Southwest Michigan apple maturity report – Oct. 6, 2021

This is the sixth weekly apple maturity report for the southwest Michigan region.

Evercrisp apples in a tree.
Evercrisp apples are developing a red blush, with harvest expected in a few weeks. Photo by Diedre Scholtz.

This apple maturity report for the southwest Michigan region is sent out every week (usually on Wednesdays) following the Michigan State University Extension fruit team apple maturity calls on Wednesday morning.

Highlights for this week

Apple harvesting in the area is winding down. Approximately 90% or more of the Golden Delicious have been harvested in Berrien County, and essentially all the Ida Red blocks. About half of the Red Delicious blocks have been picked. Fujis and a few Braeburns are being harvested.

Detailed information by variety

Mac, Gala, Honeycrisp, Jonagold, Jonathan and Empire

No more reports for these varieties, now at or beyond full maturity.

Golden Delicious

This variety was sampled for the fourth week. Firmness dropped 2 pounds since last week and is now averaging of 14.7 pounds. This is at the lower range considered ideal for long term controlled atmosphere (CA) storage. Starch conversion average jumped from 4.4 to 6.2 this week, and well above the 3.0 point where fruit is mature. Fruit in this firmness category is suited for short term CA storage or more immediate use.

Golden Delicious – Sampled Oct. 4, 2021

Site

Firmness (lbs)

Red color range (%)

Starch

Soluble solids (Brix)

1

14.5

0

6.2

13.6

2

17.1

20-30

5.4

16.2

3

14.3

0

6.2

13.8

4

14.0

15-25

6.4

14.4

5

14.0

0

6.6

11.8

Average

14.7

 

6.2

14.0

Max

17.1

 

6.6

16.2

Min

14.0

 

5.4

11.8

Recommended

17-15

 

3.0

 

 

Golden Delicious maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 13

17.6 (16.0-20.0)

2.9 (1.0-4.2)

12.0

Sept. 20

17.4 (16.0-19.1)

3.5 (2.6-4.8)

13.1

Sept. 27

16.8 (15.0-18.0)

4.4 (3.0-5.8)

14.3

Oct. 4

14.7 (14.0-17.1)

6.2 (5.4-6.6)

14.0

Red Delicious

This variety was sampled for the fourth week. Firmness is testing an average of 14.8 pounds, again dropping almost 2 pounds for the second week, and below the recommended range for short term CA storage. Starch conversion for the five sites tested an average of 5.5 well into the internally mature zone. Flavor is generally good due to relatively high brix. Two sites had watercore symptoms in the flesh, with one site severe. Fruit picked at this point should be moved quickly to the consumer. This variety ripened about two weeks ahead of the predicted harvest date, Oct. 3, for central Berrien County.

Red Delicious – Sampled Oct. 4, 2021

Site

Firmness (lbs)

Red color range (%)

Starch

Soluble solids (Brix)

1

15.2

100

4.4

13.3

2

15.0

100

5.4

13.7

3

15.0

100

5.8

12.9

4

16.0

100

4.8

12.9

5

13.0

95-100

7.0

13.2

Average

14.8

 

5.5

13.2

Max

16.0

 

7.0

13.7

Min

13.0

 

4.4

12.9

Recommended

18-16

 

2.5

 

 

Red Delicious maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 13

18.4 (17.2-20.2)

2.8 (2.0-4.0)

10.2

Sept. 20

17.4 (16.2-19.0)

3.8 (2.6-6.0)

11.4

Sept. 27

16.4 (15.0-17.3)

4.2 (3.0-5.6)

12.4

Oct. 4

14.8 (13.0-16.0)

5.5 (4.4-7.0)

13.2

Fuji

This variety was sampled for the fourth week, and flesh firmness is now testing an average of 15.7 pounds, slightly less than last week and in the short term CA storage range. Starch conversion tested 4.7, slightly higher than last week, and considered to be internally mature. Red blush ranges from 20 to 95%. So far, the five sites tested have been free of watercore. Fuji has a revised predicted harvest date of Sept. 28 for central Berrien County.

Fuji (Main season) – Sampled Oct. 4, 2021

Site

Firmness (lbs)

Red color range (%)

Starch

Soluble solids (Brix)

1

17.0

60-90

4.0

14.5

2

16.0

60-90

4.8

13.1

3

16.1

70-95

4.0

14.2

4

14.3

40-60

5.8

13.3

5

15.0

20-70

4.8

13.3

Average

15.7

 

4.7

13.7

Max

17.0

 

5.8

14.5

Min

14.3

 

4.0

13.1

Recommended

18-16

 

3.0

 

 

Fuji maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 13

17.5 (16.2-20.0)

3.4 (3.0-4.2)

11.2

Sept. 20

19.0 (16.1-21.0)

3.0 (2.0-4.0)

12.6

Sept. 27

16.0 (15.0-17.0)

4.3 (3.0-4.3)

13.1

Oct. 4

15.7 (14.3-17.0)

4.7 (4.0-5.8)

13.7

Ida Red

This variety was harvested for the third week and was predicted to be ready for fresh market harvesting approximately Oct. 10 in central Berrien County. Fruit firmness is testing an average of 15.6 pounds, at the point appropriate for medium duration CA storage. Starch conversion is now slightly higher than last week and is now at an average of 3.8. Most blocks have been harvested.

Ida Red – Sampled Oct. 4, 2021

Site

Firmness (lbs.)

