Southwest Michigan apple maturity report – October 17, 2023
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EmailSouthwest Michigan apple harvest focuses on Evercrisp, Rome and Braeburn apples.
This is our final weekly southwest region apple maturity report for the season. View Michigan State University Extension’s Apple Maturity page for regional reports throughout the state and additional resources.
Report overview
Fruit of Fuji, Red Delicious, Yellow Delicious and IdaRed are generally well mature and harvested in the area. Harvesting of Evercrisp, Rome and Braeburn are underway in the central Berrien County area. Fruit quality has been generally good this year with little or no watercore. Weather has been favorable for harvesting operations.
Evercrisp
This variety is averaging 4.4 for the starch test, a jump from last week’s 2.9. The mature starch threshold is 3. The current average firmness reading of 20.3 pounds is still very firm—the long term controlled atmosphere (CA) storage target value for this variety is 18 pounds. We currently do not have a predicted harvest date for this variety, but based on the firmness and starch tests, harvesting of more mature sites with better blush development would be appropriate. Brix has reached an average of 14.1. Like Fuji, this variety is prone to watercore in some years if harvested overmature. No watercore was detected this week in the three orchards sampled in southwest Michigan. Red blush development for this variety is decent for fruit that are well exposed to sunlight. Evercrisp is a tip-bearing variety and may need special attention to pruning to avoid excessive shading in the lower canopy.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
Sep. 25 |
67.5 (50-90) |
23.4 (22.7-25.4) |
1.7 (1-3) |
12.6 (10.9-13.3) |
|
Oct. 2 |
70 (50-90) |
21.2 (19.6-22.4) |
3.3 (2.4-3.6) |
13 (12.3-14.4) |
|
Oct. 9 |
71 (50-95) |
19.8 (17.7-21.6) |
2.9 (2.4-3.8) |
13.8 (12.4-14.6) |
|
Oct. 16 |
80 (60-98) |
20.3 (18-23.2) |
4.4 (3.2-6.2) |
14.1 (12.3-14.7) |
*Starch values according to the 1-8 scale developed by Cornell University.
Braeburn
This variety is averaging 4.7 for the starch test--the mature starch threshold is 2.5. The current average firmness reading of 19.1 pounds is very firm—the long term CA storage target value for this variety is 18 pounds. Brix is inching up, but still relatively low.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
Oct. 2 |
68.5 (50-98) |
20.3 (18.7-22.2) |
3.7 (2.6-4.6) |
10.9 (9.7-11.4) |
|
Oct. 9 |
76.0 (40-95) |
19.4 (18.4-20.4) |
3.7 (2-5.8) |
11.6 (10.1-13.1) |
|
Oct. 16 |
82 (60-98) |
19.1 (18.5-20) |
4.7 (4.2-5.4) |
11.6 (10.4-13.1) |
*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.
