Major Apple Scab Infection With Rains Predicted 23rd and 24th March In Virginia
A major scab infection is predicted for the rains predicted in forecast 23 to 24 March spanning from Winchester to Tyro to Rustburg, VA and all nearby locations. My recommendation would be to apply anilinopyrimidine (AP) fungicide Vangard (3 oz/A), or Scala (5 fl oz/A), or Luna Tranquility (12 fl oz/A) with mancozeb (2.5 lb/A) before this block of rainy weather for maximum efficacy. These AP fungicides work best in cool weather in spring and can be applied before or 72 hr after the time when rain event began and caused scab infection (kick-back activity), however, use the kick-back mode of activity only in an emergency i.e. if you know you did not have any fungicide applied before this infection. Vangard (3 oz/A), Scala (5 fl oz/A), or Luna Tranquility (12 fl oz/A) with mancozeb (2.5 lb/A) are preferable choice can be applied once more (at TC) and keep in mind that they are not effective for juniper rusts. Mancozeb will pick up any any early rust infections at this point, but be ready to apply DMI fungicides (Group 3) at PK bud for rust as galls on cedars open.