Rust mushroom is a pest that affects various crops. The mushroom mushroom, which primarily settles on cereals - wild, cultivated, is quite widespread. This mushroom provokes the development of stem (linear) rust.
Where is my food, there I am
In recent years, rust fungus has spread quite widely. This is due to changes in agriculture: more and more territories in different parts of the planet are planted with those cereals on which it can settle. Joint evolution closely links rust fungi and cereals. As observations have shown, the greatest variety of forms of the pest is inherent in those areas where many plants grow on which the fungus can settle. Actively cultivated by man plants are gradually spreading throughout the planet, and with them the rust mushroom is becoming more widespread.
Biology has been studying this specific form of life for quite some time. In particular, it was possible to identify that the spore-bearing stage of development in rust fungi suggests the presence of five varieties of spores: basidio-, tele- ureo-, etsidiospores, and spermogonia. The latter are formed like pycnids. But tele-spores exist consisting of only one cell or two, and can also include many cells. Such spores are covered with a thicker shell than others.
Both there and here
The life cycle of rust fungi involves interaction with different plants, that is, the parasite changes hosts from time to time. The social stage requires an intermediate, and telio, uredinio - the main. In some cases, the spread of mushrooms is explained by the fact that their owner, with the help of humans, captures new spaces - for example, they sow a fundamentally new crop field in a country where such a plant did not exist before. However, in rare cases, the opposite situation is observed: if the plant suffered from rust fungi and the cereal “moved” to another locality in the form of clean, uninfected seeds, then the culture is freed from the parasite, which cannot be eliminated in its original place due to its high prevalence.
How does this happen?
The rust fungi shown in the photo (in this article you can see several varieties of parasites) are able to germinate inside the host. This is called a germ tube that penetrates the tissue of the carrier through the mouth. Over time, the fungal mycelium grows directly in the plant tissues, develops by filling living cells with haustoria, through which the parasite receives the necessary nutritional components.
When penetrated into the host plant, smut and rust fungi spread using hyphae. Parasitic, host cytoplasms contact the ends of the haustorium, where there is no membrane, but a membrane is present. This allows the parasite to pump nutrients from the plant.
I'll take the sweetest
It is known that rust parasitic fungi can exist on certain plants, and each malicious plant has a fairly narrow list of possible carriers - usually one or another cereal genus.
Special parasitic forms are usually divided into races. They differ from each other in that different rust fungi infect various plant varieties. For example, it is known that stem rust on human-grown wheat is more than three hundred physiological races of parasites. Different states must take into account how many and which particular parasites are currently observed in cultivated plants. Based on the information received, it is possible to determine which diseases caused by rust fungi are easier to defeat, which are more difficult. It is also possible to identify more resistant cereal varieties and those that are easier to “give up” to parasites.
Rust cancer
A dangerous pest can nest on trees as well. A fairly characteristic form of rust affects the fir, causing cancerous tumors. They have been popularly known under the name "witch's panicles" for a long time. In some of its phases, the parasite lives on shoots, tree branches, and also eats from the trunk. Uredo, tele-stages occur on cloves. This cycle of development of rust fungi affects the stalk, stellate.
Bazidiospore, progressing on the grass, gradually moves to a tree. The first to suffer young fir shoots, twigs. You can notice infection by thickening in the form of couplings. The year after the initial defeat, the shoots give rise to very peculiar branches covered with yellow needles: they are short, grow vertically upward, have an unhealthy appearance. Already in the summer, acidia appear on the branches, in autumn, the affected needles fly around. From year to year in this place will be escidia - short, cylinder-shaped, red, rounded. Pads are usually observed on the needles from below. The spore-bearing stage of development in rust fungi is located along the midrib.
What's next?
When the spore-bearing stage of development of rust fungi ripens, mature spores fall off, due to which they again infect grass - asterisk and other suitable carriers. Mycelium is formed in the leaves, which provides nutritional components for the two stages of the parasite. Over time, ripe fruits appear on the leaf through tears. In the spring, another infection of the tree occurs and the mushroom threads germinate in the fir. Usually mushroom mycelium nests in cambium, the wood of young shoots.
