Cereals are perhaps the most common crop. In order to get large yields of such plants, of course, like any other, you need to take care of them. When growing cereals, much attention is paid to the prevention of various kinds of fungal diseases. Infection with such infections significantly reduces productivity, and therefore, causes huge losses to agricultural enterprises. Most often, cereals are infected with smut. This fungal disease can in some cases destroy the entire crop of wheat, rye, or, for example, corn.
What causes
Actually, mushrooms are called an extensive group of organisms, numbering more than 100 thousand species. In the system of the organic world, they, like animals or plants, form a separate unit. Apart from this, parasites stand in it. Smut varieties of the fungus are included in this category.
These parasites belong to the group of basidiomycetes. To date, scientists know about 1000 of their species. For order, they are all combined into 40 genera. Smut fungi are widespread almost throughout the Earth. These parasites are found in the steppes, forests, deserts and even in the ice of the Arctic.
Cereals most often infect smut fungi Basidiomycetes (Ustilaginales order). In the development cycle, this parasitic organism has mycelium, spores, idiospores and gems.
Smut is a disease that is easy to determine
It is not difficult to distinguish cereal infected with this type of fungus from healthy. The ear of such a plant acquires an absolutely black, coal color. From here, in fact, the name of the disease went. Grains smut fungi often eat completely. Instead, in the end, only black spores of the parasite remain in the ear.
How does cereal infection with smut fungi
Diseases caused by Basidiomycetes for researchers have long remained a real mystery. Scientists explained the blackening of the ear at first as a metabolic disorder inside the plants. Later, it was also suggested that such changes appear as a result of the life of any insects or ciliates.
The spores of smut fungi in blackened plants were found by researchers only at the end of the 19th century. Since then, the fight against this cereal disease has, of course, become easier.
Crop infection occurs with smut most often during harvesting. The spores of the parasite stick to the grains and can be stored with them on elevators until the seed. For a long time, they can also be in the soil itself, perfectly tolerating adverse weather conditions.
The spores of this parasite do not need a rest period. They sprout immediately after environmental conditions change to suitable ones - air temperature and soil moisture increase. The mycelium can begin to develop from spores in the fall or next spring.
During sowing spores fall into the ground also with grains. The mycelium at the initial stage, the parasite forms not too large. But in the future, the developing mycelium infects the sprouts of cereal crops that emerged from the grain. Then the mycelium gradually spreads inside the stem of an ear of wheat, rye, etc., as the plants grow. Around the time of flowering crops, it reaches the panicle. Immediately after this, the mycelium significantly accelerates its development. As a result, the spike begins to gradually blacken, and grains - replaced by spores of the parasite.
How mycelium develops
Smut - this disease is not only common, but also difficult to treat. A feature of the fungi Basidiomycetes is a very strong and viable mycelium. It usually extends over the affected tissue between cells, but sometimes it can penetrate through the cells.
Before decay into spores, the mycelium Basidiomycetes begins to branch very strongly. At the same time, her hyphae are divided by additional transverse partitions. After some time, the membranes of the mycelial cells mucilage, and then are replaced by denser ones. Next, the cells are laced from the main branch of the mycelium. Such isolated areas are called smut spores. On the ear, they form a clearly visible black mass (sometimes dense, sometimes dusty).
The whole plant of the mycelium of this species of fungi usually does not penetrate. Depending on the specific type of pathogen, it can be seen, for example, in the ovaries of cultures, in the stem, in parts of the ear.
What types of smut exist
So, how the infection of crops occurs with smut fungi and how this parasite develops, we found out. Basidiomycetes can affect all types of cereals, as well as corn. Depending on the place of the main concentration of the mycelium and on the signs, the following types of smut are distinguished:
stem;
bubbly;
solid;
dusty;
dwarf.
By the nature of the manifestation in cereals , smut is divided into solid and dust. In the first case, only the grains themselves are affected in the plant. Their shells are almost completely preserved. In them, as in bags, are the spores of the fungus.
When infected with smut smut, the plant is destroyed almost completely. The spores of the fungus do not linger on the ear. Gusts of wind very quickly spread them throughout the field.
What harm does the mushroom do?
As already mentioned, smut is an illness that, under certain circumstances, can destroy the entire crop. Inflict parasite fungi of this variety on plants and indirect harm. Ears infected with mycelium poorly develop, become weak, cannot resist all kinds of infections. At the same time, among other things, their winter hardiness and drought resistance are also significantly reduced. Many diseased smut plants do not even have time to gouge out by the harvest. In particular, smut causes severe damage to winter crops .
Flour from wheat, rye, etc., infected with smut, turns out to be of poor quality. At the manufacturing stage, infected grains have to be additionally sieved from fungal spores. However, bakery products from such flour are still tasteless. Products, unfortunately, acquire a characteristic smut flavor.
How to fight
To prevent smut crops, you should:
You should also try to grow in the fields only resistant varieties of cereals. Many breeders have been bred. For example, smut smut rarely develops on such varieties as Kinelskoe 92, Kharkov 86, Saratov 3, etc.
Dressing is usually carried out by keeping the planting material in warm water (about 47 ° C) for 3 hours. Also, smut spores can be killed with special preparations, for example, Vitavax.
As already mentioned, the infection of cereals with this disease can also occur directly through the ground. In addition to the alternation of agricultural plant species, measures such as peeling in the spring should be taken.
What damage can a summer resident cause?
Fungal diseases of cereals are actually very dangerous. However , of course, they rarely grow grain in the cadastre of suburban plots in their gardens. But in the garden, smut can cause quite noticeable harm. Very often it is encountered, for example, by summer residents who grow corn. This popular culture is usually infected with a bubbly smut. In this case, the fungus affects not only panicles and cobs, but also other parts of the plant. The parasite usually develops on young, not yet roughened corn tissue. Crop losses during infection of the cobs on average reach 50%.
In order to protect plants, in the garden, as well as on the fields of agricultural enterprises, you should first of all adhere to the rules of crop rotation. If this condition is met, the summer resident, most likely, will not have to face such a problem as blistering smut of corn.
Also, to reduce the risk of crop loss due to the fungus, it is worth using seed only of smut resistant varieties and etch it before planting with Triticonazole. The corn bushes themselves need to be treated with a fungicide from time to time for prevention. In autumn, all plant debris should be collected from the beds and burned. At the same time, the earth itself on the site must be dug up to the shovel bayonet.