Southwest Michigan apple maturity report – August 28, 2024
Print
EmailVery warm weather over the past week has been pushing along fruit ripening.
This is our weekly southwest region apple maturity report. Reports are sent out following the Michigan State University Extension fruit team apple maturity calls on Wednesday morning. View Michigan State University Extension’s Apple Maturity page for regional reports throughout the state and additional resources.
Overview for this week
Harvesting of Gala for fresh market and Jonathan and Empires for taffy is underway. Honeycrisp is maturing rapidly.
Gala (Standard)
The table gives a summary for main season Gala varieties sampled from five orchards in Berrien County. All five Gala sites tested mature, according to the starch and firmness tests. The average firmness of 17.2 is appropriate for mid-range duration fruit storage. The predicted harvest date for 2024 for central Berrien County is Aug. 24, which is approximately two weeks ahead of the normal date of Sept. 8 for the region.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|---|---|---|---|---|
|
Aug. 19 |
86 (70-98) |
18.9 (16-22) |
5.0 (2.8-7.4) |
11.6 (11-12.3) |
|
Aug. 26 |
87 (70-97) |
17.2 (14.7-22.3) |
6.0 (4.2-7.0) |
12.8 (12.1-13.4) |
*Starch values according to the 1-8 scale developed by Cornell University.
Mac
Starch indices this week are in the mature range, at or above the mature threshold of 5. Fruit firmness dropped about 1 pound since last week and is approaching the category recommended for short-term controlled atmosphere (CA) storage. The predicted harvest date for central Berrien County in 2024 is Aug. 25.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|---|---|---|---|---|
|
Aug. 19 |
60 (20-98) |
15.3 (14.4-16) |
4.1 (4-4.2) |
11.8 (11.3-12.8) |
|
Aug. 26 |
87 (75-99) |
14.2 (14.0-14.3) |
5.3 (5.0-5.5) |
14.3 (14.2-14.4) |
Honeycrisp
Starch conversion for this variety jumped from 1.9 for last week to 5.0 this week—the mature starch threshold is 3.5. Fruit are internally mature. It is best to harvest prior to 6 on the starch scale for best storage characteristics. The current average firmness reading is 14.9 pounds, now consider best for short-term CA storage (15 lbs). This variety is maturing ahead of the predicted peak harvest date for central Berrien County at Aug. 29.
Like other varieties, Honeycrisp stores better if harvested early in the maturation process. Refer to this article by MSU researcher Randy Beaudry on Honeycrisp harvest and storage recommendations. Very few main season Honeycrisp have been harvested as of Monday of this week.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|---|---|---|---|---|
|
Aug. 19 |
48.0 (45-55) |
15.7 (14.3-16.4) |
1.9 (1.4-2.8) |
10.8 (10.3-11.4) |
|
Aug. 26 |
56.6 (35-67.5) |
14.9 (14.2-15.6) |
5 (4.2-6.0) |
11.6 (11.1-12.1) |
*Starch values according to the 1-8 scale developed by Cornell University.
Empire
This variety is averaging 2.2 for the starch test—the mature starch threshold is 3.5. The current average firmness reading is 18.3 lbs., compared to the desired minimum firmness for long-term CA storage of 16 lbs. The predicted peak harvest date for central Berrien County for fresh market CA storage is Sept. 7. Some picking of Empire for taffy apples is underway in the area.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|---|---|---|---|---|
|
Aug. 26 |
59.3 (40-89) |
18.3 (17.4-19.7) |
2.2 (1.6-3.0) |
11.0 (9.9-12.3) |
*Starch values according to the 1-8 scale developed by Cornell University.
Jonathan
This variety is averaging 2.9 for the starch test—the mature starch threshold for fresh market is 3.5. The current average firmness reading is 19.0 lbs., the desired minimum firmness for long-term CA storage is 16 lbs. The predicted peak harvest date for central Berrien County is Sept. 10. This variety is being harvested in this area now for taffy apples.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|---|---|---|---|---|
|
Aug. 26 |
68.5 (57-75) |
19.0 (17.6-20.3) |
2.9 (2.8-3.0) |
10.8 (9.9-11.4) |
*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:
- Predicted apple harvest dates for 2024 from MSU Extension.
- The 2024 Michigan apple crop forecast, as given at the USApple Outlook meeting
- 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.
