Protectant fungicides such as Bravo and Captan are effective during both stages, however, they must be applied before a wetting event. SI's should be rotated with non-SI protectant fungicides to prevent resistance development and for better overall control of brown rot. Other fungicide options exist, including Rovral and Vanguard for blossom blight. Scab Maturity Squash mounts performed on 23 and 24 April from apple leaves collected in Groton, MA and Amherst, MA showed less maturity than expected. Keep in mind that this is a small sample and with very warm temperatures, development will speed-up.
Some eastern orchards are at tight cluster now.
If we get significant rain, we should see disease pressure by early next week. As the weather warms up, overwintered adult become active and feed on apple fruit buds which may cause flower abscission. TPB populations vary considerably between orchards and white sticky traps placed at silver tip help determine the need for a prebloom treatment. However, few TPB have been caught in traps and numbers are well below spray threshold. However, were heavy activity of TPB are monitored, optimum spraying time should be between late tight cluster and late pink.