Managing frogeye leaf spot on susceptible varieties
There are several things to learn from this study:
1. If the strobilurins are effective, use them at the higher rates. This will diminish the chances of fungicide resistance developing in the population.
2. The triazoles are equally effective, if applied at the right rates and timings.
3. Through the management of many, many pathogens with fungicides, it is always best to rotate classes of chemistries rather than combining them. The only reason to combine chemistries is if you have multiple pathogens to control and you need more than one active ingredient in the tank.
Finally – the best approach to managing this disease though is to use a resistant variety, they are the same price as the susceptible and you won’t have to worry about this.