East Michigan apple maturity report – Oct. 9, 2019

Growers are harvesting Golden Delicious and eyeballing Red Delicious. Empire harvest is mostly wrapped up.

General apple harvest comments

Most apple growers are close to two-thirds of the way to finishing harvest. In testing done this week, Golden Delicious are now ready to begin harvest and Rome, Autumn Gala, CandyCrisp and EverCrisp are quickly to follow. There is a long list of varieties that need more time to mature, including Red Delicious, Idared, Northern Spy and Crispin. I sampled the next batch of varieties to get an early read on their maturity, including Braeburn.

The sixth apple harvest report for the 2019 apple harvest season follows with more details on the 12 varieties tested this week, one of which is a new variety this week. Our predicated apple harvest dates for east Michigan are three to four days later than the normal dates. Here is the link for the 2019 apple predicted harvest dates article that was emailed to area growers as well as being published on our Michigan State University Extension Fruit & Nuts News website in August.

Apple maturity in east Michigan for apples harvested Oct. 7

Variety

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Golden Delicious

15 (0-40)

0 (0-0)

17.3 (15.7-18.6)

4.2 (1.1-5.6)

15.7

Red Delicious

33 (0-80)

100 (100-100)

18.0 (16.6-20.7)

2.6 (2.3-2.8)

12.5

CandyCrisp

40 (40-40)

 

16.8 (15.0-17.5)

2.0 (1.0-4.0)

13.7

Idared

60 (40-80)

88 (80-89)

16.6 (15.5-18.2)

1.9 (1.4-2.3)

13.8

Northern Spy

90 (60-100)

34 (34-34)

19.6 (18.8-21.6)

2.8 (1.8-3.3)

13.3

Crispin

0 (0-0)

10 (7-13)

20.4 (19.7-21.0)

1.6 (1.0-2.1)

13.6

Rome

20 (0-40)

87 (81-92)

22.5 (21.1-22.9)

3.4 (3.1-3.6)

13.3

Autumn Gala

100 (100-100)

 

22.2 (19.5-24.3)

3.5 (1.0-6.0)

14.6

EverCrisp

70 (60-80)

 

20.8 (20.1-21.4)

3.2 (2.4-3.9)

14.5

Fuji

27 (0-60)

92 (75-100)

20.3 (18.2-22.2)

2.8 (2.5-3.0)

14.0

Cameo

0 (0-0)

90 (50-100)

19.4 (19.1-19.6)

2.5 (2.0-3.0)

13.9

Braeburn

20 (0-40)

 

23.9 (23.2-24.5)

1.3 (1.2-1.4)

12.7

Individual variety results

Golden Delicious

Golden Delicious was sampled for the fourth week of the season, Smoothee was the most common strain tested. In last week’s report I stated that most Golden blocks were ready to be color picked, and this week most of the rest of the fruit are ready to be harvested. The predicted harvest date for Golden Delicious was Oct. 3. Fifteen percent of the fruit tested had internal ethylene levels over 0.2 parts per million (ppm). The pressure has dropped a pound but remains firm at 17.3 pounds. The average starch index is 4.2 this week. The blush on Goldens is 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. 16

7 (0-20)

11 (6-14)

18.1 (17.4-18.7)

2.0 (1.0-2.6)

13.4

Sept. 23

5 (0-20)

4 (0-15)

18.1 (16.7-20.4)

3.0 (1.0-5.0)

14.0

Sept. 30

0 (0-0)

9 (4-13)

18.3 (16.5-19.7)

2.8 (1.0-4.3)

15.0

Oct. 7

15 (0-40)

0 (0-0)

17.3 (15.7-18.6)

4.2 (1.1-5.6)

15.7

Red Delicious

Red Delicious was sampled for the third week of the season. Most of the Reds tested this week were Redchief strain, some early strains have been spot picked this past week. Based on this week’s data, Red Delicious are still not ready to begin harvest. The predicted harvest date for Red Delicious was Oct. 5, but it was not ready to be picked on that date.

