Southwest Michigan apple maturity report – September 24, 2025
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EmailApple harvest in southwest Michigan is shifting focus to mid- and late season varieties.
This is our weekly southwest region apple maturity report. Due to some staff changes, there will not be a southwest apple maturity report next week on Oct. 1. We will do our best to continue apple maturity articles over the next month as we transition to a new tree fruit Extension specialist in the region. View Michigan State University Extension’s Apple Maturity page for regional reports throughout the state and additional resources.
Overview
Favorable picking conditions and rapid ripening throughout southwestern Michigan has allowed for efficient harvesting of early varieties across the region. Empires, Jonagolds, Golden Delicious and Fuji varieties are at or near maturity depending on farm location. Commonly grown cultivars such as Red Delicious, Fuji, Honeycrisp, Jonagold, Granny Smith and Braeburn can have problems with watercore. Advanced maturity (ripe fruit) is a required feature for the development of watercore, so factors such as hot days, and hot days plus cool nights, that advance fruit maturity can promote watercore development.
Blocks with light crop loads will mature three or four days sooner than the predicted harvest dates while heavy crop loads will mature up to a week later than the predicted dates.
The Michigan apple crop forecast for 2025 is above average at 30 million bushels, as given at the US Apple Crop Outlook on Aug. 15th (https://usapple.org/news-resources/2025-26-apple-crop-outlook ). The tables below give a summary for select varieties that are currently nearing harvest sampled from 3 orchards in Berrien County.
Empire
Empires are at or near full maturity at many locations, with some early pickings already complete. This variety is averaging between 2-4 for the starch test, either at or very near the mature starch threshold of 3.5. The current average firmness reading is 18.9 pounds compared to the desired minimum firmness for long-term controlled atmosphere (CA) storage of 16 pounds, so storage prospects look good at this point.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
Sep. 22 |
87 (65-100) |
18.9 (15.3-23) |
2.7 (2-4) |
11.8 |
*Starch values according to the 1-8 scale developed by Cornell University.
Jonagold
Jonagolds are mostly mature, with some sampled Jonagold becoming overripe, slightly earlier than anticipated. Sampled fruits are between 4-6 for the starch test—the mature starch threshold for fresh market is 3.5 and over maturity threshold is 5.5. The average firmness reading is 14.3 pounds, which is softer than the desired minimum firmness of 15 pounds for short-term CA storage. Plant growth regulator applications, such as Retain, were applied the week of Aug. 18 in some of the sampled Jonagolds.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
Sep. 22 |
64.5 (45-90) |
14.3 (12.5-16.5) |
7.1 (6-8) |
12.5 |
*Starch values according to the 1-8 scale developed by Cornell University.
Golden Delicious
This variety is averaging 4.9 for the starch test, which is considered mature (threshold is 3 for ripe, 6.5 for over mature). The current average firmness reading is 15.4 pounds, which is at the desired minimum firmness for short-term CA storage. Retain applications made in some sampled blocks on Sept. 8.
|
Collection Date |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
Sep. 22 |
15.4 (13.3-19.2) |
4.9 (4-7) |
16.2 |
*Starch values according to the 1-8 scale developed by Cornell University.
Fuji
This variety advanced in maturity quickly over the last week and is now averaging 3.8 for the starch test—the mature starch threshold for fresh market is 3 (over mature is 7). The current average firmness reading is 18.3 pounds, which is at the desired minimum firmness for long-term CA storage. Some growers may delay picking to wait for better size, blush and brix.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
Sep. 22 |
54.5 (15-100) |
18.3 (14.8-21.5) |
3.8 (3-6) |
12.7 (12.3-13.1) |
*Starch values according to the 1-8 scale developed by Cornell University.
Ida Reds
This variety is averaging 2.6 for the starch test—the mature starch threshold for fresh market is 3.5. The current average firmness reading is 16.4 pounds, which is at the desired minimum firmness for long-term CA storage. We seem on track for the predicted peak harvest date for central Berrien County on Oct. 1, about a week ahead of historical norms.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
Sep. 22 |
75 (50-100) |
16.4 (14.5-19) |
2.6 (1-4) |
12.3 |
*Starch values according to the 1-8 scale developed by Cornell University.
Apple maturity sampling parameters
- Color % = the visual percentage of red color (blush) from 0 to 100; range shown is for the orchard averages.
- Firmness in lbs pressure, skin off, as measured with a FT Penetrometer; range is for the site averages.
- Starch: 1 = all starch (solid blue staining), 8 = no starch (white); range is for the site averages. Starch Iodine Index Chart.
- Brix = % sugar measured with Atago PAL-1 Pocket Refractometer
|
Suggested firmness and starch index levels for long-term and shorter-term controlled atmosphere (CA) storage by variety. |
|||||
|---|---|---|---|---|---|
|
Variety |
Firmness (lbs)* |
Starch Index* |
|||
|
Short CA |
Mid-CA |
Long CA |
Mature |
Over mature |
|
|
McIntosh |
14 |
15 |
16 |
5 |
7 |
|
Gala |
16 |
17 |
18 |
3 |
6 |
|
Honeycrisp |
15 |
16 |
17 |
3.5 |
7 |
|
Empire |
14 |
15 |
16 |
3.5 |
6 |
|
Early Fuji |
16 |
17 |
18 |
3 |
7 |
|
Jonagold |
15 |
16 |
17 |
3.5 |
5.5 |
|
Jonathan |
14 |
15 |
16 |
3.5 |
5.5 |
|
Golden Delicious |
15 |
16 |
17 |
3 |
6.5 |
|
Red Delicious |
16 |
17 |
18 |
2.5 |
6 |
|
Idared |
14 |
15 |
16 |
3.5 |
6 |
|
Fuji |
16 |
17 |
18 |
3 |
7 |
|
Rome |
15 |
16 |
18 |
3 |
5.5 |
|
Braeburn |
16 |
17 |
18 |
2.5 |
7 |
See the following helpful resources for more information:
- More information on harvest management tools and timings from MSU Extension.
- Post harvest treatments to extend apple life.
- Guidelines from MSU Extension to check for apple maturity in your own orchard, including specific pressure and starch recommendations by variety.
- Predicting apple maturity and starch chart from Cornell University.
