Wheat smut: prevention and control measures
Wheat smut is a type of fungal disease that can lead to a deterioration in the quality of the crop as a whole or its individual part. This infection spreads through cereals. Known types of wheat diseases include the following types of smut:
- Indian;
- hard;
- dusty;
- dwarf;
- stem.
Each of the types of the disease has its own characteristics and applies to a particular cereal. Common types of fungal disease of wheat include hard and dusty smut.
hard smut
The causative agent of the disease is Tilletia caries. It is possible to determine the defeat of this disease if you notice the destruction of its inner part. From the outside, wheat remains unchanged.
The teliospore of hard smut can be introduced into the environment during harvesting or initial processing of grains. Thus, there is an infection of healthy grain, as well as soil.
This disease is dangerous for soft wheat varieties. The manifestation of the disease is usually observed during the milky ripeness of the cereal. The main signs of hard smut:
- spikelets are small in size and flattened;
- scales are characterized by extension;
- the grains are swollen and longer than those of a healthy cereal;
- wheat has a characteristic blue-green color;
- there is an unpleasant odor;
- instead of grain, a spore mass with a black color is found;
- the ear loses weight and does not drop when ripening.
dust smut
Head smut is caused by Ustilago tritici. At the time of a progressive disease on the plant, not only the inner part, but also the shell of the grain is affected. Most often, the infection affects spring and winter wheat.
The disease begins its cycle of development during the growing season of the plant, affecting its lower part. The infection is transmitted from an infected seed to a healthy one, with the help of wind.
The dust smut has the following characteristics:
- accelerated earing of the plant;
- the height of diseased wheat is greater than healthy;
- the ear has a scorched appearance;
- weak tillering of cereal is noticed;
- the infected grain has a thin gray shell.
Loose smut is considered a dangerous disease that can completely deprive the farmer of the entire crop. The disease develops rapidly if there is a low air and soil temperature in the territory, there is an autumn drought.
The plant will become infected faster if the timing for planting seeds is not met.
Infection and its causes
In some cases, infection with wheat smut can occur if the spores of the infection are in the soil. This way of transmission of the fungus is not very common. Usually infection of a healthy plant comes from a diseased plant. A fragile infected cereal breaks into pieces, spores come out of it, which, with the help of the wind, fall on another plant.
An increase in the risk of infection is observed in such situations:
- with a fairly deep immersion of the seeds during planting;
- during long autumn droughts;
- when wheat is planted incorrectly.
The best temperature for activating spores is considered to be plus two - plus five degrees Celsius.
If you plant spring wheat early or winter wheat too late, you can lose the crop completely, by creating a favorable environment for the development of the disease.
Preventive measures
In order to protect your crop from infection with smut wheat, you must follow the following rules:
- During sowing, use healthy material.
- Carry out timely dressing.
- Isolate seeds from the rest of the wheat, at least at a distance of a meter.
- Sow wheat within set time limits. Late or early sowing increases the risk of disease.
- Use for sowing a cereal variety that is resistant to this infection.
In order to prevent infection with wheat smut, it is necessary to use fungicides to dress the planting material.
For this purpose, TMTD and pentatiuram are most often used. It is necessary to carry out the procedure with those seeds that were collected from fields affected by the disease, even by 0.0001 percent. It is worth doing this work fifteen days before the moment of sowing. To eliminate the fungus in the planting material, you can use Raxil or Vitovax.
To suppress pathogens, experienced farmers use Seticor 050 (in the amount of 0.75-1.0 l / t), Devident Star 036 (in the amount of 1.0-1.25 l / t.). During the harvesting process, fungus spores may linger on inventory or containers. Therefore, every item used needs to be disinfected. For this, it is worth using a 1% formalin solution.
Seed dressing - effective smut control
In the case of hard and dusty smut, seed dressing will be an effective control measure. Ways:
- Dry. In this type of dressing, powder pesticides are used. This work is done by a machine. Seeds are usually treated with granosan, mercuran, hexachlorobenzene and TMTD. This method is imperfect, since the chemicals do not adhere well to cereals.
- With hydration. Etching occurs with a sprayed suspension of a pesticide. As a result, you can notice good seed germination, a decrease in the number of infected cereals, as well as good yields. Processing is carried out using special machines, for example, PZ-10. It is worth etching with those chemicals that are used in the dry method.
- wet method involves the use of formalin solution. This is a complex method of seed disinfection, so it is used for small amounts of cereals. Wet pickling is three operations that are performed sequentially: wetting, languishing and drying. This type of work should be used five days before sowing.
- Semi-dry dressing similar to the previous one, but does not require drying the grains.
How to fight if the wheat is already mowed
During the fight against smut, agrotechnological and organizational and economic complex processes are used. The spores that cause smut are stored in the soil on which the wheat grew. Their life activity will depend on environmental conditions. According to scientists, there are methods that help to accelerate the death of smut spores, that is, to stimulate self-disinfection of the soil.
If the soil is moist and warmed up by ten to twenty degrees, then adding manure to it and fertilizing it with minerals can kill smut spores. Such conditions contribute to the death of the infection and the grains that sprout will not be infected with the disease.By cultivating the soil well, acquiring high-quality seeds and fulfilling all agrotechnical requirements, you can reduce the percentage of smut infection.
In addition, an excellent method of disinfecting the soil will be the introduction of top dressing into it. Manganese and boron introduced into the soil will greatly increase the plant's resistance to disease.
Use of contaminated wheat
After harvesting and detecting smut disease, the question arises: can the infected cereal be used?
Smut spores can give wheat an unpleasant odor and an unnatural color. That is why such flour produces poorly baked bread, which has a sweet aftertaste and smells unpleasant. The grains that were affected by the smut are a harmful impurity that is not advisable to use for eating.
In order to get rid of the smut of wheat, it must be washed in a washing machine, treated three times with a brush apparatus. This procedure will clean the surface of the cereal. After that, you need to mix clean and clogged grain. According to quality standards, smut grain in wheat should not exceed ten percent.
For information on what Indian smut of wheat is, see the following video.