Look at the rape leaf color symptomatic management
Rapeseed often forms a large number of "red leaf seedlings" in winter. In order to facilitate the management of seedlings and symptomatic diseases, according to the reasons for the formation of red leaf seedlings, the corresponding prevention measures are introduced separately: Nitrogen deficiency: the plant is short, the new leaves are born slowly, the leaves are small and small, yellow-green to yellow, and the leaf margin is red. Control measures: 8 to 10 kg of urea per acre or 20 to 30 kg of ammonium bicarbonate, or 750 to 1000 kg of human excrement for water; late nitrogen deficiency, with 1 to 2% urea solution foliar application. Phosphorus deficiency: Rape is a phosphorus-loving crop, which requires more than twice as much phosphorus as cereal crops. In the absence of phosphorus, the plants are short, slow-growing, delayed leaves, small leaf area, dark green leaves, lack of luster, purple-red spots or plaques on the edges, and veins on the petioles and leaves on the back of the leaves turn purple. Control measures: use 25 to 30 kg of superphosphate to drill or apply water to each acre. The earlier the effect is better, the later use of 1% superphosphate leaching solution. Boron deficiency: Brassica napus is a boron-loving crop. The content of boron in dry matter is 32.5 to 36 times higher than that of wheat and rice. In the absence of boron, the leaves initially become dark green, the leaf shape becomes smaller, and the leaf quality is thickened. It becomes brittle, and the ends of the leaves are rolled back and wrinkled. Thereafter, it turns purple from the edge of the middle blade below, and develops to the inside, and then turns blue-violet; the veins and its surrounding tissues turn yellow, resulting in a piece of blue-purple spots. Finally, part of the leaf edge is dead, the whole leaf turns yellow and falls off early. Control measures: Spray with 0.1~0.2% borax solution on the foliar surface. Waterlogging: There is too much rain before the winter, or transplanting in the plate field, the water filtration is not smooth, causing the waterlogging to damage the roots and the seedlings, the leaf color becomes dark red, and some will also rotten the dead seedlings. Control measures: timely ditch drainage, reduce groundwater level; cultivating loose soil, improving soil permeability and promoting root development. Freezing damage: When the temperature suddenly drops below 0 °C in winter, the leaves will also appear red when frozen. Control measures: Combine the cultivating and clearing ditch, cultivate the roots of the soil, increase the application of organic fertilizers, and reduce the freezing damage. Disclaimer: Some articles on this website are transferred from the Internet. If legal rights of third parties are involved, please inform this website. phone Crispy Pepper,Chili Slices Shredded Chili Snack,Authentic Crispy Peppers,Canned Crispy Chili Snack Guizhou Guisanhong Food Co., Ltd , https://www.guisanhong.com