Northwest Michigan apple maturity report – September 13, 2023
Print
EmailHoneycrisp starch removal ratings are showing fruit is more mature than anticipated for this time of the year. Overall, apples are maturing about seven days ahead of most years.
This is the second 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.
From our testing again this week, apples seem to be maturing faster than anticipated. This situation is very apparent in Honeycrisp while McIntosh and Gala are ripening ahead of most years but at a slower pace than we are observing in Honeycrisp. Other apple growing regions in Michigan are also reporting apples maturing one week ahead of our normal harvest windows, but there is variability between orchards and regions. Most of the Honeycrisp apples in the state appear to be ripening at a faster pace than our 2023 predicted harvest dates. Growers are harvesting Premier Honeycrisp and SweeTango at this time. Most growers with GingerGolds have finished harvested, perhaps other than growers furthest to the north.
Color has improved this week, which is welcomed after observing starch removal reading higher than anticipated. Brix levels are not as high as we expected given some of the starch readings, and overall brix do seem to be a on the lower side for the advanced ripening in some varieties. However, MSU professor Randy Beaudry anticipates fruit sugars to rise in the coming week given the current status of the advanced ripening. Cooler nights should also improve color over the next few nights.
Growers are eager to keep moving along in harvest or begin harvest if they do not have some of the early varieties. Despite the rains, our well-drained soils have helped keep orchard conditions good for the harvest window.
Weather
The most notable weather-related occurrence was the tremendous amounts of rains we received in certain areas of northwest Michigan last week on Sept. 6. There was a huge amount of variability between Enviroweather stations across the region:
- Northwest Michigan Horticulture Research Center (NWMHRC): 3.25 inches
- Eastport: 2.72 inches
- Elk Rapids: 3.41 inches
- Kewadin: 2.41 inches
- Williamsburg: 3.19 inches
- OMP: 4.84 inches
- East Leland: 4.24 inches
- Northport: 3.51 inches
- Benzonia: 0.03 inches
- Onekama: 0.05 inches
Notably, Benzie and Manistee counties received almost no rain compared to the other areas in northwest. Despite these readings of rainfall from Enviroweather stations, we have heard reports of upwards of 6-plus inches of rain in some areas, and Lake Leelanau and Leland areas received over 7 inches of rain on Sept. 6. These uncharacteristic amounts of rainfall could be concerning for potential fruit storage issues as fruit with more water may be less likely to be stored for as long as fruit with less internal water. However, we have no good data on excess water and fruit storability.
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
- 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.
|
Apple maturity in northwest Michigan for apples collected on Sept. 5, 2023 |
||||
|---|---|---|---|---|
|
Variety |
Color % (range) |
Firmness lbs. (range) |
Starch (range) |
Brix % |
|
Honeycrisp |
60.2% (20-95) |
18.3 (15-22) |
3.8 (1-7) |
11.5 (8.8-14.3) |
|
Gala |
72% (5-100) |
21.8 (19-23) |
1.4 (1-2) |
10.6 (8.6-13.6) |
|
McIntosh |
75.8% (20-100) |
18.6 (15-23) |
1.8 (1-3) |
10.5 (9.7-11.9) |
Honeycrisp
This is the variety growers most need to pay attention to at this time. This variety is ripening much faster than anticipated, and the harvest dates are fast approaching according to the limited testing we have done this week. Most notably, the starch index is an average of 5.2 with a range of 3.3 – 6.6. Fruit is considered mature when the starch readings are in the 3.5 and above. Despite the high starch index, color improvement is needed prior to harvest. The color in our samples varies from 51-73.5% with an average of 61%; growers are hoping our predicted cool nights will improve color. Brix levels remain the same as last week for Honeycrisp. Firmness in our samples is still on the higher side with an average of 17.7.
|
Collection date |
Location |
Color |
Firmness |
Starch Index |
Brix |
|---|---|---|---|---|---|
|
9/12/2023 |
NWMHRC |
51.0% |
19.7 |
6.6 |
12 |
|
9/12/2023 |
NWMHRC |
50.5% |
19.5 |
5.8 |
12.7 |
|
9/12/2023 |
NWMHRC |
73.5% |
17.3 |
5.8 |
11.9 |
|
9/12/2023 |
Orchard 1 |
58.0% |
16.3 |
3.3 |
11 |
|
9/12/2023 |
Orchard 2 |
69.5% |
15.9 |
5.3 |
11.4 |
|
9/12/2023 |
Orchard 3 |
63.0% |
17.5 |
4.6 |
10 |
|
Average |
|
61.0% |
17.7 |
5.2 |
11.5 |
Gala
This variety has matured some since last week, but starch removal only increased by one this week. Color did improve by about 10%, and the brix is the same average as last week. This variety is ripening much slower, or so it appears in our testing, than Honeycrisp. Growers further south have begun Gala harvest, but our apples are not mature or moving quickly toward mature from the past two weeks of testing. Some Gala that did not have irrigation are on the small side. Firmness is still excellent on Gala samples tested.
|
Collection date |
Location |
Color |
Firmness |
Starch Index |
Brix |
|---|---|---|---|---|---|
|
9/12/2023 |
NWMHRC |
88% |
21.8 |
3.7 |
12.6 |
|
9/12/2023 |
Orchard 4 |
87% |
19.5 |
2.2 |
9.4. |
|
9/12/2023 |
Orchard 5 |
62% |
19.4 |
2.2 |
9.7 |
|
9/12/2023 |
Orchard 6 |
86% |
20.8 |
1.6 |
10.7 |
|
Average |
|
81% |
20.4 |
2.4 |
10.6 |
McIntosh
This variety is starting to eat better with that classic Mac flavor, but the starch index and other parameters show that the fruit are not mature. Starch index is slightly higher this week, but the brix levels are almost exactly the same as last week. Color on McIntosh has improved across all samples, and the average color for this week is 80%. Firmness of McIntosh is also still looking good for this variety.
|
Collection date |
Location |
Color |
Firmness |
Starch Index |
Brix |
|
9/12/2023 |
Orchard 3 |
66% |
16.6 |
2.5 |
10.3 |
|
9/12/2023 |
Orchard 4 |
90% |
17.6 |
2.3 |
10.3 |
|
9/12/2023 |
Orchard 6 |
98% |
17 |
3.5 |
11.2 |
|
9/12/2023 |
Orchard 6 |
79% |
17.4 |
3.2 |
10.8 |
|
9/12/2023 |
Orchard 7 |
66% |
18.3 |
2.6 |
10.8 |
|
Average |
|
80% |
17.4 |
2.8 |
10.7 |
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.
|
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 |
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 |