As of yesterday morning, June 30, we had accumulated 228 wetting hours since May 18, approaching the 250-hour threshold for specific treatment against the SBFS fungal complex at our usual AREC monitoring site at elevation 950 ft. But at a lower AREC elevation (910 ft), we have greatly surpassed this threshold with 334 CWH. Again this illustrates the importance of elevation for wetting hour accumulation. Remember to scout your lower orchard areas regularly for onset of SBFS appearance and adjust your fungicide program accordingly.
With the continued dry weather this past week, powdery mildew remains active where shoots are continuing to grow. Since mildew spores were first observed Apr 9, we have had 49 dry weather “mildew infection days”.
This past week in visits to Frederick County and central Virginia orchards, we saw more fire blight than we would like to see. This seemed to occur as a result of marginal protection at late bloom. For the most part, it does not appear to be spreading actively any more, but the presence of dead wood in the trees raises the concern of increased inoculum levels for the rot fungi, especially bitter rot, as we approach harvest. Bitter rot was already evident in one Nelson county orchard and small, over wintering fruit mummies seemed to the likely inoculum source in that situation.
