Southwest Michigan apple maturity report – August 30, 2023
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EmailApples in southwest Michigan are expected to mature a few days earlier than last year.
This is the first of our weekly southwest region apple maturity reports. Reports are sent out on Wednesdays following the Michigan State University Extension fruit team apple maturity calls on Wednesday morning. See the following helpful resources for more information:
- Predicted apple harvest dates for 2023 from MSU Extension.
- More information on harvest management tools and timings from MSU Extension.
- 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.
- Starch chart for Honeycrisp apples developed by Washington State University.
How to read the maturity tables
We test apple varieties that are nearing maturity in the southwest Michigan area with a focus on Berrien County. We are reporting average values for firmness, starch index and brix for several samples for each variety. Maximum and minimum values are included for the highest and lowest average for individual orchards.
2023 overview
In general, apples in central southwest Michigan are predicted to mature a few days earlier than 2022, and three to six days earlier than the long-term average. Crop load is generally good to very good in most locations with Honeycrisp being somewhat more variable.
Gala (Standard)
This variety is generally testing immature to barely mature, depending on the site, according to the starch test and firmness. This agrees with the predicted harvest date of Sept. 2. One site averaged 3.2 on the starch test, with 3 considered mature, and one site had an average firmness of 17.3 pounds, which is a typical value for apples going into long term storage. Early season Gala strains such as Wildfire and Foxtrot are already mature.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
Aug. 29 |
62 (60-65) |
18.6 (17.3-20.0) |
2.1 (1-3.2) |
10.2 (9.7-11.2) |
*Starch values according to the 1-8 scale developed by Cornell University.
Premier Honeycrisp
This early ripening sport of Honeycrisp shows great color and mature firmness and starch conversion. Harvest of this variety is underway in the region.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
Aug. 30 |
99 (98-100) |
15.2 (11.2-19.4) |
6.8 (6.0-8.0) |
13.6 |
*Starch values according to the 1-8 scale developed by Cornell University.
Early Fuji
Strains tested include September Wonder, Daybreak and Nickell. Red color is generally adequate with green background, and internal starch just over the mature threshold of 3. Firmness is still very good, allowing harvest to be delayed for better background color and sugar development.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (Brix) |
|
Aug. 30 |
57 (40-75) |
16.0 (15.0-17.4) |
3.6 (2.8-4.6) |
11.7 (11.4-12.1) |
Mac
Strains tested include Ruby and Linda Mac. Starch indices are still in the immature range, below the mature threshold of 5. However, fruit firmness is averaging 14.9 in the mid-range storage category. This is not ideal, indicating a potential for shorter shelf life for this variety in 2023. Predicted harvest date for central Berrien County in 2023 is Sep. 4.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
Aug. 29 |
45 (20-60) |
14.9 (14.3-15.2) |
3.4 (3-4) |
12.0 (10.8-12.9) |
Maia SM (Sweet Maia)
This is a new apple variety from a cross of Honeycrisp and Winecrisp from the Midwest Apple Improvement Association (MAIA). Sweet Maia apparently ripens with early Gala strains with characteristic sweetness and crispness.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
Aug. 30 |
97 (95-100) |
18.6 (16.3-22) |
8 (8-8) |
14.3 |
Apple maturity sampling parameters
- Color % = the visual percentage of red color (blush) from 0 to 100; range is of all fruits tested.
- Firmness in pounds pressure = measured with a FT Penetrometer; range is of all fruits tested.
- Starch: 1 = all starch, 8 = No starch; range is of all fruits tested. Using Cornell Starch Iodine Index Chart.
- Starch for Honeycrisp: a separate starch chart for Honeycrisp apples developed by Washington State University (scale 1-6).
- Brix = % sugar measured with Atago PAL-1 Pocket Refractometer
Looking for more? View Michigan State University Extension’s Apple Maturity 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 |
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 |
