Southwest Michigan apple maturity report – Oct. 9, 2019

Red Delicious harvest is finishing up, with Fuji and Ida Red next in line.

General apple harvest comments

Continued mild weather is helping to speed up harvest and improve apple quality. Brown marmorated stink bug activity is relatively light and seems to be associated with orchards close to field crops. San Jose scale damage seems to be more common in older trees where spray coverage is more difficult.

Samples collected for this report are from the central Berrien County region, targeting more mature fruit on the outside of the tree canopy. Fruit in the interior of the tree will be less advanced than shown here. Sites with heavier soils and greater crop loads will generally be less mature.

Apple maturity in southwest Michigan for apples harvested Oct. 7, 2019

Variety

Firmness lbs. (range)

Starch (range)

Brix %

Golden Delicious

16.5 (15.0-19.3)

4.8 (3.0-6.6)

13.5

Red Delicious

16.0 (15.0-17.0)

4.7 (3.4-6.0)

11.7

Ida Red

16.4 (16.0-17.0)

2.4 (2.0-3.0)

11.6

Fuji (late season)

17.8 (17.1-18.4)

3.5 (3.0-4.8)

13.2

Rome

21.7 (20.0-23.0)

3.0 (3.0-3.0)

11.8

Cameo

18.2 (18.0-18.4)

3.0 (2.6-3.4)

13.0

Braeburn

21.8 (20.0-23.0)

3.1 (2.6-3.8)

10.7

Evercrisp*

21.0                       

3.6

16.2

* Based on one site

Individual variety results

Golden Delicious 

Golden Delicious was sampled for the fourth week. Starch conversion this week is averaging 4.8 compared to 4.1 for the previous week, with 3 as the target for mature for this variety. Fruit firmness this week averaged 16.5 pounds and is below the general guideline of a minimum of 17 pounds firmness for best long-term controlled atmosphere (CA) storage. Over 95% of the area’s Golden Delicious fruit have been harvested. Skin finish is generally good.

Golden Delicious maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 16

17.5 (17.0-18.0)

1.6 (1.0-2.0)

11.4

Sept. 23

17.6 (16.0-19.0)

3.5 (2.8-4.0)

12.4

Sept. 30

17.1 (16.0-19.0)

4.1 (2.0-5.0)

12.5

Oct. 7

16.5 (15.0-19.3)

4.8 (3.0-6.6)

13.5

Red Delicious 

Red Delicious was sampled for the third week. Fruit at 16.0 pounds firmness or lower are suited for short-term CA storage and more immediate consumption, with the average for this week at 16 pounds firmness. Starch conversion is now averaging 4.7, with a reading of 3.5 or greater considered sufficiently mature for harvesting. The predicted peak harvest date for Red Delicious in central Berrien County is Oct. 7. About two-thirds of the Red Delicious in the area have been harvested.

Red Delicious maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 23

17.1 (16.0-18.1)

3.3 (3.0-4.0)

10.7

Sept. 30

16.5 (16.0-18.0)

3.5 (3.0-4.6)

10.9

Oct. 7

16.0 (15.0-17.0)

4.7 (3.4-6.0)

11.7

Ida Red

The current starch test average of 2.4 is still well below the mature threshold of 3.5. Minimum recommended firmness for long-term CA storage is 16 pounds, currently averaging 16.4. The predicted harvest date for Ida Red in central Berrien County is Oct. 15.

Ida Red maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 23

18.0 (17.0-18.0)

1.7 (1.0-2.0)

10.5

Sept. 30

17.3 (16.2-20.0)

2.2 (2.0-3.0)

11.3

Oct. 7

16.4 (16.0-17.0)

2.4 (2.0-3.0)

11.6

Fuji (late season varieties)

The current firmness is testing at 17.8, about 1 pound less than last week and above 16 pounds, which is the recommended minimum firmness for long-term CA storage. Accordingly, harvest can be delayed to wait for better size, brix and skin color. The recommended minimum starch reading for maturity is 3.0, the current reading is 3.5. The predicted harvest date for Fuji for central Berrien County is Oct. 28.

