Toivonen, P. M. A. 2015. Comparison of I_AD 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 I_AD 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 I_AD values were associated with firmness retention in all years. Seasonal differences in temperature patterns were possible factors affecting the starch-iodine index. I_AD was more consistent between seasons for monitoring maturity.