The kingdom of fungi is the most ancient and most widely represented biological community on Earth.
To see some of them, especially in the mushroom season, is a joy to a person, others literally poison the life of gardeners and indoor plants lovers.
Causative agent
Ascomycetes - who is it? What are they dangerous for plants?
Translated from the Greek - just "bag", "bag". Marsupial mushroom. An imperfect organism (mycelium), which has a vegetative body in the form of thin filaments (hyphae) and special organs for carrying spores (reproduction cells) - bags. Ascomycete itself reproduces itself by asexual (without reproductive cells) and sexually (through the interaction of specialized cells).
80% of plant diseases are associated with spore organisms. The causes of fungal diseases are not always the same, the fight against them is protracted.
The essence of the fungal damage to a plant is in its penetration through the stomata of the leaf surface or damage left by pests and intensive germination into the plant's body.
Rapidly spreading, the mycelium creates at its ends - due to the merger of male and female gametes - more than 100 bags (each with 8 reproductive spores). On the surface of the sheet bag, closing, form a "saucer" with a diameter of 400 microns.
Thin filaments (hyphae) of the fungus, intertwining, form tufts and new fruiting organs. The main purpose of multimeter threads is absorption of water and nutrients from a plant. The period of maturation of the dispute in bags at a temperature of 20 degrees Celsius - 2-3 weeks. Flows of water or air, they are transferred to other plants, connecting for a new act of fertilization.
Asexual (vegetative) reproduction is characteristic of marsupial fungi under optimally favorable weather conditions. Then on the surface of the mycelium from the usual spores (separated from the hyphae) conidia grow - fixed disputes, ready to turn into a new organism with the functions of reproduction and settlement.
Reference: In the mushroom world, ascomycetes number over 30,000 species. Their role in nature is not unambiguous: they support the completeness of the biological cycles of nitrogen and carbon, are the basis of lichens, are included in the menu of invertebrates, rodents and even larger animals - boars and deer.
Description and photo of rubella grapes
Rubella grapes as a fungal infection. This disease of grape vines is named after the color of the spots-thickenings that appear on the first leaves in May-June. So why do grapes turn red leaves? Sometimes, however, the nature of the spots may be quite different:
- mildew infestation;
- defeat of the plant by spotted necrosis (bacteriosis);
- defeat spider mite;
- the presence of fluorine in fertilizer borsuperphosphate;
- significant potassium deficiency;
- heavy overload bushes.
For rubella is characterized by color changes between the streaks of the sheet, forming a triangular graphic, the leaves seem to rust. Indisputable evidence of infection is the particular type of spot:
- in white varieties: grape leaves are covered with brown spots, with a narrow yellowish border, or completely yellow spots;
- in color varieties (pink, red, black) - dark red spots on the leaves of grapes with a greenish-yellow outline on the edge.
Rubella is not an economically significant grape disease. It is not treated as the fungus penetrates into the vegetative organs of the plant. The parasite has the property of forming a persistent addiction to fungicides (chemicals). Combating rubella, mainly - preventing the spread and change of ecology of the environment.
Reference: The disease was first described by the Swiss biologist G. Muller at the beginning of the last century, who discovered it in the vineyards of Thurgau (in the northeast canton of Switzerland).
In the photo below you can get acquainted with the signs and appearance of defeat rubella grapes:
Types of disease
Experts of fruit growing distinguish the nature of this disease, classifying it as:
- infectious;
- non-infectious.
In the first case, the vine of the first 3-4 years of life is affected by the transfer of spores from neighboring plants, including weeds and litter.
In the second - the cause of the disease are:
- soil composition (stony, poor in nutrients, in particular - potassium);
- disturbance of water balance in the plant nutrition;
- weak bush;
- heavy rains;
- drought;
- low night temperatures.
Non-infectious rubella can be easily overcome by improving the whole agricultural background or changing the feeding system.
Reference: Systemic mildew control can weaken the process of infection with ascomycete.
Effects
The settlement of the simplest organism into leaves, more rarely - the brush of grapes, leads to:
- the thickening of the leaf plate and the manifestation of its fragility: the leaves are folded and dried, up to reset;
- changes in leaf productivity as a photosynthetic apparatus;
- the weakening of the plants that are undernourished;
- growth disorders;
- the appearance of deformed fruits that do not reach full maturity;
- decrease (up to 80%) or complete elimination of the crop;
- re-infection at the end of the growing season (September).
Important: Rubella grapes, not identified in a timely manner, can already completely deprive the bush leaves at the beginning of the growing cycle.
