What fungicides to use early in the season?
The fungicides most effective in controlling phomopsis are also effective in controlling early-season (foliar) black rot. The broad-spectrum fungicide mancozeb (Dithane, Manzate, Penncozeb and Manex) is the most effective material for controlling these diseases early in the season. It is recommended to save the use of SI’s (e.g., Nova and Elite) and strobilurins (e.g., Abound, Sovran, Flint) until later in the season when they are needed for control of multiple diseases. Both of these groups of fungicides are prone to resistance development, so are best used at critical disease control periods (immediate pre-bloom until second postbloom). Do not use these materials more than three times per season regardless of the material. Rotating these two fungicide groups can help delay the development of resistance. JMS Stylet Oil or sulfur may be used to control powdery mildew early in the season. However, powdery mildew generally is not a great concern at this time, except in susceptible cultiv
