East Michigan apple maturity report – Sept. 26, 2018

The typical order of apple variety harvest is very different this season, with maturity of several varieties jumping ahead of others. Jonagold, Jonathan, Golden Delicious and some early Red Delicious strains are ready for harvest.

September 26, 2018 - Author:

General apple harvest comments

The list of varieties ready for harvest has grown quickly this week. Many apple varieties are not maturing in their typical order of ripening this season. Many varieties are maturing much earlier than predicted. A shorter list of varieties is very slow to mature this season, such as Empire, Cortland and Idared. McIntosh, although harvested already, was also slow to mature this season. Thus, most growers are shuffling their order of varieties being harvested to reflect this much different growing season.

Growers are harvesting Jonathan, SnowSweet, Jonagold and Golden Delicious. Based on this week’s Apple Maturity Project data, a few blocks of Red Delicious, Northern Spy and Empire are also ready to begin harvest. Cortland, Idared and Crispin are not ready for harvest. More details on the maturity of each of these varieties follow.

This was the fourth week of our apple harvest season to collect apple samples. Samples were collected Monday, Sept. 24, from a number of orchards in east Michigan and were analyzed yesterday at the Department of Horticulture Post Harvest Lab at Michigan State University. The number of varieties tested this week dropped back from 11 last week to 10. However, the number of samples collected has grown by a third this week. This list of varieties tested this week includes Empire, SnowSweet, Jonathan, Jonagold, Cortland, Golden Delicious, Red Delicious, Idared, Northern Spy and Crispin.

Close to a third of the brown marmorated stink bug (BMSB) MSU monitored trapping locations are catching high numbers, many close to 50 BMSB over a week. Some growers are applying insecticides to control them. A good amount of sooty blotch and flyspeck, woolly apple aphid and San Jose scale continues to be found at many farms. A number of blocks are seeing lenticel rot and black rot symptoms.

Here is the link for the 2018 Predicted Harvest Dates article that was posted to the MSU Extension in July. A list of predicated harvest dates for east Michigan is listed at the end of this article as well. Spend time in your orchard every few days to evaluate the maturity of your apple varieties.

Apple maturity in east Michigan for apples harvested Sept. 24

Variety

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Empire

10 (0-40)

78 (69-91)

16.2 (15.1-17.2)

3.0 (1.9-4.9)

12.5

SnowSweet

25 (0-50)

75 (59-90)

17.0 (16.5-17.4)

6.9 (6.9-6.9)

14.7

Jonathan

57 (10-90)

94 (86-99)

16.0 (15.5-16.6)

5.3 (2.5-7.0)

14.2

Jonagold

53 (48-60)

66 (47-73)

16.0 (15.5-16.6)

7.1 (6.3-7.8)

13.8

Cortland

33 (30-40)

81 (73-91)

14.7 (14.1-15.2)

2.3 (1.7-2.2)

12.5

Golden Delicious

3 (0-10)

9 (5-21)

16.6 (16.1-17.1)

5.1 (4.7-5.8)

13.7

Red Delicious

23 (10-60)

93 (90-97)

16.0 (15.1-17.1)

4.0 (1.6-5.9)

11.4

Idared

48 (20-80)

73 (65-80)

16.4 (14.9-17.8)

1.8 (1.2-2.6)

12.6

Northern Spy

80 (30-100)

62 (40-93)

18.0 (16.0-21.9)

3.4 (1.9-5.2)

12.7

Crispin

8 (0-20)

8 (2-19)

17.9 (17.0-19.0)

2.4 (1.0—5.2)

12.0

Individual variety results

Empire was sampled for the third week of the season. Based on this week’s data and as I stated last week, Empire is a variety that is slowly and steadily moving toward maturity. Most sites are not ready to harvest at this time, however there are a few early maturing sites where the harvest window is just opening for the beginning of Empire harvest. The predicted harvest date for Empire was Sept. 18. The fruit color has improved to 78 percent and the average starch index is up from 2.4 last week to 3.0 this week. At some farms the starch index is averaging 4.9, these blocks are ready to begin 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. 10

8 (0-10)

67 (63-70)

18.9 (16.5-20.5)

1.7 (1.2-2.1)

11.3

Sept. 17

8 (0-20)

69 (60-75)

17.7 (16.6-18.9)

2.4 (1.6-3.3)

11.9

Sept. 24

10 (0-40)

78 (69-91)

16.2 (15.1-17.2)

3.0 (1.9-4.9)

12.5

SnowSweet is a fairly new variety for many east Michigan apple growers and was sampled for the second week of the season. It is written in several references that SnowSweet is ready for harvest two weeks after Honeycrisp. Based on my limited sampling and testing of this variety for the last two weeks in this very hot and early growing season, they were ready to harvest earlier than today, Sept. 26. Based on these two weeks of sampling, SnowSweet were ready to harvest last week and that this week they are over-mature. The fruit color is up this week to 75 percent, fruit firmness averaged 17.0 pounds and the starch index is 6.9. The fruit are very sweet, this week the brix averaged 14.7 percent.

