CropsMethods of protection
In production regions where powdery mildew is chronically severe, it is often very difficult to control the development of this disease in the vineyard. In fact, only preventive chemical protection can effectively control it.
- Use a grape variety less sensitive .
- Avoid excessive planting densities.
- Control the vigor of the vine:
- Choose a poorly vigorous rootstock;
- Limit nitrogen fertilization;
- Practice grassing.
- Regular cleaning of the surroundings of the plots so that they are well ventilated.
- Disbudge and trim the vine, remove leaves from the grapes in order to improve the ambient microclimate and allow fungicides to protect them well.
-
Use a risk forecasting model and / or follow plant health bulletins. ( PPE IFV )
-
Carry out preventive fungicide treatments at key phenological stages ( e-phy ):
- On sensitive grape varieties, fungicidal protection will be implemented from the "2-3 leaves" stage until the end of the "cluster closure" period;
- On not very sensitive grape varieties, it will be carried out from the "separate flower buds" stage until the "cluster closure".
In organic, anti-powdery mildew protection is mainly based on the use of wettable or powdered sulfur. Be careful, even in the absence of rain, the persistence of sulfur does not exceed 10 days. Several "alternative" products are also available, but their effectiveness is more or less relative.
It should be noted that this chemical protection must be of high quality between the pre-flowering stages and the closure of the bunches, and the vines must be fully protected. We should add that the fungicidal treatments having side effects with regard to powdery mildew, carried out after the clusters have closed, make it possible to limit attacks on the leaves and therefore prevent the formation of cleistothecia at the origin of part of the disease. primary inoculum the following year. Curative applications on oidized clusters are ineffective and therefore unnecessar