Grand Rapids area apple maturity report – Sept. 29, 2021

This is the eighth apple maturity report for the Grand Rapids, Michigan, region.

Red apples hanging from a tree.
Idared fruit in an orchard in Sparta, Michigan, on Sept. 27, 2021. Maturity is moving along quickly in later varieties, and after a few cooler nights, color is developing nicely. Photo by Anna Wallis, MSU Extension.

This is the eighth 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.

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

Weather – In the Grand Rapids, Michigan, area, harvest is moving along quickly! Weather has been beautiful. Aside from a few rainy days last week, conditions have been clear, sunny and temperatures very moderate.

Maturity in many varieties is advancing very quickly. We are seeing many varieties entering harvest windows slightly earlier than predicted harvest dates. It is very important to be testing fruit earlier than normal to detect fruit that is maturing ahead of expected targets.

Jonagold and Empire untreated fruit have been harvested or will be in the next week.

Golden Delicious is ready for harvest now.

Red Delicious is moving quickly and should begin harvest very soon for long term storage. Considerably earlier than predicted harvest date.

Ida Red maturity is moving quickly, should be picked in the next week.

Ambrosia internal qualities show fruit are mature, but color is less than excellent in some locations. Harvesting now.

Evercrisp, Fuji, Rome and Braeburn are still immature, but showing increasing signs of ripening.

Predicted harvest dates according to the Maturity Model in Enviroweather are approximately normal or slightly early for later varieties. At this time, the season appears to be a few days ahead of normal.

Mixed maturity is evident in most varieties and locations. Multiple picks may be needed to harvest fruit at the appropriate maturity for successful storage conditions.

Empire

This variety has been harvested in most locations. Model-predicted harvest date was Sept. 22 for this variety and they seem to be coming in right on target. Fruit treated with AVG or 1-MCP is delayed as expected.

Empire sampled Sept. 29

Variety

Location

Fruit Weight (g)

Ethylene (% >0.2ppm)

Red Color (%)

Background color (5-1)

Firmness (lbs)

Starch (1-7)

Soluble Solids (°Brix)

Empire

Belding3

180

100%

68.0

2.1

14.5

5.6

11.7

Average

 

180

100%

68.0

2.1

14.5

5.6

11.7

Max

 

 

 

80.0

3.0

17.4

8.0

11.7

Min

 

 

 

50.0

1.0

8.7

4.0

11.7

Recommended

 

 

 

 

 

14-16

3.5-6

 

Empire 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

.

0%

93.0 (85-100)

1.6 (2-1)

19.6 (16.8-22.8)

2.2 (2-4)

13.0 (13.0-13.0)

20-Sep

167

20%

51.8 (10-90)

3.0 (3-3)

17.8 (14.9-21.9)

3.6 (1-6)

12.4 (10.1-14.1)

27-Sep

180

100%

68.0 (50-80)

2.1 (3-1)

14.5 (8.7-17.4)

5.6 (4-8)

11.7

Jonagold

The harvest window is beginning to open for Jonagold for fresh market. Color is less than excellent in most places, although a few locations or fruit at the end of rows are coloring nicely. Background color is changing from green to yellow noticeably. Harvest is expected to begin for most locations in the next week to 10 days. Model predicted harvest was Oct. 1, but we expect actual harvest to be slightly earlier where color is adequate and crop load is light.

Jonagold sampled Sept. 29

Variety

Location

Fruit Weight (g)

Ethylene (% >0.2ppm)

Red Color (%)

Background color (5-1)

Firmness (lbs)

Starch (1-7)

Soluble Solids (°Brix)

Jonagold

Ridge2

258

100%

67.5

2.0

15.4

6.1

14.5

Jonagold

Ridge3

301

100%

72.0

1.9

16.1

6.3

17.0

Jonagold

Ridge4

283

100%

59.5

1.8

16.2

6.5

15.5

Average

 

280

100%

66.3

1.9

15.9

6.3

15.7

Max

 

 

 

90.0

2.0

18.5

8.0

17.0

Min

 

 

 

30.0

1.0

11.0

4.0

14.5

Recommended

 

 

 

 

 

15-17

3.5-5.5

 

Jonagold 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

245

27%

28.7 (10-60)

2.7 (4-2)

19.3 (14.0-26.1)

4.0 (2-7)

13.1 (12.4-13.9)

20-Sep

253

77%

.

.

17.3 (13.5-22.0)

5.6 (3-8)

14.2 (12.0-17.0)

27-Sep

280

100%

66.3 (30-90)

1.9 (2-1)

15.9 (11.0-18.5)

6.3 (4-8)

15.7 (14.5-17.0)

Golden Delicious

This variety should be harvested now. Color has improved from green to yellow in most location and size is very good. Minimal red color was observed, with only a touch of blush on a few fruit. Evaluation of starch clearing, firmness, and sugars all indicate fruit is mature. Flavor of fruit is also showing noticeable development. Our predicted harvest date for Goldens was Oct. 1 and that date seems to be a bit on the late side according to the fruit we are testing. Many Golden blocks have a light crop load and are ripening faster than expected.

