Apple fruits grow at a relatively uniform rate during much of the season. While many factors influence the rate of fruit growth, such as weather, tree vigor, crop load, etc., the interacting effects of these factors are fairly well established 2-3 months after bloom. Throughout the remainder of the season, the growth rate follows a predictable pattern. As a result, the harvest size of Mclntosh apples can be accurately predicted from fruit size measurements on August 1.