1, seed dressing control corn underground pests The main threat to corn seedlings comes from underground pests and armyworms. Whether it is spring corn or summer corn, soil pests such as cockroaches, cockroaches, and wireworms are often present in the soil at the time of sowing. After sowing the corn, the underground pests will steal the seeds. When the corn germinates, it will bite the roots and underground stems, resulting in incomplete emergence, seedling wilt, and the seedlings will not be guaranteed. Therefore, the use of coated corn seeds can prevent and control the above-mentioned underground pests in the areas where earthworms, cockroaches, and needles occur. When corn seeds are not coated, seed dressing before sowing is a key measure to ensure seedling integrity. The corn seed dressing can use the following agents: 50% phoxim EC and 40% methylisophos-methyl EC, all of which are seeded at a seed weight of 0.1%. 50% methamidophos EC is seeded at 0.5% of seed weight. When seed dressing, the insecticide is diluted with water by 50-100 times. Then use the sprayer to spray the liquid while stirring the corn seed, and mix well and then boring for 3-4 hours. Slightly dry it and sow. 2. Prevention and control of tigers 2.1 Ground Tiger Symptoms Ground tigers are also a type of underground pests. Their larvae are commonly called silkworms and silkworms, while northern tigers and yellow tigers are common in the north. (1) Small tiger: Before and after the spring corn was sown, it was the time when the young tigers searched for their eggs. In addition to corn, the hosts of small tigers include weeds such as small bindweed, leeks, grey vegetables, and spiny vegetables. Before the spring corn was sown, these weeds in the field became a breeding ground for small tigers. The small tigers laid eggs on these weeds. The pre-emergence young larvae of spring corn are fed first in the heart and weeds of the weeds. When corn emerges and then it is transferred to the heart and leaves of corn, the corn leaves appear many small translucent spots. In the stage of small larvae, they can be seen both in weeds and in corn during the day. When the little larvae grow up, they move from the ground to the ground. In the soil around these wilting plants that appear in the field, we can certainly find hidden larvae. These larger larvae hide here during the day and come out to feed at night, snapping off the base of the stem, causing a lack of seedlings in the field. Small tigers have a tendency to turn seedlings, which means that when the damaged corn seedlings die, it is transferred to other corn seedlings to continue the damage. (2) Yellow tigers: Yellow tigers appear about one month later than the small tigers, and their damage characteristics are different. The yellow tigers bite on the young leaves and bite through the heart during the small larvae stage. After the victim leaves are unfolded, these small rows of holes are left. These dead seedlings in the field are the typical symptoms of the old yellow tiger. When the larvae grow up, they bite a hole from the base of the seedlings of the maize seedlings, drill into the stems, and feed on the inside of the stems, resulting in hollows, and the heart leaves die first. Yellow tigers also have the habit of turning seedlings. Not only is spring corn, summer corn is also harmed by yellow tigers. 2.2 Prevention of the hazards of tigers (1) Before the broadcast In the spring corn field, deep plowing is required before sowing, eliminating weeds, reducing the amount of eggs laid by ground tigers, and killing newly hatched larvae; early weeding in summer corn fields is required. (2) Spreading poisonous soil, spraying powder and liquid medicine at the early stage of damage In the early stages of the damage caused by the tigers in the ground, poisonous soil, spraying powder and liquid medicine can be spread on the ground. Early detection and early prevention and control are the key to controlling the damage of the ground tiger. In the early stage of the damage to the ground tiger, whether it is yellow tigers or small tigers, not only small individuals, but also activities in the ground during the day and night, is a good time to use drugs. When the damage rate of heart and leaves of corn seedling reaches 5%, it can be controlled and sprayed in the field. It can spray 50% phoxim EC 1000-1500 times, 2.5% chlorinated EC 3000 times and so on. The spraying liquid is 50 kg per mu. Must be even, not only sprayed on corn, but also sprayed on weeds. You