Fuji (main season) maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 23

20.5 (19.4-22.0)

3.2 (2.4-4.4)

11.8

Sept. 30

18.9 (18.3-20.4)

3.3 (3.0-4.4)

12.5

Oct. 7

17.8 (17.1-18.4)

3.5 (3.0-4.8)

13.2

Rome

A minimum of 3.0 for the starch index is recommended for harvesting, with current regional average of 3.0. Since the current firmness is testing well above 18 pounds—the recommended minimum firmness for long-term CA storage—harvest can be delayed to wait for better size, brix and skin color. The predicted harvest date for Rome for central Berrien County is Oct. 15. Harvesting of some fruit for processing is underway.

Rome maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 30

23.0 (23.0-23.2)

3.0 (3.0-3.0)

11.5

Oct. 7

21.7 (20.0-23.0)

3.0 (3.0-3.0)

11.8

Braeburn

A minimum of 3.0 for the starch index is recommended for harvesting for fresh for Braeburn. Since the current firmness is testing well above 16 pounds—the recommended minimum firmness for long-term CA storage—harvest can be delayed to wait for better size, brix and skin color. The predicted harvest date for Braeburn for central Berrien County is Oct. 28.

Braeburn maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 30

23.8 (22.0-26.0)

2.2 (1.6-2.8)

10.4

Oct. 7

21.8 (20.0-23.0)

3.1 (2.6-3.8)

10.7

Cameo

A minimum of 3.0, the current average for the starch index, is recommended for harvesting for fresh. Current firmness is 18.2 pounds. Harvest can be delayed to wait for better size, brix and skin color. Other harvesting indicators are 50% red color (for original strain) and background beginning to change from green to cream white.

Cameo maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 30

20.0 (19.0-21.0)

2.5 (2.0-3.0)

12.3

Oct. 7

18.2 (18.0-18.4)

3.0 (2.6-3.4)

13.0

Evercrisp (MAIA 1)

A minimum of 3.0 for the starch index is recommended for harvesting for fresh for Evercrisp, the current average is 3.6. The current firmness is testing 21.0 pounds at the Southwest Michigan Research and Extension Center in central Berrien County, well above the minimum of 18 pounds for best long-term CA storage—harvest can be delayed to wait for better size, brix and skin color.

This variety is known for high brix levels, currently testing 16.2%. Our best guess is this variety harvests about 15 days after Red Delicious, or approximately Oct. 15 this year for central Berrien County. This is a relatively new variety and so the optimal pressure and starch test readings are still not known. Changing of background color from green to a lighter green or slight yellow appears to be a good indicator of a mature apple.

Evercrisp maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 30

24.0

3.0

14.5

Oct. 7

21.0                       

3.6

16.2

 

Normal and predicted 2019 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

2018 Predicted peak harvest date

2019 Predicted peak harvest date

Paula Red

Aug. 22

 Aug. 20

Aug. 28

Zestar

Aug. 22

 Aug. 20

Aug. 28

Gingergold

Aug. 20

 Aug 18

Aug. 26

McIntosh

Sept. 10

 Sept 8

Sept. 16

Gala

Sept. 8

 Sept 6.

Sept. 14

Early Fuji

Sept. 3

 Sept. 1

Sept. 10

Honeycrisp

Sept. 13

 Sept. 13

Sept. 20

Empire

Sept. 19

 Sept. 23

Sept. 26

Jonathan

Sept. 22

 Sept. 24

Sept. 30

Jonagold

Sept. 22

 Sept. 24

Sept. 30

Golden Delicious

Sept. 25

 Sept. 27

Oct. 1

Red Delicious

Sept. 28

 Oct. 1

Oct. 7

Ida Red

Oct. 5

 Oct. 8

Oct. 15

Rome

Oct. 5

 Oct. 8

Oct. 15

Fuji

Oct. 20

 Oct. 22

Oct. 28

Braeburn

Oct. 20

 Oct. 22

Oct. 28

Goldrush

Oct. 26

 Oct. 28

Nov. 3

 

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

Braeburn

16

17

18

3.0

7.0

*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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