Grand Rapids area apple maturity report – Aug. 3, 2022
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EmailEarly maturity testing results, early varieties just beginning to show signs of maturity in the Grand Rapids area.
In this report, we’re sharing some very early results of maturity testing. We will begin our weekly apple maturity reports in the next week or so. Reports are sent out every week (usually on Wednesdays) following the Michigan State University Extension fruit team apple maturity calls on Wednesday morning.
- Predicted apple harvest dates for 2022 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.
How to read the maturity tables
Each week, we test apple varieties that are nearing maturity in the Grand Rapids, Michigan, area. 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.
Zestar
Starting to color, seeds beginning to brown, and flavor just beginning to develop. Some starch clearing just beginning.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Ethylene (% >0.2ppm) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (°Brix) |
|
Aug 1 |
170 (170-170) |
6.5 (15-5) |
5 (5-5) |
NT |
0 (0-0) |
2 (2-2) |
11 (11-11) |
Premier Honeycrisp
A touch of color just beginning in earliest fruit, but background still very green. Seeds just starting to turn brown. No starch clearing, flavor and sugars still poor.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Ethylene (% >0.2ppm) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (°Brix) |
|
Aug 1 |
185 (210-160) |
5.75 (10-5) |
4.65 (5-4) |
NT |
20.225 (23.33-17.41) |
1 (1-1) |
(11.4-10.4) |
*Starch values according to the 1-6 scale developed by WSU
Paula Red
Red color coming along, background still very green. Very little starch clearing just beginning. Sugars and flavor just beginning. A small amount of watercore was evident in the samples we collected.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Ethylene (% >0.2ppm) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (°Brix) |
|
Aug 1 |
170 (170-170) |
25 (30-0) |
4.7 (5-0) |
NT |
17.8 (22.21-15.19) |
1.6 (2-1) |
(12.2-12.2) |
Ginger Gold
Sizing well and a little starch clearing just beginning, but otherwise still very immature. Background still very green, sugar and flavor development just beginning.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Ethylene (% >0.2ppm) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (°Brix) |
|
Aug 1 |
185 (190-180) |
2.25 (5-0) |
4.6 (5-0) |
0 (-) |
10.865 (25.1-19.09) |
1 (1-1) |
(10.8-10.5) |
Wildfire Gala
Coloring well, but otherwise still very immature. Background still very green, little sugar or flavor development.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Ethylene (% >0.2ppm) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (°Brix) |
|
Aug 1 |
110 (110-110) |
32 (50-10) |
4.4 (5-4) |
0 (-) |
20.03 (29.67-19.93) |
1 (1-1) |
(9-9) |
Apple maturity sampling parameters
- % 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
- 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.
- Starch For Honeycrisp: a separate starch chart for Honeycrisp Apples developed by Washington State University (scale 1-6).
- 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. |
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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 |
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 |