Grand Rapids area apple maturity report – Oct. 13, 2021
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EmailThis is the 10th and final apple maturity report for the Grand Rapids, Michigan, region.
This is the 10th and final apple maturity report for the 2021 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.
For general information about how samples are collected and processed, please refer to Apple Maturity Report #1.
- Considerations for the 2021 harvest season can be found in this article.
- 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
For each variety evaluated, we provide data from our evaluations in a table. In each, a row is provided for each sample tested. This allows you to see how the varieties may be progressing in different regions or specific locations. An average is included 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. Recommended values are included for each variety at the bottom of the table. These suggested values for firmness and starch index were also published in a standalone table format. Firmness ranges encompass long and short-term storage recommendations.
Updates for this week
This will be the last report of the season. Harvest is wrapping up quickly and many of our sample locations were harvested at the time of collection for this report.
Conditions have continued to be warmer than normal over the past week, with highs in the 70s degrees Fahrenheit and lows mostly remaining in the 50-60s. This is less than ideal for red color development. In addition, we have had a considerable amount of rain and wind in the past week. Approximately 0.5 inches of accumulation was recorded Friday evening into Saturday in Sparta, Michigan, and an additional 0.65 inches Sunday through Tuesday. Heavy wind knocked leaves and, in some cases, a little fruit off of trees.
There is considerable variability in maturity and quality for many varieties due to the extended bloom, warm season and ample rainfall this season. Overall, fruit is softer and more mature this year than it has been in the previous two years. As a result, fruit going into bins may be a wide range of quality, which will have important impacts on storage. It will be critical to do everything possible to ensure optimum storage conditions. This includes cooling fruit quickly, and treatment with 1-MCP.
Red Delicious is continuing harvest this week in most locations.
Fuji is showing signs of maturity and harvesting this week in most locations.
Evercrisp is showing signs of maturity and should begin harvest this week or next week.
Rome and Braeburn are also showing signs of maturity and picking in most locations.
Red Delicious
This variety is continuing to be harvested in many locations this week. Only one sample was collected for testing this week and other sample locations have been harvested. Ethylene development is evident in many samples with some over the 0.2 ppm climacteric. Pressures have decreased this week. Typically, we like to see pressure of about 15 pounds at the consumer end, and fruit harvested at this pressure are beyond the appropriate condition for long term controlled atmosphere (CA) storage. Model predicted harvest was Oct. 7 for this variety.
Red Delicious sampled Oct. 11
|
Variety |
Location |
Fruit Weight (g) |
Ethylene (% >0.2ppm) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-7) |
Soluble Solids (°Brix) |
|
Red Delicious |
Ridge4 |
181 |
100% |
92.0 |
1.0 |
14.6 |
4.4 |
13.5 |
|
Average |
|
181 |
100% |
92.0 |
1.0 |
14.6 |
4.4 |
13.5 |
|
Max |
|
|
|
80.0 |
1.0 |
13.0 |
3.0 |
|
|
Min |
|
|
|
100.0 |
1.0 |
15.5 |
6.0 |
|
|
Recommended |
|
|
|
|
|
16-18 |
2.5-6 |
|
Red Delicious weekly averages
|
Collection Date |
Fruit Weight (g) |
Ethylene (% Fruit >0.2ppm) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (°Brix) |
|
13-Sep |
190 |
40% |
89.0 (75-100) |
2.2 (3-1) |
18.1 (16.0-21.0) |
2.3 (2-3) |
11.5 (10.9-12.0) |
|
20-Sep |
190 |
30% |
17.0 (15.0-20.0) |
2.7 (2-5) |
12.5 (11.0-14.5) |
||
|
27-Sep |
200 |
47% |
84.6 (60-100) |
1.2 (2-1) |
16.0 (14.0-19.0) |
3.6 (2-7) |
13.2 (14.0-14.0) |
|
4-Oct |
215 |
80% |
89.8 (65-100) |
1.0 (2-1) |
15.6 (13.0-17.8) |
4.3 (3-7) |
13.5 (12.6-13.9) |
|
11-Oct |
181 |
100% |
92.0 (80-100) |
1.0 (1-1) |
14.6 (13.0-15.5) |
4.4 (3-6) |
13.5 |
Rome
Overall, Rome is mature or nearly mature and picking in most places. Firmness decreased a bit again this week, but still needs a bit more time in this particular block. In other locations, apples are ready to harvest. Sugars and starch did not change much from last week but are close to the appropriate range for harvest. Model predicted harvest was Oct. 14, and we anticipate it to be close to accurate but like everything else this season, they might come in slightly earlier. There was no color bleeding in any of the Romes we sampled.
