4.1 Prevention methods for plant protection against diseases in organic agriculture

Cultivation measures and soil care


Plant and row spacing are specified depending on the crop and are usually designed to optimize yield. The microclimatic conditions within a crop can be influenced with training systems such as leaf wall management. Soil activation with compost or green manure has a positive effect on the crop. Supplementary irrigation must always be used in a crop-optimized manner.

Foliage management in orchards and vineyards creates a loose plant structure with good ventilation and exposure. While winter pruning establishes the basic shape of permanent crops, summer pruning or thinning reduces leaf mass and stingy shoots. Together, these measures contribute to good aeration and exposure and allow for rapid drying, which minimizes fungal diseases. In principle, the rule is as much leaf mass as necessary, as little leaf mass as possible.

In addition, diseases can be prevented by varying the height of the trunk: for example, the higher the foliage wall starts in the vineyard, the less the splash effect, in which spores of Plasmopara viticola are catapulted by rain from the ground to the lowest layer of foliage. It is also essential to remove stingy shoots on the trunk to prevent P. viticola from "shimmying up" to the foliage zone of the cultivar. In berryfruits, tail systems are preferable to shrub systems.

Soil activation can be accomplished with compost, green manuring, or greening with nitrogen-fixing plants. Generally, greening provides water competition to the crop, but at the same time provides a continuous source of nutrients to optimize plant growth. This leads to an increase in resistance to fungal or bacterial pathogens. A plant overfed by mineral fertilizers - especially nitrogen - is very quickly attacked and damaged by fungi (e.g. Botrytis sp.). Optimally nourished plants, on the other hand, can actively defend themselves against pests and thus resist infestation for longer. Herbaceous plantings with water-saving plants are preferable in planting. Care should be taken not to let the greening become too high because of the microclimatic moisture development and the associated risk of fungal attack. Mowing, rolling or undercutting with "Greenmanager" are possibilities to keep the green cover short. In addition, the greening prevents the spread of pathogens with the soil erosion by wind through its action as an erosion prevention. Supplementary irrigation must necessarily be interrupted during rainfall.