There are many reasons for the occurrence of red leaf in rape, and the corresponding measures must be taken to distinguish the situation. The nitrogen-deficient plants are dwarf, and the new leaves are born slowly. The leaves are small and small, yellow-green to yellow, and the leaf margins are red. Control measures: apply 8 to 10 kilograms of urea or 20 to 30 kilograms of ammonium bicarbonate per acre, or use 750 to 1,000 kilograms of human waste to pour water. Phosphorus-deficient plants grew slowly and were dwarfed, the leaves became smaller, the leaves became thicker, the leaves were dark green, lacking luster, and purple spots or plaques appeared on the edges, and the petioles and leaf veins on the back of the leaves turned purple. Prevention and control measures: 25-30 kg of superphosphate per acre topdressing or watering pouring, while spraying 2% of superphosphate soaking liquid; or continuous spraying of 0.2% potassium dihydrogen phosphate solution 2 or 3 times. The potassium deficiency develops from the old leaf to the heart leaf, and gradually changes from a yellow spot to a light brown spot until it becomes a brown-red spot. Prevention and control measures: Apply 10 to 12 kg of potassium chloride or 75 to 100 kg of plant ash per acre, or spray 0.2% potassium dihydrogen phosphate solution continuously for 5 to 7 days at a time, spraying 2 to 3 times continuously. The sulfur-deficient plants are dwarf, the leaves are light green, and the leaves have large nicks that collapse into cups. The dorsal, leaf veins, and stalks of the leaves turn purple. Prevention measures: 1 to 2 kg of sulfur powder or 50 kg of gypsum powder per acre is applied in combination with cultivator. Boron-deficient boron deficiency, thickening or rewinding of leaves, shrinking and uneven, dark green leaves, leaf edge to the entire leaf becomes purple or purple. Prevention measures: 100-150 grams of borax plus 25-50 kilograms of water per acre, sprayed once every 7-10 days. The drought of rape seedlings at the seedling stage and the lack of soil moisture will make it difficult for the roots to absorb water and attract fertilizers, resulting in slow growth, short dwarfing of the plants, and turning of the leaves into light red. Preventive measures: Watering in time, adopt furrow irrigation methods, and do not flood irrigation to prevent rot-root dead seedlings. Excessive waterlogging or poor drainage, resulting in waterlogging injury, dark red leaves, and some rotten root dead seedlings. Prevention and control measures: timely drainage and drainage, reducing groundwater level; cultivating loose soil, improving soil permeability, and promoting root growth. When the freezing temperature drops sharply below 0°C in winter, the leaves of rapeseed will turn red after being frozen. Prevention and control measures: Combine with cultivator clearing the ditch, cultivating soil and removing roots, adding organic fertilizer, applying 75-150 kg of ash per acre, or 1000-1500 kg of fire-soil ash to prevent freezing damage. Universal Surgical Pack,Sterile Universal Pack,Disposable Universal Pack,Disposable Sterile Universal Pack Xinxiang Huaxi Sanitary Materials Co., Ltd. , https://www.huaximedical.com