West central Michigan apple maturity report – Oct. 10, 2018

Updates on maturity status of Jonagold, Mutsu/Crispin, Golden Delicious, Idared, Red Delicious, Rome, Winesap, Fuji and EverCrisp.

General harvest comments

Golden Delicious and Empire have been picked heavily over the past week, and these varieties will be done at most locations by the end of the week. Most of the Rome in the area are gone as well. Growers are still cleaning up some Jonagold and Honeycrisp in spots, but harvest of these varieties is generally over. Red Delicious and Idared still need about one more week in most locations. Harvest of late varieties like Fuji and EverCrisp are at least two weeks out.

Wet weather has made some orchards very muddy and harder to navigate, but harvest has gone on at a pretty steady pace all the same. More fly speck showed up this week across many of the late season varieties that were sampled. The amount of rain that we had in the tail end of the season is challenging that last summer fungicide cover this year. Color continues to be excellent.

Only one brown marmorated stink bug was caught in a tower trap in Hart, Michigan, this week, but spots of damage continue to come through the lab each week. We may see a slight uptick in activity with some warmer weather this week, so I will be curious to see if any more show up in the traps when they are checked next week.

As mentioned last week, growers continue to notice a touch of San Jose scale showing up in many locations they have not seen it before. It is easily observable at this time of year on fruit, particularly on the calyx end. It is too late to do anything about it this year, but those hot spots should be slated for management next year to prevent the issue from spreading further. This is a great time of year to pinpoint hot spots for this pest based on what shows up in bins. This pest generally seems to be on the rise in the area, so make sure this pest is on the radar as we look at next year’s game plan.

Individual variety results

The scales used to rate these different metrics on these charts are as follows:

  • Background color: scale 1-4; 1 is fully yellow and 4 is fully green.
  • Russet: scale 1-4; 1 is no russet and 4 is severe russet.
  • Pressure: always listed in pounds, and two pressure scores are recorded for each apple tested.
  • Watercore: scale 1-4; 1 is no watercore and 4 is severe watercore.
  • Bleeding: scale 0-4; 0 is no bleeding of red color into flesh and 4 is severe bleeding of red color in to flesh.
  • Red: listed as a percentage of the whole fruit with red color.

Jonagold was sampled for the fifth and final time this week. It was over-mature at the only sampling location this week, and very little is left in the area. Final clean-up of this variety will wind down by the end of the week in most of the region. Color on Jonagold is particularly nice this year.

Regional summary data for Jonagold, west central MI 2018

Sample date

Firmness lbs. (range)

Starch index (range)

Brix % (range)

Sept. 10

18.86 (15.5-21)

2.2 (2-4)

12.16 (11-13.5)

Sept. 17

17.51 (14-20.5)

3.13 (2-6)

12.21 (10-13.5)

Sept. 24

16.45 (14.5-18)

4.1 (3-7)

12.67 (10.5-14)

Oct. 1

15 (12.9-18.2)

4.8 (3-6)

13.78 (12.8-14.8)

Oct. 8

13.77 (12.5-15)

6 (5-7)

13.24 (12.5-14.1)

 

Jonagold, Hart area

Fruit No.

Red (%)

Background color

Russet

Pressure 1

Pressure 2

Brix (%)

Watercore

Bleeding

Starch index

1

80

3

2

13.1

13.1

12.8

1

0

6

2

90

3

2

13.8

14.8

13.4

1

0

6

3

95

3

2

15

14.2

13.4

1

0

6

4

85

3

1

13

14

12.5

1

0

7

5

85

3

1

13.8

13

12.7

1

0

6

6

95

3

2

13.8

14.3

13.6

1

0

5

7

90

3

2

14

13.9

13.1

1

0

6

8

85

3

1

14.8

13.1

14.1

1

0

6

9

90

3

2

13.1

14.1

13.7

1

0

6

10

75

3

2

12.5

14

13.1

1

0

6

Ave.

87

3

1.7

13.69

13.85

13.24

1

0

6

Mutsu/Crispin was sampled for the fourth time this week and is at least a week away from maturity. It is considered ready for CA storage at a starch index of 3 and 16-18 pounds of firmness. No blister spot was observed on the samples this week. As per usual for this variety, size is excellent. A good touch of red blush has developed on one side of Mutsu/Crispin this season.

