East Michigan apple maturity report – Oct. 7, 2020

Empire and Golden Delicious harvest are well along. Fuji and Cortland are mature as well and are ready for harvest. Demand for fresh apples and sweet cider has been very strong at farm markets.

Golden Delicious apples

General apple harvest comments

Based on this week’s data from the apple maturity project, Empire, Golden Delicious, Cortland and Fuji are ready for harvest. Snows are overmature at this time. Other varieties, like Northern Spy, Crispin, Rome, EverCrisp and Cameo, are fast approaching maturity. Red Delicious are slow to mature this season.

Monday was the sixth week of apple harvest to collect apple samples from a number of orchards in east Michigan to test their maturity. Empire, Cortland, Golden Delicious, Red Delicious, Idared, Northern Spy, Crispin and EverCrisp were sampled again this week. New varieties added this week are Snow, Rome, Autumn Gala, Cameo, Fuji and Enterprise to get an early read on their maturity. On Monday afternoon, these samples were delivered to the Department of Horticulture Post Harvest Lab at Michigan State University and analyzed yesterday. The raw data was forwarded on to me last night, analyzed further and the result of this effort is today’s sixth east Michigan apple harvest update.

Apples have continued to size well this season, with most varieties picking out long. Most growers have kept up with harvest this season. Fruit color has continued to improve with cooler weather. Golden Delicious finish is very good this season. The average brix or sugar levels have taken another nice jump in the past week.

As I shard last week, demand for fresh apples at farm markets, farmers markets and pick-your-own sales have been outstanding so far this fall, with many growers reporting record sales again for this past Saturday.

The flavor of sweet cider continues to improve as brix or sugar levels have increased and more varieties are available to be added to the blend. Demand for sweet cider has also been very strong this fall. Many east Michigan cider makers are needing to buy cider apples to keep up with cider demand.

Most growers are finding their storages are rather empty for this time of the season. This has not been the result of poor yields, but more the result of increased demand for fresh market sales and high demand for cider and processing apples.

Bitter pit is continuing to be seen this week in Red Delicious and Northern Spy. Blister spot is continuing to be seen in Crispin or Mutsu.

The normal and predicated apple harvest dates for east Michigan continue to be a part of today’s apple harvest report. The predicted harvest dates are based on temperatures from spring to 30 days after bloom and do not take into account summer temperatures, which can push development earlier or later than predicted. Keep in mind these predicted dates are for peak harvest, so some fruits might be ready ahead or behind these dates as we move through maturity.

These predicted harvest dates are a few days behind normal or most years, but as we are continuing with harvest many apple varieties are ready to harvest a few days ahead of normal. See the MSU Extension article, “Predicted 2020 apple harvest dates” by Phil Schwallier, for more details on how these dates are calculated.

On the apple crop pest front, brown marmorated stink bug (BMSB) trap catch numbers collected on Monday and Tuesday, Oct. 5 an 6, have dropped off considerably. Do a good job of scouting for the adults and nymphs as well as damage to fruit.

Apple maturity in east Michigan for apples harvested Oct. 5, 2020

Variety

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Empire

13 (0-40)

93 (88-97)

15.9 (15.7-16.3)

4.0 (3.3-5.1)

14.7

Cortland

100 (100-100)

87 (85-89)

15.3 (15.0-15.6)

4.9 (4.0-5.8)

14.0

Snow

100 (100-100)

61 (50-80)

11.9 (10.0-15.0)

6.5 (4.0-7.0)

15.0

 

Golden Delicious

77 (50-100)

26 (20-33)

16.9 (16.6-17.1)

4.3 (2.3-5.7)

16.0

Red Delicious

90 (80-100)

92 (87-92)

16.7 (16.5-16.9)

2.4 (1.6-3.2)

13.5

Idared

80 (20-100)

81 (74-90)

16.3 (15.8-17.7)

2.1 (1.6-2.4)

13.9

Northern Spy

93 (70-100)