Golden Delicious sampled Sept. 29

Variety

Location

Fruit Weight (g)

Ethylene (% >0.2ppm)

Red Color (%)

Background color (5-1)

Firmness (lbs)

Starch (1-7)

Soluble Solids (°Brix)

Golden Delicious

Ridge2

174

0%

11.5

2.4

14.9

6.3

14.0

Golden Delicious

Ridge3

192

20%

5.1

2.8

17.6

4.3

14.5

Golden Delicious

Ridge4

215

60%

3.0

2.1

16.8

4.2

16.0

Average

 

194

27%

6.5

2.4

16.4

4.9

14.8

Max

 

 

 

25.0

3.0

19.3

7.0

16.0

Min

 

 

 

0.0

1.0

12.3

2.0

14.0

Recommended

 

 

 

 

 

15-17

3-6.5

 

Golden 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

185

7%

.

2.6 (3-2)

18.6 (13.8-24.9)

2.5 (1-6)

13.0 (12.4-13.7)

20-Sep

186

13%

.

.

17.3 (14.8-19.5)

3.6 (2-6)

13.6 (12.0-15.0)

27-Sep

194

27%

6.5 (0-25)

2.4 (3-1)

16.4 (12.3-19.3)

4.9 (2-7)

14.8 (14.0-16.0)

Red Delicious

This variety is maturing quickly and has entered the window for long term CA storage in most locations. Ethylene development is evident in many samples with some over the 0.2 ppm climacteric. Pressures, starch, and sugars are just entering acceptable harvest ranges. Model predicted harvest was Oct. 7 for this variety but we expect actual harvest to be slightly earlier.

Red Delicious sampled Sept. 29

Variety

Location

Fruit Weight (g)

Ethylene (% >0.2ppm)

Red Color (%)

Background color (5-1)

Firmness (lbs)

Starch (1-7)

Soluble Solids (°Brix)

Red Delicious

Ridge2

228

100%

83.9

1.1

16.1

4.5

14.0

Red Delicious

Ridge3

182

0%

82.5

1.2

17.0

3.1

12.0

Red Delicious

Ridge4

190

40%

87.5

1.2

15.0

3.1

13.5

Average

 

200

47%

84.6

1.2

16.0

3.6

13.2

Max

 

 

 

100.0

2.0

19.0

7.0

14.0

Min

 

 

 

60.0

1.0

14.0

2.0

12.0

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)

Idared

This variety is showing signs of maturity and just beginning to enter the harvest window. Model predicted harvest was Oct. 7, but we expect actual harvest to be slightly earlier.

Idared sampled Sept. 29

Variety

Location

Fruit Weight (g)

Ethylene (% >0.2ppm)

Red Color (%)

Background color (5-1)

Firmness (lbs)

Starch (1-7)

Soluble Solids (°Brix)

Idared

Ridge2

164

100%

82.5

1.7

15.8

4.1

14.0

Idared

Ridge3

201

60%

80.0

2.0

16.8

2.9

13.5

Idared

Ridge4

193

60%

75.5

1.9

16.5

2.3

13.5

Average

 

186

73%

79.3

1.9

16.4

3.1

13.7

Max

 

 

 

95.0

3.0

19.0

7.0

14.0

Min

 

 

 

50.0

1.0

11.8

2.0

13.5

Recommended

 

 

 

 

 

14-16

3.5-6

 

Idared 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

150

37%

63.5 (30-95)

2.1 (3-1)

19.5 (14.5-23.5)

2.3 (1-5)

12.0 (11.8-12.1)

20-Sep

169

40%

.

.

19.0 (15.0-24.0)

2.4 (1-5)

12.0 (12.0-13.0)

27-Sep

186

73%

79.3 (50-95)

1.9 (3-1)

16.4 (11.8-19.0)

3.1 (2-7)

13.7 (13.5-14.0)

Ambrosia

Ambrosia is still a new variety for the area, and we are learning about maturity for our region. Internal qualities indicate fruit is very near or ready for harvest. Color is variable; it is still less than excellent in some places and other locations there is nice bright red development. It appears to be a heavy ethylene producing apple, with many fruit producing significant amounts in our sample last week and again this week.

Starch clearing is difficult to interpret, with an interesting mosaic pattern. Clearing appears to begin throughout the flesh even while some of the cortex is still not clear. Overall, this variety needs a little more time for red color development if possible. In some areas, internal qualities indicate the fruit are ready for harvest. In other areas that grow Ambrosia, they pick it about the same time as Red Delicious.

