Grapes are susceptible to various bacterial,viral and fungal diseases. In addition, it is damaged by various pests. On average, the annual yield loss of grapes due to diseases and exposure to pests is about 30%, and if the necessary protective measures are carried out poorly or late, more than 40-50% are needed. In this article we will talk about such pests as ticks.
On grape plants can parasitize up to70 of the most different types of mites, but the most common of them is grape pruritus. It is almost impossible to distinguish it with the naked eye. Felted grape mite pruritus refers to one of the representatives of eriofoid four-legged mites. You can meet him almost everywhere where grapes are cultivated. Lives mainly on the leaves, at least - on the inflorescences.
The body of an adult female worm-like cylindricalforms. The color is milky white or yellowish. The length is 0.17–0.21 mm. The male is slightly smaller - up to 0.14 mm. The pest shield is triangular with many longitudinal lines. There are several setae on the back of the shield. On the abdomen there are many rings with microscopic spikes.
Females hibernate, hiding in bark cracks, underscales of buds, in fallen leaves. Sometimes in the same kidney can sometimes be immediately around 1000 ticks. In the spring, when the opening of the eyes begins, they come into activity and migrate. Pests are spread by wind, birds and insects.
During the period of shoot growth, the mites move toblooming leaves, stick to them from the bottom and begin to actively feed. Substances present in the saliva of a grape pest cause active cell division and deformation of leaf tissue. Under the influence of enzymes that itch marks out, in the foci of their most active nutrition, leaves form concave oval areas, covered with a white thick felt layer. Accordingly, on the upper side of the sheet, one can observe bulges.
With mass reproduction grape miteaffects 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 out and die off, while the development of a grape bush is generally inhibited. If inflorescences are affected by the pest, the petals are compacted, begin to redden and crumble.
If the grape pruritus does not lead an active struggle, then it can lead to a strong decrease in yield. Prefer better grape varieties that are resistant to felt mites.
In case of detection of single nests of ticks by 1or 2 leaves, they can simply be torn off and attributed to the territory of the vineyard. With the defeat of a large number of leaves without purposeful and active control of these pests simply can not do. It is not necessary to tear off all the affected grape leaves, as this can cause much more damage to the bush than mites do.
Inexperienced winegrowers often trypest control with the help of such a universal remedy as Bordeaux mixture, but the result of such measures is zero, because it is a fungicide, able to cope well only with plant diseases.
What if there is an itch on the grapes? Control measures in it are as follows:
When processing grape leaves should beconsider one moment. The drug should be applied to the leaves just below. This is done as follows: the spray nozzle is placed on the surface of the earth and gradually lift up, processing the inside of the affected leaves. Only in this way you can reach the pest. Conducting treatment from above is ineffective. The effectiveness of spraying can be judged by the absence of damage on new leaves. Sometimes it is enough to carry out one treatment, but, as a rule, 2-3 are needed in order for the tick on grape leaves to be finally destroyed.
Traditional literature recommendsorganophosphate toxic chemicals. However, many grape mites have already developed immunity to this group of chemicals. If you increase the dose, it will badly affect the plant and the suitability of the crop for food.
A good alternative is the drug "Envidor" on the basis of spirodiclofen. It is not so toxic to humans and is also quite effective against ticks.
In addition, it is possible to use preparations of the avermectin group, especially in the case when no more than 20-30 days are left before harvesting.
When a grape felt mite appeared on the plant, control measures should also be applied to agrotechnical ones: timely remove the pruning of the vine and old leaves, clean the trunks and sleeves of the old bark.
This grape mite is more dangerous than an itch,since when it appears, the leaves die off quickly. It settles on the underside of the leaf, pierces its skin and sucks the juice. First, in the places of punctures appear yellow dots, which, growing, merge into large spots. On the upper side, the leaf turns yellow or brown, depending on the grape variety. When the tick is populated at the beginning of July, the leaves gradually begin to die off, which largely affects the yield.
Spider mite secretes saliva, turning intothin web. There are eggs laid by females and young larvae. Pests overwinter under the bark of perennial branches of grapes. Laying eggs and feeding, they begin at bud break. Spider mites reproduce massively and quickly enough. One female in 10 days can lay up to 100 eggs. With favorable weather for the pest, it is possible to develop up to 7 or 8 generations during the growing season.
Due to its small size and weight, the mite is able tocarried by the wind. The fight against the pest because of 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.
Ways of struggle are the same as in the case offelt mite, but need more frequent frequency spraying. In addition, it is not recommended to plant ornamental flowers next to the grapes, because spider mites often grow on them and they will definitely pass to the grape bush.
It can be found in almost every zone.viticulture. Females overwinter 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.
This grape mite is most commonin the southern regions of viticulture. Females hibernate in cracks in the bark and under the scales of the kidneys. Activated at an average temperature of 7-8 degrees and migrate to young leaves. During the growing season can develop from 5 to 11 generations.
