East Michigan apple maturity report – Oct. 14, 2020

Red Delicious, Fuji, Northern Spy and Rome harvest are well along. Some Idared, Crispin and Cameo blocks are mature. Demand for fresh apples and sweet cider remains very strong at farm markets.

Apples

General apple harvest comments

Apple harvest is moving along quickly for most growers, with many reporting they will be done with in 10 to 14 days if the good weather holds up. Most growers have kept up with harvest this season. Apples have continued to size well this season, with most varieties picking out long.

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.

Based on this week’s data from the apple maturity project, Red Delicious, Fuji, Northern Spy and Rome are ready for harvest. For other varieties, like Idared, Crispin and Cameo, some blocks are also ready to begin harvest. Golden Delicious are overmature. Fruit color has continued to improve over the past week. The average brix or sugar levels have taken another nice jump in the past week, up from an average of 14.7% last week to 15.8% this week. 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.

This Monday was the seventh week of apple harvest to collect apple samples from a number of orchards in east Michigan to test their maturity. Golden Delicious, Red Delicious, Idared, Northern Spy, Crispin, Rome, Autumn Gala, EverCrisp, Cameo, Fuji and Enterprise and were sampled again this week. Varieties sampled this week for the first time are Braeburn and Winesap 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 this morning, analyzed further and the result of this effort is todays east Michigan apple harvest update.

Many fruit growers marketing fresh apples at farm markets, farmers markets and pick-your-own farms reported record sales again this past weekend. 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.

Brown marmorated stink bug activity increased this past week with warmer temperatures. The adults are starting to move into buildings in search of overwintering sites. Do a good job of scouting for the adults and nymphs as well as checking for damaged fruit in the orchard and as fruit is being graded.

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.

Apple maturity in east Michigan for apples harvested Oct. 12, 2020

Variety

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Golden Delicious

100 (100-100)

18 (10-40)

16.2 (13.0-19.5)

4.7 (3.0-7.0)

16.9

Red Delicious

100 (100-100)

89 (80-95)

17.4 (15.0-20.0)

3.4 (2.0-5.0)

16.0

Idared

95 (80-100)

86 (75-94)

16.5 (15.7-17.8)

3.2 (2.1-3.8)

14.6

Northern Spy

100 (100-100)

61 (47-74)

19.0 (18.1-19.8)

5.0 (3.5-5.7)

14.8

Crispin

100 (100-100)

21 (10-32)

18.5 (18.3-18.6)

3.2 (1.7-4.6)

15.5

Rome

100 (100-100)

85 (84-85)

20.7 (20.6-20.7)

5.8 (5.6-6.0)

15.6

Autumn Gala

100 (100-100)

71 (25-95)

22.2 (18.0-25.0)

3.1 (2.0-5.0)

16.8

EverCrisp

80 (80-80)

84 (82-86)

24.8 (23.0-26.6)

4.0 (3.7-4.2)

17.7

Cameo

60 (20-100)

77 (77-86)

18.0 (17.8-18.2)

4.5 (3.8-5.1)

17.6

Fuji

60 (60-60)

95 (70-90)

17.6 (15.5-23.5)

6.5 (3.0-8.0)

14.8

Enterprise

60 (60-60)

80 (50-90)

18.1 (15.5-23.0)

2.7 (1.0-5.0)

15.7

Braeburn

90 (80-100)

70 (48-91)

22.9 (22.7-23.1)

2.5 (2.1-2.9)

14.0

Winesap

50 (0-100)

89 (82-96)

19.5 (18.6-20.4)

1.4 (1.0-1.8)

15.3

Individual variety results

Golden Delicious was sampled for the fourth week of the season. This week I had a limited number of samples, as most Goldens have been harvested. Smoothee was the only stain sampled again this week. Many Golden Delicious blocks started to be harvested almost two weeks ago. 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 77% last week to 100% this week. Fruit color or blush is good for Goldens, this week a little lower at 18%. The average starch index is up from 4.3 last week to 4.7 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

Oct. 12

100 (100-100)

18 (10-40)

16.2 (13.0-19.5)

4.7 (3.0-7.0)

16.9

Red Delicious was sampled for the fourth week of the season, with the number of Red Delicious samples reduced this week as many Red blocks have been harvested. The only strain tested this week was Red Chief. Based on this weeks’ data, Red Delicious are mature. They were picking easy this week, with some fruit drop. The predicted harvest date for Red Delicious was Oct.  3, they were not mature on this date.

The percentage of fruit with internal ethylene levels over 0.2 ppm is up from 90% last week to 100% this week. Fruit color remains excellent at 89%. The average starch index is up from 2.4 last week to 3.4 this week. I usually look for a starch index to be in the range of 2.5 to 3.0 to begin seeing the Red Delicious harvest window open. Some bitter pit and watercore is being seen in Red Delicious this week.

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

Oct. 12

100 (100-100)

89 (80-95)

17.4 (15.0-20.0)

3.4 (2.0-5.0)

16.0

Idared was sampled for the fourth week of the season. Based on this weeks’ data, Idared are very close to being ready to harvest. Some blocks are ready to harvest now. The predicted harvest date for Idared was Oct. 9, but they were not ready to begin harvest by that date.

The percentage of fruit with internal ethylene levels over 0.2 ppm is up from 80% last week to 95% this week. Fruit color is good and remains about the same at 86%. The pressure has remained steady and firm at 16.5 pounds this week. The average starch index is up from 2.1 last week to 3.2 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

Oct. 12

95 (80-100)

86 (75-94)

16.5 (15.7-17.8)

3.2 (2.1-3.8)

14.6

Northern Spy was sampled for the third week of the season. Based on this weeks’ data, Northern Spy are ready to begin harvest, with a few blocks testing to be overmature. They have matured quickly in the past week. The predicted harvest date for Northern Spy was Oct. 10, some blocks were ready to begin harvest on that date, while others needed a few more days to mature.

