The growth and length of rapeseed before twitching have a great influence on rapeseed yield. By observing the changes in the leaf color of rapeseed, we can understand in a timely manner what nutrients are lacking in rapeseed and take targeted measures to promote the robust growth of rapeseed and lay a good foundation for seizing the harvest of rapeseed. The order of occurrence of whole leaves of red leaves begins with the old leaves and then develops towards the new leaves. A leaf occurs in order, starting from the leaf margin and gradually expanding to the entire leaf. The reason for the occurrence of nitrogen deficiency, can be applied per acre 8 to 10 kg of urea or ammonium bicarbonate 15 to 20 kg. In the dark purple phosphorus deficiency, the plant leaves are small, the leaves are not flat, the leaves are dark green and lusterless, the petiole is purple, and the dark purple stiff leaves finally become. The whole plant withered and died. Can be applied per acre of superphosphate 25 ~ 30 kg or foliar spray of 0.3% potassium dihydrogen phosphate 2 ~ 3 times. The purplish blue spot begins with the middle and lower leaves and then develops upwards and downwards. The leaves are dark green, small in leaf shape, thick and crispy in leaf, and leaf-side reeled, with purple-red to blue-purple leaves, and finally developed into purple-blue spots. This is due to the lack of boron. Can be sprayed with 0.1%~0.2% borax or 50~60 kg boric acid solution per acre. The brown coke edge symptoms begin with the old leaves and then develop towards the new leaves. The early leaves showed yellow-white spots, and the cobs and light brown spots gradually appeared at the tips of the leaves and leaves. In severe cases, the entire plant withered. The reason was potassium deficiency. Each acre can be topped with 7 to 10 kg of potassium chloride or 75 to 100 kg of plant ash. Straightening Brush,Hair Straightener Brush,Best Hair Straightening Brush,Hair Straightener Brush Price Shenzhen Jie Zhong Lian Investment Co., Ltd. , https://www.meizons.com