2017 Apple Maturity Assessments—Week Three

Week 3 maturity assessments indicate a need to be ready for an early apple harvest and possible spray applications to prevent preharvest drop.
2017 Apple Maturity Assessments—Week Three - News

Updated: September 8, 2017

2017 Apple Maturity Assessments—Week Three

Premier Honeycrisp, Honeycrisp, Buckeye Gala, and Ultima Gala

This was our third week of maturity sampling. Apple fruit were again spot-picked on size and color from Adams County orchards. With the continued cooler temperatures and rainfall, fruit of these four apple cultivars continued to increase in red color.

Premier Honeycrisp fruit had much better size but less red color than the Galas. The ground color on the Premier was no longer green, but whitish yellow. The Premier Honeycrisp fruit were very loose and have started to drop. Not surprisingly, many of the Premier fruit had lost much of their starch (See Photo 1). As soon as we had picked our maturity samples, the picking crew arrived to harvest fruit for market.

Photo 1: Fruit color and starch staining pattern of representative samples of Premier Honeycrisp (upper) and Honeycrisp (lower) fruit harvested on August 15, 2017 in Adams County. This variable starch staining pattern in the Premier Honeycrisp apples was typical of the spot-picked fruit sampled. Photo: Kathy Hunt, University of Maryland

Many of the red Gala fruit we picked were 100% red, making it difficult to judge their ground color. While they have good red color, fruit in our sample blocks is still small, as they have a relatively low seed count. In addition to becoming redder, the Buckeye Gala and Ultima Gala are also getting softer and beginning to lose their starch (See Photo 2). With a starch pattern index that ranged from 3.4 to 5.4 using the eight point Cornell scale, Gala fruit are approaching storage maturity. About ten percent of the fruit we sampled had the typical half-inch stem end cracks. We also noticed that the Gala fruit sampled were picked easily. Almost all the spot-picked fruit came off without attached spur wood and leaves. With this year's early bloom, many people have been expecting an earlier harvest this year.

Photo 2: Fruit color and starch staining pattern of representative samples of Buckeye Gala (lower) and Ultima Gala (upper) apples harvested on August 15, 2017 in Adams County. The loss of starch in the core and flesh regions was similar in both red Gala cultivars. Note: The fruit in the lower right hand corner with the least starch present has two small stem-end cracks. Photo: Kathy Hunt, University of Maryland

The rapid tree-ripening of Premier Honeycrisp, coupled with the easy release of Premier, Buckeye Gala and Ultima Gala underscores the need to get ready for apple harvest and consider your need for stop-drop materials.

Here is a brief summary of the data from our third week's samples:

CultivarDiameter (inches)Red Color (%)Ground ColorFirmness (pounds)Soluble Solids (°Brix)
Premier Honeycrisp3.165Light Yellow1413
Honeycrisp3.410Light Green18.211.7
Buckeye Gala375Whitish Yellow18.912.3
Ultima Gala2.795Whitish Yellow17.911.3

Instructors

Tree Fruit Cultural Practices and Production Systems Sustainable Specialty Crop Production Support for Next Generation Farmers from Diverse Backgrounds

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