Southwest Michigan apple maturity report – Oct. 13, 2021

This is the seventh and final weekly apple maturity report for the southwest Michigan region.

Red apples in a tree.
Braeburn apple (Kumeu Crimson strain is shown) is rounding up the end of the harvest season in southwest Michigan. Photo by Bill Shane, MSU Extension.

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

Nearly all Golden Delicious and about two-thirds of the Fujis have been harvested in Berrien County. Approximately 50% of the Rome and Braeburn fruit have been harvested. Trap catches of brown marmorated stink bugs remain relatively high in some orchards. Damage by stink bug can be confused with other problems such as bitter pit and apple maggot.

We would like to thank the following growers/orchards who allowed us to sample their orchards for these maturity studies: Steve Weckworth, Marc and Randy Willmeng, Wendzel, Kurt and Kyle Weber, Mark Epple, Mike Piedt, Greg Prillwitz, Dean Froelich, Bryan Bixby, and Ed Czuba.

Detailed information by variety

Mac, Gala, Honeycrisp, Jonagold, Jonathan, Empire, Golden Delicious, Red Delicious, IdaRed and Fuji

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

Rome

This variety was harvested for the third week and is predicted to be ready approximately Oct. 10 in central Berrien County. Fruit firmness is still excellent at an average of 19.3 with starch conversion testing an average of 4.0 and considered internally mature. According to these tests, Rome harvest can still be delayed, if needed, because fruit is very firm. Some blocks have been harvested for processing.

Rome – Sampled Oct. 11, 2021

Site

Firmness (lbs.)

Red color range (%)

Starch

Soluble solids (°Brix)

1

19.1

85-98

4.0

11.9

2

19.0

85-98

4.0

11.8

3

20.0

80-98

4.0

11.9

4

19.0

70-100

4.0

11.4

Average

19.3

 

4.0

11.8

Max

20.0

 

4.0

11.9

Min

19.0

 

4.0

11.4

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

Oct. 11

19.3 (19.0-20.0)

4.0 (4.0-4.0)

11.8

Braeburn

This variety was harvested for the third week. Fruit firmness is excellent at an average of 18.8 pounds, with starch conversion testing an average of 4.4, and considered internally mature. Braeburn was predicted to be ready approximately Oct. 27 in central Berrien County but these tests indicate some blocks are ready. Harvest can be delayed if desired due to excellent firmness to wait for better skin color and higher brix.

Braeburn – Sampled Oct. 11, 2021

Site

Firmness (lbs.)

Red color range (%)

Starch

Soluble solids (°Brix)

1

19.0

15-60

4.2

10.7

2

18.0

60-95

5.2

11.6

3

19.0

70-98

4.6

12.3

4

19.0

50-85

3.4

11.4

Average

18.8

 

4.4

11.5

Max

19.0

 

5.2

12.3

Min

18.0

 

3.4

10.7

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

Oct. 11

18.8 (18.0-19.0)

4.4 (3.4-5.2)

11.5

Evercrisp

This variety was harvested for the third week. Fruit firmness is still excellent at an average of 19.3 pounds, about the 1 pound less than last week. Starch conversion jumped from 2.7 last week to 4.4 for this week and are now considered internally mature. Penn State University recommends using starch index of 4-6 for long term storage and 6-7 for direct sales market. Cooler nighttime conditions are needed to intensify the red blush to improve its appeal in the marketplace. Evercrisp, like Fuji, is prone to watercore and internal browning in storage if picked too late. No watercore was seen for these two sites but has been reported at other locations.

Evercrisp – Sampled Oct. 11, 2021

Site

Firmness (lbs.)

Red color range (%)

Starch

Soluble solids (°Brix)

1

20.1

50-85

4.8

15.3

2

18.4

70-98

4.0

14.2

Average

19.3

 

4.4

14.8

Max

20.1

 

4.8

15.3

Min

18.4

 

4.0

14.2

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

Oct. 11

19.3 (18.4-20.1)

4.4 (4.0-4.8)

14.8

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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