Question: Sick vine
hi, in my garden there are four plants of Muscat grapes, the one that makes small white bunches, the poto are frequently found in a sunny area but every year they get a disease that I cannot identify much less cure. towards the month of July the new leaves begin to fill with a sticky white powder affecting even the small clusters that are growing that rot within days while the leaves dry up and slowly the plant thins out. In 30 I have never been able to taste a bunch of them. How can I save them ??
Answer: Sick vine
having no photographs or detailed explanations, I show you which are the main fungal diseases of the vine, which are among the main suspected for the problems affecting your plants; typically the vines in Europe are affected by downy mildew, powdery mildew and botrytis; these are fungal diseases, which can affect leaves, wood and even fruit, and have different symptoms depending on the disease, but also depending on the climate. Downy mildew manifests itself as almost transparent, almost circular spots which appear on the foliage; typically affects young leaves, but has a development that extends over time, and typically in summer a sort of whitish powder comes out of the spots, and very often the downy mildew also spreads to small fruits or fruits, causing atrophy or rapid rot . This pathogen is very harmful to vines, and is usually treated (if possible prevented) with various interventions, which are carried out at scheduled intervals throughout the year. Powdery mildew is a widespread fungal disease throughout Italy, and not only on the vine but also on all crops, it is typically recognized on the leaves of roses; tends to develop more when the climate is hot during the day, and cool and humid in the evening and at night, so in addition to the spring climate, the development of powdery mildew is favored by watering provided in summer in the evening, which is maintained on the foliage even for many hours. The type of appearance of powdery mildew is that of light spots, covered with a thin white powder, similar to flour; as it develops, it ruins leaves, flowers and fruits. The last pathogen that affects the grapevine a lot is botrytis, also called gray mold; from the name it is clear that your appearance is not white, but gray, and forms a sort of blanket, with a felt appearance, which covers the leaves, buds and clusters, both young and well developed, causing them to rot. Against all these pathogens, the first thing to do is to correctly cultivate the plants, which must be placed in a well-sunny and well-ventilated area; watering (where necessary) should be provided during the early morning hours, if this is not possible and in case of watering in the evening, let's water the soil well, avoiding wetting the foliage. In addition to this, periodic treatments based on various types of fungicides are practiced, both suitable for organic farming and not suitable for this type of agriculture; typically in small-sized crops, copper-based products are used, which are used already in autumn and late winter, and then on a monthly basis. However, these fungi tend to persist even on fallen leaves, or between the cracks of the stems, for this reason it is good to also treat the wood and collect and destroy the fallen foliage, as well as treat the soil around the plant that has shown symptoms of these diseases. .
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