Northwest Michigan apple maturity report – September 11, 2024
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EmailApples are ripening one to two weeks before most years, and growers are actively harvesting Honeycrisp. Other varieties will be right on the heels of this variety with ripening.
General comments
The weather was cool and damp over the weekend, but the region did not receive any notable rainfall to combat our dry conditions. The cool weather has been replaced with the continued hot and dry weather that we saw through most of August. The weather is predicted to be warm through next week. Daytime temperatures are predicted to be in the mid-80s, and today (Sept. 11) and tomorrow are predicted to top out at 88 degrees Fahrenheit in Traverse City, Michigan; nighttime lows will only be in the low 60s. This weather will continue to push apple maturity along. Growers will need to be nimble and ready to move on harvesting all varieties. Growers also need to be using the plant growth regulator (PGR) tools in the toolbox to best manage harvest this season.
As in last week’s report, when we look at the overview of all the starch removal readings from all varieties this week, it looks like all varieties will mature at a similar time. Again, we may see some separation between varieties as the weather becomes more variable, but again, growers need to be able to jump on harvest as soon as fruit is ripe on their farm. A separation in maturity between varieties will be less likely if we do get the hot and dry weather that the forecasts are predicting. With all of the varieties maturing at similar time, the use of Retain and/or Harvista will be critical to manage harvest.
Growers need to be working closely with their packers and/or processors to determine optimal harvest timings. Harvest will depend on the end result of the fruit: farm market versus short- and long-term storage. Growers should be monitoring their own fruit to know the optimal harvest times.
This is the third official week for apple testing in northwest Michigan. Reports are sent out on Wednesday every week, following the Michigan State University Extension fruit team apple maturity calls on Wednesday morning. Other relevant information on apple maturity can be found in the following links:
- Predicted apple harvest dates for northwest Michigan 2024 from Michigan State University (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
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.
Honeycrisp
Honeycrisp firmness remains similar from last week to this week, but still consistent with the last few weeks. The firmness range is almost the same as last week. Color in Honeycrisp blocks remain similar to last week, but when driving by Honeycrisp orchards, the apples are more noticeable from the road. Our color ranges from 50-100% with an average of 77%, almost the same as last week. Brix also remains the same this week, and the 12% sugar mark is welcomed after what seemed to be a slower start to brix accumulation this season. Another reminder for growers to focus on this important variety and to work with the packer to ensure proper harvest timing. This higher value variety can be less grower friendly than other apples, so growers need to be on the ball for Honeycrisp harvest. Growers need to make use of the key PGR tools to harvest this variety at optimal timing.
|
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) |
|
3-Sept |
74.6% (40-95) |
19.0 (15.5-23.5) |
3.2 (1-7) |
12.1 (9.5-14.6) |
|
10-Sept |
77% (50-100) |
18.6 (15.5-22) |
4.4 (2-7) |
12.0 (10.1-14.3) |
Gala
Gala size is still quite variable across blocks, but the fruit looks more uniform this week compared to earlier in the season. Color is similar to last week, and the range of color is 50-100%. Galas are still testing firm with an average of 21.6 this week. Starch is the most notable change this week, and the numbers have jumped from an average of 1.9 last week to 3.6 this week; again, we noticed some variability in starch removal numbers as the range is 1-8. Brix in Gala increased from 10.7 last week to 12.0 this week. Galas are also eating better this week.
|
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) |
|
3-Sept |
82.5% (50-100) |
22.3 (19-23) |
1.9 (1-4) |
10.7 (9.2-13.8) |
|
10-Sept |
90.1% (50-100) |
21.6 (17.5-23) |
3.6 (1-8) |
12.0 (9.2-14.5) |
McIntosh
McIntosh color is variable, likely as a result of the particular strain and the size of the trees where we collect the samples—most trees are large with big canopies. Color remains similar to last week, but firmness has dropped almost two pounds over the past week. Starch removal has also increased in the past week, the average is 3.2. Brix in McIntosh is still reading below 12 with an average of 11.1 this week.
|
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) |
|
3-Sept |
65.5% (5-100) |
19.3 (16-23) |
2.1 (1-4) |
11.1 (8.2-12.4) |
|
10-Sept |
65% (15-100) |
18.5 (16-22) |
3.2 (2-8) |
11.6 (10.2-14.1) |
Rome
We had a request to test a Rome sample this week. As expected, this variety is still hard, underripe but has good color. The range of starch removal is between 1-4 with an average of 1.4. Brix tested an average of 10.4.
|
Collection Date |
Red Color (%) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids |
|
10-Sept |
75.3% (60-90) |
22.9 (20-23) |
1.4 (1-4) |
10.4 (9.6-11.3) |
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!