Toivonen, P. M. A. 2015. Comparison of IAD and starch-iodine indices at harvest and how they relate to post-storage firmness retention in Ambrosia™ apples over three growing seasons. Can. J. Plant Sci. 95: 1177-1180. Starch-iodine index and IAD values were recorded for Ambrosia™ apples at harvest and compared with firmness retention after controlled atmosphere storage. The starch-iodine index correlated with firmness retention only in 2012. Harvest IAD values were associated with firmness retention in all years. Seasonal differences in temperature patterns were possible factors affecting the starch-iodine index. IAD was more consistent between seasons for monitoring maturity.