Ambrosia sampled Sept. 29

Variety

Location

Fruit Weight (g)

Ethylene (% >0.2ppm)

Red Color (%)

Background color (5-1)

Firmness (lbs)

Starch (1-7)

Soluble Solids (°Brix)

Ambrosia

Ridge3

203

60%

76.5

1.1

16.6

6.0

16.8

Ambrosia

Ridge4

217

40%

63.0

1.4

15.7

5.2

14.0

Average

 

210

50%

69.8

1.3

16.2

5.6

15.4

Max

 

 

 

90.0

2.0

18.5

7.0

16.8

Min

 

 

 

50.0

1.0

14.0

4.0

14.0

Recommended

 

 

 

 

 

 

 

 

Ambrosia 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

220

70%

30.5 (10-45)

1.6 (2-1)

17.6 (15.0-20.9)

3.5 (1-6)

11.9 (11.3-12.5)

20-Sep

206

100%

.

.

15.7 (13.5-22.0)

5.5 (3-8)

14.2 (12.0-17.0)

27-Sep

210

50%

69.8 (50-90)

1.3 (2-1)

16.2 (14.0-18.5)

5.6 (4-7)

15.4 (14.0-16.8)

Rome

Overall, Rome is still a little immature. Color is developing nicely but firmness, sugars, and starch indicate it still needs a bit more time. 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 Sept. 29

Variety

Location

Fruit Weight (g)

Ethylene (% >0.2ppm)

Red Color (%)

Background color (5-1)

Firmness (lbs)

Starch (1-7)

Soluble Solids (°Brix)

Rome

Ridge3

158

0%

86.4

2.9

24.1

2.8

11.8

Average

 

158

0%

86.4

2.9

24.1

2.8

11.8

Max

 

 

 

100.0

3.0

29.0

4.0

11.8

Min

 

 

 

50.0

2.0

15.5

2.0

11.8

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 (23-27)

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

Fuji

Overall, Fuji is still somewhat immature, but should be watched closely. Color is still developing, pressures are high, and starch is continuing to clear. Randy Beaudry reminds us each year that this variety is typically mature right after Red Delicious, and that we often wait a little longer than probably necessary to harvest, typically while waiting for color development. This variety does not stain well with iodine, and starch pattern fades quickly. Internal ethylene is being produced in a number of fruit. Our predicted harvest date is Oct. 20, but we anticipate actual harvest date to be considerably earlier – especially if color improves.

Fuji sampled Sept. 29

Variety

Location

Fruit Weight (g)

Ethylene (% >0.2ppm)

Red Color (%)

Background color (5-1)

Firmness (lbs)

Starch (1-7)

Soluble Solids (°Brix)

Fuji

Ridge2

217

40%

74.0

2.9

16.5

3.7

14.5

Fuji

Ridge3

206

60%

85.0

2.2

18.6

3.6

14.5

Fuji

Belding1

240

60%

53.0

3.0

18.0

4.2

13.9

Fuji

Belding3

240

40%

73.0

3.0

21.1

2.9

13.2

Average

 

226

50%

71.3

2.8

18.5

3.6

14.0

Max

 

 

 

95.0

3.0

23.4

5.0

14.5

Min

 

 

 

40.0

1.0

14.0

2.0

13.2

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)

Evercrisp

Overall, Evercrisp is still very immature. A little more red color development has taken place, but more is necessary and background color is very green. This is a high ethylene producing variety, which was detected in all samples. Starch clearing is just beginning. Soluble solids are high, which is likely a contribution of the Fuji parentage.

Evercrisp sampled Sept. 29

Variety

Location

Fruit Weight (g)

Ethylene (% >0.2ppm)

Red Color (%)

Background color (5-1)

Firmness (lbs)

Starch (1-7)

Soluble Solids (°Brix)

Evercrisp

Ridge1

179

80%

58.0

2.5

22.8

3.6

15.0

Evercrisp

Ridge2

225

100%

77.5

3.3

22.5

2.5

16.0

Evercrisp

Ridge4

282

100%

59.0

4.5

24.3

3.7

16.0

Evercrisp

Belding1

220

100%

24.5

4.0

23.4

2.4

12.3

Evercrisp

Belding3

230

80%

33.0

4.0

26.8

2.0

13.2

Average

 

227

92%

50.4

3.7

23.9

2.8

14.5

Max

 

 

 

90.0

5.0

30.9

8.0

16.0

Min

 

 

 

0.0

2.0

20.0

1.0

12.3

Recommended

 

 

 

 

 

 

 4-6

(storage)

 

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)

Braeburn

One sample was taken this week of this variety. Overall, Braeburn is still very immature. Fruit is very firm, low in sugars and starch clearing is just beginning.

Variety

Location

Fruit Weight (g)

Ethylene (% >0.2ppm)

Red Color (%)

Background color (5-1)

Firmness (lbs)

Starch (1-7)

Soluble Solids (°Brix)

Braeburn

Ridge4

180

20%

63.0

2.9

19.3

2.3

11.5

Average

 

180

20%

63.0

2.9

19.3

2.3

11.5

Max

 

 

 

80.0

3.0

22.8

3.0

11.5

Min

 

 

 

45.0

2.0

13.0

1.0

11.5

Recommended

 

 

 

 

 

 

 3.5

 

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.

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

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