can also spread poisonous soil for prevention and treatment. Use 50% phoxim EC and 40% methylisotriphosin EC. The specific method is to add 0.5kg of water and 125-175kg of fine soil to each agent. In the evening, the poisonous soil is spread in the vicinity of the root of the seedlings, and 20 kg per mu, forming a width of about 6 cm, to prevent larvae from entering the soil. (3) Manual control When the yellow tiger larvae start stolons, or the young tiger larvae are buried underground in the daytime, the artificial control effect is good. The method is to look for emerging dead seedlings and wilt seedlings in the fields. Remove the soil around the wilt seedlings and excavate the older larvae of the young tigers. Find the older larvae of the yellow tiger in the hole at the base of the dead stem. Kill these larvae. 3, prevention and control of armyworm In addition to underground pests, summer corn is often attacked by armyworms. Mythimna separata, also known as shaving worms, five insects and so on. Mythimna separata can damage the seedlings at the seedling stage, and can also be used as a light-harvesting leaf in the later period. It is a kind of pest with very serious damage. Insect armyworms occur in the North China region for 3 generations a year, but they do not normally live in winter. Every spring in the second and third months of spring, the adult Mythimna adults spend the winter in the south, and they swarm in groups and move to the north. The first generation is less in number and is mainly harmful to winter wheat. There was a generation of adults before and after the harvest. Adult armyworm adults hide in grasshoppers, dwarf trees, barns, etc. during the day and come out at night. When night falls, when we watch the wheat fields, we will see a herd of adult armyworms flying in groups. The body of adult armyworm is light yellow or light brown, with two light yellow round spots on the forewings, a larger round spot on the outer side than the inner side, and a small black spot below it, with a dark slash on the forewings. Adults need to suck nectar to nourish the body and provide nutrients for gestation. Adult armyworm also has a strong phototaxis, so you can use black light to kill adults. In the evening, adults of the armyworm lay their eggs in the corn field, and most of the eggs are produced in the dead leaves of corn, on the corn seedlings being removed, and on the residues of wheat plants. After the harvest, the second generation of armyworm larvae occurs and begins to harm the summer corn seedlings. The third generation of larvae occurred in the middle of August and harmed the middle and late stages of corn. Most of the larvae that have just emerged from the egg hide in the heart and leaves, crawling when bowed, an arch movement forward, this is the identification characteristics of the larvae before the third instar. These small, translucent spots on the heart of summer corn are caused by the newly hatched larvae feeding the leaf, and larvae can be found on the victim's heart. The larvae that grow up grow peristalticly and do not feed on the leaves. Instead, they eat large chewing leaves and eat the corn. No traces of larvae have been found on such corn seedlings. The older larvae lurked in the soil near the affected seedlings in the daytime, about 1-2 cm deep, and the body curled into a ring. Only when night falls, do you fill out the hungry day. After the third instar, the size of the armyworm is very high, and it is very resistant to insecticides. Therefore, the key to controlling the armyworm is to apply it to the larvae before the soil is introduced. In order to do this, attention should be paid to observation, and field investigations should be strengthened to prevent and treat drugs when there are small translucent spots on the heart. The following pesticides can be used to control the seedlings of summer corn seedlings: 50% methamidophos EC 1000 times, 50% phoxim EC 1000-1500 times, and 80% dichlorvos 1000-1500 times, spraying 40 per mu. -50kg liquid; 25% Diflubenzuron No. 3 glue Suspension dissolves in 40-50kg water per mu 30-40g, Diflubenzuron can not kill the armyworm immediately, only effective after 2-3 days of application. The corn seed coated with the seed coating agent at the time of sowing also has a certain control effect on the armyworm. Sunflower Seeds 361,Wild Sunflower Seeds,Raw Taste Sunflower Seeds,Bigs Sunflower Seeds Inner Mongolia Hengxintonghui Supply Chain Management Services Co.,LTD , https://www.hxthfood.com