How is corn yellow leaf disease to return a responsibility? What elements are missing in albino and purple seedlings? How to prevent and cure?

In the process of corn growth, maize seedling leaves will change, which is mostly caused by the lack of elements necessary for corn growth in the soil. What about the corn yellow leaf disease? There are albino seedlings, purple seedlings is the lack of what elements? How to prevent and cure it?

How is corn yellow leaf disease to return a responsibility?

Corn is a zinc-sensitive crop, zinc deficiency will lead to albino seedlings, seemingly yellow corn seedlings. It is better to apply zinc fertilizer based on basic fertilizer.

1. Element deficiency

Zinc deficiency was found during the growth period, resulting in the symptoms of not growing tall and having small leaves. Can be sprayed with Demer leaf corn foliar fertilizer or sugar alcohol chelate zinc, efficient, safe and rapid zinc supplement.

2. Sowing too deep

If sowing is too shallow, it is not easy to emerge seedlings, but if it is too deep, the seedlings will be weak and yellow, and the sowing depth should be controlled at 3-5 cm; while sowing, applying a certain amount of seed fertilizer can promote the growth of seedlings, such as applying 3 kg of diammonium phosphate per mu during sowing, which can effectively prevent the yellowing of corn at seedling stage.

3. Seedling intercropping and seedling setting are not timely.

After emergence, maize seedlings should be fixed at 3-4 leaves and 6-7 leaves, so as to avoid seedling crowding, compete for fertilizer, water and glory, and form weak seedlings, diseased seedlings and yellow seedlings, and the number of seedlings per mu should be flexibly controlled according to different varieties.

4. Insufficient watering

Maize was not watered enough before or after sowing, and the seeds could not get enough water, which affected normal germination and emergence of seedlings, resulting in weak seedlings and yellowing at seedling stage.

5. Disease

If the seedling stage encounters long-term low temperature, overcast and rainy weather, it will cause the occurrence and epidemic of maize seedling blight. Most of the seedling blight began to occur in the second and third leaf stage, the leaves of the diseased seedlings yellowed and withered, the edges of the diseased seedlings were scorched, and the leaves gradually yellowed and withered from the bottom up; the root hairs were less, and the roots became brown and developed poorly, resulting in weak yellow seedlings.

6. Waterlogged seedlings

The seedling stage of corn often coincides with the rainy season, poor drainage in low-lying plots or stagnant water at the rolling place during wheat harvest, resulting in yellow seedlings.

7. Herbicide harm

Improper use of herbicides, arbitrarily increasing the amount of herbicides, blindly mixed with other pesticides, high concentration of herbicides, interuse of sprayers, and the effects of fake and shoddy herbicides on later cropping will lead to corn yellow seedlings.

8. Insect pests

The main pests in maize seedling stage were cotton bollworm, golden needle worm, aphid, armyworm, thrips, Swedish pole fly, ground tiger, sunflower pink scale and so on. The nymphs and female adults concentrated in the base, root and leaf sheath of maize seedlings and absorbed juice, which caused the damaged corn leaf sheath to become yellow and dry at first.

Prevention and control measures: first, select good varieties before sowing, pick out blighted grains, mildew grains, bad grains, and small seeds to ensure that the purity and purity of seeds are more than 98%, and the germination rate is more than 90%. The second is to accelerate germination and sow seeds, using seed coating or soaking seeds with fertilizer and water. The third is suitable time seedling, remove small seedling, weak seedling, diseased seedling and field weed when corn has 3-4 leaves. Fourth, the seedlings should be supplemented with nitrogen fertilizer to promote the early growth and rapid development of seedlings. Fifth, if there are dry clods before and after emergence, the dry clods should be broken in time.

What happened to corn albino seedlings?

