West central Michigan apple maturity report – September 30, 2015

Weather continues to be outstanding for Michigan apple harvest.

General comments

In the Grand Rapids, Michigan, area, the weather has been very conducive for harvest with dry, sunny days. Many growers are keeping up with harvest very well and we are past the half way point for the Grand Rapids area.  Cooler predicted temperatures this week will be wonderful for color and sugar development.

Comments heard in the last week from growers and industry representatives include:

  • Adequate labor supply with good quality picking skills.
  • Moving through harvest very steadily – some blocks picking short, some a little long.
  • Initial reports that some growers could be finishing up by Oct. 15 for the majority of their harvest.
  • Where did all these darn woolly apple aphids come from?

Woolly apple aphids – several reports are coming in from around the whole state on this pest. It’s much too late to do anything to control them, and a pesticide spray would be ineffective at this time. There are many beneficial insects that attack woolly apple aphids and they are most likely present this late in the season, so let them work for you. Make a note of the blocks with the problem and look to address management in the 2016 season at the best timing.

There is quite a bit of variability from site to site this season – more so than usual. Growers should be doing in-field maturity testing earlier and more often this season so as not to miss something. If you need guidance on how to do in-field maturity testing, please don’t hesitate to ask.

For the Hart/Shelby, Michigan, area, growers can expect harvest dates for that area to be behind the Grand Rapids area using this guide: along the lakeshore approximately six days behind Grand Rapids; areas inland about four days behind.

Normal and 2015 peak harvest dates for varieties for the Grand Rapids area

Variety

Normal date

2015 predicted date

Jonathan

9/28/15

9/29/15

Jonagold

9/28/15

9/29/15

Golden Delicious

10/2/15

10/3/15

Red Delicious

10/5/15

10/5/15

Idared

10/10/15

10/10/15

Rome

10/15/15

10/15/15

Fuji

10/25/15

10/25/15

Braeburn

10/25/15

10/25/15

Goldrush

11/1/15

11/1/15

Individual variety results

Gala harvest is nearly complete for the general Grand Rapids area for Gala. Fruit quality has been good, but could be declining quickly for blocks not treated with ReTain or Harvista. Untreated fruits are getting greasy and are quickly moving out of the window for even short-term CA storage.

Gala 2015 maturity sampling records

Date of Sample

Avg. ethylene (ppm)

% Fruits with ethylene over 0.2 ppm

Red color % (range)

Background color (range)
1=yellow

5=green

 

Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Aug. 24

0.0694

5

80 (50-95)

2.25 (1-5)

22.4 (18.9-26.4)

2.75 (1-7)

10.3 (9-11)

Aug. 31

0.26

30

91 (70-100)

1 (1-2)

16.7 (12.5-18.5)

2 (1-4)

10 (9-11)

Sept. 8

1.364

87

69 (40-85)

3.7 (1-7)

18.9 (10.8-24.3)

3.7 (1-7)

11.8 (10.2-14.5)

Sept. 15

1.737

95

89 (75-95)

1.5 (1-3)

18.7 (14-23.3)

5.5 (1-8)

12.5 (11.5-14)

Sept. 22

2.170

100

90 (80-98)

1

18.8 (14-21.6)

5.8 (2-8)

12.1 (11-13.5)

Sept. 29

1.908

100

90 (75-98)

1

16.3 (13-18.5)

7.6 (6-8)

13.1 (12-15)

McIntosh are nearly finished for harvest on the Ridge. Fruits that remain are suitable for fresh sales or short-term CA storage unless treated with harvest management materials.

McIntosh 2015 maturity sampling records

Date of sample

Avg. ethylene (ppm)

% Fruits with ethylene over 0.2 ppm

Red color % (range)

Background color (range)
1=yellow
5=green

 

Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Aug. 24

0

0

78 (60-95)

2.9 (1-5)

18.5 (15.8-24.2)

2.4 (1-4)

11.5 (10-13)

Aug. 31

0.0084

0

90 (70-98)

1.5 (1-3)

13.7 (11.5-15.5)

3.4 (3-4)

10.9 (10.5-11)

Sept. 8

0.0064

0

84 (70-100)

3.4 (3-4)

17.5 (14-25.3)

4.4 (4-6)

12.2 (12-13)

Sept.15

0.0294

0

90 (70-100)

4

15.2 (13.5-18)

6

12.4 (12-13)

Sept. 22

28.149

60

92 (85-98)

1.2 (1-2)

18.2 (15-21)

6.2 (6-7)

12.4 (11.5-14.2)

Sept. 29

59.232

100

96 (90-98)

1

13.8 (12-16)

7

13.3 (12.5-14)

Most Honeycrisp blocks have wrapped up the major harvest push. Fruits that remain are the greenest fruits from the center of the trees – this explains why it seems that our maturity indices are going backwards according to the numbers. Many Honeycrisp are moving through the fresh markets quickly which is very good given the amount of bitter pit this year.

Honeycrisp 2015 maturity sampling records

Date of sample

Avg. ethylene (ppm)

% Fruits with ethylene over 0.2 ppm

Red color % (range)

Background color (range)
1=yellow
5=green

 

Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Aug. 24

0.0472

0

30 (5-80)

4.4 (2-5)

21.3 (18-27.1)

1(1-1)

11.1 (10.2-12)

Aug. 31

0.1425

20

67 (40-80)

1.5 (1-3)

17.7 (15.5-22.5)

1(1-1)

11.7(11-12)

Sept. 8

0.2464

70

32 (10-45)

2.6 (2-3)

17.7 (14.3-22.1)

1.9(1-4)

11.4 (10.9-12)

Sept.15

3.0168

100

53.3 (20-90)

2.4 (1-4)

16.7 (13.5-19.8)

3.9(1-7)

12.3(11-13)

Sept. 22

13.198

100

74 (45-95)

1.6 (1-3)

17.9 (14-21)

6.8 (5-8)

12.6 (11.5-14.9)

Sept. 29

8.276

87

67 (30-90)

1.6 (1-3)

15.2 (13-18)

6.8 (5-8)

12.8 (10-14.5)

This is our fourth week of sampling Jonagold on the Ridge. Our predicted harvest date for Jonagold was Sept. 29 for long-term CA. This date is accurate or even a few days late for some blocks and Jonagold harvest should be started in all blocks that do not have harvest management application made.  Keep a close eye on Jonagold as they could quickly move out of condition quickly this year.

