Northwest Michigan apple maturity report – August 29, 2024
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EmailApples are maturing early this year, and growers are picking Premier Honeycrisp now.
We started testing apple maturity last week, but this week is the first actual report. Reports are sent out every week (usually on Wednesdays), following the Michigan State University Extension fruit team apple maturity calls on Wednesday morning.
- Predicted apple harvest dates for northwest Michigan for 2024 from Michigan State University (MSU).
- More information on harvest management tools and timings.
- 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
Each week, we test apple varieties that are nearing maturity in northwest Michigan. We are reporting average values for several samples for each variety. Maximum and minimum values are included for the highest and lowest individual fruits evaluated for each to give a full spectrum of the maturity.
General comments
Apples are early this year, and growers should be ready to harvest as soon as their fruit is mature. In many cases, it has been surprising to see just how early fruit are maturing. In southwest Michigan, Honeycrisp, Gala and McIntosh are all mature at this time. Most of the starch removal testing is showing 5-plus for all these varieties. The Hart and Ridge areas are very similar in their maturation testing, and northwest Michigan is not that far behind. We have seen some variability in color between blocks, and we hope nights will cool down to further improve color. We have also noticed small fruit in some blocks, which is quite unexpected with all the rain we have had this season.
Premier Honeycrisp
Most growers are harvesting Premier Honeycrisp this week. Color is variable across the different blocks. We have observed some orchards with terrific color while others are almost entirely still green with just a touch of red starting to show up. We have also seen Premiers dropping with some recent winds. Start the first pick of Premier as soon as you can.
Ginger Gold
Ginger Gold size is good from all the samples. This variety is typically one of the earliest we pick in northern Michigan. This year, despite the early season, Ginger Golds seem to be behind Honeycrisp, and they seem to be maturing slower than most years.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (% Brix) |
|---|---|---|---|---|
|
20-Aug |
11% |
10.8 (25.1-19.09) |
1 (1-1) |
(10.8-10.5) |
|
27-Aug |
9% (0-30) |
20.3 (18-23) |
1.7 (1-3) |
11.5 (10.5-12.7) |
Honeycrisp
Honeycrisp firmness remains similar from last week to this week. Comments from other areas in the state have shown firmness to be dropping rather quickly in this variety. Color in most Honeycrisp blocks is marginal in our area, and other regions’ educators have also commented that color is lacking thus far. There is some concern over lack of color and firmness if the fruit continues to color slowly. Brix has increased over 1% from last week. Honeycrisp are eating fairly well considering the starch is only at 2. Honeycrisp size appears to be good across blocks.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (% Brix) |
|---|---|---|---|---|
|
20-Aug |
54.3% (15-85) |
19.5 (17-23) |
1.2 (1-5) |
10.1 (9-11.4) |
|
27-Aug |
57.5% (15-95) |
20.5 (17.5-23) |
2.1 (1-6) |
11.3 (9.1-12.9) |
Gala
Gala size is quite variable across blocks, and Gala at the Northwest Michigan Horticulture Research Center are much smaller than usual. We thought our thinning was adequate, but the fruit is still small. Color is also all over the board with this variety. Some blocks have good red color while others are still quite green; note the range below on both dates is from 25/30-100% color. Galas are still testing very firm, and starch has jumped just a bit in the last week. Brix in Gala are also still quite low, and some apples are testing out with a brix of 8%. Gala fruit seem much starchier in flavor than Honeycrisp at this time.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (% Brix) |
|---|---|---|---|---|
|
20-Aug |
58.8% (30-100) |
22.6 (19.5-23.5) |
1 (1-1) |
9.6 (8.2-11.1) |
|
27-Aug |
73.3% (25-100) |
22.55 (20-23) |
1.6 (1-7) |
10.7 (8.3-11.9) |
McIntosh
We have few McIntosh blocks near the research station, and most trees are big with older strains of Macs. Color is variable, but it has improved over the past week. Firmness is still quite good in this typically softer variety. Starch removal has not changed over the past week, and brix is low with some variability.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (% Brix) |
|---|---|---|---|---|
|
20-Aug |
59.3% (25-90) |
20.6 (18-23) |
1.2 (1-2) |
9.8 (8.4-11) |
|
27-Aug |
69.25% (25-100) |
21.7 (19-23) |
1.4 (1-3) |
10.25 (8.3-12.3) |
Apple maturity sampling parameters
- Color % = the visual percentage of red color from 0 to 100; range is of all fruits tested
- Firmness in pounds pressure = measured with a Güss Fruit Texture Analyzer; 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.
- 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 (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 |
Be sure to check out our MSU Starch Index Chart!
