Red leaves lead to growth stagnation of rapeseed how to control red leaves of rapeseed

After the occurrence of red leaves in rape, the green leaf area decreased, the photosynthesis decreased, the growth stagnated and the growth was poor. There are many factors leading to the red leaves of rape, which should be remedied after finding out the causes.

Red leaves of rapeseed

The main results are as follows: 1. Waterlogging damage: serious waterlogging damage, resulting in poor root growth, weakening absorption, nutritional imbalance, hindering the formation of chlorophyll and increasing anthocyanins, resulting in red leaves. Remedial measures: immediately clear the ditch and drain, lower the groundwater level, enhance soil permeability, and promote rape to root early.

2. Soil drought: soil drought, lack of water, causing leaf margin shrinkage and leaf redness. Remedial measures: timely watering, thin fertilizer and water to drench the roots to meet the needs of rape for water and fertilizer.

3. Soil hardening: soil hardening affects soil permeability and reduces the absorption of rape roots, which leads to the redness of leaves. Remedial measures: timely deep ploughing, scattered moisture and ventilation, application of urea 10kg per mu to promote growth.

4. Barren soil: barren soil leads to poor development, slow growth and red leaves of rape. Remedial measures: early application of topdressing fertilizer, application of urea 10~15kg per mu, and supplement of phosphate fertilizer about 15kg.

5. Phosphorus deficiency at seedling stage: the emergence of leaves was slow, the leaves were erect, the middle and lower leaves were dark green, the petioles and veins were purplish red. Rape is deficient in phosphorus at seedling stage, but foliar fertilizer can be sprayed. The specific method is: spray 1% 2% superphosphate leaching solution, spray once a week, generally spray 1% twice, each time the amount of liquid 40~50kg per mu.

6. vegetable seedlings are dense: the population is too large, the seedlings are crowded, the individual is thin, and the phenomenon of fighting for fertilizer, water and glory appears, so that the leaves turn yellow and red. For this kind of red leaf seedlings, quick-acting fertilizer should be applied immediately.

7. The damage caused by aphids: the leaves are reddish and thin. 50~60kg water with 50 g of 40% dimethoate emulsion, or spray water 60kg with 50 g of 80% dichlorvos emulsion.

8. Low temperature freezing injury: after rape was attacked by low temperature, the root absorption was weakened, resulting in physiological lack of fertilizer, a large number of anthocyanins were formed in the leaves, and the leaves became purple-red. Remedial measures: increase the application of phosphorus and potassium fertilizer, combined with ditch cleaning, cultivate the soil and root, improve the growth microclimate of rape in winter and enhance the ability of low temperature tolerance.