Recent research at North Carolina State University and University of Kentucky led to development of a sooty blotch/flyspeck warning system. This system advises growers to apply their second-cover fungicide spray after 175 hours of wetness have been measured since the first-cover fungicide spray was applied. In contrast, the conventional practice is to apply the second-cover spray 10 to 14 days after the first-cover spray. |
 Using
a weather datalogger
in your orchard or SkyBit
remotely sensed data, you start counting wet hours (due to rainfall
or dew) from the time you apply the first-cover fungicide spray. Wetting
periods less than 4 hours long are not counted in the 175-hour total.
Simply add up the hours in wet periods 4 hours or more long, day by
day, until you reach a total of 175 hours; then it’s time to
apply the second-cover fungicide spray. This spray should include
a benzimidazole fungicide (either Topsin-M or Benlate; remember that
Benlate will not be sold after January 2002). After the second-cover
spray is applied, you should return to a protectant cover-spray fungicide
program for the remainder of the season. |
| Click
here for more information
on the ISU Horticulture Farm Trials. Click here for more information on the Cooperating Grower Trials. |
Email:
mgleason@iastate.edu Telephone:
(515) 294 0579 Address: 312 Bessey Hall, Iowa State University, Ames IA
50011