Rome sampled Oct. 11
|
Variety |
Location |
Fruit Weight (g) |
Ethylene (% >0.2ppm) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-7) |
Soluble Solids (°Brix) |
|
Rome |
Ridge3 |
172 |
0% |
88.0 |
2.0 |
19.9 |
3.5 |
12.7 |
|
Average |
|
172 |
0% |
88.0 |
2.0 |
19.9 |
3.5 |
12.7 |
|
Max |
|
|
|
75.0 |
2.0 |
19.0 |
3.0 |
|
|
Min |
|
|
|
95.0 |
2.0 |
21.7 |
5.0 |
|
|
Recommended |
|
|
|
|
|
15-18 |
3-5.5 |
|
Rome weekly averages
|
Collection Date |
Fruit Weight (g) |
Ethylene (% Fruit >0.2ppm) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (°Brix) |
|
20-Sep |
180 |
0% |
78.5 (60-90) |
3 (3-3) |
24.5 (23.0-27.0) |
2.7 (2-3) |
11.3 |
|
27-Sep |
158 |
0% |
86.4 (50-100) |
2.9 (3-2) |
24.1 (15.5-29.0) |
2.8 (2-4) |
11.8 |
|
4-Oct |
183 |
0% |
87.0 (75-100) |
1.9 (3-1) |
22.1 (19.5-26.0) |
3.3 (3-4) |
12.8 |
|
11-Oct |
172 |
0% |
88.0 (75-95) |
2.0 (2-2) |
19.9 (19.0-21.7) |
3.5 (3-5) |
12.7 |
Fuji
Fuji is nearly mature in most locations. Internal characteristics (starch, sugars and pressure) indicate fruit is mature. Color is much improved from last week but less than excellent. Water core was observed in a number of fruit this week but was relatively minor. This variety does not stain well with iodine, and starch pattern fades quickly. Internal ethylene is being produced in a nearly all fruit. Model-predicted harvest was Oct. 20 but we believe fruit is internally ready for harvest. A few more days may help to improve color.
Fuji sampled Oct. 11
|
Variety |
Location |
Fruit Weight (g) |
Ethylene (% >0.2ppm) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-7) |
Soluble Solids (°Brix) |
|
Fuji |
Belding1 |
250 |
100% |
50.4 |
2.3 |
17.1 |
5.1 |
13.5 |
|
Fuji |
Belding3 |
240 |
100% |
85.0 |
2.0 |
19.2 |
4.4 |
15.1 |
|
Fuji |
Ridge2 |
239 |
100% |
83.5 |
2.0 |
14.3 |
6.3 |
15.7 |
|
Fuji |
Ridge3 |
266 |
100% |
92.5 |
1.2 |
17.1 |
6.6 |
17.0 |
|
Average |
|
249 |
100% |
77.9 |
1.9 |
16.9 |
5.6 |
15.3 |
|
Max |
|
|
|
95.0 |
3.0 |
21.2 |
7.0 |
17.0 |
|
Min |
|
|
|
4.0 |
1.0 |
13.0 |
4.0 |
13.5 |
|
Recommended |
|
|
|
|
|
16-18 |
3-7 |
|
Fuji weekly averages
|
Collection Date |
Fruit Weight (g) |
Ethylene (% Fruit >0.2ppm) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (°Brix) |
|
20-Sep |
205 |
55% |
46.3 (5-80) |
6.5 (4-3) |
19.6 (14.5-23.2) |
1.9 (1-4) |
13.5 (11.4-15.5) |
|
27-Sep |
226 |
50% |
71.3 (40-95) |
2.8 (3-1) |
18.5 (14.0-23.4) |
3.6 (2-5) |
14.0 (13.2-14.5) |
|
4-Oct |
233 |
85% |
76.9 (40-100) |
2.1 (3-1) |
16.9 (14.8-21.0) |
4.6 (1-7) |
14.2 (12.8-15.8) |
|
11-Oct |
249 |
100% |
77.9 (40-95) |
1.9 (3-1) |
16.9 (13.0-21.2) |
5.6 (4-7) |
15.3 (13.5-17.0) |
Evercrisp
Overall, Evercrisp is still nearly mature. A little more red color development has taken place but more is necessary. Background color is still fairly green but improving. This is a high ethylene producing variety, which was detected in all samples. Pressure decreased a little this week but is still very high and starch is continuing to clear. Soluble solids are high, which is likely a contribution of the Fuji background. Water core was detected in several fruit in two samples this week.
Evercrisp sampled Oct. 11
|
Variety |
Location |
Fruit Weight (g) |
Ethylene (% >0.2ppm) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-7) |
Soluble Solids (°Brix) |
|
Evercrisp |
Belding1 |
239 |
100% |
62.5 |
2.6 |
19.9 |
5.6 |
14.2 |
|
Evercrisp |
Belding3 |
260 |
100% |
58.5 |
2.8 |
22.7 |
2.2 |
14.5 |
|
Evercrisp |
Ridge1 |
188 |
100% |
71.0 |
2.2 |
18.7 |
6.5 |
17.1 |
|
Evercrisp |
Ridge4 |
316 |
100% |
55.0 |
2.4 |
23.7 |
5.9 |
17.2 |
|
Average |
|
251 |
100% |
61.8 |
2.5 |
21.2 |
5.0 |
15.8 |
|
Max |
|
|
|
90.0 |
4.0 |
29.0 |
8.0 |
17.2 |
|
Min |
|
|
|
25.0 |
2.0 |
16.0 |
2.0 |
14.2 |
|
Recommended |
|
|
|
|
|
|
|
|
Evercrisp weekly averages
|
Collection Date |
Fruit Weight (g) |
Ethylene (% Fruit >0.2ppm) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-6) |
Soluble Solids (°Brix) |
|
20-Sep |
233 |
73% |
14.3 (10-40) |
4 (4-4) |
25.1 (20.5-31.1) |
1.9 (1-4) |
13.5 (11.4-15.5) |
|
27-Sep |
227 |
92% |
50.4 (0-90) |
3.7 (5-2) |
23.9 (20.0-30.9) |
2.8 (1-8) |
14.5 (12.3-16.0) |
|
4-Oct |
234 |
90% |
57.3 (10-90) |
3.1 (4-2) |
23.1 (17.0-28.0) |
3.9 (2-7) |
15.0 (12.9-16.0) |
|
11-Oct |
251 |
100% |
61.8 (25-90) |
2.5 (4-2) |
21.2 (16.0-29.0) |
5.0 (2-8) |
15.8 (14.2-17.2) |
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.
|
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 |
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 |
