Grape gray mold: remedies, treatments and information on how to treat botrytis of grapes or gray mold of the vine.
Theregray moldis a mushroom from the family ofSclerotiniaceae. Its scientific name isBotrytis cinerea and it is - unfortunately - a very famous parasite that attacks a large number of plants, including thegrapes.
In viticulture, the fungusBotrytis cinereait is commonly called gray rot or gray mold. The name is linked to the ash gray color assumed by thegrapesdue to the sporata of this parasitic species. The disease triggered by the fungusBotrytis cinereait is saidbotrytis. As stated, the gray mold attacks different plant varieties, from vegetables to ornamental plants (see Gray mold on hydrangeas) and fruit.
This mushroom has a very complex life cycle. The optimal conditions for engraftment occur with temperatures between 16 - 25 ° C and very high humidity rates. On early vines such as Tocai, Pinot bianco, Pinot grigio, Chardonnay, Riesling and others, gray mold infections of grapes can occur even in the period following flowering. The attack of the fungus, in this context, develops on the wounds left by the fall of the floral caliptrees.
Grape gray mold: struggle, remedies and treatments
Prevention of grape gray mold
While prevention is better than cure, the first remedy isgray grape moldit is precisely prevention. The screws can be more or less sensitive to botrytisbased on different cultural factors. We should aim to prevent gray mold right from the choice of rootstock and clone but, when there is a need to look for remedies for botrytis in grapes, it is impossible to act in these terms.
To prevent thegray grape moldwe should:
- reduce nitrogen fertilization.
- Carry out an early and more moderate leaf removal of the cluster area.
- Remember to carry out treatments against the various grape moths.
- Perform covering fungicide treatments.
Above all, for prevention, it is necessary to carry out a specific treatment against grape botrytis.
Chemical fight against gray grape mold
The chemical fight is a remedy to be used with caution. Plant protection products should be reserved only for sensitive grape varieties and plots at risk. An abuse of chemical compounds would result in faster selection of a fungal strain resistant and immune to antifungals and antibacterials currently on the market.
There botrytisit is contracted from the vineyard through micro-wounds due to the detachment of flower parts and the sudden swelling of the skin. Hail or insect damage can also favor the rooting ofgray mold.
Generally, chemical treatments are performed in four steps.
- One specific at the end of flowering.
- A treatment to be performed before the closure of the bunch.
- A treatment to be done at the beginning of veraison.
- One last pre-harvest treatment.
Each treatment has different purposes.
- The first treatment is performed withantiperonosporicsand aims to minimize early contamination.
- The second treatment is performed to destroy the conidia before the cluster closes completely.
- The third treatment limits any late contamination.
- The fourth treatment is especially crucial for theliveslong exposed to atmospheric phenomena (hail) or to attacks by particular parasites. This treatment is recommended for vineyards destined to produce fine wine.
In the chemical fight it is necessary to be scrupulous also to avoid that the residues ofantibotritisthey can remain on the grapes first of all and in the wine secondly. Products against gray mold can be detected in wines: respecting the time of treatment is essential so that the concentrations found in the grapes are below the maximum residual limits established by law. Not only is the period important, even the application of the products must be carried out with wisdom and attention, otherwise the treatment itself will be ineffective.
Copper-based preventive treatments
The Bordeaux mixture is effective in the prevention and treatment performed at the onset of the disease.
Act promptly by eliminating (as far as possible) the moldy parts and spraying the plants with Bordeaux mixture: the treatment should be repeated about every 10 days until the problem is completely resolved.
Bordeaux mixture is also a widely used remedy in organic farming and for this reason it can be found in any agricultural consortium. Those who prefer to buy and sell online can buy a one kg bag of Bordeaux mixture (wettable powder) at a price of 10.90 euros with free shipping. For all information, please refer to the product sheet: Bordeaux mixture.