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.

Keeping pace with harvest this season has been a challenge for many. Accelerated fruit maturity, excessive heat, high humidity, and frequent rainfall has complicated harvest activities (Figure 1). Pending upon cultivar, fruit maturity is running 7 to 14 days earlier than "normal". In some cultivars, we've observed rapid reductions in fruit firmness and poor red fruit color development. Fortunately, an upcoming shift in our weather pattern will bring drier air and cooler temperatures for the 1st half of next week.

‘Co-op 39’ (CrimsonCrisp®) fruit weight is up 12% to 142g and fruit firmness is down 1.1 lbs to 21.7 lbs (Table 1, Figure 2). All fruit quality parameters remain relatively the same as last week and are on target for harvest for long term storage except for marketable blush which has narrowly increased 8% from 63% to 68%.

‘Smoothee’ (Gibson Golden Delicious) starch pattern index has increased 1.2 fold from last week to 2.2 (Table 2, Figure 3). Based on last years data, this cultivar carries a lower starch pattern index value then other cultivars at harvest. Fruit firmness (15.6 lbs) along with all other fruit quality parameters, suggests that these fruit are on target for harvest for long term storage.

Granny Smith were evaluated for the first time this season and are immature at this sampling interval (Table 3, Figure 4).

'Honeycrisp' (Royal Red Honeycrisp®) were spot picked last week so this weeks evaluation is based on the remaining apples on the tree. Skin cracking has been observed across many Honeycrisp blocks this season.Marketable blush remains low at 3% and may be difficult to achieve this season (Table 4, Figure 5). Fruit firmness (15.3 lbs), soluble solids (14.5%) and starch pattern index (5.1) suggest that remaining fruit are on the threshold of being harvested.

‘Red Delicious’ marketable blush surprisingly decreased 27% this week to 49% (Table 5, Figure 6). This is likely an artifact of the fruit sampling procedure. Based on last years data, this cultivar carries a lower soluble solids value then other cultivars at harvest. Fruit firmness (14.9), soluble solids (9.5) and average starch pattern index (3.5) suggest these fruit are ready for harvest for long term storage.

If of interest, please see our previous posts for more detailed information on how to manage fruit maturity. Specifically:

• Using PGRs to Manage Apple Preharvest Drop, Fruit Maturity, and Harvest Timing
• Apple Harvest Management Considerations: Special Focus on Gala

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 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 the Henderson County Master Pomology Program. This dedicated team of volunteers inspired the initiation of this pilot program and is assisting with data collection. I will share more information about this group in the near future.