Messenger is now labeled in California as a disease management for powdery mildew and Botrytis bunch rot on all varieties of grapes, and bacterial speck in tomatoes. It may also be used for bacterial leaf spot on peppers and on foliar bacterial diseases in other fruiting vegetables.
Messenger is a foliar-applied and enhances the plant's ability to ward off attacks by disease organisms. The unconditional label expansion was approved by the California Department of Pesticide Regulation (CDPR), which first labeled Messenger in California last year for use on strawberries. Messenger previously received Federal EPA approval for full commercial use on more than 40 crops in April 2000. It is produced and marketed by Eden Bioscience Corp., Bothell, Wash.
Interim Eden president Brad Powell said more California crops will be added to Messenger's label in the future.
Messenger is a patented technology that improves plant protection and crop production. The active ingredient in Messenger is based on a naturally occurring protein called harpin. Foliar applications trigger natural defense systems in the plant to protect against disease, reducing both incidence and severity of infection and leading to higher yields.
In nine wine grape trials, Messenger alternated with grower standard fungicides maintained disease control and significantly boosted yields compared to the grower standard alone without compromising brix, pH, or tartaric acid. It is not recommended as a stand-alone product, but used in rotation with traditional fungicides.
Messenger is recommended for use in tomatoes the same way, in rotation with a grower's standard disease control program to improve overall yields.
Messenger use rates are low, and it does not disrupt predatory mites or beneficial insects. It is virtually nontoxic and leaves no detectable residue on treated crops. Worker re-entry restrictions are four hours and there is no pre-harvest interval.