Branches are only the first stage of tree infection. Then the mycelium penetrates deeper into the tree trunk, the cambium dies, the trunk in this place becomes thicker, and the bark is covered with cracks from the bottom up. Over time, it cracks and falls off, and the wound opens to the environment. Such growths cover the entire tree trunk, slowly increasing in size. On average, the circle increases by 6 mm per year, and the height - by 7-13 mm.
Dangerous and large
It is known that a witch panicle exists for up to two decades. A tree infected with cancer can look healthy for decades. In many ways, the condition of the plant depends on which element was affected by the parasite. If the fungus grows in the crown, the top or part of it dies out. The most dangerous are lesions of the under-crown sections of the trunk. The tree dies when the fungus captures half the circumference of the trunk.
The thickenings that cover the infected trunk are covered with cracks. Through them, fungi provoking putrid processes get into the tree. Often a similar tree falls during a windbreak. The appearance of new wounds, the progress of putrefactive processes are not only dangerous to the life of the tree, but also reduce its value for the national economy, since the percentage of useful wood extracted from the plant is reduced.
Who is the worst?
As statistical studies show, white, Siberian, Caucasian fir species are more susceptible to the disease. Rust mushrooms, somewhat different from each other in terms of nutrition, appear in a variety of forest plantations, both old and young. The risk of infection of a tree growing in a humid area is increased. In addition, the likelihood of rust is greater when the grass cover by an impressive percentage consists of intermediate hosts, that is, cloves. The percentage of incidence in pure fir forests is quite high.
Currently, it is the rust mushroom that is one of the main reasons for the large areas of dead wood in the forests of our country. It is because of it that the quality of plantings is greatly reduced. In the areas of fir rust mushroom is very widespread. Periodically, measures are taken to prevent infection, but so far their results are unsatisfactory.
Mycology: Uredinales
Mushrooms of this category cause significant damage to agriculture and forestry from year to year. Fungi are widespread throughout the planet, but in different countries different measures are used to control them in terms of effectiveness. The pleomorphism of such fungi is quite characteristic, and yet the number of stages differs greatly in different species. Based on this feature, it is customary to distinguish several groups.
Modern science knows parasites that are single-hosted and heterogeneous, with an incomplete and complete development cycle. The first all the time live on the same plant. Quite often, these affect flax, sunflower. But the second group is the parasite that settles on the mountain ash and juniper. There is a fungus that grows alternately on wheat and barberry or on buckthorn, reed. If a particular plant normally goes through all possible stages during its existence, it is called a full-cycle mushroom. Another option is also possible - when there are only a few of all the possible stages of development. Such are most widespread in temperate latitudes, where the duration of the growing season is greatly limited by weather factors.
Puccinium
Puccinia is the most typical example of a fungus that changes hosts over several periods of existence. This fungus provokes rust on cereals. In addition to cereals, the parasite also lives on bushes of barberry. This is a heterotallic fungus that has several stages, numbered from zero to four in the classics. In spring, heterosexual basidiospores fall on the leaves of the plant, release hyphae and penetrate into the tissues of the plant, then move along the intercellular spaces with the spread of haustorium through the cells.
During this period, you can see that on the barberry on the leaves from above appear reddish small dots - spermatogonia. An alternate name for this stage is picnic. They are also heterosexual. If the sheet is cut across and examined with magnification, you can see bodies that resemble jugs in shape, immersed in the parenchyma. The parasite consists of mycelium formed by cells filled with ginger oil. Spermogony is a source of pycnospores moving to the surface of a diseased leaf. Male germ cells do not spread the infection, mycelium is not produced.
We pass, we pass, we do not linger!
