Northwest Michigan apple maturity report – October 11, 2023
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EmailGrowers are moving through apples as fast as they are able given the wet conditions over the past week. As most varieties are testing in the mature range, they are fair game for harvest.
This is the sixth apple maturity report for 2023 for northwest Michigan. Reports are sent out every week (usually on Wednesdays) following the Michigan State University Extension fruit team apple maturity calls on Wednesday morning.
This weather has slowed harvest, but growers are trying get over their acreage the best that they are able. The crop is quite large in many orchards, and pickers are doing their best to move through the orchards. There are reports of growers that are finished with this year’s harvest while others are in various stages of finishing up their blocks. Second pick Honeycrisp is ongoing, and Galas harvest is in full swing. All processing fruit is fair game for harvest now too. Fruit is looking beautifully colored on the trees, and the recent cooler weather has helped improve overall color of all varieties. As expected, fruit firmness was lower this past week compared to tests earlier in the season. Brix levels look good even with all the rain.
Weather
The weather turned suddenly as it often does in Michigan. We hit a daytime high of 70 degrees Fahrenheit on Oct. 5, then things went south. Conditions cooled dramatically, and we have hovered in the 50s F since that last warm day. In addition to the cooler weather, we have had a lot of rain. We received some rainfall each day for the past six days, although rainfall amounts have varied, we topped out on Oct. 10 with 0.44 inches recorded at the NWMHRC (Northwest Michigan Horticulture Research Center) Enviroweather station. The forecast is predicting a continuation of cool and wet through the weekend.
How to read 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 maturity. All samples included in the reports have been untreated with ReTain or Harvista, unless otherwise noted.
- Predicted apple harvest dates for 2023 from MSU Extension.
- 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.
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Apple maturity in northwest Michigan for apples collected on Oct. 10, 2023 |
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|
Variety |
Color % (range) |
Firmness lbs. (range) |
Starch (range) |
Brix % |
|
Evercrisp |
73.2% (45-90) |
21.2 (19-23) |
3.1 (2-7) |
14.8 (12-19.3) |
|
Ida Red |
78% (one sample) |
16.8 |
4 |
13.6 |
|
Fuji |
80% (one sample) |
19.1 |
6.5 |
10.8 |
Fuji
We do not have a lot of Fujis in our region because the later strains can be difficult to ripen in cool years. From our one sample of Fuji at the NWMHRC, this sample is still testing firm at 19.1 pounds. Our apples are testing mature, but Brix is still quite low for this variety. Color has improved in the past week.
Ida Red
This variety is approaching mature, and the color from our one sample is good: 78%. Firmness of Ida Reds is lower than the two other harder apple varieties. The Brix from our single sample is 13.6
Evercrisp
This variety can sometimes be a challenge to mature in our region where we do not have the heat units we get in more southerly parts of the state. This year however, we are on track for this variety to be ripe, and the starch readings were similar to last week and are hovering around 3; however, there is still variability in apples collected from orchards and within blocks. Brix of this variety is excellent, and ranges from 12-19.3 (!) with an average of almost 15 this week. Color has improved tremendously compared to last week; an increase of almost 30%. Firmness is excellent in this variety, but the overall firmness results from NWMHRC apples was lower than the other orchards tested. This variety is certainly moving along this season.
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Evercrisp maturity sampling for the harvest season |
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Sample date |
Color % (range) |
Firmness lbs. (range) |
Starch (range) |
Brix % |
|
Oct. 3, 2023 |
44% (15-70) |
22.8 (21.5-23) |
2.8 (2-7) |
14.0 (13.5-14.7) |
|
Oct. 10, 2023 |
73.2% (45-90) |
21.2 (19-23) |
3.1 (2-7) |
14.8 (12-19.3) |
Apple maturity sampling parameters
- Ethylene (% fruits with internal ethylene over 0.2 ppm) = indicates when ethylene begins to influence fruit ripening and it cannot be held back easily after this is reached.
- Color % = the visual percentage of red color from 0 to 100; range is of all fruits tested. Indicates surface area covered in red and intensity of red color.
- Background color: 5 = Green, 1 = Yellow; 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
Looking for more? View Michigan State University Extension’s Apple Maturity page for regional reports throughout the state and additional resources.
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Suggested firmness and starch index levels for long-term and shorter-term controlled atmosphere (CA) storage by variety. |
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|---|---|---|---|---|---|
|
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 |