This week, 33% of fruit tested had internal ethylene levels over 0.2 ppm and the pressure is 18.0 pounds. The average starch index is up from 2.5 last week to 2.6 this week. We usually look for a starch index for Red Delicious to be around 2.5 to 3.0 for fruit that is intended for long-term storage, but for fresh sales I look for the starch index to be in the 3.5 to 4.0 range. Red Delicious still eat really 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. 23

10 (0-40)

93 (70-100)

18.6 (17.2-19.4)

2.1 (1.9-2.4)

11.8

Sept. 30

45 (0-100)

100 (100-100)

18.9 (16.3-19.9)

2.5 (2.0-3.0)

12.8

Oct. 7

33 (0-80)

100 (100-100)

18.0 (16.6-20.7)

2.6 (2.3-2.8)

12.5

CandyCrisp

CandyCrisp was sampled for the third week of the season. This is not a widely planted apple variety in east Michigan and they do not stain the same as most varieties for the starch test. Based on this week’s data, CandyCrisp are ready to begin harvest. The predicted harvest date for CandyCrisp is Oct. 10. Forty percent of fruit tested had internal ethylene levels over 0.2 ppm and the pressure has dropped from 20.2 pounds last week to 16.8 pounds this week. The average starch index is unchanged for the last three weeks at 2.0, but as I stated earlier, it does not stain well.

CandyCrisp 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. 23

0 (0-0)

7 (0-10)

18.9 (16.5-22.0)

2.0 (1.0-3.0)

13.7

Sept. 30

0 (0-0)

8 (0-10)

20.2 (16.0-23.5)

2.0 (2.0-2.0)

13.7

 

Oct. 7

Oct 7

40 (40-40)

 

16.8 (15.0-17.5)

2.0 (1.0-4.0)

13.7

Idared

Idared was sampled for the third week of the season and are still not ready to begin harvest. The predicted harvest date for Idared is Oct. 11, and I do not believe it will be mature by this date. This week, 60% of the fruit tested had internal ethylene levels over 0.2 ppm and the pressure dropped from 19.0 pounds last week to 16.6 pounds this week. The average starch index is unchanged at 1.9. We usually look for a starch index for Idared to be around 3.5 for long-term storage fruit.

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. 23

0 (0-40)

56 (48-65)

18.8 (17.9-20.1)

1.6 (1.5-1.9)

13.2

Sept. 30

25 (0-40)

84 (75-91)

19.0 (17.9-20.4)

1.9 (1.6-2.2)

13.3

Oct. 7

60 (40-80)

88 (80-89)

16.6 (15.5-18.2)

1.9 (1.4-2.3)

13.8

Northern Spy

Northern Spy was sampled for the third week of the season, with more blocks tested this week. Based on this weeks’ data, Northern Spy are close but not quite ready to begin harvest. The predicted harvest date for Northern Spy is Oct. 12, and I believe it will be mature by or close to this date. Ninety percent of fruit tested had internal ethylene levels over 0.2 ppm and the pressure is 19.6 pounds. The average starch index is up from 1.9 last week to 2.8 this week

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. 23

40 (0-80)

31 (30-32)

22.2 (20.3-24.1)

1.4 (1.0-1.8)

12.7

Sept. 30

35 (20-60)

30 (3-46)

21.6 (19.3-23.9)

1.9 (1.4-2.1)

12.7

Oct. 7

90 (60-100)

34 (34-34)

19.6 (18.8-21.6)

2.8 (1.8-3.3)

13.3

Crispin

Crispin or Mutsu was sampled for the third week of the season and are not ready to begin harvest. The predicted harvest date for Crispin is Oct. 13, and I believe it will be mature close to this date. None of fruit tested had internal ethylene levels over 0.2 ppm and the pressure is 20.4 pounds. The average starch index is only 1.6 this week. I saw slightly more blister spot in Crispin this week.

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. 23

20 (0-40)

3 (1-5)

21.0 (20.3-21.6)

2.1 (2.0-2.1)

12.5

Sept. 30

0 (0-0)

11 (2-22)

21.5 (20.3-23.7)

1.9 (1.0-2.6)

13.4

Oct. 7

0 (0-0)

10 (7-13)

20.4 (19.7-21.0)

1.6 (1.0-2.1)

13.6

Rome

Rome was sampled for the second week of the season, with the number of blocked tested increased. Based on this week’s data, Rome are ready to begin harvest. However, they are still very firm and eat a little green. The predicted harvest date for Rome is Oct. 15. Twenty percent of fruit tested had internal ethylene levels over 0.2 ppm and the pressure is still very firm at 22.5 pounds. The average starch index is 3.4 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 %

Sept. 30

0 (0-0)

82 (60-100)

23.9 (21.5-26.0)

3.1 (3.0-4.0)

13.7

Oct. 7

20 (0-40)

87 (81-92)

22.5 (21.1-22.9)

3.4 (3.1-3.6)

13.3

Autumn Gala

Autumn Gala was sampled for the second week of the season, with a limited number of blocks tested. Based on this week’s data, Autumn Gala is close but not quite ready to begin harvest. They still eat just a little green and are very firm at 22.2 pounds. The predicted harvest date for Autumn Gala is Oct. 21 on my chart, and I believe it will be mature well before this date. Some references state Autumn Gala matures close to Idared, while others put it to be mature 10 days later. One hundred percent of fruit tested had internal ethylene levels over 0.2 ppm.

