Diseases, parasites et treatments
Various mushrooms, causing diseases prejudicial to the harvest can attack the vine. The principle diseases are downy mildew and powdery mildew. The ALADIN, AMANDIN, CANDIN and PERDIN vine plants are insensitive to the mildews and therefore need from none to 2 treatments before and after the beginning of flowering, and depending on the conditions such as humidity or the proximity of other vineyards.
ALL OTHER VINE PLANTS MUST BE PROTECTED FROM DISEASE BY PREVENTIVE TREATMENTS
Caused by a microscopic mushroom which attacks the leaves and the bunches of grapes. On the leaves, it produces first yellowish stains called oil spots, and then the underside of the leaf becomes a downy white colour. Finally some burnt zones appear on the leaf. On the grape bunches it leads to a browning and eventual drying of the grapes.
Must be started from the 15th of May until harvest. Treatment is generally performed using Bouillie Bordelaise mixed at a strength of 15g per litre of water. It must be repeated every fortnight and sooner if washed off by 25 to 30 mm of rain or watering.(See Bouillie Bordelaise product).
The mushroom responsible for this disease develops on the surface of the green parts of the vine. - On the leaves, it produces diffused grey-white powdery stains. - On the green shoots, the same powdery coating develops, and then later the wood develops dark brown stains. - On the grape brunches, if contamination occurs at the time of flowering the grape berries will fall, if later the grapes are covered with grey powder and then burst.
Must be started from the 15th of May at the same time as the treatment of Downy Mildew but can be stopped at the end of July with the beginning of ripening. We recommend that you use a solution of 10 grams Wettable Sulphur per litre of water (see THIOVIT product on our shop page) which has the advantage of being able to be mixed with the Bouillie Bordelaise and this treated at the same time. You can also use flowers of sulphur for dusting, but be careful to apply during the coolest part of the day to avoid burning.
Grey rot (Botrytis)
This fungus attacks mainly the grape berries, which turn first a brown colour, and then rotting the surface becomes a downy grey colour. The vine varieties with the thinnest skins are the most sensitive.
This is optional but it ensures healthy grapes even in a year with a humid climate, and should be performed twice around the 15th of June and the 10th of July. The spraying should be done directly onto the bunches of grapes. You can use any of the standard anti-rot products from usual garden shop The risk of botrytis can be limited by aerating the grapes. To achieve this you must prevent the adjacent bunches from touching by cutting away some of the grapes and also at the beginning of ripening by removing the leaves over the grape bunches to facilitate the flow of air. In areas of strong sunshine it is best to remove the leaves on only one side of each row, the one most in the shade.
This manifests itself by the appearance of blisters on the top of the leaves with a white downy surface on the bottom side. It is caused by the bites of the acarian invisible to the naked eye.
Dusting easily eliminates this parasite with flowers of sulphur, or by using a commercially available acaricide.
Red spider mite
The damage starts in the sring with leaves scraggy looking wich yellow and shrivel up.
Spraying with a commercially available acaricide easily arrests any eventual attack by red spider mite.