Southwest Michigan apple maturity report – September 28, 2022
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EmailStill many Golden and Red Delicious remain to be picked. Golden Delicious is starting to drop in some orchards.
This is our weekly southwest region apple maturity report. 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.
Additional notes
Pristine plus Captan or Merivon plus Captan would be the best preharvest materials to minimize storage rot problems.
Distinguishing between stink bug and bitter pit damage on apples is not always easy. Articles from Cornell and Michigan State University can help.
The Michigan Department of Agriculture and Rural Development (MDARD) has a Pesticide Applicator Credit Report on MDARD’s website under recent additions section. Michigan pesticide applicators can look up the number of credits they have accumulated.
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.
Jonagold
No new samples this week. Samples last week were fully mature. The predicted harvest date for central Berrien County is Sept. 21.
Empire
No samples this week—fruit is well mature. The predicted harvest date for central Berrien County is Sept. 18.
Fuji (Main season)
Starch conversion is averaging 3.5, considered mature. Fruit firmness dropped about 1.5 pounds since last week and is still relatively high. Fuji is highly susceptible to watercore, which becomes more of a problem on fruit harvested past optimum maturity. The predicted harvest date for central Berrien County is Sept. 24.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|
Sep 6 |
55 (30-65) |
21 (19-24) |
2.4 (2-3) |
11.4 (10.4-12) |
|
Sep 12 |
48 (25-62) |
19.3 (18-20.4) |
2.8 (1.8-3) |
11.4 (10.6-12.1) |
|
Sep 19 |
67 (55-82) |
19 (18-19.8) |
3.0 (2.6-3.8) |
12.1 (11.3-12.8) |
|
Sept 26 |
58.3 (25-72.5) |
17.6(16.5-18.8) |
3.5 (3-4) |
12.7 (11.5-14) |
Golden Delicious
This is the third week of sampling. Fruit background color is starting to brighten. Starch conversion has moved from an average of 3.1 last week to 3.9 for this week, with 3.0 considered mature. Firmness is 16.8, close to the threshold of 17 for long term controlled atmosphere storage. The predicted harvest date for central Berrien County is Sept. 24. Storage of this variety is best at 32-33 F in air or controlled atmosphere (CA) storage. Golden Delicious can lose water relatively rapidly in storage if humidity is low.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|
Sep 12 |
16.7 (12-30) |
17.1 (16.1-18) |
1.9 (1.2-2.4) |
11.4 (10.5-12.2) |
|
Sep 19 |
14.4 (0-37) |
17.3 (16-18.1) |
3.1 (1.6-5.2) |
12.4 (11.5-13.8) |
|
Sept 26 |
28.5 (20-45) |
16.8 (15.8-17.7) |
3.9 (2-6) |
12(11.9-13.6) |
Red Delicious
This is the third week of sampling. Starch conversion is averaging 2.9, slightly higher than last week, with 2.5 as the threshold for mature. Current fruit firmness at 16.7 pounds, with the threshold of 18 for best long-term CA storage. Fruit maturity is somewhat ahead of the predicted harvest date for Red Delicious for central Berrien County of Sept. 29.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|
Sep 12 |
98 (98-99) |
17.4 (16.4-18) |
2.7 (2-3) |
9.9 (9.3-10.8) |
|
Sep 19 |
94 (80-99) |
18 (16.7-20.4) |
2.4 (2-4) |
9.7 (9-10.7) |
|
Sept 26 |
100 (99-100) |
16.7 (16-18.1) |
2.9 (2-3.6) |
10.4 (9.7-11.6) |
IdaRed
This is the second week of sampling. Fruit background color is still relatively green. Starch conversion is averaging 2.3, with 3.5 considered mature. Firmness has dropped nearly 2 pounds since last week, now averaging 16.6 pounds. The predicted harvest date for IdaRed for central Berrien County is Oct. 6.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|
Sep 19 |
70.3 (67-72) |
18.4 (17.6-18.8) |
1.8 (1.4-2.0) |
10.8 (10.2-11.7) |
|
Sept 26 |
71.6 (62.5-77.5) |
16.6 (15.9-17.3) |
2.3 (2-3) |
11.3 (9.9-12.3) |
Rome
First samples were taken this week. Internal starch is averaging 3.4, with 3 considered mature. Firmness is still excellent at 21.2 pounds. Predicted harvest date for central Berrien County is Oct. 6.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|
Sept 26 |
90.5 (84-99) |
21.2 (20.2-21.8) |
3.4 (3-4) |
11.1 (10.3-11.5) |
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 based on averages for orchards tested.
- Starch: 1 = all starch, 8 = all starch converted; range is based on averages for orchards tested using Cornell Starch Iodine Index Chart.
- 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 |
|
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.
