Monday, July 1, 2013

Last week's extended wetting and accumulated wetting hours

Last week was relatively dry, but with a 13-hr wetting period of June 29-30 with 0.14 in. of rain at 67°.

As of this morning, July 1, we had accumulated 251 wetting hours- just exceeding the 250-hour threshold for specific treatment against the sooty blotch and flyspeck fungal complex. For purposes of predicting development of the sooty blotch and flyspeck (SBFS) fungal complex, we record accumulated wetting hours from rainfall or dew, starting 10 days after petal fall. At 250 hours the organisms causing sooty blotch and fly speck symptoms are expected to be present on non-treated fruits, and symptoms will appear after a brief incubation period. Typically, symptoms will appear earlier in orchards at lower elevations where more wetting hours accumulate.