Typical Symptoms and Control Methods of Zinc Deficiency in Rice, Corn, Wheat, and Other Crops

Zinc supplementation in crops can increase crop yields and is an essential element for crop growth. Zinc is a growth element and participates in the metabolism of auxin.So what are the typical symptoms of zinc deficiency in crops such as rice, corn, and wheat? What are the control methods?

What are the typical symptoms of zinc deficiency in crops such as rice, corn, and wheat?

1. Rice: leaves lose green color and turn white, brown spots appear, plants become stunted, often called “stiff seedlings”, “stunted clumps”, “white seedling disease” and “stunted seedling disease”.

2. Corn: leaves lose green color and have brown spots, forming “mottled white seedlings”, and the ears have missing kernels and bare tips.

3. Wheat: white-green stripes or bands appear on both sides of the leaf veins, internodes are short, heading and flowering are delayed and uneven. In severe zinc deficiency, heading cannot occur, and the ears are small with light kernels.

4. Cotton: during the seedling stage, leaves lose green color, edges curl upward, stem elongation is inhibited, internodes shorten, plants appear clustered, the growth period is delayed, and yield is low.

5. Fruit trees: zinc deficiency can cause multiple symptoms. “Little leaf disease”, where new leaves become smaller and rosette-like clusters appear at the top; “small fruit disease”, where fruits are small with thick skin, woody flesh, more residue and less juice.

6. Vegetables: middle and upper leaves lose green color and turn yellow, young leaves are small, often called “little leaf disease”. Plants are short, internodes are shortened, clustered, fruits are small with thick skin, yield is low, and quality is poor.

What are the control methods for zinc deficiency in crops such as rice, corn, and wheat?

1. Rice: For each mu of zinc-deficient field, apply 10-20 loads of farmyard ash and manure plus 1500 grams of zinc sulfate heptahydrate or 2000 grams of boron-zinc-iron-magnesium fertilizer, and spray zinc-containing foliar fertilizer, such as 150 grams of boron-zinc-iron-magnesium fertilizer mixed with 60 kg of water and sprayed over the whole field; or 200 grams of Daodou Yiciqing; or 3 pills of Xiandan. Through plant fertilization and foliar spraying, rice plants will recover growth in about 4 days, the leaves will turn green, new heart leaves will grow, and white roots will increase.

2. Corn:

(1) Spray zinc fertilizer. Generally, the spraying concentration for fruit trees is 0.5%-1.0% zinc sulfate solution, while the spraying concentration for vegetables can be lower, using 0.1%-0.2% zinc sulfate solution, or liquid micro-fertilizer can also be sprayed.

(2) Drain accumulated water.

3. Wheat:

(1) Actively use formula fertilizer. By using Woli brand wheat formula fertilizer containing the trace element “zinc” essential for wheat growth and other nutrients, wheat will not develop physiological diseases, and it saves labor, trouble, and time, with a low price and good economic value.

(2) Promote balanced fertilization. That is, fertilize evenly according to soil fertility. First, do not apply a single chemical fertilizer alone for a long time; second, fertilize reasonably according to soil fertility and target yield; third, determine a reasonable ratio and method for split fertilization according to the characteristics of wheat during its growth period, and eliminate the bad habit of one-time heavy fertilization.

(3) Apply base fertilizer. Use 1~2 kg of zinc sulfate heptahydrate per mu, mix it with chemical fertilizer or sand and soil when preparing the land and apply it to the soil, generally once every 3~5 years.

(4) Seed soaking. Put the selected wheat seeds into a 0.05% zinc sulfate heptahydrate solution, soak for 12~24 hours, remove and dry before sowing.

(5) Spray foliar fertilizer. A 0.30%~0.40% zinc sulfate heptahydrate solution can be sprayed on the leaves, continuously 2~3 times, with an interval of 5~7 days, preferably mixed with amino acid and humic acid foliar fertilizer.

4. Cotton:

It is best to use 0.8~1.6 kg per mu of “Liugao Base Fertilizer King · Cotton High-Yield Long-Effect Formula” as base application before plowing or as topdressing at the seedling stage (note not to mix it with urea, and be careful to avoid using zinc fertilizer adulterated with magnesium sulfate); for foliar spraying, a 500-fold solution can be used, or half a packet, 25 grams, of “Blue Jingdian · Six-in-One Yield-Increasing Formula”, sprayed once each at the seedling stage and the squaring stage.

5. Fruit trees:

(1) Increase the application of organic fertilizer to improve the overall nutritional level of the trees. High-quality coarse fertilizer contains multiple nutrients. Humic acid during the decomposition of organic matter can improve the availability of soil zinc and at the same time reduce the adverse effects of harmful elements on diseased trees. Therefore, in northern orchards, 50,000 kg of organic fertilizer should be applied per hectare each year. Orchards with fewer organic fertilizer sources should adopt the method of alternate-year application, and should not reduce the amount applied per unit area at one time.

(2) According to the soil conditions of the tree species, reasonably configure the application ratio of nitrogen, phosphorus, and potassium. In orchards with more severe zinc deficiency, the application amount of phosphate fertilizer should be controlled.

(3) Rely on scientific research institutions and technology extension departments, adopt advanced technology, carry out plant leaf analysis and soil nutrient diagnosis, formulate reasonable fertilization plans, reduce blind fertilization, and improve orchard production efficiency.

(4) For orchards already deficient in zinc, the following methods are suitable for remediation:

a. Spray fertilizer. Generally, after spraying zinc sulfate, symptoms can improve quickly. Before germination, 50-100 times diluted zinc sulfate can be sprayed. During the growing season, in order to reduce the harm of zinc sulfate to the orchard, the concentration should be lowered to below 0.2%.

b. Soil fertilization. Base application and topdressing methods can be used. For base application, mix zinc sulfate evenly with decomposed organic fertilizer and apply it to the soil. For topdressing, mix zinc sulfate evenly with nitrogen fertilizer and apply it to the soil. The application amount is 25-40 kg of zinc sulfate per hectare (or 30-50 grams per tree).

c. Tree trunk infusion. Carry out infusion at the roots or trunk, and the concentration of zinc sulfate should preferably be below 0.1%.

d. Spray boron-zinc Bordeaux mixture. The specific method is, when preparing Bordeaux mixture, reduce the amount of copper sulfate by 30%-50% and replace it with the same amount of zinc sulfate, which can both prevent and control zinc deficiency and protect the tree body.

6. Vegetables:

On low-zinc soil, the amount of phosphate fertilizer should be strictly controlled, and on low-zinc soil, phosphate fertilizer and zinc fertilizer should be applied at the same time. For foliar spraying of zinc fertilizer, generally use 0.1%~0.5% zinc sulfate solution. When applying zinc sulfate to the soil, the amount per hectare is 15-30 kg.