Grand Rapids area apple maturity report – September 17, 2025
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EmailHoneycrisp and Gala harvest are wrapping up across the region, and sugar levels and red color are excellent.
Apple maturity testing will occur weekly for the Grand Rapids, Michigan, region beginning now through the end of harvest. Reports will be sent out every week, following the Michigan State University Extension fruit team apple maturity calls on Wednesday mornings.
Honeycrisp and Gala are being harvested this week. Some growers are harvesting McIntosh and Jonagold. Empire are close to maturity. Golden Delicious are mature according to the starch rating and are still very firm. Red Delicious are immature. Apple maturity is advancing steadily, especially with this hot weather. With advancing maturity, applying preharvest management tools may be needed to help maintain fruit quality and manage labor. For later maturing varieties, a product like aminoethoxyvinylglycine (AVG; ReTain) can be used, and applications at 28, 14 or seven days before harvest are recommended. For a 1-MCP product (Harvista), applications are recommended closer to harvest at seven or three days.
Weather over the past few days has been warmer with low temperatures in the 50s and high temperatures have been in the 70s and 80s in the region. Temperatures will continue to be hot over the next few days with highs in the 70s and 80s and lows in the 50s.
How to read maturity tables
Each week, an apple maturity report will be provided and will include average values for several apple samples for varieties nearing maturity. Maximum and minimum values are included in tables below for the highest and lowest individual fruits evaluated for each to give a full spectrum of maturity. All samples included in the reports have been untreated with ReTain or Harvista, unless otherwise noted. Samples were collected from three locations in Kent County.
For more information about apple maturity testing, review these resources compiled by the MSU Extension tree fruit team.
- Predicted apple harvest dates for 2024 from MSU.
- More information on harvest management tools and timings can be found in this article.
- Guidelines from MSU to check for apple maturity in your own orchard, including specific pressure and starch recommendations by variety.
- New starch charts for evaluating apple maturity in Michigan from Michigan State University
- Predicting apple maturity and starch chart from Cornell University.
- Starch chart for Honeycrisp Apples developed by Washington State University.
Maturity information for the Grand Rapids region
Gala
Gala fruit were sampled from three locations in Sparta. Red color is similar to last week at 92%, and background color is yellow. Fruit firmness is at 18.7 pounds of pressure. Starch is at 3.6, and sugars are excellent at 13.4 Brix. Average fruit diameter is 2.7 inches. Fruit could be harvested for mid- or long-term storage depending on the site. For long-term storage, recommended pressure is 18 pounds and the recommended starch rating is 3.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|
Aug 26 |
141 (149-132) |
80 (99-40) |
2.3 (4-1) |
20.4 (22.6-16.9) |
1.8 (4-1) |
10.2 (10.7-9.6) |
|
Sept 2 |
125 (131-120) |
93 (100-75) |
1.3 (3-1) |
21.5 (24.1-18.9) |
2.2 (5-1) |
11.3 (12.0-10.8) |
|
Sept 8 |
134 (140-126) |
92 (100-60) |
1.5 (3-1) |
19.7 (21.7-16.2) |
3.0 (7-1) |
13.1 (15.5-12.0) |
|
Sept 15 |
140 (142-138) |
92 (99-80) |
1.7 (3-1) |
18.7 (20.5-16.8) |
3.6 (7-2) |
13.4 (13.7-13.0) |
Jonagold
Jonagold fruit were sampled from three locations in Sparta. Red color is similar to last week at 64%, and background color is changing to more yellow-green. Fruit firmness is at 19.2 pounds of pressure. Starch is now at 5.1, and sugars are excellent at 13.2 Brix.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|
Sept 2 |
199 |
30 (40-10) |
4.8 (5-4) |
22.0 (24.7-20.4) |
2.2 (3-1) |
11.1 |
|
Sept 8 |
177 (215-141) |
67 (95-25) |
4 (5-3) |
19.8 (21.3-18.5) |
3.6 (5-2) |
12.3 (12.7-11.5) |
|
Sept 15 |
194 (234-150) |
64 (100-15) |
3.9 (5-3) |
19.2 (20.9-16.9) |
5.1 (7-3) |
13.2 (13.6-12.7) |
*Average values from Sept 2 are reported from one sampling location.
Empire
Empire fruit were sampled from one location in Sparta. Red color is 62%. Red color decreased as a function of fruit sampling this week. Background color is changing from green to yellow green. Fruit firmness is at 18.6 pounds of pressure. Starch rating is an average of 3, and sugars are at 11 Brix.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|
Sept 8 |
137 |
72 (80-50) |
4 (5-3) |
19.8 (20.9-18.5) |
1.4 (2-1) |
10.6 |
|
Sept 15 |
143 |
62 (80-35) |
3.6 (4-3) |
18.6 (21.6-17.3) |
3.0 (6-2) |
11.0 |
*Average values from Sept 8 and 15 are reported from one sampling location.
Golden Delicious
Golden Delicious were sampled from two locations in Sparta. There is a slight blush on some fruit covering an average of only 4.25% of the fruit surface, and background color is green. Fruit firmness is at 19.0 pounds of pressure. Starch is at 4.7 on average, and sugars are excellent at 14.3 Brix.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|
Sept 15 |
123 |
4.25 (30-0) |
4.65 (5-4) |
19.0 (21.1-16.7) |
4.7 (6-3) |
14.3 (14.3-14.2) |
Red Delicious
Red Delicious fruit were sampled from two locations in Sparta. Red color is 93%, and background color is yellow-green. Fruit firmness is at 19.1 pounds of pressure. Starch is at 2.1, and sugars are excellent at 13 Brix. Fruit are still immature.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|
Sept 15 |
132 (140-123) |
93 (100-70) |
3.5 (4-2) |
19.1 (21.6-17.0) |
2.1 (3-1) |
13 (13.9-12.0) |
Apple maturity sampling parameters
- Color % = the visual percentage of red color from 0 to 100; range is of all fruits tested. Indicates surface area covered in red and intensity of red color.
- Background color: 5 = Green, 1 = Yellow; range is of all fruits tested.
- Firmness in pounds pressure = measured with a Güss Fruit Texture Analyzer; range is of all fruits tested.
- Starch For Honeycrisp: will typically be rated using the standard Michigan State University starch scale (1-8). However, a separate starch chart for Honeycrisp Apples developed by Washington State University (scale 1-6) also exists.
- Brix = % sugar measured with Atago PAL-1 Pocket Refractometer
Looking for more? View Michigan State University Extension’s Apple page for regional reports throughout the state and additional resources.
|
Suggested firmness and starch index levels for long-term and shorter-term controlled atmosphere (CA) storage by variety. |
|||||
|---|---|---|---|---|---|
|
Variety |
Firmness (pounds)* |
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 |
6 |
|
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 |
|
Brix Guide |
Low |
Fair |
Good |
Excellent |
|
All varieties |
Less than 11 |
11 |
12 |
13 |
|
Honeycrisp |
Less than 12 |
12 |
12 |
Greater than 14 |
