2018 Apple Maturity Assessment: Week Three

Premier Honeycrisp apples are ripening quickly and Mid-Atlantic growers have begun picking.
2018 Apple Maturity Assessment: Week Three - News


Spot-picked apples we tested from Pennsylvania this week had softened, lost starch, increased in sugar, and had varietal flavor. These appeared to be riper on the inside than would be expected by just looking at their ground color and surface color.

In July we started maturity sampling in Adams County, focusing on Premier Honeycrisp apples grown at 1,200 feet elevation. Fruit were spot-picked in the same commercial orchard and block we have monitored during the past two years. While there is not 60% red color at that location, tree ripening of the fruit has really begun.

During the past week, fruit size and the percentage of red color increased, and the ground color changed from yellowish green to greenish yellow. These fruits lost 2.5 pounds of firmness and had a dramatic change in their starch staining pattern. This loss of starch led to an increase in sweetness, as measured by taste and soluble solids.

The following table shows data from our pre-harvest samples of Premier Honeycrisp taken in the same orchard block during the past three weeks. As you can see, harvest maturity data changed dramatically this week.

CultivarDiameter (inches)Red Color (%)Ground ColorFirmness (pounds)Starch Pattern (1 – 8)Soluble Solids (°Brix)
25-Jul-182.89Light Green18.91.410.9
31-Jul-182.919Yellowish Green16.42.810.9
7-Aug-183.135Greenish Yellow13.96.212.1

Rapid maturation and tree ripening are the hallmark of early-season apples. During the past few years, this has been particularly problematic with varieties that tree-ripen in August. Honeycrisp and Jonagold were selected by fruit breeders working in cool growing areas. Having been selected for cool climates, they are particularly prone to rapid ripening and pre-harvest drop when grown in the warmer Mid-Atlantic region.

Be sure to watch your August apples very closely to avoid picking overripe fruit with a short shelf-life.

Variation in color development, size, and starch staining pattern of spot-picked Premier Honeycrisp apples in Adams County this week. Photo: Kathy Hunt, University of Maryland