Tree stage:
3/28/98 – green tip
4/1/98 – half inch green
4/14/98 – tight cluster
4/21/98 – loose cluster
4/29/98 – early bloom
5/4/98 – nearly petal fall

Apple scab infection periods:

4/8/98 – 4/10/98 : 36 hours (combining two wet periods) at an average temperature of 41

4/16/98 – 4/18/98: 36 hours at 50 degrees

4/19/98: infection period in southern RI only

4/23/98: infection period

5/4/98: infection period – continued until 5/11/98

5/17/98: release of last primary scab spores should have occurred. End of Primary scab season!