Grand Rapids area apple maturity report – September 24, 2025
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EmailMcIntosh, Empire and Jonagold are being harvested. Golden Delicious and Ambrosia are mature.
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 harvest are finishing this week. McIntosh, Jonagold and Empire are also being harvested at some locations. Golden Delicious and Ambrosia are mature according to the starch rating and are still very firm. Red Delicious are immature. With advancing maturity, applications of pre-harvest 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 7 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 week was hot with low temperatures in the mid and upper 50s and low 60s and highs in the 70s and 80s across the region, according to the Sparta Enviroweather station. A storm system over the weekend brought rain and slightly cooler weather, and a total of 2.14 inches of rain has fallen since Sept. 20, according to the Sparta Enviroweather station. Daytime temperatures will remain steady over the next few days with highs in the 70s and lows in the 50s. Chances of rain are forecasted through the end of the week.
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
Jonagold
Jonagold fruit were sampled from three locations in Sparta. Red color is similar to last week at 69%, and background color is yellow-green. Fruit firmness is at 18.2 pounds of pressure. Starch is now at 6.8, and sugars are excellent at 13.8 Brix. Average fruit diameter is 3.0 inches.
|
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) |
|
Sept 22 |
196 (241-134) |
69 (97-40) |
3.8 (5-3) |
18.2 (19.9-16.3) |
6.8 (8-4) |
13.8 (14.1-13.5) |
*Average values from Sept. 2 are reported from one sampling location.
Fuji
Fuji fruit, which includes the strain Aztec Fuji, were sampled from four locations in Sparta. Red color is an average of 67%, and background color is green. Fruit firmness is at 20 pounds of pressure. Starch is at 2.4, and sugars are good at 12.6 Brix. Average fruit diameter is 2.7 inches. Fruit are almost mature. 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) |
|
Sept 22 |
143 (191-113) |
67 (95-30) |
4.7 (5-4) |
20.0 (22.8-17.3) |
2.4 (4-1) |
12.6 (13.4-11.2) |
Empire
Empire fruit were sampled from one location in Sparta. Fruit were treated with ReTain. Red color has improved and averaged at 94% red color. Background color is yellow-green. Fruit firmness is still high at 20.1 pounds of pressure. Starch rating is at an average of 2.8, which is similar to last week. Sugars are at 11.8 Brix. Average fruit diameter is 2.7 inches.
|
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 |
|
Sept 22 |
138 |
94 (99-85) |
3.3 (4-3) |
20.1 (21.8-18.8) |
2.8 (3-2) |
11.8 |
*Average values from all dates are reported from one sampling location.
Golden Delicious
Golden Delicious were sampled from three locations in Sparta. There is a slight blush on some fruit covering an average of only 17.2% of the fruit surface, and background color is still green. Fruit firmness is at 18.5 pounds of pressure. Starch is at 6.8 on average, and sugars are excellent at 15.6 Brix. Average fruit diameter is 2.6 inches. According to the table below, Golden Delicious are mature and are ready for harvest.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|
Sept 15 |
123 |
4.3 (30-0) |
4.7 (5-4) |
19.0 (21.1-16.7) |
4.7 (6-3) |
14.3 (14.3-14.2) |
|
Sept 22 |
129 (139-122) |
17.2 (40-0) |
4.5 (5-3) |
18.5 (22.7-15.9) |
6.8 (8-6) |
15.6 (16.1-15.0) |
Ambrosia
Ambrosia were sampled from three locations in Sparta. Fruit have excellent red cover for Ambrosia with 62% red color over the fruit surface, and the background color is yellow green. Fruit firmness is at 18 pounds of pressure. Starch is at 5.8 on average, and sugars are excellent at 14.2 Brix. Average fruit diameter is 2.7 inches. Be sure to check Ambrosia fruit every few days to test for maturity at individual orchard locations. This variety can quickly change from immature to mature.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|
Sept 22 |
147 (153-142) |
62 (80-40) |
3.2 (4-2) |
18.1 (19.1-15.8) |
5.8 (8-4) |
14.2 (14.8-13.2) |
Red Delicious
Red Delicious fruit were sampled from two locations in Sparta. Red color is 94%. Background color is yellow-green. Fruit firmness is at 18.3 pounds of pressure. Starch is at 2.4. Sugars are good at 12.2 Brix. Fruit are still immature. Average fruit diameter is 2.5 inches.
|
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) |
|
Sept 22 |
127 (132-121) |
94 (100-70) |
3.8 (5-3) |
18.3 (20.3-17.0) |
2.4 (4-1) |
12.2 (12.5-11.8) |
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 |