62 (47-68)

20.6 (18.6-24.2)

3.3 (2.3-4.2)

14.35

Crispin

25 (0-80)

18 (9-34)

18.1 (16.6-19.6)

3.0 (1.5-4.9)

13.8

Rome

60 (20-100)

84 (83-84)

21.2 (20.3-22.0)

3.5 (3.4-3.6)

14.3

Autumn Gala

100 (100-100)

68 (60-80)

22.8 (19.0-27.0)

2.5 (1.0-3.0)

14.5

EverCrisp

90 (80-100)

85 (83-86)

22.7 (21.8-23.6)

3.4 (2.5-4.2)

16.6

Cameo

25 (17-33)

83 (77-89)

17.3 (16.8-17.7)

3.0 (2.7-3.3)

16.1

Fuji

63 (20-100)

76 (64-91)

18.6 (18.0-19.2)

4.6 (3.4-6.2)

14.3

Enterprise

0 (0-0)

76 (60-90)

18.8 (16.0-23.0)

1.1 (1.0-2.0)

14.1

Individual variety results

Empire was sampled for the fourth week of the season. Based on this weeks’ data, the harvest window for Empire opened in some blocks last week and in all other blocks has opened this week. Growers have been harvesting since then, and they are eating much better this week. The predicted harvest date for Empire was Sept. 23, so they matured later than this date.

The percentage of fruit with internal ethylene levels over 0.2 parts per million (ppm) is still low at 13%. Fruit color has improved this week to 93%. The average starch index is up from 3.2 last week to 4.0 this week. The brix or sugar level has also improved to 14.7% this week. I generally look for a starch index above 3.5 to begin Empire harvest.

Empire maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 14

10 (0-40)

70 (63-77)

19.5 (17.4-21.0)

2.3 (1.8-2.7)

12.9

Se

Sept. 21

5 (0-20)

73 (63-82)

18.5 (17.3-19.4)

2.9 (2.0-3.6)

13.5

Sept. 28

23 (0-40)

86 (83-88)

17.1 (16.0-18.1)

3.2 (2.6-4.1)

14.3

Oct. 5

13 (0-40)

93 (88-97)

15.9 (15.7-16.3)

4.0 (3.3-5.1)

14.7

Cortland was also sampled for the fourth week of the season. Based on this weeks’ data, Cortland maturity progressed quickly in the past week and are now ready for harvest. The predicted harvest date for Cortland was Sept. 28, so they are maturing well behind this date.

The percentage of fruit with internal ethylene levels over 0.2 ppm is up from 70% last week to 100% this week. Fruit color is still excellent at 87%. The average starch index is up sharply from 2.1 last week to 4.9 this week.

Cortland maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 14

50 (0-100)

82 (82-82)

16.9 (16.7-17.1)

1.1 (1.0-1.2)

13.6

Setp. 21

Sept. 21

60 (0-100)

84 (70-93)

16.1 (15.1-16.6)

1.7 (1.4-1.9)

14.0

Sept. 28

70 (40-100)

90 (86-93)

15.4 (14.7-16.1)

2.1 (1.9-2.3)

13.7

Oct. 5

100 (100-100)

87 (85-89)

15.3 (15.0-15.6)

4.9 (4.0-5.8)

14.0

Snow was sampled this week for the first time of the season and maybe the first time to be included in the testing of varieties for the apple maturity project. This is an old variety that still has strong demand at many farm markets in the region.

Based on one weeks’ worth of data, Snow are overmature. The percentage of fruit with internal ethylene levels over 0.2 ppm is 100%. Fruit color is good at 61%. The fruit firmness is only 11.9 pounds and the average starch index is 6.5. The harvest window for Snow would be before Empire, maybe in the Jonathan and Jonagold harvest window.

