Measures to combat phylloxera on grapes and prevention, pest-resistant varieties

Harvesting a high grape harvest is not as easy as it seems at first glance. Only winegrowers know what problems can be encountered in the process of growing fruit. In the first place is the fight against diseases and the destruction of insects. Phylloxera is an aphid on grapes that affects the entire plant. By recognizing the pest in time and taking the right control measures, the vineyard can be saved. Phylloxera was introduced from North America in the late nineteenth century.

Description of the pest

Phylloxera is a type of aphid. She looks different. Appearance depends on gender, age, stage of development, and location of the pest. The largest in size is an asexual female disperser with wings. A smaller, wingless female that damages the root system. She has a long proboscis. The color is yellow with a brown tint. The female leaf is half the size, with a short proboscis, yellow in color.

The sizes of males and females involved in the reproduction of offspring are even smaller. Proboscis and wings are missing. Females are yellowish, males are orange. The smallest is the first instar larva. Lemon-colored, with external digestion.

Kinds

There are several types of phylloxera. Among them are: wingless, winged, sexual, gall.

Wingless

Aphids infect the roots of the bush. Hardy larvae overwinter underground. In the spring they become more active, degenerating into females with a long proboscis. With its help, they feed on root sap. Harmful substances in the saliva infect the rhizome through the proboscis.

Winged

Winged phylloxera infects the green part of grapes and lays eggs on the leaves. The emerging aphid mates, promoting the emergence of a sexual generation of larvae.

Sexual

The sexual generation of larvae moves from an infected plant to a healthy one. Transported by wind, irrigation water, and rain.

Gallovaya

The gall form spreads on young leaves. Phylloxera form tubercles on the leaves from which larvae emerge. Pests move from leaf to leaf, infecting the plant.

Development cycle of grape aphids

There are two development cycles for phylloxera.

Full

The full cycle characteristic of American varieties begins in the spring. The larva, emerging from the winter egg, crawls onto the leaf, sticking to it. The root species of the pest partially emerges from the formed gall. Aphids descend underground and continue to damage the rhizome.

In August, some of the larvae transform into winged forms that lay eggs on the bark of the plant. After winter the cycle repeats.

Incomplete

On European varieties, aphids develop in an incomplete cycle. Infection begins immediately from the roots. Larvae emerge from the eggs laid by the female. Moving underground, they infect new bushes. In autumn, most of the pests die. Overwintered first generation larvae continue to reproduce next year.

Causes of phylloxera

The causes of grape phylloxera are an infected seedling or an incorrectly selected variety for a given climate. The composition of the soil also matters.

On what soils does aphid infestation occur?

Loose soil is excellent for pest breeding. Sandy soil has a detrimental effect on phylloxera.

Conditions for the development of the parasite on grapes

Aphids reproduce well on varieties that are highly susceptible to this disease. These are mainly European species. In young vineyards with shallow roots.

Phylloxera is well adapted to any weather conditions

Distribution methods

The first method of propagation is passive: wind, heavy rains, which entail rain and mud flows.

The second is by humans: the use of infected garden tools, stakes, on shoes, when purchasing a plant infested with pests.

The third is the independent movement of parasites.

Forms of the disease and characteristic signs

There are several forms of the disease.

Root

To identify infection of grape roots with phylloxera, it is necessary to free the upper part of the root system from soil at the end of July and carefully examine it.

An infected root has the following signs: small swellings appear on thin roots, and clusters of aphids are visible on large roots. The root dries out and the bark crumbles.

Leafy

The leaf form is much easier to detect than the root form. If spherical, convex, rough spots appear on the leaves on the inside of the leaf, this is a sign of the first infection.

Winged

Winged aphids also attack leaves by laying eggs on the inside of the leaf.

How dangerous is infection for grapes?

Phylloxera is very dangerous for grapes. If the fight against this pest is not started in time, the young shrub will die within three years.

Effects on the harvest

In an infected vineyard, most of the berries do not ripen, and the amount of harvest decreases.

Danger to the bush

An aphid that has settled on a plant sucks the juice out of it, damages the protective layer of the plant, and introduces an infection. After this, the process of decay begins. The bush gradually fades, growth slows down, infections become more numerous, and the plant dies.

Tools and materials for pest control

They destroy the pest mechanically, biologically, and chemically. The mechanical method is the most labor-intensive. The affected parts are removed by hand and burned. Insects are washed off with a stream of water from a hose. Affected plants are uprooted, subsequently treating the soil with chemicals.

As a biological remedy, parsley seeds are sown around the vineyard and between the plants. The smell repels insects.

When aphids appear, systemic chemicals are used to spray the plants.

Folk methods of struggle

To prevent and control the pest, you can resort to the use of folk remedies.

Iron sulfate solution

1. Dilute 300 grams of iron sulfate in ten liters of water. Treat the shrub with the resulting solution in early spring.
2. To destroy root aphids, a groove is made around the bush. A composition prepared from 10 liters of water and 500 grams of iron sulfate is poured into it. After the earth has absorbed the solution, fill the ditch with earth.

Spraying with slaked lime

In the fall, after harvesting, you can fight phylloxera using slaked lime.

Dilute half a liter of lime in ten liters of water, add half a liter of diesel fuel. Treat the grapes with the resulting solution.

Treatment with herbal infusion

If aphids were discovered at the initial stage of development, a herbal infusion will help get rid of them.

You need to take 200 grams of the following herbs: chamomile, wormwood, shag, tobacco. Pour five liters of boiling water over the herbs and leave for 10 hours. Dilute the strained broth in 20 liters of water. The prepared infusion can be sprayed not only on the bush, but also on the soil.

Chemicals

If aphids were found on grape leaves, the affected bush should be cleaned before treating the affected bush with chemicals. To do this, it is necessary to conduct a thorough inspection of the plant and remove damaged greenery. Then burn it.

Treat the cleaned bush with any of these preparations:

• pyrethroids;
• phosphororganic compounds;
• neonicotinoids.

Following the instructions, dilute the drug and spray the green part of the bush.

If the root is infected, it is necessary to treat the soil with carbon disulfide. Seventy milliliters per square meter.

Preventive measures

Getting rid of phylloxera is very difficult, almost impossible. Therefore, it is worth spending more time on preventive work. To avoid purchasing contaminated grapes, you should not make purchases from strangers in spontaneous markets.

Before planting, the seedling should be immersed for several minutes in a weak solution of an insecticidal preparation.

It is worth paying attention to the soil in which the grapes will grow. Sandy soil can serve as good protection against aphids. In such soil, phylloxera quickly dies, and the roots practically do not rot.

If it is not possible to grow grapes in sandy soil, when planting you need to dig a hole deeper than usual and fill the bottom with sand.

The seedlings are planted at a sufficient distance from each other for good ventilation. For prevention, grapes should be treated with fungicides and insecticides. The first spraying is carried out in the spring, after the leaves appear. The next treatment is before flowering. The final spraying is carried out after the formation of ovaries.

Rating of phylloxera-resistant varieties

If you choose varieties from your own roots, the more resistant ones are: Krasnostop AZOS, Kubanets, Cabernet AZOS.

With proper care, the following varieties have good immunity to the disease: Muscat, Chocolate, Samorodok, Moldova, Antey.