What are the symptoms of corn rough shrinkage disease? How to prevent and cure? What kind of medicine should I take?

Maize rough dwarf disease is a corn virus disease caused by maize rough dwarf virus, commonly known as "dwarf corn" and "slope", also known as "corn cancer". It is mainly transmitted by the virus-carrying gray planthopper in a persistent way. So what are the symptoms of corn rough dwarf disease? How to prevent and cure? What kind of medicine should I take?

Maize rough dwarf disease is the main disease of maize seedling stage, seriously affect the growth of maize, reduce maize yield, generally can cause 20% to 30% yield reduction, serious up to more than 60%, or even no harvest.

It is expected that corn rough dwarf disease will attack this year. Are you ready for prevention and control in advance?

What are the symptoms of rough shrinking disease corn?

The main results are as follows: 1. The growth of diseased plants is inhibited, but the average height is only a few tens of centimeters, the internodes are swollen and shortened, and the plants are seriously dwarfed.

2. The root system of diseased plant is less and short, which is less than half of that of healthy plant, so it is easy to pull up from the soil.

3. the diseased plant has long leaves without jointing, and the leaves are densely clustered, short and pointed.

4. The originally clear and smooth veins on the leaves will also become intermittent and disorganized. With the development of the disease, obvious strips will appear on the leaf back of the plant and the leaf veins on the leaf sheath.

5. The lightly diseased plant has poor development of male ear, less loose powder, short female ear, less filament and less fruit. The male ear of the seriously diseased plant can not be extracted, or although it can be extracted, it has few branches and no pollen, and the female ear is deformed and sterile or has few grains.

Incidence regularity of Maize rough Dwarf Disease

Maize rough dwarf disease is a maize virus disease caused by maize rough dwarf virus (MRDV). It is transmitted by gray planthopper in a persistent way. The nymph or adult of gray planthopper overwintered under the weeds and under the wheat seedlings in the field, which was the source of infection at the beginning of the next year.

The occurrence of maize rough dwarf disease largely depends on the number of gray planthopper in the field and the number of infected individuals. The disease of early sowing corn is more serious than that of late sowing corn, and the disease of corn with many weeds near the field, canal and roadside is also serious. the disease is also serious in wet and weedy corn close to vegetable fields, and there are some differences among different varieties.

Control measures of Maize rough Dwarf Disease

Agricultural prevention and control

1. Don't plant spring corn according to the situation.

In recent years, it is in the epidemic year of maize rough dwarf disease. If the farming system is reformed, spring corn is not planted, other crops are planted, and the transmission of the virus source is cut off, the disease can disappear as soon as possible.

2. Select disease-resistant varieties

This is the most economical and effective way to solve the harm of maize rough dwarf disease. Different maize varieties have different resistance to rough dwarf disease.

3. Adjust the sowing date of corn.

Avoid the peak period of transmission of gray planthopper. The corn sown in the first and middle of May coincided with the peak of gray planthopper transmission after emergence, and the corn was susceptible to disease at the 5-leaf stage, so the incidence was the highest.

Therefore, adjusting the sowing date can make the seedling stage avoid the peak period of virus transmission and reduce the degree of disease. The methods of early sowing in spring corn, early sowing with plastic film mulching and late sowing in summer corn should be carried out in accordance with local conditions, and the planting area in serious disease areas should be reduced as much as possible.

4. Remove weeds

Gramineae weeds in fields, fields and ditches are the intermediate hosts of gray planthopper transmission. Before maize emergence, clearing weeds on the edge of the field, roadside and ditch to reduce intermediate hosts can prevent gray planthopper from migrating to corn after emergence, thus reducing the source of toxin.

5. Strengthen field management

Corn seedling stage should strengthen field management, promote early seedling development, and find susceptible plants to be pulled out as soon as possible. At the same time, timely watering to prevent and cure the occurrence of virus disease aggravated by drought.

Chemical control

Chemical control should pay attention to four key periods, choose low-toxic and efficient pesticides, unified prevention and control, in order to achieve good results.

The main results are as follows: (1) the seed coating agent or corn seed dressing agent containing internal insecticides was used to treat the corn seeds in order to ward off the gray planthopper, and at the same time, it can also play a better role in the control of seed poisoning.

(2) in the early stage of wheat filling, it is a critical period to control the young nymphs of the first generation of gray planthopper. At this time, we should grasp the development trend of gray planthopper in time and concentrate on the unified use of drugs in the peak period of young nymphs. Spraying weeds in wheat fields, roadsides and ditches with internal absorption pesticides such as imidacloprid (10 g / mu) or buprofezin (50 g / mu), and paying attention to the use of sufficient water when spraying. Spray evenly to ensure the effect of insect control.

(3) at the mature stage of wheat, because the gray planthopper tends to be tender and green, at the end of May and the beginning of June, the adults of the first generation of gray planthopper migrated from the wheat field to the surrounding spring corn field and transferred to harm the spring corn seedlings. at this time, the corn seedlings with 3-5 leaves are in the sensitive period. Therefore, we must seize the opportunity, in the early stage of the migration of gray planthopper, in the corn field, use prolene (50 grams) or use imidacloprid (20-30 grams) and virus A (50 grams) mixed with water spray, once every 3-5 days, spray 3-4 times in a row, have a good preventive effect on the disease.

(4) 4.5% cypermethrin 20 ml can be selected or used in the initial stage of infection, and the disease can be effectively controlled by spraying after adding special liquid fertilizer for corn. The use of antiviral agents must highlight the word "early". After the 5-leaf stage of corn, its control and treatment effect is poor.