Depuis les premiers tests de fongicides effectués il y a 10 ans,des évolutions majeures ont permis de continuer à protéger la plante dans un contexte économique devenu difficile, tout en limitant davantage l'impact des traitements sur l'environnement. Ten years of experiments have led to the discovery of the most efficient fungicides for controlling sunflower phomopsis. The treatments were always found to contain fenpropimorph or fluzilazol, both associated with other active ingredients.
The progress made since 1992 is quite spectacular. Knowledge of the characteristics of actions of the most widely used fungicides has led to an increase in the average level of effectiveness thanks to improved positioning. Increased awareness of the products' capabilities, linked to an improved representation of the levels of sensitivity of crop types has made it possible to cut down the number of treatments.
The optimal time for protection against sunflower phomopsis is more often than not between stages E1 and E3. The preventive treatment date using fluzilazol-based (preventative) products should always precede that for curative fenpropimorph-based products by approximately one week. Spring-time climatic conditions, which are extremely favourable for the fungus may require an early treatment, but the application of two treatments should still only be undertaken in exceptional circumstances.
