Scab and rust infection period

A scab and rust infection period ended Monday morning, May 3: 11 hr, 72 deg., 0.4 in. rain. Heavy secondary/primary apple scab from the April 14 infection period is now evident on unprotected shoot leaves. Consider options for stronger "catch-up" treatments if your orchard was not properly covered for the earlier infection periods March 28 and Apr 14 or the more recent ones which could result in damaging secondary fruit infection, Apr 24-25, Apr 25-27, and May 2-3.

Secondary mildew infection is also apparent from ongoing infections which occurred on at least 21 days in April.

Apple Blossom Festival weekend temperatures were actually slightly warmer than those indicated as predicted below, resulting in possible fire blight infection on late bloom wherever wetting occurred. The warmer temperatures should also bring earlier than predicted blossom blight symptom development this week.

For purposes of monitoring cumulative wetting hours for sooty blotch and flyspeck development, we are using Apr 19 as petal fall and wetting hour accumulation of wetting hours begins 10 days later, Apr 29. So far we have accumulated 11 hours toward the 250-hr threshold.