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 (09.04.2025)

‘Co-op 39’ (Crimson Crisp®) apples were harvested last week and thus at an appropriate maturity stage for long term storage.

‘Red Delicious’  fruit quality parameters remain mostly unchanged from last weeks assessment (Table 1, Figure 1). Starch pattern index rating averaged 4.2 this week increasing 1.2x from the previous week. A 6% decrease in both fruit firmness and fruit weight was observed. Soluble solids continue to remain low at 9.1%, where target specification is 12-14%.

‘Smoothee’ (Gibson Golden Delicious) fruit quality parameters this week suggest these apples are nearly acceptable for harvest for long term storage (Table 2, Figure 2).

Granny Smith were evaluated as part of this report for the first time this season. Starch pattern index rating averaged 2.9 and soluble solids 11.6 which are nearly on target for harvest for long term storage purposes (Table 3, Figure 3).

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 09.02.2025 in Edneyville, NC.

‘Smoothee’ (Gibson Golden Delicious)

Figure 2. ‘Smoothee’ (Gibson Golden Delicious) superficial appearance at the stem-end (top), shoulder (middle), and starch pattern (bottom) on 09.02.2025 in Edneyville, NC.

Granny Smith

Figure 3. Granny Smith superficial appearance at the stem-end (top), shoulder (middle), and starch pattern (bottom) on 09.02.2025 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.