SnowSweet 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. 17

10 (0-20)

60 (60-60)

18.0 (17.9-18.0)

6.6 (6.3-6.9)

14.9

Sept. 24

25 (0-50)

75 (59-90)

17.0 (16.5-17.4)

6.9 (6.9-6.9)

14.7

Jonathan was sampled for the third week of the season. Based on this week’s data, most strains and sites are ready for harvest, while a limited number of other blocks need a few more days to mature. Went I back to collect another sample this week, I found some blocks were harvested already. The predicted harvest date for Jonathan was Sept. 21. Fruit color has risen to 94 percent this week, fruit firmness dropped from 18.2 pounds last week to 16.0 pounds this week, and the average starch index rose from 3.8 last week to 5.3 this week. Note that the range of starch index is very broad, from 2.5 to 7.0. The brix or sugar content is 14.2 percent. Most blocks are eating very good.

Jonathan 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. 10

65 (30-100)

95 (92-98)

20.5 (20.5-20.5)

1.9 (1.5-2.2)

13.1

Sept. 17

70 (40-90)

89 (75-97)

18.2 (16.8-19.8)

3.8 (2.1-5.3)

13.5

Sept 24

57 (10-90)

94 (86-99)

16.0 (15.5-16.6)

5.3 (2.5-7.0)

14.2

Jonagold was sampled for the second week of the season. Based on this week’s data, Jonagold are ready to harvest, with many blocks being over-mature. The predicted harvest date for Jonagold was Sept. 21, but based on two weeks of data it appears it was ready to harvest earlier. The fruit color has improved to 66 percent this week, with fruit firmness averaging 16.0 pounds and the starch index averaged a surprising 7.1, with a range of 6.3 to 7.8. So, many Jonagold blocks may be over-mature for long-term storage.

Jonagold 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. 17

27 (0-50)

47 (33-59)

16.6 (15.3-18.4)

5.3 (4.1-6.2)

14.0

Sept 24

53 (48-60)

66 (47-73)

16.0 (15.5-16.6)

7.1 (6.3-7.8)

13.8

Cortland was sampled for the third week of the season, most blocks tested this week were Redcort with a few regular Cortland blocks added in. Based on this week’s data, Cortland are maturing very slowly this season and are still not ready to begin harvest. The predicted harvest date for Cortland was Sept. 22, but they were not mature on this date. The fruit color has improved to 81 percent this week, but the starch index has dropped back from 2.6 last week to 2.3 this week. I think this drop in starch index is the result of adding in some standard Cortland blocks. They are still eating green.

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. 10

45 (0-90)

75 (68-81)

17.3 (16.1-18.5)

1.1 (1.0-1.1)

12.7

Sept. 17

25 (0-50)

71 (57-85)

16.6 (15.8-17.3)

2.6 (2.0-3.2)

13.5

Sept. 24

33 (30-40)

81 (73-91)

14.7 (14.1-15.2)

2.3 (1.7-2.2)

12.5

Golden Delicious was sampled for the second week of the season. Based on this week’s data, most Golden blocks are ready to begin harvest, especially for fruit destined for long term and CA storage. The fruit color or blush has not developed yet in many blocks, some growers are waiting for better color on Goldens. They matured very close to the predicted harvest date of Sept. 23. The fruit firmness was 16.6 pounds this week and the average starch index jumped from 3.6 last week to 5.1 this week. They are eating much better this week.

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. 17

5 (0-10)

0 (0-0)

17.0 (15.7-18.6)

3.6 (3.0-4.3)

13.4

Sept. 24

3 (0-10)

9 (5-21)

16.6 (16.1-17.1)

5.1 (4.7-5.8)

13.7

Red Delicious was sampled for the second week of the season with increased sampling this week. Based on this week’s data, some early maturing Red Delicious strains and sites are ready to begin harvest, while most others need more time to mature. The predicted harvest date for Red Delicious is Sept. 29, or the end of the week. The fruit color is very good at 93 percent, fruit firmness averaged 16.0 pounds and starch index averaging 4.0. As was the case for Jonathan, the range of starch index is very broad, from 1.6 to 5.9. Many blocks are still eating green.

