Management of apple scab requires information on the development of pseudothecia of V.-inaequalis. One method often used to assess ascospore maturity and discharge is the examination of crushed pseudothecia. Previously described techniques for the preparation and interpretation of pseudothecial squash mounts have been based on the assumption that asci examined at various times in the spring represent the season''s total production of asci. The number of asci per pseudothecium increases in early spring and then decreases in subsequent weeks. A new technique is described that used the maximum number of asci recorded per pseudothecium to correct for exclusion of undeveloped asci in early spring and exclusion of disintegrated asci in late spring. Corrected assessments more accurately depict the seasonal development of V. inaequalis and can be used to detect more accurately the depletion of the supply of ascospores.