Red color range (%)

Starch

Soluble solids (Brix)

1

15.2

75-98

3.8

12.5

2

15.3

75-98

3.4

12.5

3

15.0

20-90

3.6

10.0

4

14.4

70-98

6.2

13.9

5

18.1

80-98

2.2

13.6

Average

15.6

 

3.8

12.5

Max

18.1

 

6.2

13.9

Min

14.4

 

2.2

10.0

Recommended

16-14

 

3.5

 

 

Ida Red maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 20

18.1 (16.1-20.0)

2.0 (1.0-2.8)

12.6

Sept. 27

16.0 (15.0-17.0)

3.6 (2.6-6.2)

12.9

Oct. 4

15.6 (14.4-18.1)

3.8 (2.2-6.2)

12.5

Rome

This variety was harvested for the second week and is predicted to be ready approximately Oct. 10 in central Berrien County. Fruit firmness is still excellent at an average of 20.5 pounds, with starch conversion testing an average of 3.5, and considered internally mature. According to these tests, Rome harvest can be delayed because fruit is very firm. Some blocks have been harvested for processing.

Rome – Sampled Oct. 4, 2021

Site

Firmness (lbs.)

Red color range (%)

Starch

Soluble solids (Brix)

1

21.0

90-98

4.0

12.1

2

20.0

60-95

3.0

11.3

3

21.0

85-100

3.6

11.4

4

20.0

15-85

3.2

11.3

Average

20.5

 

3.5

11.5

Max

21.0

 

4.0

12.1

Min

20.0

 

3.0

11.3

Recommended

18-15

 

3.5

 

 

Rome maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 27

21.0 (19.2-21.0)

3.5 (3.0-4.0)

11.4

Oct. 4

20.5 (20.0-21.0)

3.5 (3.0-4.0)

11.5

Braeburn

This variety was harvested for the second week and is predicted to be ready approximately Oct. 27 in central Berrien County. Fruit firmness is excellent at an average of 19.8 pounds with starch conversion testing an average of 4.0, and considered internally mature.

Braeburn – Sampled Oct. 4, 2021

Site

Firmness (lbs.)

Red color range (%)

Starch

Soluble solids (Brix)

1

21.1

60-95

3.4

10.4

2

20.0

40-60

5.4

11.5

3

19.0

30-75

3.2

10.7

4

19.0

50-90

4.0

11.1

Average

19.8

 

4.0

10.9

Max

21.1

 

5.4

11.5

Min

19.0

 

3.2

10.4

Recommended

18-15

 

3.5

 

 

Braeburn maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 27

21.1 (20.3-22.0)

2.9 (1.4-4.0)

10.9

Oct. 4

19.8 (19.0-21.1)

4.0 (3.2-5.4)

10.9

Evercrisp

This variety was harvested for the third week and is predicted to be ready approximately Oct. 27 in central Berrien County. Fruit firmness is excellent at an average of 20.6 pounds, about the same as last week. Starch conversion is testing an average of 2.7 and not yet considered internally mature. Penn State University recommends using starch index of 4-6 for long term storage and 6-7 for direct sales market. Fruit appearance is still relative immature. Evercrisp, like Fuji, is prone to watercore and internal browning in storage if picked too late, so keeping an eye on the starch index is recommended.

Evercrisp – Sampled Oct. 4, 2021

Site

Firmness (lbs.)

Red color range (%)

Starch

Soluble solids (Brix)

1

20.2

50-80

2.4

12.8

2

21.0

60-80

3.0

15.0

Average

20.6

 

2.7

13.9

Max

21.0

 

3.0

15.0

Min

20.2

 

2.4

12.8

Recommended

18-15

 

3.5

 

 

Evercrisp maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 27

21.5 (21.0-22.0)

2.5 (2.0-3.0)

13.6

Oct. 4

20.6 (20.2-21.0)

2.7 (2.4-3.0)

13.9

How to read the maturity tables

For each variety evaluated, each row in the data table is a different orchard block. Maximum and minimum values are the highest and lowest individual fruits evaluated for each. 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.

Firmness in pounds pressure = measured with a FT Penetrometer using a 7/16 inch (11 millimeters) diameter probe, peel removed; range is for the average at each site.

Starch: 1 = no starch conversion, 8 = No starch; range is for average of the sites. Using Cornell Starch Iodine Index Chart.

Brix = % sugar measured with Atago PAL-1 Pocket Refractometer

Additional apple maturity helps

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

 

Normal and predicted 2021 peak harvest dates for apple varieties in central Berrien County in southwest Michigan based on weather data at the Southwest Michigan Research and Extension Center, Benton Harbor, MI.

Variety

Normal date SW

2020 Predicted 1st significant harvest date

2021 Predicted 1st significant harvest date

Paula Red

22-Aug

25-Aug

13-Aug

Zestar

22-Aug

25-Aug

13-Aug

Gingergold

20-Aug

23-Aug

11-Aug

Early Fuji

3-Sep

6-Sep

25-Aug

Gala

8-Sep

11-Sep

31-Aug

McIntosh

10-Sep

13-Sep

1-Sep

Honeycrisp

13-Sep

15-Sep

4-Sep

Empire

18-Sep

21-Sep

21-Sep

Jonathan

22-Sep

24-Sep

25-Sep

Jonagold

22-Sep

24-Sep

25-Sep

Fuji

25-Sep

28-Oct

28-Sep

Golden Delicious

25-Sep

27-Sep

28-Sep

Red Delicious

28-Sep

20-Sep

3-Oct

Ida Red

5-Oct

7-Oct

10-Oct

Rome

5-Oct

7-Oct

10-Oct

Braeburn

20-Oct

22-Oct

25-Oct

Goldrush

26-Oct

28-Oct

27-Oct

Please note that the predictions are for the first significant harvest date rather than peak harvest. Also note that the normal harvest date for Fuji is approximately three weeks ahead of the normal date given in previous years reports. Newer strains of Fuji have much earlier and more extensive red blush development than older strains. In the past, harvest of Fuji was delayed past optimum internal maturity to wait for better blush development. This delay has resulted in increased storage problems, including watercore and internal browning.

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