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. 17

30 (0-60)

99 (98-100)

17.2 (17.0-17.4)

3.7 (3.6-3.8)

11.4

Sept 24

23 (10-60)

93 (90-97)

16.0 (15.1-17.1)

4.0 (1.6-5.9)

11.4

Idared was sampled for the first week of the season to get an early read on its maturity. Based on only one week of data, Idared are not ready to begin harvest. The predicted harvest date for Idared is Oct. 4. I doubt they will be ready for harvest by this date. The fruit color is OK, averaging 73 percent, with the starch index of 1.8. They are eating very green.

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. 24

48 (20-80)

73 (65-80)

16.4 (14.9-17.8)

1.8 (1.2-2.6)

12.6

Northern Spy was sampled for the first week of the season to get an early read on its maturity. Based on only one week of data, I was surprised to see some early blocks are ready to begin harvest, but most blocks need a few more days to mature. The predicted harvest date for Northern Spy is Oct. 3. The fruit color is OK at 62 percent. The starch index averaged 3.4, however, the range of starch index is quite broad or wide starting at 1.9 and extending to 5.2. Some blocks are eating fine at this time, while most are still eating on the green side.

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. 24

80 (30-100)

62 (40-93)

18.0 (16.0-21.9)

3.4 (1.9-5.2)

12.7

Crispin or Mutsu was sampled for the second week of the season. Based on this week’s data, a few blocks of Crispin are ready to begin harvest, but most are not ready yet. The predicted harvest date for Crispin is Oct. 6. The fruit color is still very green, with the starch index of 2.4. However, the range of starch index is quite broad, ranging from an average of 1.0 to 5.2. I have not seen any blister spot showing yet in Crispin. Most blocks are still eating green.

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. 17

0 (0-0)

0 (0-0)

18.3 (16.0-20.5)

2.3 (1.0-4.0)

11.4

Sept. 24

8 (0-20)

8 (2-19)

17.9 (17.0-19.0)

2.4 (1.0-5.2)

12.0

Predicted peak fresh market apple harvest dates for East Michigan

Each year we publish predicted harvest dates for three varieties for many locations across the state. This year's “Predicted 2018 apple harvest dates” were published July 10. These predicted harvest dates are based on a long-established formula using the bloom date and temperatures for 30 days post-bloom. The information in this article lists the bloom and harvest dates for Deerfield and Romeo, Michigan.

The following table has predicted apple harvest dates for east Michigan. It has been expanded to include more apple varieties and 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. Due to the early start to our growing season and much above normal temperatures this summer, I believe our actual harvest dates may be a few days ahead of these predicted harvest dates for most varieties. Keep a close eye on the weekly apple harvest updates for possible revisions of these dates.

Normal and 2018 peak harvest dates for apple varieties in east Michigan

Variety

Normal date

2018 predicted date

Paula Red

8/22

8/17/18

Gingergold

8/23

8/20/18

Gala

9/8

9/5/18

McIntosh

9/13

9/7/18

Early Fuji

9/14

9/9/18

Honeycrisp

9/16

9/12/18

Empire

9/20

9/18/18

Jonathan

9/23

9/21/18

Jonagold

9/23

9/21/18

Cortland

9/25

9/22/18

Golden Delicious

9/29

9/23/18

Red Delicious

10/1

9/29/18

CandyCrisp

10/5

10/3/18

Ida Red

10/6

10/4/18

Northern Spy

10/8

10/3/18

Crispin

10/9

10/6/18

Rome

10/11

10/7/18

Autumn Gala

10/17

10/14/18

EverCrisp

10/19

10/17/18

Fuji

10/22

10/18/18

Braeburn

10/23

10/21/18

Winesap

10/26

10/24/18

Goldrush

10/31

10/29/18

 

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

*Firmness is measured with a mechanical 11-millimeter wide probe inserted into the pared flesh of a fruit to a distance of 8 millimeters. Starch index is measured on equatorial cross section of an apple stained with iodine solution and rated using the Cornell University starch-iodine index chart for apples on a 1-8 scale (Predicting Harvest Date Window for Apples by Blanpied and Silsbey, Cornell Extension Bulletin 221.)

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

Tags: apple harvest 2018, apple maturity reports, east apple maturity report, msu extension


Other Articles in this Series

Michigan State University Michigan State University Close Menu button Menu and Search button Open Close