Signum, a new fungicide with interesting properties in resistance management of fungal diseases in strawberries.

Signum, a new fungicide developed by BASF, was applied during 6 successive years against fungal diseases in strawberries. The product is formulated as a water dispersible granule, containing 6.7 % pyraclostrobin and 26.7 % boscalid. Pyraclostrobin is similar in chemistry to other strobilurin fungicides like kresoxim-methyl and trifloxystrobin, registered for fruit disease control. Boscalid belongs to the class of carboxyanilides. Both components in the premix formulation combine two different biochemical modes of action in the fungal cell respiration. Therefore, this co-formulation gives a broad-spectrum activity and also a reduced resistance risk for different target pathogens. Botrytis cinerea is the most important disease on strawberry-fruits and thus the control of fruit rot is mainly focused on this fungus. In average over 6 years, Signum has not only given a very good control against Botrytis fruit rot, but it has also shown a high performance in the control of Colletotrichum. Besides, Signum provides good control of powdery mildew (Podosphaera aphanis) and limits the shift to other fruit rots like leather rot (Phytophthora cactorum and leak (Rhizopus, Mucor). The availability of several categories of fungicide families with a different mode of action gives opportunities in alternating different fungicides and is the best guarantee for a sustainable control of fruit rot in all kinds of strawberry production methods. Signum should be integrated in an overall disease management program. Trials, in which the applications of Signum were timed on disease forecasting, based on environmental factors favorable for Botrytis development, were very promising. This tool can also help in establishing the IPM-concept in the production of strawberries.