|Basic information on primary and secondary apple scab infection periods|
|Background Information for this page|
|Return to Apple list for Greenville RI|
|Weather data for Greenville RI. Forecast values begin May 1, 2015|
| Each expected ascospore release is
tracked as a separate event. Infection
periods representing separate ascospore releases can overlap. Wetting period duration is compared against
the Revised MillsTable by MacHardy et al. for daytime rains during the
primary scab season to estimate release of ascospores. Wetting period duration for night-only
rains during primary scab season, and after the completion of ascospore
maturation (secondary scab season) are compared to the Jones revision of the
Mills table to estimate if wetting was long enough for infection to occur.
The increase in natural resistance to scab infection in the weeks after petal fall is not factored into the Mills table. Because of this, some of the summer wetting periods rated as scab infection periods may in fact have been too sort to cause late season infections. Dry hours in middle of a wet period are not counted toward duration of the wet period. As a result, wetting period duration is not simply the difference between start and end times.
The estimates shown below should only be used as supplements to on-site observations.
|Infection period 1.
Begin: Monday, April 20 at 7 AM ---> End: Thursday, April 23 at 12 PM.
Growth stage at start of period: Between Green Tip and Quarter Inch Green
Best guess is that this infection period accounts for 0.6 % of the season's total primary scab infection risk.
|Wetting period following April 22, 8 PM rain was too short for scab infection.|
|Wetting period following April 27, 10 PM rain was too short for scab infection.|
|Infection period 2.
Begin: Tuesday, May 05 at 10 PM ---> End: Friday, May 08 at 12 PM.
Growth stage at start of period: Between Open Cluster and Full Pink
Best guess is that this infection period accounts for 1 % of the season's total primary scab infection risk.