Generally from the 4-leaf stage, the leaf color at the base of the new leaf becomes light yellowish white, 5-6 leaf stage, 1-3 leaves under the heart leaf appears light yellow and light green stripes, but the vein is still green, the base appears purple stripes, after 10-15 days, the purple gradually becomes yellowish white, the mesophyll becomes thinner, showing a "white seedling", and in severe cases, the whole field is white. The zinc-deficient corn plant is short, the internodes are short, the leaf pillows overlap, the heart leaves grow slowly and look flat-topped, and the serious white leaves gradually dry up, even the whole plant dies.

Cause: zinc deficiency in soil.

Prevention and control measures:

1. Zinc fertilizer is used as seed fertilizer. 1.5-2kg zinc sulfate per mu and 15-20kg fine soil are mixed evenly and sprinkled next to the seeds when sowing corn.

2, zinc fertilizer dressing seeds, 1 kg zinc sulfate mixed with 25 kg corn seeds, the method is to use 2-3 kg warm water, dissolve 1 kg zinc fertilizer, after all dissolved, the zinc fertilizer solution is evenly sprayed on the corn seeds, so that the seed surface stained with zinc fertilizer, dry after sowing.

3. Spraying zinc fertilizer on the leaves, spraying zinc glycol chelate zinc on the seedlings with zinc deficiency, spraying once every 7 days, generally spraying 2-3 times can make the seedlings return to normal.

What happened to the purple corn seedlings?

The seedling leaf and leaf sheath changed from green to red, and finally showed purple. The symptoms generally appeared in the 3-leaf stage of maize, and the most obvious in the 4-5 leaves. The root system was underdeveloped, the stem was small, the growth was slow, the leaves changed from green to purple, and the leaves withered in severe cases.

Cause of occurrence:

Because of the lack of phosphorus in the soil, the absorption capacity of roots decreased and the synthesis of chlorophyll was blocked, resulting in the change of leaves from green to purple. After the emergence of maize seedlings, if encountered with low temperature, it will often make maize leaves turn red or purple, but with the increase of temperature, the phenomenon of red seedlings will gradually alleviate and disappear in the later stage.

In addition, red seedlings can be caused by low-lying water in the field, harm by underground pests, heavy soil, too deep or shallow sowing, burning seedlings caused by improper fertilization and poisoning caused by improper chemical treatment.

Prevention and control measures:

Increase the application of phosphate fertilizer as base fertilizer, generally apply 40-50 kg calcium superphosphate and mature fermented organic fertilizer as base fertilizer. Once purple seedlings appear, 0.2% potassium dihydrogen phosphate can be sprayed on the leaves for 2-3 times; leveling the land and digging drainage ditches, so that the rain stops dry and the fields do not accumulate water.

What happened to the yellow and green seedlings of corn?

The leaves of maize seedlings are thin and narrow, the plant type is short, the leaves appear yellow and green stripes, and in severe cases, the leaves are dark brown, and finally scorch and die. The symptoms start from the lower leaves and gradually transfer to the upper leaves, which affects the yield greatly and is prone to lodging.

Cause: potassium deficiency in soil.

Prevention and control measures: increase the application of potassium fertilizer, without potash fertilizer can be applied in the seedling stage of plant ash, potassium deficiency is serious, in the 3-leaf stage with potassium dihydrogen phosphate or plant ash leaching solution foliar spraying, the effect is immediate, the yield is obvious.

What happened to corn seedlings with stiff leaves?

It mainly occurred before the 3-leaf stage of seedlings, showing small seedlings, light green leaves, increased black root and soft cotton atrophy. After transplanting, except the new leaves are green, the outer leaves are yellow and stiff, the stress resistance is poor, and dead leaves and seedlings are easy to appear.

Causes: the soil is too hard; the proportion of chemical fertilizer is too large, which leads to root burning and sprouting, and the soil is too dry after sowing.

Prevention and control measures: reasonably adjust the conditions of fertilizer, water and gas. The mature organic fertilizer was mainly used in the seedling stage, and urea was not or rarely used as the base fertilizer. Phosphate fertilizer should be applied after retting. The soil is suitable for humidity, and strong seedlings are transplanted. Rigid seedlings have emerged to strengthen fertilizer and water management, promote their recovery as soon as possible, and seriously replenish seedlings in time.