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Soybean diseases and pests: scoop, spider mite and measures to combat them with photo

Soybean diseases and pests: scoop, spider mite and measures to combat them with photo
Anonim

Soya is one of the most popular crops. In recent years, it has been especially in demand in the food industry. The plant gives good yields with proper care. However, there are a number of problems associated with growing this crop that you need to be aware of. There are many diseases and pests of soybeans. They are found everywhere in the areas of growth of this plant. The following will be discussed about the most famous.

Soybean diseases

Diseases can kill a plant both at the stage of seedling growth and during the formation of beans. They can greatly reduce yields or completely destroy all crops.

Fusariosis

This is an imperfect fungus disease that is ubiquitous in soybean growing areas. The disease affects both seedlings and adult plants.

A clear sign of the presence of Fusarium in seedlings is uneven thickening and deformation of the stems.

The cotyledons are covered with brown ulcers. They may have a pinkish tinge if excessive moisture is present.

When flowering, the disease can cause drying, falling, twisting and yellowing of the leaves.

Before the ripening period, due to Fusarium, the fruit leaves become discolored, covered with an orange bloom when there is high humidity.

Cercospora

Disease spread everywhere. In a plant with cercosporosis, all parts above the ground are affected.

There are two varieties of the manifestation of the disease: spots that have an ashy hue, or dark brown. A dark gray coating appears on the leaves. On beans, stem and seeds, it does not form. Soybean varieties resistant to cercosporosis do not exist. Reduces yield by 2-3 times.

Peronosporosis

Peronosporosis, or downy mildew, is very common, but the most harmful effect is observed in areas with high humidity. It can manifest itself in two forms: with general oppression or with leaf spot.

In the first variant, spots appear on the leaves and cotyledons. They cover the entire plate or its base.

The second type is observed during the formation of fruits. Pale green spots appear on the leaves at this moment, eventually acquiring a brown tint. Diseased leaves fall off.

Powdery mildew

This disease is most common in areas with a warm and humid climate. The nature of its manifestation is the appearance on the leaves, stem and pods of a cobweb plaque with a white tint.

Distributed everywhere, with excessively rapid development, the yield may drop by 10-15%.

Rusty spotting

The causative agent of the disease is the fungus Septoria glycines. Another name for the disease is septoria.

It is characterized by the appearance of red-brown spots, with a huge number of pycnidia, on the cotyledons. The spots on the beans are much smaller than on the leaves. On the stem, the shape of the spots is longer, they have a brown-brown color.

High humidity and hot weather can trigger the rapid development of the disease. Most active in August after July showers. Causes the death of leaves, thereby greatly reducing the yield of soybeans.

Pink mold

When grains, beans, leaves, and sometimes stems are infected, white and then pink pads develop.

The disease is especially active during soybean ripening and in a humid environment.

Affects a large number of plants, sometimes found on the remains of rotting plants. Pink mold can also attack beans and seeds.

Rust

Distribution in almost all areas of cultivation, in temperate and warm climates. With severe damage and high disease activity, the yield drops dramatically.

Ascochitosis

The disease affects all parts of the plant that are above the ground. The sign is brown or gray spots on the cotyledons and leaves. Seeds with this disease have very low germination. And yields at high humidity can drop by 15-20% or more.

Soybean pests

Soybean pests are no less dangerous than diseases. There are many known insects capable of destroying plants.

Sprout fly

Insect that is the larva of a fly. Its size is about 4-5 mm. Usually underground, it destroys seeds, which reduces seedlings by 20% or more. Later, it attacks the cotyledons and stems, which can lead to the withering of the plant

Soy leaf beetle

The bug is about 5-6 mm in size. The insect is especially dangerous for a young plant. The larvae attack the stems and cotyledons, and the adults gnaw holes in the leaves. Soybeans that are planted near the forest are more harmful.

Soybean black-banded flea

Small insect 3mm in size. Attacks cotyledons and stems of seedlings. For adult plants during this period is not dangerous. And in the summer, it already destroys the seeds of an adult crop.

How to deal with pests and diseases?

For the effective destruction of harmful insects and various diseases in soybeans, you should know about the basic measures to combat them.

Pre-treatment of seeds with insecticides provides reliable protection. It is also effective to control insects in the initial stages, when they have not yet reached their maximum size. The most effective are the following drugs:

  • Lepidocide;
  • Entobacterin;
  • Gomelin;
  • Bitoxybacellin.

A solution of 1% Bordeaux mixture is sprayed for the first time on the beans when they are formed, and the next treatment should be carried out after 10 days.

Ground sulfur is applied to seedlings to prevent powdery mildew and rust.

The importance is the preliminary preparation of seeds for sowing: they must be collected from he althy areas and carefully sorted. This will be the key to a good harvest.

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