Southwest Michigan apple maturity report – September 13, 2023
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EmailHoneycrisp and Gala apple varieties are maturing quickly in 2023 in southwest Michigan.
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.
Report overview
Growers are finishing up Gala harvest in the area. Honeycrisp and Jonagold are maturing quickly. Recent rains have slowed harvesting efforts.
Gala (Standard)
This variety continues to ripen quickly with internal starch conversion of this variety nearly complete, now at 7.4 out of a possible 8. The predicted harvest date is Sept. 2 for central Berrien County. Fruit firmness dropped about 2 pounds since last week, now at 16.1 pounds, which is considered suitable for short-term controlled atmosphere storage. Brix increased to an average of 12.3.
|
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) |
|
Sep. 5 |
87 (60-98) |
18.2 (16.8-18.8) |
6.2 (5-7) |
11.5 (10.8-11.9) |
|
Sep. 12 |
82 (40-99) |
16.1 (14.8-17) |
7.4 (6.4-8) |
12.3 (10.9-13.2) |
*Starch values according to the 1-8 scale developed by Cornell University.
Honeycrisp (Standard)
This variety is testing mature with starch index of 6.8, above the mature threshold of 3.5, and firmness averaging 14.6 pounds which is considered appropriate for short-term controlled atmosphere storage. Many of the Honeycrisp in the area have not been picked as of this week.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|---|---|---|---|---|
|
Sep. 5 |
56.5 (30-90) |
15.6 (14.8-17.1) |
5.8 (4.4-6.6) |
12.1 (11.3-13.1) |
|
Sep. 12 |
76 (30-98) |
14.1 (13.8-14.1) |
6.8 (6.5-7.2) |
12.6 (11.7-13.3) |
*Starch values according to the 1-8 scale developed by Cornell University.
Empire
The current average firmness reading of 17 pounds is close to the long-term controlled atmosphere storage target value of 16 pounds. The predicted peak harvest date for Central Berrien County is Sept 14. Approximately 50% of the area Empire crop has been harvested for processing. Background color is a yellow green. Note: The apparent drop in starch reading this week is likely due to sampling orchards already harvested.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|---|---|---|---|---|
|
Sep. 5 |
65 (30-98) |
16.3 (15.4-17.1) |
5 (4.6-5.6) |
10.1 (9.4-11.6) |
|
Sep. 12 |
78.4 (40-99) |
17 (16.1-17.6) |
2.9 (2.8-3) |
10.8 (10-11.9) |
*Starch values according to the 1-8 scale developed by Cornell University.
Jonagold
This variety is averaging 5.1 for the starch test, over the starch threshold of 3.5, which is considered mature. The current average firmness reading of 16.8 pounds is close to the long-term controlled atmosphere target value of 17 pounds. Background color is still noticeably green. This variety is maturing ahead of the predicted peak harvest date of Sept. 19 for central Berrien County.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|---|---|---|---|---|
|
Sep. 12 |
77.2 (50-100) |
16.8 (15.9-18) |
5.1 (2.6-7) |
11.8 (10-12.9) |
*Starch values according to the 1-8 scale developed by Cornell University.
Fuji
This variety is averaging 2.5 for the starch test, below the starch threshold of 3, considered mature. The current average firmness reading of 19.2 pounds compared to the long-term controlled atmosphere target value of 18 pounds. This variety appears to be maturing close to the predicted peak harvest date of Sept. 23 for central Berrien County.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|---|---|---|---|---|
|
Sep. 12 |
65.8 (40-98) |
19.2 (17.9-20) |
2.5 (2-3) |
10.8 (10.1-12) |
*Starch values according to the 1-8 scale developed by Cornell University.
Golden Delicious
This variety is averaging 2.3 for the starch test, still under the mature starch threshold of 3. The current average firmness reading of 16.9 pounds is close to the long-term controlled atmosphere target value of 17 pounds. The predicted peak harvest date for central Berrien County is Sept. 24. Background color is noticeably green.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|---|---|---|---|---|
|
Sep. 12 |
16.6 (8-40) |
16.9 (16-17.3) |
2.3 (1-3.6) |
11.2 (9.9-11.9) |
*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 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 |
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.
- 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.
- Starch chart for Honeycrisp apples developed by Washington State University.
