production is generally sown in late March, all using live broadcast.

The cultivation techniques of spring dew rapeseed are as follows:

First, choose a good species

To choose high-quality, disease-resistant, high-yield, convulsion-resistant varieties.

Second, the application of base fertilizer

Under normal circumstances, the application of high-quality fully decomposed farmyard manure 3000 ~ 5000 kg, diammonium phosphate 20 ~ 25 kg, potassium sulfate 10 ~ 15 kg or 45% of ternary compound fertilizer 40 ~ 50 kg.

Third, seed treatment

Before planting, put the seeds in a well-lit place for 3 to 4 hours, then soak the seeds in 50 ° C warm water for 20 to 30 minutes, then soak seeds in 20 ° C ~ 30 ° C water for 2 to 3 hours, and dry them. Direct sowing; or germination at 15 ° C ~ 20 ° C, 24 hours out of the buds for sowing.

Fourth, fine sowing

Usually planted in late March, about 350 grams of acres. Before sowing, the soil is watered to make water, and it is planted after water seepage. When planting, open 5 furrows 1 m wide, the ditch depth is 1.5-2 cm, and the seeds are evenly spread in the ditch.

V. Field management

When two true leaves are unfolded (2 leaves and 1 heart), the first seedlings are 3 to 4 cm in length; the second seedlings are fixed in 4 leaves and 1 heart, and the seedlings are 8 to 10 cm in length. 40,000 or so. In the seedling stage, there is less water. Under normal circumstances, it will not be watered or watered. After the seedlings are finished, watering should be carried out 3 to 4 times during the growth period. 15 times before harvesting, 1 time of fertilizer, 20-25 kg of urea or 20 kg of ammonium sulfate.

Six, prevention of pests and diseases

1. Prevention and treatment of diseases. The diseases that are prone to occur in spring rapeseed rapeseed are mainly sclerotinia, downy mildew and black rot. In the prevention and treatment of diseases, the leaves of old leaves should be removed in time, and pesticides can be used for prevention and control when the disease rate reaches more than 10%. Commonly used pesticides are: carbendazim, chlorothalonil, methyl thiophanate and the like. Spraying 50-75 kg of liquid per acre, generally 2 times, 5 to 7 days apart.

2. Pest control. The pests of rapeseed are mainly aphids, leaf miners and the like. If aphids are found, they should be sprayed with 20% chlorpyrifos 2000 times or 2.5% 1800 times. When the stalk of the larvae of the leaf miner has just appeared, 90% of the crystal trichlorfon can be used in an amount of 50 to 70 grams per mu, and 60 kg of water is sprayed.

Seven, timely harvest

Spring 茬 茬 油 油 一般 一般 generally can be harvested about 60 days after the broadcast. After the morning, the market will affect the output, and too late will affect the quality of the product.