Grapes are susceptible to various bacterial, viral and fungal diseases. In addition, it is damaged by various pests. On average, the annual loss of grape harvest due to diseases and pests is about 30%, and in case of poor quality or untimely implementation of the necessary protective measures - and more than 40-50%. In this article, we will talk about pests such as ticks.
Grape felt mite itching: general information
Up to 70 different types of mites can parasitize on grape plants, but the most common of them is grape itch. It is almost impossible to distinguish it with the naked eye. The felt grape mite itch refers to one of the representatives of the eriophoid four-legged mites. You can meet him almost everywhere where grapes are cultivated. Lives mainly on leaves, less often on inflorescences.
Morphology
The body of an adult female is worm-shaped cylindrical. Color - milky white or yellowish. Length - 0.17-0.21 mm. The male is slightly smaller - up to 0.14 mm. shield uthe pest is triangular with many longitudinal lines. There are several bristles on the back of the shield. The abdomen has many rings with microscopic spines.
Biology
Females overwinter, hiding in cracks in the bark, under scales of buds, in fallen leaves. In one kidney, sometimes there can be about 1000 ticks at once. In the spring, when the buds open, they become active and migrate. Pests are carried by wind, birds and insects.
During the growth of shoots, mites move to blossoming leaves, stick to them from the underside and begin to actively feed. Substances present in the saliva of the grape pest cause active cell division and deformation of leaf tissues. Under the influence of enzymes that secrete itching, in the foci of their most active nutrition, concave oval areas appear on the leaves, covered with a white thick felt layer. Accordingly, bulges can be observed on the upper side of the sheet.
During mass reproduction, the grape mite infects a significant part of the leaves on the bush, which change color and become red-brown. The growth of leaves is disturbed, photosynthesis is reduced, some of them dry up and die, while the development of the grape bush as a whole is inhibited. If the inflorescences are affected by the pest, the petals become denser, begin to turn red and crumble.
If grape itch is not actively fought, it can lead to a strong decrease in yield. It is better to give preference to grape varieties that are resistant to felttick.
Itch on grapes: control measures
If single nests of ticks are found on 1 or 2 leaves, they can simply be cut off and taken outside the vineyard. With the defeat of a large number of leaves, it is simply impossible to do without a targeted and active fight against these pests. You should not cut off all the affected grape leaves, as this can cause much more damage to the bush than ticks do.
Inexperienced growers quite often try to control pests with such a universal remedy as Bordeaux mixture, but the result of such measures is zero, because it is a fungicide that can only cope well with plant diseases.
What to do if there is an itch on the grapes? The control measures in it are as follows:
- After autumn leaf fall, it is recommended to carefully spray the head, sleeves and vine of each bush with 5% lime decoction. If this is not done in the autumn, in the spring, before bud break, the vineyard is sprayed with 7% carbolenium emulsion.
- In early spring, before the buds have blossomed, spraying with the Dnok solution can give a good result.
- When the shoots reach 5 cm, you can use a grape mite remedy such as colloidal sulfur.
- In the event of a mass outbreak of ticks (more than 5 individuals on 1 leaf) in the summer, the destruction of pests is carried out by insectoacaricides and acaricides.
- During the growing season, the fight against grape mites can be carried out using"Phosfamide", "Fozalona", "Pliktran", "Omaita", "Talstara", "Mitaka", "Apollo", "Ortus" and others.
When processing grape leaves, one thing should be considered. The drug must be applied to the leaves only from below. This is done as follows: the spray nozzle is placed at the very surface of the earth and gradually lifted up, treating the inside of the affected leaves. This is the only way to get to the pest. Carrying out processing from above is ineffective. The effectiveness of spraying can be judged by the absence of lesions on new leaves. Sometimes it is enough to carry out one treatment, but, as a rule, 2-3 are necessary to finally destroy the tick on grape leaves.
Traditional literature recommends organophosphate pesticides. However, many grape mites have already developed immunity to this group of chemicals. If you increase the dose, it will have a bad effect on the plant and on the suitability of the crop for food.
Envidor based on spirodiclofen is a good alternative. It is not as toxic to humans and is quite effective against mites. Also, avermectin preparations can be used, especially when there are no more than 20-30 days left before harvest.
Agrotechnical control methods
When a grape felt mite appeared on a plant, control measures should be applied and agrotechnical: remove in a timely mannertrimming vines and old leaves, clearing stems and sleeves from old bark.
Spider vine mites
This grape mite is more dangerous than the pruritus, because when it appears, the leaves die off quickly. It settles on the underside of the leaf, pierces its skin and sucks out the juice. First, yellow dots appear at the puncture sites, which, growing, merge into large spots. From the upper side, the leaf turns yellow or brown - depending on the grape variety. With the mass settlement of the tick in early July, the leaves gradually begin to die off, which largely affects the crop.
Spider mites secrete saliva that turns into a thin web. It contains eggs laid by females and young larvae. Pests hibernate under the bark of perennial grape sleeves. They begin to lay eggs and feed when the buds open. Spider mites multiply massively and quickly enough. One female can lay up to 100 eggs in 10 days. If the weather is favorable for the pest, development of up to 7 or 8 generations during the growing season is possible.
Due to its small size and weight, the tick is able to be carried by the wind. Pest control due to the protective web is very difficult. In addition, the processing of grapes is inconvenient due to the location of ticks on the underside of the leaf.
Methods of dealing with spider mites
Control methods are the same as in the case of felt mites, but a more frequent spraying frequency is needed. In addition, it is not recommended to plant next todecorative flowers with grapes, because spider mites very often settle on them, which will definitely go to the grape bush.
Grape bud mite
It can be found in almost every viticulture zone. Females hibernate in the eyes at the base of the scales, on the rudimentary leaves of the main and replacement buds. The time of activation and the beginning of feeding of ticks falls on the period of spring sap flow, when the average daily air temperature is 7-8 degrees Celsius. The appearance of eggs occurs in the first half of May.
Leaf mite
This vine mite is most commonly found in southern viticulture areas. Females hibernate in cracks in the bark and under the scales of the kidneys. They are activated at an average air temperature of 7-8 degrees and migrate to young leaves. During the growing season, from 5 to 11 generations can develop.