Ways to combat infectious form
What to do if red, yellow or brown spots appeared on the leaves of the grapes if the leaves rust? In fruit growing, there are three generally accepted ways to combat fungal diseases:
- chemical (using fungicides);
- biological (fungi do not tolerate competition);
- mechanical (agrotechnical measures).
But the most effective is the prevention of the possibility of injury.
- The chemical method of combating plant disease, at today's level of production of fungicides, provides the highest efficiency and financial savings. Main condition: toxic to parasites should not be toxic to humans. Otherwise, the tool does not justify the goal - the ripening of suitable for eating fruits that are useful for our body. Preparations for the treatment of plants are:
- contact type, directly affecting the affected surface ("Rovral", "Omite", Bordeaux liquid (8% solution);
- systemic type, when the drug is injected to penetrate into all systems of the plant ("Fundazole", "Kvadris", "Strobe", «Topsin-M", "Topaz", "Byleton";
- combined - combining properties of the first and second type ("Reedom", "Gold", "Carbis Top").
In the fight against the causative agent of rubella, mildew preparations are very effective: copper oxychloride (0.3% solution), polycarbacin, arceride, polychrome. It is not by chance that the fungus does not manifest itself where the vine was treated for downy mildew.
Chemical preparations have one minus: pathogens become accustomed to them, and a change in the synthesized substances or an increase in the dose is required.
- Biological agents for the control of fungal infections are non-toxic, but they also do not provide the long lasting lasting effect that gardeners are counting on. They are used mainly in the early stages of the disease, combined with popular methods tested over the years.
Universal is very popular among biological products "Gaupsin", whose effectiveness for all types of garden and garden plants, including grapes, is 90%. It is with complete safety of the drug for humans and other living organisms: higher animals, fish, bees. The effectiveness of its microflora is productive for 2 weeks, it does not accumulate in the plant, does not affect the taste of the fruit. Store "Gaupsin"it is possible in the summer at room temperature - 4 months, in a cold place - up to six months.
The biological treatment also includes the recommendation of treating the bushes with a solution of an extract from wood ash and laundry soap (water ash - 1/10; 50 g. Of soap). The frequency of treatment is once every 10 days, until the end of the growing season.
- Mechanical means of struggle include:
- removal of affected leaves and shoots;
- removal of stepsons;
- embossing of previously affected fruit shoots, leaving foliage above the clusters; stepchildren in this case - do not delete;
- timely garter shoots;
- destruction of waste pruning and dry waste;
- removal of weeds from the radical circle, digging the ground;
- pruning bush under the winter;
- additional application of potash fertilizers.
Important: "Grapes do not like sweat, but the sun and the earth." For the health of the vine is very important soil composition, the presence of potassium in it.
Means of prevention
There are no special preventive measures for rubella. This fungus appears before the pathogen of powdery mildew, but is sensitive to preventive sprays against mildew. Here are some rules for the prevention of this disease:
- Both sides of the leaf should be treated with fungicides. In the spring it is better to use organic preparations, as copper can cause burns.
- At the beginning of vegetative growth, it is necessary to eliminate contact of the plant with old leaves.
- It is recommended to monitor the mode of illumination and ventilation of the bush.
- After the initial treatment of young shoots and removal of infected leaves, you need to take care of sufficient foliage of the bush, reducing the length of pruning and maintaining healthy stepchildren.
- Qualitatively improve the fertility of the soil by applying organic fertilizers: manure, compost, humus.
- Spray with potassium nitrate (1%) at the beginning or at the end of a day (up to 5 times with an interval of 10 days), combining it with the introduction of potash fertilizers under the plant root.
- All pests of grapes (insects, birds), violating the integrity of the plant, open the "gate" for the fungal infection. The prevention of ascomycetes is the protection of the vines from pests.
Is it possible to avoid the threat of infection?
The main condition for a healthy specimen in your garden will be a thoughtful selection of varieties. After all, most European grape varieties are vulnerable to spore infections. And the handsome "Cardinal", and the basic stock "Queen of Vineyards", and "Muscat Hungarian", and "Pearls of Saba" have only one weak point - susceptibility to fungal infections.
Creating with their use of new hybrid forms, as a rule, aims to eliminate this disadvantage, at least in part. Therefore, in the descriptions of varieties should always look at the data, talking about the resistance of grapes to any kind of fungus, to high humidity, to low temperatures, soil fertility and the characteristic density of a mature brush. Most often, the fungus affects painted varieties and hybrids on "isabelny" rootstocks.
It is believed that among all types of vines only black "winter grapes" (Vitis cinerea), growing in Texas, are guaranteed against fungal diseases and grape rubella as well.
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