Southwest Michigan apple maturity report – September 7, 2022
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EmailMain season Gala harvest is just beginning in some southwest apple blocks.
This is 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.
- Predicted apple harvest dates for 2022 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.
- 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 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.
Gala (Main season types)
Gala internal maturity continues to improve with fruit pressure averaging 19.3 lb, and starch conversion averaging 3.7, with 3 considered mature. The predicted central Berrien County harvest date is Sep. 6.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (°Brix) |
|
Aug 22 |
60 (55-65) |
22.3 (21-24) |
1.1 (1-1.6) |
10.2 (9.4-11.3) |
|
Aug 29 |
82 (62-95) |
21.1 (20-23) |
2.8 (1.6-4.4) |
11.2 (10.2-12.4) |
|
Sep 6 |
83 (65-90) |
19.3 (17.2-21) |
3.7 (2-5.6) |
12.0 (11.3-13.1) |
Mac
Strains tested include Ruby and Linda Mac. Starch indices are averaging 4.2, close to mature (5 and above). Fruit firmness dropped about 1 lbs for the second week in a row, now an average of 15.3, which is in the midrange controlled atmosphere storage zone. Predicted harvest date is Sep. 8 for central Berrien County.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (°Brix) |
|
Aug 22 |
54 (40-75) |
17 (16-18) |
2.4 (1-3) |
11.6 (10.8-12.4) |
|
Aug 29 |
54 (30-73) |
16.1 (15.2-17) |
3.4 (3-4.2) |
12.2 (11-13.7) |
|
Sep 6 |
64.3 (40-73) |
15.3 (15-16) |
4.2 (3.4-4.6) |
12.9 (12.1-13.4) |
Jonagold
Internal starch conversion is averaging 2.3, still immature, still with excellent firmness. Newer Jonagold varietal strains have good blush, but all strains have greenish backgrounds. The predicted harvest date for central Berrien County is Sep. 21.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (°Brix) |
|
Aug 29 |
N/A |
19.4 (18.2-21) |
2 (2-2) |
12 (11.7-12.2) |
|
Sep 6 |
73.4 (50-99) |
18.5 (17-21.3) |
2.3 (2-3.2) |
11.4 (10.8-12) |
Empire
First samples were taken this week. Fruit firmness and starch conversion are averaging in the immature range. The estimated harvest day for central Berrien County is Sep. 18.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (°Brix) |
|
Sep 6 |
59 (45-75) |
18.9 (18-19.4) |
2.4 (2-3) |
11.1 (10.4-11.9) |
Fuji (Main season)
First samples were taken this week. Fruit background color is still relatively green. Starch conversion is averaging 2.4, still immature but moving toward the mature range of 3.0. Firmness is still high. The predicted harvest date for central Berrien County is Sep. 24.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (°Brix) |
|
Sep 6 |
55 (30-65) |
21 (19-24) |
2.4 (2-3) |
11.4 (10.4-12) |
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 |
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 |
|
Normal and predicted 2022 peak harvest dates for apple varieties in central Berrien County in southwest Michigan based on weather data at the Southwest Michigan Research and Extension Center, Benton Harbor, MI. |
||
|
Variety |
Normal date |
2022 Predicted peak harvest date |
|
Zestar |
22-Aug |
20-Aug |
|
Paula Red |
22-Aug |
20-Aug |
|
Gingergold |
20-Aug |
18-Aug |
|
Gala |
8-Sep |
6-Sep |
|
McIntosh |
10-Sep |
8-Sep |
|
Early Fuji |
3-Sep |
1-Sep |
|
Honeycrisp |
13-Sep |
11-Sep |
|
Empire |
19-Sep |
18-Sep |
|
Jonathan |
22-Sep |
21-Sep |
|
Jonagold |
22-Sep |
21-Sep |
|
Fuji |
25-Sep |
24-Sep |
|
Golden Delicious |
25-Sep |
24-Sep |
|
Red Delicious |
28-Sep |
29-Sep |
|
Ida Red |
5-Oct |
6-Oct |
|
Rome |
5-Oct |
6-Oct |
|
Braeburn |
20-Oct |
21-Oct |
|
Goldrush |
26-Oct |
27-Oct |
Predictions are for the first significant harvest date rather than peak harvest. Also note that the normal harvest date for Fuji is approximately three weeks ahead of the normal date given in previous years reports. Newer strains of Fuji have much earlier and more extensive red blush development than older strains. In the past harvest of Fuji was delayed past optimum internal maturity to wait for better blush development. This delay has resulted in increased storage problems, including watercore and internal browning.