Regional summary data for Mutsu/Crispin, west central MI 2018

Sample date

Firmness lbs. (range)

Starch index (range)

Brix % (range)

Sept. 17

18.15 (17-20.5)

2

11.02 (10-12.5)

Sept. 24

16.64 (14.8-17.6)

2.1 (2-3)

10.94 (11-13)

Oct. 1

16.11 (13.9-20.8)

1.7 (1-2)

11.27 (11.3-13.3)

Oct. 8

15.73 (14-18.8)

2.7 (2-2)

12.47 (12.2-13.5)

 

Mutsu/Crispin, Weare township area

Fruit No.

Red (%)

Background color

Russet

Pressure 1

Pressure 2

Brix (%)

Watercore

Bleeding

Starch index

1

15

4

3

14.8

16.9

12.1

1

0

3

2

10

4

2

14

15.6

11.9

1

0

3

3

5

4

2

17

16.2

12.5

1

0

2

4

5

4

2

14.6

15.8

11.8

1

0

3

5

5

4

2

18.8

16.8

13.5

1

0

2

6

5

4

3

15.8

16.3

12.6

1

0

3

7

5

4

2

17.1

15

11.9

1

0

2

8

10

4

3

16.2

17.7

12.8

1

0

3

9

5

4

2

12.9

15.4

12.2

1

0

3

10

5

4

2

13.7

14

13.4

1

0

3

Ave.

7

4

2.3

15.49

15.97

12.47

1

0

2.7

Golden Delicious was sampled for the fourth time this week and is ready for harvest across the region. This variety was picked heavily over the past week, so I was already down to just one site of my original five when I collected the weekly samples on Monday, Oct. 8. This variety will be finished at most spots within the week; it is quickly getting soft and moving towards over-maturity.

Regional summary data for Golden Delicious, west central MI 2018

Sample date

Firmness lbs. (range)

Starch index (range)

Brix % (range)

Sept. 17

17.79 (13-21)

1.72 (1-5)

12.17 (10-15)

Sept. 24

17.42 (13.3-26.2)

2.08 (1-4)

14.24 (12.8-16.5)

Oct. 1

16.38 (13.6-20.2)

2.7 (1-5)

15.14 (14.4-18.8)

Oct. 8

14.44 (13-16)

4.6 (4-7)

16.02 (14-17.2)

 

Golden Delicious, Weare township area

Fruit No.

Red (%)

Background color

Russet

Pressure 1

Pressure 2

Brix (%)

Watercore

Bleeding

Starch index

1

5

3

2

16

13

16.4

1

0

4

2

5

3

2

14.5

15

17.2

1

0

7

3

10

2

2

15

14

16.6

1

0

4

4

10

3

2

16

15.5

15

1

0

4

5

10

2

2

15

14.3

14

1

0

4

6

10

2

2

15

14.5

15.9

1

0

6

7

10

1

2

14

12.5

17.3

1

0

5

8

15

3

2

16

13

16.4

1

0

4

9

10

3

2

12.5

12.5

15.5

1

0

4

10

15

2

2

16

14.5

15.9

1

0

4

Ave.

10

2.4

2

15

13.88

16.02

1

0

4.6

Red Delicious was sampled for the third time this week. It still needs a few more days—it is considered mature for CA storage at a starch index of 2.5 and 16-18 pounds of firmness, and is not considered over mature until a starch index of 6. Fruits sampled this week are still shy of even the earliest side of maturity, and growers have other priorities this week. It barely moved ahead from last week. A touch of water core showed up this week, so we will hope that does not increase in coming days. Color is excellent on this variety and no bleeding of red color from the peel was observed this week.

Regional summary data for Red Delicious, west central MI 2018

Sample date

Firmness lbs. (range)

Starch index (range)

Brix % (range)

Sept. 24

15.46 (13-16.5)

2.1 (1-3)

10.69 (10-11.5)

Oct. 1

15.16 (12.2-17.6)

2.27 (2-5)

11.53 (10.6-12.8)

Oct. 8

15.23 (12.2-16.8)

2.28 (2-4)

11.68 (10.8-13.4)

 

Red Delicious, Ludington area, site 1 of 2

Fruit No.

