West central Michigan apple maturity report – September 4, 2024
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EmailGala and September Wonder Fuji harvest has begun in the west central region. Honeycrisp are mature, and red color development has greatly improved since last week.
In the west central Michigan region, harvest of Gala and September Wonder Fuji is underway for some growers. Honeycrisp is now mature (Figure 1) and could be harvested for medium and short-term storage. Jonagold and Empire were also tested for maturity this week. These varieties will mature shortly.
Weather over the past few days has been mixed with hot days in the upper 80s a week ago and cool temperatures over the past few days with highs in the 70s and lows in the 40s. This seems to be the weather trend this summer with temperatures oscillating from periods with temperatures above normal followed by periods with temperatures below normal. Temperatures this weekend will also be below normal with highs in the 50s and rain.
How to read maturity tables
Each week, an apple maturity report will be provided and will include average values for several apple samples for varieties nearing maturity. Maximum and minimum values are included in tables below 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. Samples were collected from two to six locations across Oceana County (Figure 2).
For more information about apple maturity testing, review these resources compiled by the Michigan State University Extension tree fruit team:
- Predicted apple harvest dates for 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.
- New starch charts for evaluating apple maturity in MSU.
- Predicting apple maturity and starch chart from Cornell University.
- Starch chart for Honeycrisp Apples developed by Washington State University.
Maturity information for the west central region
Honeycrisp
Fruit were sampled from six locations on Sept. 4 in Oceana County. Red color averaged 82%, but red color development was variable across sites. Red color and size will continue to improve over the next few days following warmer daytime temperatures and cool nights in the 40s through the end of the week. Background color is yellow green, and fruit are mature. Pressure decreased to an average of 15.9 lbs., and starch rating averaged at 5.1 (Figure 3). Sugars are similar to last week at 12.2 degrees Brix. Harvest may need to be delayed for color development although pressure and starch should be carefully monitored for this variety to determine the best storage options to maintain optimal quality.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|---|---|---|---|---|---|---|
|
Aug 19 |
181 (192-175) |
76 (98-55) |
3.6 (5-2) |
19.5 (22.4-17) |
1.4 (4-1) |
11 (11.6-10.1) |
|
Aug 28 |
222 (258-197) |
76(99-50) |
3.5 (5-1) |
16.2 (21.5-11.8) |
4.1 (8-1) |
12.0 (13.2-11.5) |
|
Sept 4 |
233 (275-189) |
82.4 (100-50) |
2.9 (4-1) |
15.9 (18.3-13.8) |
5.1 (8-2) |
12.2 (13.2-11.6) |
Gala
Gala fruit were sampled from eight locations in Oceana County this week. Samples in the table below are for Brookfield and Pacific Gala. Red color is similar to last week, and background color is light yellow. Fruit firmness was lower than last week with an average of 11.7 lbs. of pressure. The pressure range varied across sites. Fruit are mature, and sugars are fair with an average of 11.5 Brix.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|---|---|---|---|---|---|---|
|
Aug 12 |
132 (142-123) |
81 (99-30) |
3.3 (5-2) |
22.4 (25.6-17.3) |
1.1 (2-1) |
9.3 (9.8-9.0) |
|
Aug 19 |
150 (175-133) |
92 (100-50) |
2.8 (5-1) |
17.3 (23.6-17.8) |
1.2 (2-1) |
9.8 (10.5-9.2) |
|
Aug 28 |
183 (218-146) |
92 (100-60) |
2.0 (4-1) |
18.4 (22.0-15.4) |
2.2 (6-1) |
10.6 (11.5-9.8) |
|
Sept 4 |
181 (205-152) |
92 (100-50) |
1.8 (5-1) |
11.7 (22.5-15.5) |
3.9 (7-1) |
11.5 (12.7-10.6) |
September Wonder Fuji
Fruit were sampled at two locations in Oceana County this week. Fruit are mature. Red color development improved to 79% compared to last week. Background color is yellow green, and firmness decreased to 14.6 lbs. of pressure. Starch rating is 3.4, and sugars improved to good at 12.2 Brix according to the Brix guide below.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|---|---|---|---|---|---|---|
|
Aug 12-15 |
141 (154-129) |
52 (70-40) |
4.6 (5-3) |
18.3 (21-15.8) |
1.6 (3-1) |
9.9 (10.5-8.7) |
|
Aug 19 |
144 (160-133) |
60.2 (98-40) |
4.5 (5-3) |
17.2 (21-15.3) |
2.3 (8-1) |
10.1 (11.8-9.1) |
|
Aug 28 |
148 (151-143) |
66.2 (95-50) |
3.5 (5-1) |
17.3 (19.5-13.8) |
2.1 (3-1) |
10.8 (11.9-9.2) |
|
Sept 4 |
180 (190-170) |
79 (98-50) |
3.5 (5-3) |
14.6 (16.6-11.9) |
3.4 (7-2) |
12.2 (12.7-11.6) |
Jonagold
Fruit were harvested from three locations in Oceana County. Fruit have developed excellent red color with an average of 91% red color. Background color is green, and fruit have an average pressure of 17.2 lbs. Recommended pressure for long-term controlled atmosphere (CA) storage is 17 lbs. Fruit is close to mature with a starch rating of 2.7. This variety may be mature by the end of this week. Sugar levels are 10.9 Brix.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|---|---|---|---|---|---|---|
|
Sept 4 |
221 (233-213) |
92 (100-55) |
4.1 (5-3) |
17.2 (20-15.3) |
2.7 (5-1) |
10.9 (11.5-10.1) |
Empire
Fruit were sampled at three locations in Oceana County this week. Fruit are immature. Red color development is at 73.7%. Background color is green, and firmness is 16.7 lbs. pressure. Pressure recommended for long-term storage is 16 lbs. Starch is 1.6, and sugars are 10.8 Brix.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|---|---|---|---|---|---|---|
|
Sept 4 |
161 (180-142) |
74 (98-45) |
4.2 (5-3) |
16.7 (18.6-15.1) |
1.6 (2-1) |
10.2 (10.2-10.2) |
Apple maturity sampling parameters
- 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 for Honeycrisp: will typically be rated using the standard Michigan State University starch scale (1-8). However, a separate starch chart for Honeycrisp apples developed by Washington State University (scale 1-6) also exists.
- Brix = % sugar measured with Atago PAL-1 Pocket Refractometer
Looking for more? View Michigan State University Extension’s Apple 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 |
|
Brix Guide |
Low |
Fair |
Good |
Excellent |
|---|---|---|---|---|
|
All varieties |
Less than 11 |
11 |
12 |
13 |
|
Honeycrisp |
Less than 12 |
12 |
12 |
Greater than 14 |