Soybean is one of the most popular agricultural crops. In recent years, it has been especially in demand in the food industry. The plant produces 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 soybean. They are found everywhere in the areas where this plant grows. Next we will talk about the most famous ones.
Soybean diseases
Diseases can destroy the plant both at the seedling growth stage and during the formation of beans. They can greatly reduce yields or even destroy all crops.
Fusarium
This is a disease related to imperfect fungi, widespread in areas growing soybeans. 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.
During flowering, the disease can cause leaves to dry out, fall off, curl, and turn yellow.
Before the ripening period, due to fusarium blight, the fruit valves become discolored and become covered with an orange coating when there is high humidity.
Cercospora
The disease is widespread. In a plant with cercospora blight, all parts above the ground are affected.
There are two types of manifestation of the disease: spots that have an ashen tint, or dark brown spots. A dark gray coating appears on the leaves. It does not form on beans, stems and seeds. There are no soybean varieties resistant to cercospora blight. Reduces yield by 2-3 times.
Downy mildew
Downy mildew, or downy mildew, is very common, but the greatest harmful effect is observed in areas with high humidity. It can manifest itself in two forms: with general oppression or with leaf spotting.
In the first option, spots appear on the leaves and cotyledons. They cover the entire plate or its base.
The second type is observed during fruit formation.At this moment, spots of pale green color appear on the leaves, which over time acquire a brown tint. Leaves affected by the disease fall off.
Powdery mildew
This disease is most common in areas with warm and humid climates. The nature of its manifestation is the appearance of a cobwebby coating with a white tint on the leaves, stems and pods.
Distributed everywhere; if it develops too quickly, the yield can fall by 10-15%.
rust spot
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 and 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 leaf dieback, thereby greatly reducing soybean yield.
Pink mold
When infected, a coating of white and then pink pads appears on grains, beans, leaves and sometimes on stems.
The disease is especially active during soybean ripening and in humid environments.
It 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 where the crop is grown, in temperate and warm climates. With severe damage and high disease activity, the yield drops significantly.
Ascochyta blight
The disease affects all parts of the plant that are above the ground. Sign: brown or gray spots on cotyledons and leaves.Seeds with this disease have very low germination. And yields at high humidity can fall by 15-20% or more.
Soybean pests
Soybean pests pose no less danger than diseases. There are many known insects that can destroy plants.
Sprout fly
An insect that is a fly larva. 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 cause the plant to wilt
Soybean 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. Greater harm is caused to soybeans that are planted near the forest.
Soybean flea beetle
A small insect measuring 3 mm. Attacks cotyledons and stems of seedlings. It is not dangerous for adult plants during this period. And in the summer it already destroys the seeds of an adult crop.
How to deal with pests and diseases?
To effectively destroy harmful insects and various diseases in soybeans, you should know about the basic measures to combat them.
Reliable protection is provided by pre-treatment of seeds with insecticides. 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;
- Bitoxibacellin.
The beans are sprayed with a solution of 1% Bordeaux mixture for the first time when they are formed, and the next treatment should be carried out after 10 days.
Ground sulfur is used to treat seedlings to prevent the appearance of powdery mildew and rust.
The preliminary preparation of seeds for sowing is important: they must be collected from healthy areas and carefully sorted. This will be the key to a good harvest.