Snow maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Oct. 5

100 (100-100)

61 (50-80)

11.9 (10.0-15.0)

6.5 (4.0-7.0)

15.0

 

Golden Delicious was sampled for the third week of the season, again this week all the samples tested were the Smoothee strain. Many Golden Delicious blocks were ready to begin harvest last week and based on this weeks’ data, all blocks tested are now ready for harvest. The predicted harvest date for Golden Delicious was Oct. 1, so it matured very close to this date.

The percentage of fruit with internal ethylene levels over 0.2 ppm is up from 32% last week to 77% this week. Fruit color or blush is good for Goldens, this week about the same at 26%. The average starch index is up from 3.9 last week to 4.3 this week. I generally look for a starch index to be at 3.0 to begin Golden harvest. The finish on Goldens is excellent this season, maybe the best I have ever seen.

Golden Delicious maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 21

10 (0-40)

25 (23-28)

17.7 (16.2-18.7)

1.9 (1.0-2.9)

15.0

Sept. 28

32 (0-67)

23 (8-46)

17.3 (15.0-18.5)

3.9 (1.2-4.9)

15.9

Oct. 5

77 (50-100)

26 (20-33)

16.9 (16.6-17.1)

4.3 (2.3-5.7)

16.0

Red Delicious was sampled for the third week of the season, with the number of Red Delicious samples ramped up again this week to get a good read on its maturity. The strains tested this week included Scarlet Spur, Red Chief, Miller Spur and Bright-N-Early. Based on this weeks’ data, Red Delicious are maturing slowly this season and are still not ready to begin harvest. The predicted harvest date for Red Delicious was Oct. 3, and they were not mature on this date.

The percentage of fruit with internal ethylene levels over 0.2 ppm is up from 56% last week to 90% this week. Fruit color remains excellent at 92%. The average starch index is the same as last week at 2.4. I usually look for a starch index to be in the range of 2.5 to 3.0 to begin to see the Red Delicious harvest window open.

Red Delicious are still eating very green. I think maybe another week is needed to begin harvest for Red Delicious. Some bitter pit is being seen in the Red Chief strain of Red Delicious and other regions are reporting watercore issues as well.

Red Delicious maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 21

7 (0-20)

89 (83-98)

17.9 (17.6-18.3)

2.0 (1.9-2.1)

12.5

Sept. 28

56 (17-100)

94 (87-97)

16.6 (15.0-17.8)

2.4 (2.1-2.6)

13.5

Oct. 5

90 (80-100)

92 (87-92)

16.7 (16.5-16.9)

2.4 (1.6-3.2)

13.5

Idared was sampled for the third week of the season. Based on this weeks’ data, Idared are still not ready to begin harvest. The predicted harvest date for Idared is Oct. 9, or Friday of this week. I do not tink it will be ready to begin harvest by this Friday.

 The percentage of fruit with internal ethylene levels over 0.2 ppm is up from 70% last week to 80% this week. Fruit color is good and remains about the same at 81%. The pressure has dropped from 18.4 pounds last week to 16.3 pounds this week. The average starch index is up from 1.7 last week to 2.1 this week this week. I generally look for a starch index to be to 3.5 to begin to see the Idared harvest window open.

Idared maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 21

10 (0-20)

77 (75-79)

19.1 (18.8-19.4)

1.1 (1.0-1.2)

13.3

Sept. 28

70 (40-100)

83 (78-87)

18.4 (17.9-18.8)

1.7 (1.5-1.8)

13.4

Oct. 5

80 (20-100)

81 (74-90)

16.3 (15.8-17.7)

2.1 (1.6-2.4)

13.9

Northern Spy was sampled for the second week of the season. Based on this weeks’ data, Northern Spy are not ready to begin harvest. The predicted harvest date for Northern Spy is Oct. 10. Spy’s will need at least another week to see the harvest window to open. The percentage of fruit with internal ethylene levels over 0.2 ppm is 93%, which is typical for Spy’s to be a good ethylene producer. Fruit color is only fair at 62%. The average starch index is up from 2.1 last week to 3.3 this week. More bitter pit is being seen this week in Northern Spy.