The percentage of fruit with internal ethylene levels over 0.2 ppm is 100%, which is typical for Spy’s to be a high ethylene producer. Fruit color is only fair and is unchanged from last week at 61%. The average starch index is up from 3.3 last week to 5.0 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

Oct. 12

100 (100-100)

61 (47-74)

19.0 (18.1-19.8)

5.0 (3.5-5.7)

14.8

Crispin or Mutsu was sampled for the third week of the season. Based on this weeks’ data, some blocks of Crispin are ready to harvest while others are still not ready. The predicted harvest date for Crispin was Oct. 13. I think that they are ready to harvest close to this date.

The percentage of fruit with internal ethylene levels over 0.2 ppm is up from 25% last week to 100% this week. Fruit color or blush is 21%. The average starch index is 3.2 this week, up from 3.0 last week. Blister spot continues to be seen 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

Oct. 12

100 (100-100)

21 (10-32)

18.5 (18.3-18.6)

3.2 (1.7-4.6)

15.5

Rome was sampled for the second week of the season. Based on this weeks’ data, Rome’s are ready to begin harvest. They have matured quickly over the past week. The predicted harvest date for Rome is Oct. 15. The percentage of fruit with internal ethylene levels over 0.2 ppm is 100%. Fruit color is good at 85%. The average starch index is up from 3.5 last week to 5.8 this week.

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

Oct. 12

100 (100-100)

85 (84-85)

20.7 (20.6-20.7)

5.8 (5.6-6.0)

15.6

Autumn Gala was sampled for the second week of the season. Based on this weeks’ data, Autumn Gala are not ready to begin harvest but are getting close. The predicted harvest date for Autumn Gala is Oct. 21, or a week from today. They may be ready to begin a few days ahead of this date. The percentage of fruit with internal ethylene levels over 0.2 ppm is 100%. The fruit color is good at 71%. The fruit are very firm at 22.2 pounds. The average starch index is up from 2.5 last week to 3.1 this week. The brix level is up over 2.3% to 16.8%.

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

Oct. 12

100 (100-100)

71 (25-95)

22.2 (18.0-25.0)

3.1 (2.0-5.0)

16.8

EverCrisp was sampled for the third week of the season. Based on this weeks’ data, EverCrisp are ready to begin harvest. The predicted harvest date for EverCrisp is Oct. 21, so they are mature before this date. EverCrisp is a new variety for the apple maturity project, with blocks just starting to begin producing fruit. As these young blocks mature and settle down some, their maturity window may shift some to a later date. The percentage of fruit with internal ethylene levels over 0.2 ppm is 80%. Fruit color is good at 84%. The average starch index is 4.0 this week, up from 3.4 last week. The brix is at 17.7%, which is amazingly high.

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

Oct. 12

80 (80-80)

84 (82-86)

24.8 (23.0-26.6)

4.0 (3.7-4.2)

17.7

Cameo was sampled for the second week of the season. Based on this weeks’ data, Cameo are ready to begin harvest. The predicted harvest date for Cameo is Oct. 19, so they matured before this date. The percentage of fruit with internal ethylene levels over 0.2 ppm is 60%. Fruit color is good at 77%. The average starch index is up from 3.0 last week to 4.5 this week.

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

Oct. 12

60 (20-100)

77 (77-86)

18.0 (17.8-18.2)

4.5 (3.8-5.1)

17.6

Fuji was sampled for the second week of the season. As I shared in last week’s report, Fuji were ready to begin harvest at that time. Many Fuji blocks are overmature this week. The predicted harvest date for Fuji is Oct. 26, but they matured well before this date. As I also shared in last weeks’ Fuji comments, 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 60%. Fruit color is excellent this week at 95%. The average starch index is up from 4.6 last week to 6.5 this week.

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

Oct. 12

60 (60-60)

95 (70-90)

17.6 (15.5-23.5)

6.5 (3.0-8.0)

14.8

Enterprise was sampled for the second week of the season. Based on this weeks’ data, Enterprise are still not ready to begin harvest. The percentage of fruit with internal ethylene levels over 0.2 ppm is 60%. Fruit color is good at 80%. The average starch index is 2.7 this week, up from 1.1 last week.

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

Oct. 12

60 (60-60)

80 (50-90)

18.1 (15.5-23.0)

2.7 (1.0-5.0)

15.7

Braeburn was sampled for the first week of the season to get an early read on its maturity. Based on one weeks’ worth of data, Braeburn are not ready to begin harvest. The predicted harvest date for Braeburn is Oct. 28. The percentage of fruit with internal ethylene levels over 0.2 ppm is 90%. Fruit color is good at 70%. The average starch index is only 2.5, which was higher than I expected for the first week of sampling.

Braeburn 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. 12

90 (80-100)

70 (48-91)

22.9 (22.7-23.1)

2.5 (2.1-2.9)

14.0

Winesap was sampled for the first week of the season to get an early read on its maturity. Based on one weeks’ worth of data, Winesap are not ready to begin harvest. The predicted harvest date for Winesap is Oct. 30. The percentage of fruit with internal ethylene levels over 0.2 ppm is 50%. Fruit color is good at 89%. The average starch index is only 1.4.

Winesap 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. 12

50 (0-100)

89 (82-96)

19.5 (18.6-20.4)

1.4 (1.0-1.8)

15.3

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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