Grand Rapids area apple maturity report – October 18, 2023
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EmailThe Grand Rapids area is moving towards the end of harvesting apples as only a few varieties are still on the trees.
This is the sixth Grand Rapids, Michigan, area apple maturity report for the 2023 harvest season. 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 2023 from MSU Extension.
- More information on harvest management tools and timings can be found in this article.
- Guidelines from MSU Extension 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 region. 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.
Updates for this week
Temperatures have remained stable in comparison to last week with highs in the 50s degrees Fahrenheit and lows in the min 30s F. Temperatures have not approached freezing in Sparta, Michigan. This weather has encouraged color development in the last week. The MSU Enviroweather station in Sparta recorded 1.5 inches of rain this past week.
Temperatures are expected to approach freezing this week. The Enviroweather temperature inversion tool provides real time data for frost fan use. Please keep this resource in mind as we head into the weekend.
Evercrisp
Evercrisp apples were sampled at one location in Kent County this week. The sugar accumulation is exceptionally high for this variety at an average of 15.7 Brix. The firmness also remains high for this variety with an average of 21.7 pounds. Harvest has begun for this variety. Some samples exhibit watercore.
|
Collection Date |
Fruit Weight (g) |
Diameter (mm) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
10/9/23 |
216.9 (167-270) |
76.5 (71.9-81.4) |
81.5 (75-90) |
1.2 (1-2) |
22.5 (18.8-27.8) |
2.2 (1-3) |
15.3 (14.1-16.2) |
|
10/16/23 |
197.4 (140-244) |
73.8 (65.9-79.4) |
81 (65-90) |
1.4 (1-2) |
21.7 (17.1-25.6) |
2.4 (2-3) |
15.7 (14.2-17) |
Fuji
Fuji apples were sampled at two locations in Kent County this week. This variety is currently mature and moving towards overmaturity. Samples had excellent sugar accumulation at 14.4 Brix and frequently exhibited watercore associated with this sugar accumulation. The firmness of the sampled apples is in line with long term controlled atmosphere (CA) storage. Please keep in mind that watercore can impact the storage capacity of these apples.
|
Collection Date |
Fruit Weight (g) |
Diameter (mm) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
9/12/23 |
157.3 |
74.1 |
52.5 |
|
20.93 |
3.4 |
8.17 |
|
9/18/23 |
181.15 (122-236) |
75.141 (67.57-80.19) |
72.25 (30-90) |
1.725 (1-2) |
15.88 (11.75-22.17) |
4.9 (1-8) |
10.55 (8.7-12.4) |
|
9/25/23 |
179.57 (93-288) |
73.2 (60.43-89.17) |
73 (35-90) |
2.3 (1-3) |
16.7 (10.9-25.6) |
4 (1-8) |
12.12 (10-13) |
|
10/2/23 |
154.7 (83-244) |
69.983 (58.48-80.47) |
58.3 (25-90) |
1.83 (1-3) |
16.97 (11.6-23.69) |
4.87(2-8) |
12.24 (9-15.1) |
|
10/9/23 |
178.4 (109-233) |
73.1 (62.6-81) |
75.8 (45-90) |
1.7 (1-2) |
18.1 (14.1-23.4) |
3.1 (2-6) |
14.5 (13.8-15.8) |
|
10/16/23 |
190.7 (129-257) |
75.1 (65.1-82) |
79.3 (65-95) |
1.8 (1-3) |
17.65 (14-23) |
5.3 (2-7) |
14.4 (12.2-16) |
Golden Delicious
Golden Delicious apples were sampled at one location in Kent County this week. This variety is currently mature and being harvested in the area. While the firmness and starch clearing are stable compared to last week, the sugars are continuing to increase. These apples have excellent sugar accumulation with an average of 13.9 Brix. The firmness is currently below short-term CA storage recommendations for this variety.
|
Collection Date |
Fruit Weight (g) |
Diameter (mm) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
10/2/23 |
197.9 (113-288) |
74.852 (63.44-85.72) |
3.5 (0-7) |
1.7 (1-2) |
15.9185 (13.23-18.89) |
5.05 (4-7) |
12.33 (10.2-14) |
|
10/9/23 |
201 (153-254) |
74.3 (68.2-79.8) |
0 (0-0) |
1.3 (1-2) |
14.8 (12.9-17.1) |
5.6 (4-6) |
12.1 (11.2-13.2) |
|
10/16/23 |
197.8 (159-252) |
76.4 (66.9-81.6) |
7.5 (0-25) |
1 (1-1) |
15.2 (12.7-20.7) |
5.8 (5-7) |
13.9 (13.2-15.2) |
Idared
Idared apples were sampled at one location in Kent County this week. This variety is currently mature and moving into overmaturity. While sugars are below target accumulations at 10.34 Brix, both firmness and starch levels are overmature.
