Zinc fertilizer is an important fertilizer required by many crops. What are the symptoms of crop zinc deficiency? What are the effects of zinc fertilizer on plants?
Zinc deficiency symptoms in crops
Zinc deficiency symptoms of crops mainly occur in the early stage of growth, which are mainly manifested as short internodes, short plants, smaller and deformed leaves, and chlorosis or white streaks, forming leaf clusters. However, the symptoms of zinc deficiency in different crops are different.
1. Zinc deficiency in rice
Symptoms usually appear 2 to 4 weeks after transplanting. First, the middle ribs of the new leaves become chlorosis and white, and then a large number of brown spots and streaks appear on the middle and lower leaves from top to bottom and from the inside to the outside; with the development of zinc deficiency symptoms, the lower leaves are draped, brittle, and easily broken, and the tip of the leaf Withered and cracked, the new leaves are short, the upper and lower leaf occiputs are juxtaposed, the leaf sheaths are overlapped, the tillers are small and few, the plants are short, the internodes are shortened, and the roots are thin and red-brown. 2. Corn lacks zinc
Symptoms first appear in the seedling stage. The newly unearthed corn seedlings appear white. When the seedlings have 4 to 5 leaves, yellow-white stripes parallel to the veins will appear between the leaf veins; as the symptoms of zinc deficiency develop, some leaves It splits along the stripes, the leaf margins are scorched, new roots are few, the root system turns brown, the plants are short, the ears are short, and the ears are short and lack of seeds.
3. Wheat zinc deficiency
Symptoms first appear in the seedling stage. Seedling leaves appear abnormally gray-green, with chlorosis between the veins, light gray spots appear on the surface of the leaves, leaf tips and leaf edges are yellowed, and the plants are short.
4. Zinc deficiency in fruit trees
When citrus, grape, peach, pear, apricot, cherry, bayberry, apple and other fruit trees are deficient in zinc, the branches are shortened between nodes, the branches are rosette-shaped, and the leaves become smaller and clustered at the ends of the branches. When the symptoms are severe, the new branches die gradually from top to bottom, and sometimes the leaves fall off prematurely to form withered top branches, and the fruits produced are smaller.
5. Some vegetables lack zinc
When the tomato is zinc-deficient, the plant grows weak, the leaves are twisted, and the macula appears on the surface, and then the macula gradually expands, the whole plant turns yellow, the branches and leaves droop and scorch, and the fruit is smaller. When cucumber is zinc-deficient, the plant grows poorly, the edges of the old leaves turn yellow and zoom, and gradually expand in an irregular shape. Small yellow spots appear on the surface of the leaves, and the fruit is short and thick, and the peel forms wide green and narrow white stripes. The stripes are lighter green. When eggplant lacks zinc, the plant grows short, the top leaves are slender, the two sides of the leaves are rolled up, and the lower leaves are chlorosis or even completely.
The effect of zinc fertilizer on plants
Zinc fertilizer is a material with a specified amount of zinc to provide plant nutrients for its main functions. Commonly used zinc fertilizers are zinc plus selenium, zinc sulfate heptahydrate and zinc sulfate monohydrate. Basic zinc sulfate, zinc chloride, zinc oxide, zinc sulfide, zinc phosphate, basic zinc carbonate, zinc glass body, lignin zinc carbonate, zinc naphthenate emulsion and chelated zinc (Na2ZnEDTA zinc treasure) can be used as zinc fat. The latter three are organic zinc fertilizers, which are easily soluble in water.
Zinc fertilizer can be applied as base application, topdressing, seed soaking, seed dressing, spraying. Generally speaking, it can be used for foliar fertilizer spraying. Zinc fertilizer is applied to crops that are over-sensitive to zinc, such as corn, rice, peanuts, soybeans, sugar beets, kidney beans, fruit trees, tomatoes, etc. The effect of applying zinc fertilizer is better. Apply to zinc-deficient soil: It is better to apply zinc fertilizer on zinc-deficient soil, and it is not necessary to apply zinc fertilizer on zinc-deficient soil.
If the plants show symptoms of zinc deficiency in early spring, it may be due to low temperature in early spring, weak microbial activity, incomplete dissolution of fertilizer, weak root activity of seedlings, and poor absorption capacity; phosphorus? The antagonistic effect of zinc, soil environmental impact may be zinc deficiency. But when the temperature rose in the later stage, this symptom disappeared. Make base fertilizer every other year: Zinc fertilizer is used as base fertilizer for a hectare of about 20 or 25 kilograms of zinc sulfate. It should be applied evenly and applied every other year. Because zinc fertilizer has a long residual effect in the soil, it is not necessary to apply it every year.