Red (%)

Background color

Russet

Pressure 1

Pressure 2

Brix (%)

Watercore

Bleeding

Starch index

1

100

NA

1

15.1

15.1

11.1

1

0

2

2

100

NA

1

16.2

16.3

11.3

1

0

2

3

100

NA

1

15.7

15.8

11.7

1

0

3

4

100

NA

1

15

16.1

10.8

1

0

2

5

100

NA

1

13.9

13

11.5

1

0

2

6

100

NA

1

16.1

15

12.2

1

0

3

7

100

NA

1

15

14.2

10.7

1

0

2

8

100

NA

1

15.9

15.2

11.3

1

0

2

9

100

NA

1

15.1

11.7

11.7

1

0

2

10

100

NA

1

16.2

15.3

10.5

1

0

2

Ave.

100

 NA

1

15.42

14.77

11.28

1

0

2.2

 

Red Delicious, Ludington area, site 2 of 2

Fruit No.

Red (%)

Background color

Russet

Pressure 1

Pressure 2

Brix (%)

Watercore

Bleeding

Starch index

1

90

2

1

19.4

16.9

13.4

1

0

2

2

95

1

1

16.7

16.6

12.4

1

0

2

3

95

1

1

16

15.9

13.1

1

0

2

4

90

2

2

15.8

15.8

12.4

1

0

2

5

95

2

1

18.3

16.3

13.6

1

0

3

6

95

2

1

14.8

16.9

13.1

1

0

2

7

90

1

1

13.3

15

13.2

1

0

2

8

95

1

1

16.1

16.1

11.8

1

0

2

9

95

1

1

16.8

18.3

11.4

1

0

2

10

95

1

1

16.9

15.5

11.8

1

0

2

Ave.

93.5

1.4

1.1

16.41

16.33

12.62

1

0

2.1

 

Red Delicious, Benona area

Fruit No.

Red (%)

Background color

Russet

Pressure 1

Pressure 2

Brix (%)

Watercore

Bleeding

Starch index

1

85

3

1

14.5

14.3

11

1

0

3

2

65

2

1

14.1

13.1

11.7

1

0

2

3

75

2

1

14.1

12.2

11.5

1

0

4

4

85

2

1

13.5

15.1

11.5

1

0

2

5

90

3

1

14.1

15.2

11.6

1

0

3

6

75

1

1

16.5

13.1

11.7

1

0

2

7

75

1

1

14.2

14.8

11.7

2

0

1

8

80

2

1

16.3

15.6

12.1

2

0

4

9

85

1

1

14

14.2

12

1

0

2

10

85

1

1

15.1

15

11.1

1

0

2

Ave.

80

1.8

1

14.64

14.26

11.59

1.2

0

2.5

 

Red Delicious, Shelby area

Fruit No.

Red (%)

Background color

Russet

Pressure 1

Pressure 2

Brix (%)

Watercore

Bleeding

Starch index

1

90

2

1

14

14.1

12.2

1

0

2

2

85

2

1

14.8

16

10.8

1

0

2

3

95

2

1

17.7

14.3

11.4

1

0

2

4

90

2

1

17

15.2

11.3

1

0

2

5

90

2

1

14.2

14.2

10.5

1

0

2

6

85

2

1

16.8

17.1

10.7

1

0

5

7

90

2

1

14.3

15.8

11.7

1

0

2

8

95

2

1

14.8

16

10.9

1

0

2

9

100

2

1

15.7

15.7

10.6

1

0

2

10

95

2

1

17.7

15

12

1

0

2

Ave.

91.5

2

1

15.7

15.34

11.21

1

0

2.3

Idared was sampled for the third time this week. It could use another few days at most of the locations that were sampled. It is considered mature for CA storage at a starch index value of 3.5 and 14-15 pounds of firmness. Most locations have firmness that is right in the acceptable range for CA storage, but the starch index is still shy of the mature range and needs some more time. Color is excellent on this variety this year does not seem to be bleeding from the peel.