|
Collection Date |
Fruit Weight (g) |
Diameter (mm) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
|
9/25/23 |
173.1 (136-204) |
75.44 (79.59-68.23) |
61 (35-80) |
2.8 (2-3) |
14.7 (12.89-19.55) |
2.8 (2-4) |
9.48 (9-10.2) |
|
10/2/23 |
181.2 (132-259) |
76.371 (66.1-89.5) |
67.75 (45-90) |
1.85 (1-3) |
14.255 (12.48-16.55) |
3.55 (2-7) |
9.51 (8.2-11) |
|
10/9/23 |
180.1 (144-201) |
77.2 (72-80.9) |
74.5 (65-90) |
1.2 (1-2) |
12.97 (10.3-16.6) |
6.6 (4-7) |
10.8 (9.8-12.7) |
|
10/16/23 |
180.6 (124-234) |
76.4 (66.1-83.6) |
76.5 (65-90) |
2 (1-3) |
14.1 (11.9-17.7) |
6.7 (6-7) |
10.34 (9.5-10.9) |
Pink Lady
Pink Lady apples were sampled at one location in Kent County this week. This variety is moving into maturity. The sugar accumulation is good at 11.9 Brix and both the firmness and starch levels are in line with maturity.
|
Collection Date |
Fruit Weight (g) |
Diameter (mm) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
10/16/23 |
220.9 (191-281) |
80 (75.9-87.4) |
43 (20-65) |
2.4 (2-3) |
16.5 (13.7-19.5) |
3.2 (2-4) |
11.9 (11.2-13.2) |
Red Delicious
Red Delicious apples were sampled at two locations in Kent County this week. This variety is currently mature and moving towards overmaturity. Red Delicious apples are currently being harvested in the area. The firmness (16.25 pounds average) is in line with the recommended short term CA levels of 16. The sugars are fair at an average of 12.56 Brix.
|
Collection Date |
Fruit Weight (g) |
Diameter (mm) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
9/18/23 |
154.8 (117-175) |
69.63 (62.46- 74.32) |
88 (75-100) |
1.4 (1-2) |
17.56 (16.13-19.25) |
2.1 (1-4) |
10.56 (9.9-12.2) |
|
9/25/23 |
188.07 (120-258) |
72.3 (63.4-81.25) |
91.4 (75-95) |
1.1 (1-2) |
17.12 (13.98-19.97) |
2.38 (2-3) |
11.01 (10.1-12.1) |
|
10/2/23 |
260.7 (202-390) |
81.905 (74.66-94.59) |
88.25 (75-95) |
1.05 (1-2) |
15.3015 (13.53-18.28) |
2.95 (2-4) |
11.46 (10.2-13) |
|
10/9/23 |
243.04 (134-325) |
78.82 (61.3-89.1) |
88.75 (65-95) |
1 (1-1) |
14.6 (11.9-18.8) |
4.4 (2-7) |
12.56 (12-13.1) |
|
10/16/23 |
149.1 (86-259) |
66.1 (51.6-84.4) |
90.5 (80-100) |
1 (1-1) |
16.25 (9.9-22.1) |
5.1 (3-8) |
11.5 (10.5-12.5) |
Spy
Spy apples were collected at one location in Kent County this week. While the sugar accumulation is currently low at an average of 9.7 Brix, the firmness and starch clearing are well progressed and currently overmature.
|
Collection Date |
Fruit Weight (g) |
Diameter (mm) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
10/2/23 |
163.9 (105-219) |
74.81 (64.46-80.99) |
57 (35-80) |
1.7 (1-2) |
15.51 (13.64-18.31) |
7.2 (6-8) |
10.12 (8.8-11) |
|
10/9/23 |
205.3 (142-286) |
79.7 (72-88) |
49.5 (25-70) |
1.5 (1-2) |
14.1 (11.9-17.2) |
7.4 (7-8) |
11.14 (10-12.5) |
|
10/16/23 |
153.7 (96-198) |
72.8 (61.7-80.9) |
53.5 (30-75) |
1.9 (1-3) |
15.1 (13.5-19.4) |
7.6 (7-8) |
9.7 (9-11.5) |
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.
- 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.
|
Brix Guide |
Low |
Fair |
Good |
Excellent |
|---|---|---|---|---|
|
All varieties |
Less than 11 |
11 |
12 |
13 |
|
Honeycrisp |
Less than 12 |
12 |
12 |
Greater than 14 |
|
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 |
