The flowering period of soybean is an important period for obtaining yield. What are the common pests and diseases and their control methods at this time?

The flowering period of soybean is an important period for obtaining yield. What are the common pests and diseases and their control methods at this time? The flowering period of soybean is an important period for obtaining yield. After the soybean blooms, the fragrant flowers attract moths to suck nectar, among which there are many pests. While sucking nectar, such an environment is used as a high-quality breeding place. Therefore, the flowering and pod setting period of soybean is the key period to control pests and diseases. There are many reasons why spraying pesticides can play a good role in preventing and controlling pests and diseases. First of all, we should know which pests and diseases are easy to occur during the flowering and pod setting period of soybean.

Common diseases and insect pests in soybean flowering and pod-setting period generally include soybean moth, blind stinkbug, soybean leaf roller moth, soybean prodenia litura, snail and so on. Downy mildew is the most common disease, because the flowering and pod setting period of soybean is in the rainy season with high temperature and high humidity. So, what are the common pests and diseases in soybean flowering period and their control methods?

1 soybean leaf roller and its control method are COLEOPTERA pests. Soybean leaf roller is widely distributed in China, reaching Taiwan Province Province in the south, Inner Mongolia in the north, Shandong and Henan in the east and Sichuan in the west. It is one of the key pests of Orchidaceae. Soybean leaf roller moth is also called soybean leaf roller moth, soybean leaf roller moth, soybean leaf roller moth and so on.

With the appearance of warm winter weather, the total number of soybean leaf roller increased in winter, which caused great harm to soybean in main producing areas. Soybean leaf roller mainly occurs in the flowering and pod setting period of soybean. The larvae of soybean leaf roller stacked soybean leaves and spun silk into a tube, which seriously harmed the photosynthesis of soybean leaves. The larvae cultured in the early stage will continue to immediately harm the flower bones and young pods.

In the southern end of the Yellow River and the vast areas north of the Yangtze River, most of them have 2~3 generations a year, and in the warm and humid natural environment in the south, they usually have 4~5 generations. It was observed that soybean leaf roller tended to grow vigorously and planted relatively late soybean fields.

Soybean moth mainly harms soybean pods, which is very similar to soybean moth. After the pod was damaged by soybean borer and soybean leaf roller larva, the hole edge left on the pea was polluted by feces, which led to rot.

Control method of soybean leaf roller: agricultural control, nymphae of soybean leaf roller has phototropism, and the time range of nymphae can be found in the field. Using assembled black light to lure nymphs to prey can reduce the production of late larvae, and assembled black light should be widely used on a large scale. If the application area is relatively small, the relativity of pests produced in the fields around the black light will increase significantly.

Drug control: in the incubation period of soybean leaf roller larvae, 500 times of Bacillus thuringiensis and 25% beta-cypermethrin 1500 times of Bacillus thuringiensis were sprayed immediately. If the total number of pests is large, the concentration of Bacillus thuringiensis can be adjusted to 300 times, once every five days and sprayed twice continuously. At the same time, this kind of mixed pesticide can control nymphs of red-eye pests such as soybean moth and Spodoptera litura.

2 Soybean downy mildew and its prevention and control methods, especially in ultra-low temperature and humid local areas, will appear soybean downy mildew, harm soybean leaves, lead to the loss of photosynthesis, soybean leaves fall off early, and seriously limit the yield by more than 50%. Soybean downy mildew can occur from soybean seedling stage to purchase stage, and the sooner it occurs, the more serious it becomes, especially in Northeast China.

Soybean downy mildew was the first to get sick, and the lesion appeared on the reverse side of the leaf, which was not obviously soaked, then spread rapidly, and then the leaf turned green and yellow, and generally there was a gray mold layer on the reverse side. Downy mildew can also harm peas, and pathogens will spread with the wind and rain.

The key to prevent soybean downy mildew is to nip in the bud. In addition to selecting soybean varieties with strong disease resistance, measures such as crop rotation and seed dressing with aseptic coating agent can be taken to prevent and control soybean downy mildew in advance during the growth period, including spraying 300 times glyphosate aqueous solution +800 times mancozeb aqueous solution +2 1 16 days, which can obviously improve the prevalence rate of soybean downy mildew.

3 Oncomelania hupensis and its prevention and control methods Oncomelania hupensis is easy to occur in high temperature and high humidity areas. Snails belong to mollusks, and ordinary pesticides are difficult to work. Snails can hurt the young leaves and pods of soybeans. In the early stage of snail discovery in the field, spraying 0.5~ 1 kg tetraacetaldehyde molluscicide once every 15 days and twice in a row can control snails well.