Regional summary data for Idared, west central MI 2018

Sample date

Firmness lbs. (range)

Starch index (range)

Brix % (range)

Sept. 24

16.12 (14.9-21.2)

2 (1-5)

12.14 (11.4-14.4)

Oct. 1

15.09 (12.19.2)

2.1 (1-3)

12.41 (10.8-14.4)

Oct. 8

14.77 (13-16.8)

3.03 (2-4)

12.84 (12.5-13.6)

 

Idared, Ludington area         

Fruit No.

Red (%)

Background color

Russet

Pressure 1

Pressure 2

Brix (%)

Watercore

Bleeding

Starch index

1

75

4

1

17.8

14

14.8

1

0

3

2

95

4

1

14

18.4

13.5

1

0

3

3

90

4

1

14.3

14.1

13

1

0

3

4

85

4

1

16.7

15.1

13.5

1

0

3

5

75

4

1

15.7

17.6

13.4

1

0

3

6

85

4

1

15.8

16.8

13.4

1

0

4

7

85

4

1

13.1

15.3

13

1

0

3

8

75

4

2

15.4

15

12.5

1

0

2

9

65

4

1

15

15.3

13.6

1

0

4

10

75

4

1

13.9

16.3

12.9

1

0

3

Ave.

80.5

4

1.1

15.17

15.79

13.36

1

0

3.1

 

Idared, Clay-Banks area

Fruit No.

Red (%)

Background color

Russet

Pressure 1

Pressure 2

Brix (%)

Watercore

Bleeding

Starch index

1

70

2

2

13.2

14.4

12.1

1

1

3

2

75

3

2

15.8

12.7

14.9

1

0

3

3

70

3

2

14.8

15.2

12.5

1

0

4

4

65

2

2

14.9

15.3

12.8

1

0

4

5

70

2

2

13.7

12.7

11.3

1

0

4

6

85

2

2

13.7

13.7

12.9

1

0

3

7

85

2

1

16.8

16.7

13.6

1

0

3

8

75

2

2

13.3

13.6

11.7

1

0

4

9

85

2

2

13.2

15.4

12.6

1

0

3

10

95

2

2

16.8

15.3

12.8

1

0

4

Ave.

77.5

2.2

1.9

14.62

14.5

12.72

1

0.1

3.5

 

Idared, Hart area

Fruit No.

Red (%)

Background color

Russet

Pressure 1

Pressure 2

Brix (%)

Watercore

Bleeding

Starch index

1

75

3

2

14.2

13.8

12.5

1

0

4

2

70

3

2

13.3

13.8

12.1

1

0

3

3

85

2

1

13.1

14.7

12.6

1

0

4

4

90

3

2

13.3

14.9

11.8

1

0

3

5

85

3

2

12.3

14.1

11.4

1

0

2

6

75

3

2

13.1

14.2

12.1

1

0

4

7

85

3

2

16.2

13.3

13.8

1

0

2

8

80

2

2

14

15.5

12.9

1

0

3

9

80

3

2

14.3

14.9

12.2

1

0

2

10

90

3

2

12.9

13.8

12.1

1

0

4

Ave.

81.5

2.8

1.9

13.67

14.3

12.35

1

0

3.1

 

Idared, Shelby area

Fruit No.

Red (%)

Background color

Russet

Pressure 1

Pressure 2

Brix (%)

Watercore

Bleeding

Starch index

1

75

3

3

15.4

16.4

13.1

1

0

2

2

85

2

2

14.8

18.1

12.7

1

0

5

3

75

2

2

15

13.4

12.8

1

0

2

4

65

2

2

15.8

13.6

13

1

0

2

5

80

2

1

18.7

15.1

13.4

1

0

3

6

80

3

2

14

13.8

12.8

1

0

3

7

85

2

2

15.2

17.4

13.2

1

0

2

8

90

2

2

18.3

13.8

14.2

1

0

2

9

90

2

2

12.8

13.2

12.8

1

0

2

10

75

2

1

12.9

13.3

11.6

1

0

1

Ave.

80

2.2

1.9

15.29

14.81

12.96

1

0

2.4

Rome was sampled for the third time this week. Two of the three sites of Rome that I started with are harvested now, which is to be expected. Growers always harvest Rome in west central Michigan on the very earliest side of maturity so as to avoid bleeding of red color from the peel. The remaining site in the maturity work this week is on the early end of maturity and will likely be picked within the week. Rome is considered ready for CA storage at a starch index of 3.0 and firmness of 15-18 pounds. Fruit from the remaining site are still a bit on the firm side, but starch index has moved in to the low end of that range. No bleeding of red color has been observed on Rome this year, which is good news for local processors and growers alike.