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 %

Sept. 30

100 (100-100)

69 (50-90)

23.6 (22.0-25.5)

2.7 (1.0-6.0)

14.0

Oct. 7

100 (100-100)

 

22.2 (19.5-24.3)

3.5 (1.0-6.0)

14.6

EverCrisp

EverCrisp was sampled for the second week of the season and are close to being ready to harvest. They still eat on the green side and are rock hard. The predicted harvest date for EverCrisp is Oct. 23, however this variety is so new that I don’t have a long track record on predicting its maturity. Seventy percent of fruit tested had internal ethylene levels over 0.2 ppm and the pressure is still very firm at 20.8 pounds. The average starch index has quickly moved from 1.9 last week to 3.2 this 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. 30

20 (0-40)

70 (54-85)

22.8 (20.4-23.1)

1.9 (1.5-2.3)

14.5

Oct. 7

70 (60-80)

 

20.8 (20.1-21.4)

3.2 (2.4-3.9)

14.5

Cameo

Cameo was sampled for the second week of the season are not ready to begin harvest. I don’t have Cameo on the predicted harvest date list in the table that follows, but I believe it matures between Rome and Fuji, or around Oct. 20, and it should mature before this date. None of fruit tested had internal ethylene levels over 0.2 ppm and the pressure is 19.4 pounds. The average starch index is 2.5 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 %

Sept. 30

10 (0-20)

94 (92-95)

20.0 (18.9-21.1)

1.9 (1.8-2.5)

13.8

Oct. 7

0 (0-0)

90 (50-100)

19.4 (19.1-19.6)

2.5 (2.0-3.0)

13.9

Fuji

Fuji was sampled for the second week of the season. The number of Fuji blocks tested this week has also expanded, and Fuji are not ready to begin harvest. The predicted harvest date for Fuji is Oct. 23, but I believe it will be mature well ahead of this date. Seven percent of the fruit tested had internal ethylene levels over 0.2 ppm and the pressure is still very firm at 22.2 pounds. The average starch index is 2.1 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 %

Sept. 23

0 (0-0)

29 (20-40)

20.1 (17.5-23.0)

1.9 (1.0-2.0)

13.1

Sept. 30

7 (0-20)

69 (43-85)

22.2 (20.8-23.3)

2.1 (1.8-2.5)

13.9

Braeburn

Braeburn was sampled for the first week of the season to get an early read on its maturity. Based on one week’s worth of data, Braeburn are not ready to begin harvest. The predicted harvest date for Braeburn is Oct. 28, but I believe it will be mature before this date. Twenty percent of fruit tested had internal ethylene levels over 0.2 ppm and the pressure is rock hard at 23.9 pounds. The average starch index is only 1.3 this week.

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. 7

20 (0-40)

 

23.9 (23.2-24.5)

1.3 (1.2-1.4)

12.7

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 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. Keep a close eye on these weekly Apple Harvest Updates for possible revisions of these dates.


Normal and 2019 peak harvest dates for apple varieties for East Michigan

Variety

Normal date

2019 predicted date

Paula Red

8/22

8/25

Zestar

8/22

8/22

Gingergold

8/23

9/26

Gala

9/8

9/11

McIntosh

9/13

9/16

Early Fiji

9/14

9/17

Honeycrisp

9/16

9/20

Empire

9/20

9/24

Jonathan

9/23

9/27

Jonagold

9/23

9/27

Cortland

9/25

9/29

Golden Delicious

9/29

10/3

Red Delicious

10/1

10/5

CandyCrisp

10/5

10/10

Idared

10/6

10/11

Northern Spy

10/8

10/12

Crispin (Mutsu)

10/9

10/13

Rome

10/11

10/15

Autumn Gala

10/17

10/21

EverCrisp

10/19

10/23

Fuji

10/22

10/26

Braeburn

10/23

10/28

Winesap

10/26

10/30

Goldrush

10/31

11/4

*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.)

 

 

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