Over time, spermatozoa appear near hyphae of the opposite sex, which provokes the onset of the sexual process with the production of mycelium, penetrating the leaf tissue. Visually, this can be seen if you look at the greenery of the affected shrub from below - red etsii appear here. There is a separation of the mycelium, peridium rupture. In this case, disputes can spread further - they are carried away by the breeze. They will not infect barberry, since the parasite needs those nutrient components that the leaf of this plant can not give him. Therefore, the mycelium travels in search of cereals. Once on a suitable surface, he gives hyphae.
How to fight?
In general, rust can be dealt with if all infected plants are destroyed. Of course, such a tactic is not very suitable for large forestry, but it is quite applicable for a small garden plot. It is also necessary to get rid of those plants that are intermediate hosts. So that plantings on the site with a greater degree of success resist the infection by parasites, it is necessary to regularly fertilize the soil with potassium, phosphorus and various micronutrients, but reduce the amount of nitrogen fertilizers to a minimum.
It will not be superfluous to regularly use those drugs that are specially designed for the preventive treatment of garden plots from rust. Please note: some funds that were in use several decades ago are now prohibited, as their danger to humans has been identified. It is categorically not recommended to use such poisons, even if stocks remain at home.
How to warn?
The best way to deal with a problem is to always prevent its occurrence. Every effort must be made so as not to infect your site. In particular, when purchasing seedlings, cuttings, it is necessary to use the services of only trusted suppliers whose bushes are guaranteed to be healthy. You should also constantly feed the land with phosphorus, potassium, and foliar fertilizing regularly to produce with the use of useful trace elements.
All plant residues must either be completely destroyed, or taken to a place of disposal, or deeply buried in the ground. Leaving them to rot on the surface or near the surface, thereby the farmer increases the likelihood of a variety of parasites, diseases. Rust is no exception. In the spring, when the snow has just melted and the buds are still sleeping, it is necessary to conduct timely high-quality treatment of plantings with fungicides.
Save the roses
Among other plants cultivated by man, rust can even affect rose bushes. At the same time, rosehip, rose is a plant that is the main host for the parasite. Typically, infection occurs with a species of Phragmidium, which grows only on them, does not need intermediate owners.
You can suspect infection in the spring, when on the buds, stems, and neck at the root of a young rose you can see peculiar growths of bright orange color. Over time, petioles, leaves are covered with yellow, orange spots that protrude above a flat surface. Toward August, the affected areas turn black, the leaves crumble, the shoots dry. The diseased plant can not tolerate winter. The parasite feels good in high humidity, especially in the spring cool. Irregular, insufficiently plentiful watering, as well as a lack of potassium in the soil contribute to its development. If hot, dry weather sets in, the disease is noticeably weaker.
How to protect?
To protect roses from this scourge, it is necessary in the spring to carefully examine all the plantings and cut out at the soil level those places where lesions were found. These elements of plants are immediately destroyed, otherwise the infection will spread further. At headquarters, the resulting sores are cleaned, wiped with copper sulfate and treated with var. In the spring, while the kidneys are still sleeping, it is necessary to spray at times with vitriol (copper, iron). When the kidneys begin to bloom, they are treated with Bordeaux fluid. The second stage of the same processing - just before flowering. The liquid can be replaced with special agricultural preparations “Topaz”, “AbigaPik”.
Save the plum
Rust can occur on the sink if the patch is infected with Tranzschelia prunispinosae. In addition to plums, this parasite can settle on other stone fruits. Some stages of the fungus reside in the body of the anemone. Typically, trees become infected early in the summer. You can notice this by the leaves - chlorotic spots appear, which by the end of the season cover the leaves from bottom to bottom. Spores form brown pads that change color to brown. The leaves showered ahead of time, and the parasite hibernates in the leaves and in the spring affects anemones. Such an infection greatly weakens the tree.
To protect the plum, it is necessary to isolate the host plant and cut diseased individuals. All other trees should be sprayed regularly with Bordeaux fluid - at least every two weeks, but more often.