Regional summary data for Rome, west central MI 2018

Sample date

Firmness lbs. (range)

Starch index (range)

Brix % (range)

Sept. 24

21.49 (18-25.2)

2.16 (2-3)

11.65 (10.8-13.5)

Oct. 1

19.94 (17.7-21.5)

2.9 (2-4)

11.82 (10.8-12.9)

Oct. 8

19.2 (17.7-22.8)

3.3 (3-4)

12.21 (11.8-12.8)

 

Rome, Shelby area

Fruit No.

Red (%)

Background color

Russet

Pressure 1

Pressure 2

Brix (%)

Watercore

Bleeding

Starch index

1

95

4

1

19.9

15.3

12.8

1

0

3

2

75

4

1

18.1

17.2

11.5

1

0

3

3

80

4

1

20.9

21

12.5

1

0

3

4

80

4

1

19.3

18

12.4

1

0

3

5

75

4

1

19.2

19.1

11.8

1

0

4

6

70

4

1

22.8

19.2

12.2

1

0

3

7

80

4

1

20.2

17.2

12.4

1

0

4

8

95

4

1

21

20.1

12.1

1

0

3

9

90

4

1

17.7

19

12.1

1

0

3

10

90

4

1

19.8

18.9

12.3

1

0

4

Ave.

83

4

1

19.89

18.5

12.21

1

0

3.3

Winesap was sampled for the third time this week. It is likely at least another two weeks out from maturity. It is considered mature for CA storage at a starch index value of 2.5, with recommended firmness of 17-19 pounds depending on planned duration of storage. Fruits firmed up a bit this week compared to last week, but at a starch index value of only 1.8 this variety needs some more time.

Regional summary data for Winesap, west central MI 2018

Sample date

Firmness lbs. (range)

Starch index (range)

Brix % (range)

Sept. 24

16.61 (14.1-19)

2

9.44 (8.5-11.1)

Oct. 1

15.86 (13.5-18.2)

1.8 (1-2)

10.35 (8.8-13)

Oct. 8

16.57 (14.7-17.6)

1.7 (1-2)

10.89 (10.1-11.9)

 

Winesap, Weare township area

Fruit No.

Red (%)

Background color

Russet

Pressure 1

Pressure 2

Brix (%)

Watercore

Bleeding

Starch index

1

75

4

2

15.2

16.1

11.9

1

0

2

2

65

4

2

16

18.8

11

1

0

2

3

75

4

1

22.3

18.9

10.6

1

0

1

4

80

4

2

17.6

17

10.1

1

0

2

5

85

4

2

16.3

17

10.2

1

0

2

6

85

4

2

16.7

15.8

11

1

0

1

7

90

4

1

15.1

13.3

10.4

1

0

1

8

95

4

2

14.7

17

11

1

0

2

9

90

4

2

15.8

16.9

11

1

0

2

10

90

4

2

16.2

14.6

11.7

1

0

2

Ave.

83

4

1.8

16.59

16.54

10.89

1

0

1.7

Fuji was sampled for the second time this week and is probably a good two weeks away from maturity. It is considered mature at a starch index value of 3 and 16-18 pounds of firmness, depending on planned duration of storage. Starch index is not always a great predictor of Fuji maturity due to a different profile of the starch molecules inside of these fruits. Fuji looks green right now and does not eat well at all. It needs some time.

Regional summary data for Fuji, west central MI 2018

Sample date

Firmness lbs. (range)

Starch index (range)

Brix % (range)

Oct. 1

16.39 (15.2-17.4)

1.5 (1-2)

12.51 (11.9-13.1)

Oct. 8

15.87 (13.7-18.2)

2.8 (2-5)

13.65 (12.4-14.6)

 

Fuji, Weare township area

Fruit No.