Northern Spy maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 28

76 (67-100)

52 (44-59)

21.0 (20.0-22.7)

2.1 (1.1-2.6)

13.7

Oct. 5

93 (70-100)

62 (47-68)

20.6 (18.6-24.2)

3.3 (2.3-4.2)

14.3

Crispin or Mutsu was sampled for the second week of the season. Based on this weeks’ data, Crispin are still not ready to begin harvest. The predicted harvest date for Crispin is Oct. 13. They will be ready close to this date. The percentage of fruit with internal ethylene levels over 0.2 ppm is 25%. Fruit color or blush is 18%. The average starch index is 3.0 this week, up from 2.0 last week. Blister spot continues in Crispin.

Crispin maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 28

0 (0-0)

14 (9-18)

19.8 (18.7-20.8)

2.0 (2.0-2.0)

13.0

Oct. 5

25 (0-80)

18 (9-34)

18.1 (16.6-19.6)

3.0 (1.5-4.9)

13.8

Rome was sampled for the first week of the season to get an early read on its maturity. Based on one weeks’ worth of data, Rome’s are not ready to begin harvest. The predicted harvest date for Rome is Oct. 15. The percentage of fruit with internal ethylene levels over 0.2 ppm is 60%. Fruit color is good at this time at 84%. The average starch index is 3.5 this week, which is higher than I would have expected for this time of the season.

Rome maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Oct. 5

60 (20-100)

84 (83-84)

21.2 (20.3-22.0)

3.5 (3.4-3.6)

14.3

Autumn Gala was sampled for the first week of the season to get an early read on its maturity. Based on one weeks’ worth of data, Autumn Gala are not ready to begin harvest. The predicted harvest date for Autumn Gala is Oct. 21. The percentage of fruit with internal ethylene levels over 0.2 ppm is 100%. The fruit color is good at 68%. The fruit are very firm at 22.8 pounds. The average starch index is 2.5 this week.

Autumn Gala maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Oct. 5

100 (100-100)

68 (60-80)

22.8 (19.0-27.0)

2.5 (1.0-3.0)

14.5

EverCrisp was sampled for the second week of the season. Based on this weeks’ data, EverCrisp are not ready to begin harvest. The predicted harvest date for EverCrisp is Oct. 21. I think EverCrisp will be ready to begin to harvest well before this date, maybe a week from now. The percentage of fruit with internal ethylene levels over 0.2 ppm is 90%. Fruit color is good at 85%. The average starch index is 3.4 this week, which is higher than I would have expected for this time of the season. The brix is at 16.6%, which is an amazing high number for this early in the season for EverCrisp. I am still looking to find more EverCrisp blocks to sample for next week.

EverCrisp maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 28

100 (100-100)

78 (50-90)

23.5 (20.5-27.0)

2.0 (1.0-3.0)

17.5

Oct. 5

90 (80-100)

85 (83-86)

22.7 (21.8-23.6)

3.4 (2.5-4.2)

16.6

Cameo was sampled for the first week of the season to get an early read on its maturity. Based on one weeks’ worth of data, Cameo are not ready to begin harvest. The predicted harvest date for Cameo is Oct. 19. Cameo will be ready to begin to harvest before this date. The percentage of fruit with internal ethylene levels over 0.2 ppm is 25%. Fruit color is good at 83%. The average starch index is 3.0 this week, which is higher than I would have expected for this time of the season.

Cameo maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Oct. 5

25 (17-33)

83 (77-89)

17.3 (16.8-17.7)

3.0 (2.7-3.3)

16.1

Fuji was sampled for the first week of the season to get an early read on its maturity. Based on one weeks’ worth of data, Fuji are ready to begin harvest. The predicted harvest date for Fuji is Oct. 26 but looking back at several years’ worth of Fuji maturity data, I now believe that with the strains that are widely planted today, the Fuji maturity window really falls before Red Delicious.