Jonagold 2015 maturity sampling records

Date of sample

Avg. ethylene (ppm)

% Fruits with ethylene over 0.2 ppm

Red color % (range)

Background color (range)
1=yellow
5=green

 

Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Sept. 8

0.03

0

22 (5-45)

3.7 (3-4)

18.4 (14.8-21.2)

1.3 (1-2)

11.7 (11.1-12.4)

Sept.15

0.046

0

53 (30-80)

2.8 (2-3)

18.6 (15-21.6)

3.2 (1-7)

12.5 (11.5-14)

Sept. 22

0.2236

35

57 (30-75)

3.3 (2-4)

17.8 (15-21.5)

5 (2-7)

13 (12-14)

Sept. 29

0.4633

55

69 (45-95)

2.2 (1-3)

16.7 (14-21)

6.6 (4-8)

13.2 (12.5-14)

This is our second week of sampling Golden Delicious and they have definitely moved into the perfect window for long-term CA in the Grand Rapids area. The predicted harvest date for Goldens is Oct. 3 and this seems right on target. Internal ethylene is still on the low end, with only 15 percent of fruits tested over the climacteric of 0.2 ppm. Background color moved from 4.1 to 3.4, with a few fruits at the 2 level. Firmness is still excellent at 16.7 pounds, down from 18 pounds last week. Starch clearing seems to be moving quickly from 2.3 last week to 5.3 this week. Brix are excellent at 14.2 compared to last week’s 12.7.

Golden Delicious 2015 maturity sampling records

Date of sample

Avg. ethylene (ppm)

% Fruits with ethylene over 0.2 ppm

Red color % (range)

Background color (range)
1=yellow
5=green

 

Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Sept. 22

0.0410

0

5 (0-15)

4.1 (3-5)

18 (14-20.5)

2.3 (1-6)

12.7(12-13.5)

Sept. 29

0.1831

15

4.5 (0-20)

3.4 (2-4)

16.7 (14-22)

5.3 (3-8)

14.2 (13-15.5)

Red Delicious were sampled for the second week. All maturity tests indicate a move forward for and any time you have blocks with adequate color and time to harvest, you can go after Red Delicious for long-term CA storage. The predicted harvest date is Oct. 5 for the Ridge and this is appearing to be an adequate guesstimate.

Red Delicious 2015 maturity sampling records

Date of sample

Avg. ethylene (ppm)

% Fruits with ethylene over 0.2 ppm

Red color % (range)

Background color (range)
1=yellow
5=green

 

Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Sept. 22

0.368

20

68 (45-95)

2.8 (2-3)

18.4 (15-20.5)

1.5 (1-4)

10.3(10-11)

Sept. 29

4.291

45

91.9 (75-100)

1.6 (1-3)

18.1 (15.5-21.5)

2.9 (1-7)

11.2 (10-15)

This is our second week of sampling Ida Red. The predicted harvest date for Ida Red is Oct. 10 – this date might be a few days late to get started on Ida Red for long-term CA, so watch your blocks carefully. Even though the ethylene readings might seem high, this is very typical for Ida Red – for some reason, it always expresses ethylene at higher levels than other varieties. Red color improved over last week, as did brix levels. Firmness is decreased rather significantly. Starch clearing indicated a definite move forward in maturity for Ida Red.

Ida Red 2015 maturity sampling records

Date of sample

Avg. ethylene (ppm)

% Fruits with ethylene over 0.2 ppm

Red color % (range)

Background color (range)
1=yellow
5=green

 

Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Sept. 22

0.432

80

75 (50-95)

3.2 (2-5)

20.9 (18-23.5)

1.8 (1-2)

10.9(10-12)

Sept. 29

0.7727

70

81 (65-90)

2.3 (2-3)

15.5 (14-20)

3.8 (3-4)

11.6 (11-12)

We added regular season Fuji (Aztec) to our sampling this week. Fruits are showing higher ethylene levels than expected. Starch levels seem to read a bit higher, but the starch iodine test is a bit tricky with Fuji as they just don’t stain well and this needs to be taken into account. The brix are very good which is normal for Fuji.

Fuji 2015 maturity sampling records

Date of sample

Avg. ethylene (ppm)

% Fruits with ethylene over 0.2 ppm

Red color % (range)

Background color (range)
1=yellow
5=green

 

Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Sept. 29

0.444

90

52 (40-80)

2.2 (1-3)

19.6 (16.5-23)

4

13.2 (13 -14)

Romes were tested for the first week. The predicted harvest date for long-term CA storage of Romes is Oct. 15 and they are definitely at least 10 days away from any early harvest on the Ridge. No bleeding has been found so far in Romes.

Rome 2015 maturity sampling records

Date of sample

Avg. ethylene (ppm)

% Fruits with ethylene over 0.2 ppm

Red color % (range)

Background color (range)
1=yellow
5=green

 

Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Sept. 29

0.0629

10

99.5 (95-100)

1

22.4 (19.2-26.5)

4

11.6 (10.8-12)

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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