Red (%)

Background color

Russet

Pressure 1

Pressure 2

Brix (%)

Watercore

Bleeding

Starch index

1

60

4

1

16.1

17.4

14.6

1

0

2

2

45

4

1

16.3

15.5

13.5

1

0

2

3

60

3

1

16.8

15.2

13

1

0

5

4

65

3

1

13.4

15.8

13.3

1

0

3

5

65

4

2

18.2

16.1

14.1

1

0

2

6

55

3

1

18.1

14.7

13.9

1

0

2

7

70

3

1

15

13.7

14.3

1

0

3

8

65

3

1

15.1

18

12.4

1

0

3

9

65

3

1

15.2

16

13.3

1

0

3

10

45

3

1

15.7

15.1

14.1

1

0

3

Ave.

59.5

3.3

1.1

15.99

15.75

13.65

1

0

2.8

EverCrisp was sampled for the second time this week. This variety is likely still at least two weeks away from maturity based on this week’s results. It seems to be behaving like a Fuji (one of its parents) in starch index value and coloration. Firmness and brix are both extremely high on this variety and color has improved greatly from last week. The variety also seems to be particularly prone to developing water core—this has been observed on this variety elsewhere and has been the case over the past couple of years here too. This variety had easily the most water core of any variety sampled this week.

Regional summary data for EverCrisp, west central MI 2018

Sample date

Firmness lbs. (range)

Starch index (range)

Brix % (range)

Oct. 1

23.88 (21-27.9)

1.6 (1-2)

15.39 (14-7-16)

Oct. 8

21.22 (19-25.5)

2.9 (2-4)

15.03 (14.3-16.3)

 

EverCrisp, Hart area

Fruit No.

Red (%)

Background color

Russet

Pressure 1

Pressure 2

Brix (%)

Watercore

Bleeding

Starch index

1

55

4

2

19.4

19.3

15

1

0

3

2

60

4

2

20.9

20.1

14.8

1

0

3

3

55

4

1

20.1

19.9

14.3

1

0

3

4

50

4

2

19.3

20.4

14.7

1

0

3

5

45

4

2

22

22.1

14.4

1

0

3

6

70

4

2

20.8

23.7

14.4

2

0

3

7

65

4

1

21.1

19.9

15

1

0

3

8

70

4

2

25.5

18.7

15.4

1

0

3

9

60

4

3

21.4

20.9

15.1

1

0

2

10

65

4

3

25.4

25.9

16.3

2

0

2

Ave.

59.5

4

2

21.59

21.09

14.94

1.2

0

2.8

 

EverCrisp, Elbridge area

Fruit No.

Red (%)

Background color

Russet

Pressure 1

Pressure 2

Brix (%)

Watercore

Bleeding

Starch index

1

55

4

3

25.8

23.6

14.8

1

0

2

2

70

3

2

23.6

23.3

15.2

1

0

3

3

75

3

1

21.9

24.3

14.5

1

0

2

4

65

4

1

18.8

21.4

15.7

4

0

3

5

70

4

1

18.7

21.6

15.7

1

0

2

6

75

4

2

23

22.2

14.2

1

0

3

7

85

4

1

22

20.7

15.9

1

0

4

8

35

4

3

18.8

20.1

14.7

1

0

3

9

75

4

1

16.3

18.7

15.3

1

0

4

10

80

4

1

17.7

19.6

15.2

1

0

4

Ave.

68.5

3.8

1.6

20.66

21.55

15.12

1.3

0

3

 

Suggested firmness and starch index levels for long-term and shorter-term storage by variety.

Variety

Firmness (pounds)*

Starch Index*

Short CA

Mid CA

Long CA

Export CA

Mature

Over mature

Braeburn

16

17

18

--

3

7

Cortland

14

15

16

--

4

6

Empire

14

15

16

18

3.5

6

Fuji

16

17

18

--

3

7

Gala

16

17

18

--

3

6

Golden Delicious

15

16

17

--

3

6.5

Honeycrisp

15

16

17

--

3.5

7

Idared

14

15

16

--

3.5

6

Jonagold

15

16

17

--

3.5

5.5

Jonathan

14

15

16

--

3.5

5.5

McIntosh

14

15

16

--

5

7

Mutsu/Crispin

16

17

18

--

3

6

Northern Spy

16

17

18

--

3

6

Red Delicious

16

17

18

--

2.5

5

Rome

15

16

18

--

3

5.5

Spartan

17

18

19

--

4

6

Winesap

17

18

19

--

2.5

6

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


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