In cooperation with the Henderson County Master Pomology Program, we initiated an effort to monitor apple fruit maturity in commercial orchards in Henderson County, NC. The goal of this program is to provide timely updates regarding fruit maturity of several apple cultivars in the region. Data will be presented weekly to commercial apple growers via web-based updates to partly aid in harvest management decisions. Please note that the data presented is limited to the specific orchard block that we used for sampling. Do not assume that fruit at your location are at the same stage of maturity. To be clear, there is no substitute for regular monitoring of fruit quality parameters at your own operation.

Weekly Update (08.27.2025)

Cooler temperatures experienced in Edneyville, NC may have been a factor in moderating fruit maturity progression. Also, this stretch of sunny days and cool nights make for excellent conditions for red fruit color development.

‘Red Delicious’  fruit quality parameters remain mostly unchanged from last weeks assessment (Table 1, Figure 1). A 15% increase in fruit weight was observed while soluble solids continue to remain low at 8.9%, where target specification is 12-14%.

‘Co-op 39’ (Crimson Crisp®) starch pattern index rating averaged 5.5 this week increasing 1.6x from the previous week (Table 2, Figure 2). A 15% increase in marketable blush was observed. While firmness remains higher at 21lbs, all other fruit quality parameters indicate these fruit are suitable for harvest for long term storage.

‘Smoothee’ (Gibson Golden Delicious) starch pattern index rating averaged 2.3 this week increasing 1.3x from the previous week (Table 3, Figure 3). All other fruit quality parameters remain mostly unchanged but moving in the right direction towards maturity.

If of interest, please see the following posts for more detailed information on PGRs to manage fruit maturity and harvest maturity timing. Specifically:

• Using PGRs to Manage Apple Preharvest Drop, Fruit Maturity, and Harvest Timing
• Apple Harvest Management Considerations: Special Focus on Gala
• https://extension.psu.edu/fruit-harvest-determining-apple-fruit-maturity-and-optimal-harvest-date

‘Red Delicious’

Figure 1. ‘Red Delicious’ superficial appearance at the stem-end (top), shoulder (middle), and starch pattern (bottom) on 08.26.2025 in Edneyville, NC.

Co-op 39 (CrimsonCrisp®)

Figure 2. CrimsonCrisp® superficial appearance at the stem-end (top), shoulder (middle), and starch pattern (bottom) on 08.26.2025 in Edneyville, NC.

‘Smoothee’ (Gibson Golden Delicious)

Figure 3. ‘Smoothee’ (Gibson Golden Delicious) superficial appearance at the stem-end (top), shoulder (middle), and starch pattern (bottom) on 08.25.2025 in Edneyville, NC.

When should I harvest?

Optimal harvest timing is dictated by multiple factors, especially the intended market. While one size does not fit all, please see this resource from Michigan State University for some general guidelines.

Acknowledgements

We are very grateful for the cooperation of the Pat Lancaster and the team at Grandad’s Apples for hosting this project. Thank you for your generous access to your farm and fruit!

This work would not be possible without my excellent colleague, co-author, and technician, Tatiana Zuber.

We sincerely appreciate the great work of Marvin Owings, Ken Olson, Ivy Olson, Don Schwartz, Gary Medere, John Masotti, Susan Hadden, Adam Ferrell, Bill Metts, and Leigh Siracusano, who make up the Henderson County Master Pomology Program. This dedicated team of volunteers are assisting with data collection and inspired the initiation of this pilot program.