In the course of growth and development, such as the absence of trace elements will show a variety of corresponding symptoms, identify the lack of corn disease and the scientific application of trace fertilizer to remedy, is an important technology in corn cultivation. The chlorosis of the young leaves at the seedling stage of zinc deficiency is pale yellow and produces white seedlings. The middle leaves have obvious green color lines and the old leaves at the base are gray-brown. In this case, 1.5-2.0 kilograms of zinc sulphate may be applied to the leaves or 0.2-0.3% zinc sulphate solution may be sprayed on the leaves, which may be sprayed three times at intervals of 5-6 days. The old leaf of molybdenum lacked green and yellowed between the veins, the margin of leaf margin curled inwards, and the grains shrank. At this point, 0.15%-0.2% ammonium molybdate solution can be used for foliar spray. The leaf veins of young iron deficiency were chlorotic and chlorotic. The veins remained green and showed obvious stripes. The stems and leaf sheaths were purple-red. At this time, 0.2-0.3% ferrous sulfate solution was sprayed on the leaves and sprayed three times at intervals of 5-7 days. Boron-deficient young leaves do not bloom and turn white, gradually wither and die. Old leaves have white stripes between the veins, and the plants are short and thin. At this point, 85 grams of borax or 60-60 grams of boric acid can be used for foliar spraying, and can be sprayed 3 times, each time between 5 and 7 days. Symptoms of deficiency of manganese often begin with new leaves, young leaves turn yellow, there are green spots between the veins, the leaves are soft and the roots are slender and white. At this point the 0.2% manganese sulfate solution can be used for spraying 2-3 times, each time interval 7-10 days. The copper-deficient plants grew slowly and were short, and after forging and dying, they formed clumps, and the leaves were gray-yellow or red-yellow with white spots. The development of the ear was poor. Can be followed by 1 kg of copper sulfate or 0.2% copper sulfate solution for foliar spray. Portable 3 Ply Disposable Masks Non-woven Face Mask With Elastic Earloops Disposable Surgical Face Mask Dongguan Anmeixuan Electronic Technology Co., Ltd , https://www.hyashine.com