How does MetWatch help with secondary (conidial) Blackspot infections?
A grower wrote in “I seem to have been caught with a primary blackspot infection, which I don’t want to turn into a major secondary infection. Does HortPlus Metwatch predict when a condia infection has ocurred?” Dr Robert Beresford of HortResearch provides the answer. “Metwatch lists potential conidial infection events when you click ‘yes’ to night start in options. However, in a situation where severe primary infection has become established, there is no alternative but to maintain good fungicide cover for the rest of the season. It is strongly recommended to follow the black spot assessment protocol in the IFP manual. That assessment should be done about early December, and fungicide decisions should be based on the monitored black spot level, as a well as on occurrence of conidial infection periods.” So while MetWatch can provide you with information on secondary conidia infection events, you will need to exercise a different control strategy from primary infection events.
