Seedlings and leaves of purple seedling seedlings changed from green to red and finally to purple. Symptoms began to appear at the 3rd leaf stage, prominent at the 4th to 5th leaf stage, and the symptoms were obvious. The roots were undeveloped, the stems were small, the growth was slow, the leaves changed from green to purple, and finally Withered. Purple seedlings produce mainly phosphorus deficiency in the soil, the ability of root absorption decreases, and the synthesis of chlorophyll is blocked, causing the leaves to turn green from purple to purple. After the third leaf stage, purple seedlings are prone to occur at low temperatures. Purple seedlings can cause corn empty stalks and baldness and affect yield. Reduce quality. Therefore, we must increase the application of phosphate fertilizer, improve ground moisture, general Mushi 40 ~ 50 kg of superphosphate and fermented organic fertilizer as the base fertilizer, control, once the emergence of purple seedlings, 0.2% potassium dihydrogen phosphate can be used for leaf spray Apply 2 to 3 times.
Red seedling corn grows slowly after emergence, leaves are small, roots are poor, leaf color becomes pale, and then turns red. In general, due to low temperature, the root absorption capacity is weakened, the metabolism of seedlings is slow, the chlorophyll is reduced, and the leaves are red. Therefore, mulching or seedling transplanting should be carried out.
Seedlings of young maize seedlings are pale green and yellow gradually, and they die when they are severe, which can easily cause empty stalks or baldness. It is due to the fact that the seeds are not full, the seedlings are not strong, the seeds sown are too deep, the seedlings are weak, and the soil is lack of fertilizer. Therefore, good varieties with a purity of more than 98% and a germination rate of more than 90% should be selected. Grains, granules, and diseased grains should be removed. Before sowing, screening, germination sowing, early seedlings, early seedlings, and reasonable fertilizers should be selected. Promote seedlings as soon as possible.
The stiff seedlings mainly occur before the 3-leaf stage, and the seedlings are not strong and young, and they have a long stiff bar, many black roots and weak seedlings, and they die when they die. Hard ground, excessive use of chemical fertilizers, soil drought after sowing and other reasons can all contribute to the formation of stiff seedlings. Therefore, at the time of prevention and control, the base fertilizer should be dominated by organic fertilizer, combining agricultural fertilizer, chemical fertilizer and trace fertilizer; combining nitrogen, phosphorus and potassium; basic fertilizer, seed fertilizer and topdressing fertilizer combined with reasonable irrigation, weeding, and disease prevention and extermination.
White seedlings usually start from 4 leaves. The leaf color at the base of the new leaf becomes pale and yellow-white. When 5 to 6 leaves are present, the leaves appear yellowish and light green and white stripes. The base shows purple stripes, and the leaves are thin and translucent white. The plants are dwarfed, the internodes are shortened, and the leaves are clustered. In severe cases, the leaves are dry, causing the plants to die and the particles not to be collected. Caused by this phenomenon is mainly due to soil zinc deficiency, can take the following measures to prevent and control: zinc fertilizer for seed fertilizer, zinc sulfate 1.5 ~ 2.0 kg per mu, can be mixed with urea, diammonium, ammonium nitrate, etc. for fertilizer, However, seed and fertilizer are separated to prevent burning seedlings; zinc fertilizer is used for seed dressing. 1 kg of zinc sulfate is mixed with 25 kg of corn seed by using 2 to 3 kg of warm water to dissolve 1 kg of zinc fertilizer. After the solution is completely dissolved, the zinc fertilizer solution is evened out. The seeds were sprayed on the corn, so that the seed surface was stained with zinc fertilizer, dried after sowing; leaf spray zinc fertilizer, 100 to 150 grams of zinc sulfate was dissolved in 50 kg of water, dubbed a concentration of 0.2% to 0.3% zinc sulfate solution Spraying maize at the seedling stage or during the draw period, it is appropriate to spray 10 kg per acre.

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