Northwest Michigan apple maturity report – September 18, 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 continues to feel more like summer than fall. Daytime highs are still up in the 80s, and the skies have been clear with lots of sunshine. The temperatures do drop overnight, and the lows have been in the 50s and 60s. In addition to the warm weather, we have had no rainfall in weeks. Orchard conditions are dry, and rain would be welcome, but there is a slight chance of rainfall on Friday, Sept. 20, and another small chance on Sunday, Sept. 22.
Sometimes it seems like we are a broken record, but again this week as in the past two weeks, all apple varieties are maturing quickly with these weather conditions. When we look at the overview of all the starch removal readings from all varieties this week, it looks like all varieties are maturing at a similar time. In addition to all varieties maturing at the same time, the fruit is maturing quickly. There have been jumps in starch removal readings, and some of the fruit we are testing are already in the 7 range. Growers need to be moving through harvest as quickly as they are able, and again, should be making the most of the plant growth regulator (PGR) products that they have available to help manage this fast-moving harvest window.
With the continued hot weather, we asked Randy Beaudry about the storability of fruit given the potentially long time the fruit will spend in the warm sun. Hot weather will impact the ability of fruit to store, but he was clear to add that if growers do everything right, i.e., use PGRs, pick as soon as fruit is mature, condition the fruit correctly and move the fruit to storage as soon as possible, there is still a high chance that fruit will store adequately.
This is the fourth 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 fell a bit this week, but we are still seeing relatively firm fruit for this time in this warm season. Color has not changed over the past week, and most Honeycrisp here in our region have good color. Brix has also remained the same as last week. In eating many Honeycrisp during our testing process, the fruit is delicious and the flavor has been excellent across the blocks that we have tested. Fruit are maturing as evident with the starch removal measurements, and growers need to focus on this important variety and 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. Make use of the key PGR tools to harvest this variety at optimal timing.
|
Honeycrisp maturity sampling for the harvest season |
||||
|---|---|---|---|---|
|
Sample date |
Color % (range) |
Firmness lbs. (range) |
Starch (range) |
Brix % |
|
8/20/24 |
54.3% (15-85) |
19.5 (17-23) |
1.2 (1-5) |
10.1 (9-11.4) |
|
8/27/24 |
57.5% (15-95) |
20.5 (17.5-23) |
2.1 (1-6) |
11.3 (9.1-12.9) |
|
9/3/24 |
74.6% (40-95) |
19.0 (15.5-23.5) |
3.2 (1-7) |
12.1 (9.5-14.6) |
|
9/10/24 |
77% (50-100) |
18.6 (15.5-22) |
4.4 (2-7) |
12.0 (10.1-14.3) |
|
9/17/24 |
83.8% (60-100) |
17.2 (15-20.5) |
6.3 (3-8) |
12.3 (10.5-15.2) |
Gala
During harvest this week, we have eaten many Gala and they are tasting good. The starch removal has increased this week to an average of 3.6, but the range is quite extensive from 1-8. Some of the blocks we tested were more consistent in their starch readings while other blocks had more variability. Color has also increased this week, and many Gala blocks have excellent red color—you can notice Gala on trees when you drive by orchards now. Brix has also increased in the past week, and we jumped from an average of 10.7 to a 12.0 this week, which is likely contributing to the better flavor in Gala. Size is also looking better this week, which is a bit surprising given the dry conditions.
|
Gala maturity sampling for the harvest season |
||||
|---|---|---|---|---|
|
Sample date |
Color % (range) |
Firmness lbs. (range) |
Starch (range) |
Brix % |
|
8/20/24 |
58.8% (30-100) |
22.6 (19.5-23.5) |
1 (1-1) |
9.6 (8.2-11.1) |
|
8/27/24 |
73.3% (25-100) |
22.55 (20-23) |
1.6 (1-7) |
10.7 (8.3-11.9) |
|
9/3/24 |
82.5% (50-100) |
22.3 (19-23) |
1.9 (1-4) |
10.7 (9.2-13.8) |
|
9/10/24 |
90.1% (50-100) |
21.6 (17.5-23) |
3.6 (1-8) |
12.0 (9.2-14.5) |
|
9/17/24 |
82% (30-100) |
21.8 (19-23) |
4.2 (2-7) |
12.1 (10.6-13.5) |
McIntosh
Many of the McIntosh blocks in our area have been harvested. The samples we collected this week have poor color, likely the result of big trees and older strains of this variety. Firmness is still quite high in this softer variety, and the starch removal jumped a pound from last week’s samples. Brix levels also increased by one percentage point. Macs are still eating green.
|
McIntosh maturity sampling for the harvest season |
||||
|---|---|---|---|---|
|
Sample date |
Color % (range) |
Firmness lbs. (range) |
Starch (range) |
Brix % |
|
8/20/24 |
59.3% (25-90) |
20.6 (18-23) |
1.2 (1-2) |
9.8 (8.4-11) |
|
8/27/24 |
69.25% (25-100) |
21.7 (19-23) |
1.4 (1-3) |
10.25 (8.3-12.3) |
|
9/3/24 |
65.5% (5-100) |
19.3 (16-23) |
2.1 (1-4) |
11.1 (8.2-12.4) |
|
9/10/24 |
65% (15-100) |
18.5 (16-22) |
3.2 (2-8) |
11.6 (10.2-14.1) |
|
9/17/24 |
55% (10-100) |
17.9 (15-21) |
4.4 (3-7) |
12.8 (10.8-14.2) |
Jonagold
This week we sampled Jonagolds, and we were quite surprised how far along this variety seemed when we did the testing. The color on most of the apples tested was quite poor, though we did have samples with 70% color, but the overall average was less than 65%. Again, Jonagolds are planted on bigger trees across the area in most orchards. Firmness was an average of 18.9, and the starch removal readings were quite high. We had a block where all apple samples had a starch removal reading of 7. We should have tested Jonagolds earlier with the rapid maturing conditions this season. Brix were high but still variable with a range of 11.8-14.6%. Many growers are harvesting Jonagolds this week.
|
Jonagold maturity sampling for the harvest season |
||||
|---|---|---|---|---|
|
Sample date |
Color % (range) |
Firmness lbs. (range) |
Starch (range) |
Brix % |
|
9/17/24 |
57.5% (40-70) |
18.9 (17-21.5) |
5.8 (4-7) |
13 (11.8-14.6) |
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!