Affected by the continuous rainy weather in the autumn of last year, the winter rapeseed cultivation period in the middle and lower reaches of the Yangtze River was delayed by about 10 days from the normal year. In the winter, there was a rare ice and snow low temperature. The winter and spring seasonal drought in the upper reaches of the Yangtze River was slightly heavier than in previous years, most of the main producing areas. The seedlings are weak.

Spring field management should focus on “promoting spring hair, disease prevention and control, and disaster prevention and loss”.

Adding fertilizer to promote spring

The growth of rapeseed in autumn and winter is generally insufficient. Promoting spring hair is the key to the transformation of rapeseed seedlings this year, and it is also an important measure to prevent cold and early defermentation. In general, in the beginning of March, 6-8 kg of urea per mu or 12-15 kg of ammonium sulfate can be applied. Fields with heavy seasonal drought in the upper reaches of the Yangtze River in the upper reaches of the Yangtze River should be repaired by rain or combined with hydration. For late-seeded fields, the application of manure fertilizer should pay attention to the balance of nitrogen, phosphorus and potassium, and prevent the partial application of nitrogen fertilizer to cause late lodging.

Clean up the ditch

In the Yangtze River Basin, there is a lot of rain in spring. If the former is rice, the soil water content will be higher. The high humidity in the field is not only not conducive to the growth and development of rapeseed roots, early premature aging and lodging, but also aggravate the occurrence and spread of diseases. On the basis of opening the "three ditch" before winter, clear the ditch in time after the spring, keep the "three ditch" unblocked, and ensure that there is no water in the rain stop.

Disease prevention and control

During the winter season, the rapeseed producing areas have many low-temperature rains and snows, and the plants are generally frozen, and the ability to resist pests and diseases is reduced. It is recommended to adopt the “one promotion and four prevention” measures to spray appropriate pesticides at the initial flowering stage to promote growth and fruiting and prevent pests and diseases. The upper reaches of the Yangtze River are affected by the seasonal drought in winter and spring, and the aphids are heavier. It is necessary to use suitable agents for prevention and control during the flowering and flowering period. Promote drones or large mechanical sprays in conditional areas to improve control effects and operational efficiency.

Ministry of Agriculture Oil Experts Guidance Group National Agricultural Technology Extension Service Center