Causes of yellowing of rape seedlings and remedial measures

Rape has always been an important oil crop and cash crop in China, and it has a long history of planting. September is the season for planting rape in southern China and the Yangtze River Basin. But many rape growers often encounter the phenomenon of rape seedlings yellowing, so what is the cause of this? What should we do about it? Let's get to know it.

1. Causes of yellowing of rape seedlings

The yellowing of rape seedlings is generally caused by three situations: first, rape is not ploughed before sowing, rapeseed generally needs to be ploughed twice after sowing, the first time to dig a large piece of soil deeply, and then dry the soil for a week, the second time in the sowing, ploughing, at this time to be fine, and before ploughing enough base fertilizer. The second situation is that because the previous crop is broad bean field, the remaining pathogens are larger, because the disease of broad bean is larger, which will leave germs in the soil after harvest, causing harm to rape seedlings. The third is that there is no pest control, which leads to the aggravation of the disease and the yellowing of seedlings.

II. Remedial measures

The main results are as follows: 1. In the seedling stage, we should do a good job of clearing ditches and drainage to avoid the phenomenon of stagnant water, and be prepared to sow in time. Rape is more sensitive to sowing time, and certain temperature conditions are needed for rape sprouting and rooting and long leaves. When the optimum temperature for germination is 16-22 degrees and leaf emergence needs more than 10-15 degrees to proceed smoothly, the seedbed is recommended to choose the land with fertile soil and close to the water source.

2. Spraying foliar fertilizer on rape. It is recommended to use 0.1-0.3% potassium dihydrogen phosphate or potassium phosphate and other agents for foliar spraying to promote the root growth and development of rape seedlings and restore their yellowing as soon as possible. Topdressing also according to the growth of rape timely supply of nutrients, appropriate application of phosphorus and potassium fertilizer, can greatly reduce the yellowing phenomenon.

3. Proper trimming and sharpening can promote rape to produce more branches, form excellent population structure, enhance disease resistance, effectively prevent rape yellowing, and is also one of the ways to obtain high yield.

4. Timely prevention and control of diseases and insect pests is also one of the main measures to prevent the yellowing of rape seedlings. In the growth cycle of rape, the main threats of diseases and insect pests are green insects, jumping beetles, aphids and so on. It is suggested that it can be sprayed with 3000 times of 25% enemy killing solution or 40% dimethoate 1000 times solution.

The above is the introduction of the causes and remedial measures of rape seedling yellowing. I hope it can help you. If you want to know more about it, please follow us.