The percentage of fruit with internal ethylene levels over 0.2 ppm is 63%. Fruit color is good at 76%. The average starch index is 4.6, which is much higher than I would have expected for this time of the season. Based on this data, I should have been starting to sample Fuji for its maturity two weeks ago.

Fuji maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Oct. 5

63 (20-100)

76 (64-91)

18.6 (18.0-19.2)

4.6 (3.4-6.2)

14.3

Enterprise was sampled for the first week of the season to get an early read on its maturity. Based on one weeks’ worth of data, Enterprise are not ready to begin harvest. None of the fruit had internal ethylene levels over 0.2 ppm. Fruit color is good at 76%. The average starch index is only 1.1.

Enterprise maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Oct. 5

0 (0-0)

76 (60-90)

18.8 (16.0-23.0)

1.1 (1.0-2.0)

14.1

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.
  • Firmness lbs. = pounds pressure sampled from two sides of each fruit.
  • Starch: 1 = all starch, 8 = No starch; range is of all fruits tested. The higher the number, the more mature fruit is, using the Cornell Starch Iodine Index Chart.
  • Brix % = % sugar. 

Predicted peak fresh market apple harvest dates for east Michigan

Each year we publish predicted harvest dates for many locations across the state. These predicted harvest dates are based on a long-established formula using the bloom date and temperatures for 30 days post-bloom.

The following table has predicted apple harvest dates for east Michigan. It has been expanded to include more apple varieties. It lists only one date for the entire east Michigan region, which is hard to do! You can adjust these predicted harvest dates based on your actual bloom dates or on the typical harvest dates at your farm.

These dates are an estimate and will be affected by the apple strain, rootstock, crop load, fertility, soil type and other factors including weather this season. Keep a close eye on the weekly apple harvest updates for possible revisions of these dates.

Normal and 2020 peak harvest dates for apple varieties for east Michigan

Variety

Normal date

2020 predicted date

Paula Red

Aug. 22

Aug. 24

Zestar

Aug. 22

Aug. 23

Gingergold

Aug. 23

Aug. 25

Gala

Sept. 8

Sept. 10

McIntosh

Sept. 13

Sept. 15

Early Fiji

Sept. 14

Sept. 16

Honeycrisp

Sept. 16

Sept. 19

Empire

Sept. 20

Sept. 23

Jonathan

Sept. 23

Sept. 26

Jonagold

Sept. 23

Sept. 26

Cortland

Sept. 25

Sept. 28

Golden Delicious

Sept. 29

Oct. 1

Red Delicious

Oct. 1

Oct. 3

CandyCrisp

Oct. 5

Oct. 8

Idared

Oct. 6

Oct. 9

Northern Spy

Oct. 8

Oct. 10

Crispin (Mutsu)

Oct. 9

Oct. 13

Rome

Oct. 11

Oct. 14

Autumn Gala

Oct. 17

Oct. 19

EverCrisp

Oct. 19

Oct. 21

Fuji

Oct. 22

Oct. 24

Braeburn

Oct. 23

Oct. 26

Winesap

Oct. 26

Oct. 28

Goldrush

Oct. 31

Nov. 2

We are grateful to many farms and organizations who make the 2020 east Michigan Apple Maturity Program a success - either through direct funding or indirectly through cooperation.

  • Erwin Orchards, S. Lyon, Michigan
  • Hy’s Cider Mill, Romeo, Michigan
  • Spicer Orchards, Fenton, Michigan
  • Westview Orchards, Romeo, Michigan
  • Many other orchards where apple samples are collected
  • Michigan State Horticultural Society
  • Michigan Tree Fruit Commission
  • Michigan State University Department of Horticulture
  • Michigan State University AgBio Research
  • Michigan State University Extension

Looking for more? View Michigan State University Extension’s Apple Maturity page for regional reports throughout the state and additional resources.

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