Grand Rapids area apple maturity report – October 11, 2023
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EmailLater season varieties like Evercrisp, Fuji, Red Delicious, Golden Delicious and Mutsu are now mature.
This is the fifth 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.
Later season varieties like Evercrisp, Red Delicious, Golden Delicious, Mutsu and Fuji are currently mature in the Grand Rapids area. Jonagold and Ambrosia were targets for harvest this past week. Watercore has been noticed in Evercrisp, Fuji, Red Delicious and Mutsu samples.
- 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
The Michigan State University Enviroweather station in Sparta North received 1.03 inches of rain in the past week. There are more showers predicted daily throughout the next week.
The temperatures have continued to decline this week with daily highs moving from 83.7 degrees Fahrenheit to 48.4 F. Temperatures have approached freezing with the lowest recorded daily minimum at 35.3 F. Forecasted temperatures for the next week remain consist with highs in the 50s and lows in the 40s and high 30s. Frost conditions are not anticipated in the next week.
The Michigan State University Enviroweather station in Sparta North recorded 4,044.4 base 42 F growing degree days (GDD) and 2,658.3 base 50 F GDD.
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 15.3 brix. The firmness also remains high for this variety with an average of 22.5 pounds. Early harvest for this variety is currently underway in this area.
|
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) |
Fuji
Fuji apples were sampled at two locations in Kent County this week. This variety is mature with excellent sugar accumulation at 14.5 brix. Associated with this sugar accumulation, Fuji samples frequently have watercore present. 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) |
Golden Delicious
Golden Delicious apples were sampled at one location in Kent County this week. This variety is mature and being harvested in the area. These apples have good sugar accumulation with an average of 12.1 brix. The firmness is 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) |
Idared
Idared apples were sampled at one location in Kent County this week. This variety is mature and moving into over-maturity. While sugars are below target accumulations at 10.8 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) |
Jonagold
Jonagold apples were sampled at one location in Kent County this week. The sugar accumulation is still fairly low and the firmness has remained stable over time. However, this variety is overmature with little to no starch remaining at an average of 7.8 compared to the over-maturity guidelines of 5.5 for Jonagold.
|
Collection Date |
Fruit Weight (g) |
Diameter (mm) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
9/25/23 |
247.6 (129-342) |
81.2 (65.8-90.21) |
46.2 (12-85) |
2.1 (1-3) |
15.4 (13.28-19.67) |
5.25 (3-8) |
11.59 (10-13) |
|
10/2/23 |
241.15 (139-284) |
79.9805 (68.72-89.15) |
41 (5-85) |
1.45 (1-3) |
15.005 (12.94-18.19) |
7.25 (6-8) |
11.42 (10-13) |
|
10/9/23 |
194.1 (124-274) |
75.2 (64.8-84) |
30 (10-75) |
1.9 (1-3) |
15.5 (12.3-18.5) |
7.8 (7-8) |
11.1 (9-12.5) |
Mutsu
Mutsu apples were sampled at one location in Kent County this week. This variety is mature. The firmness has remained stable compared to last week and is appropriate for mid- to long-term CA storage. The sugars are excellent with an average of 13.13 brix.
|
Collection Date |
Fruit Weight (g) |
Diameter (mm) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (Brix) |
|
10/2/23 |
352.95 (171-503) |
89.7325 (73.72-103.14)) |
2 (0-15) |
1.8 (1-2) |
17.82 (14.13-20.17) |
3.85 (3-7) |
11.47 (10.5-12.5) |
|
10/9/23 |
372.3 (319-488) |
91.3 (85.9-98.8) |
7.5 (0-45) |
1.3 (1-2) |
17.5 (15.2-22.1) |
4 (3-6) |
13.13 (12.2-15.1) |
Red Delicious
Red Delicious apples were sampled at two locations in Kent County this week. This variety is currently mature and moving towards over-maturity. Red Delicious apples are being harvested in the area. The firmness (14.6 pounds average) is lower than the recommended short-term CA levels of 16. The sugars are well developed 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) |
Spy
Spy apples were collected at one location in Kent County this week. While the sugar accumulation is currently low at an average of 11.14 brix, the firmness and starch clearing are well progressed and close to over-maturity.
|
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) |
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 |