Southeast Michigan apple maturity report – Oct. 18, 2017

Harvest is winding down for most apple growers, with several apple varieties being harvested including Red Delicious, Idared, Rome and Braeburn.

General apple harvest comments

We are at that time of apple harvest where growers are seeing the end of the harvest windows for many varieties. With the exception of a few lesser-planted, late-season varieties, everything has either been harvested and or is ready to harvest.

Growers are finishing harvest of Red Delicious, Idared, Rome and Braeburn. Northern Spy, Crispin and Fiji have ben harvested. Winesap, Goldrush and Granny Smith still need more time to mature.

The region received close to 2 inches of badly needed rain late last week and over the weekend. Unfortunately, the rain over the weekend was bad timing for sales at farmers markets. Many direct marketing farms report doing about a quarter of their normal October sales.

This is the eighth apple harvest report for the season and will be my final report. This week, only five apple varieties were sampled and tested for maturity, and the number of samples for each variety was reduced as most of the crop has been harvested.

Many thanks to Hy’s Cider Mill of Romeo, Spicer Orchards in Hartland and Erwin Orchards of South Lyon for again this season being a big part of the Apple Maturity Project. Thank you also to so many other farms that gave me samples over the last nine weeks of maturity testing. This list is too long to publish, but each of you know how much we appreciate your willing participation in this effort.

The table with the normal and 2017 peak harvest dates for apple varieties in east Michigan is included at the end of this report.

Apple maturity at a glance

Apple maturity in east Michigan for apples harvested Oct. 16

Variety

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness Lbs. (range)

Starch (range)

Brix %

Red Delicious

90 (80-100)

96 (96-97)

17.8 (17.5-18.3)

5.1 (4.6-5.8)

14.7

Idared

100 (100-100)

88 (80-95)

18.2 (16.0-22.0)

4.9 (4.0-6.0)

14.4

Rome

80 (80-80)

93 (80-100)

23.1 (14.0-29.0)

5.2 (4.0-7.0)

15.0

Winesap

100 (100-100)

85 (75-95)

19.3 (17.0-22.0)

1.6 (1.0-4.0)

12.6

Braeburn

100 (100-100)

67 (50-85)

21.2 (19.0-25.0)

4.3 (1.0-6.0)

12.8

Individual variety results

Red Delicious was sampled for the fifth week of the season, and this week I sampled several strains of Red Delicious, where in the past weeks I sampled only the Redchief strain. Much of the Red Delicious crop has been harvested over the last two weeks, so this week’s data is hard to compare to previous weeks, yet it does indicate all strains of Red Delicious are now ready to harvest and some are over-mature. Red Delicious was very slow to mature this season.

There was a good amount of drop in Red Delicious again this past week as well as water core. The percentage of fruit with internal ethylene levels over 0.2 parts per million (ppm) moved slightly to 90 percent. The average starch index rose from 4.0 last week to 5.1. The predicted harvest date for Red Delicious was Sept. 28 for east Michigan.

Red Delicious 2017 maturity sampling for the harvest season

Date of sample

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness Lbs. (range)

Starch (range)

Brix %

Sept. 18

20 (0-30)

82 (75-86)

19.8 (18.9-21.1)

1.6 (1.0-2.0)

10.8

Sept. 25

57 (30-70)

92 (89-94)

17.8 (17.0-18.3)

3.5 (2.9-3.9)

12.1

Oct. 2

55 (10-100)

96 (96-96)

17.2 (15.5-18.8)

2.7 (2.1-3.2)

11.9

Oct. 9

85 (70-100)

78 (77-79)

16.9 (15.7-18.1)

4.0 (3.6-4.4)

13.1

Oct. 16

90 (80-100)

96 (96-97)

17.8 (17.5-18.3)

5.1 (4.6-5.8)

14.7

Idared was also sampled for the fifth week of the season. Many blocks have been harvested. Based on this week’s test results, Idareds are finally mature. They too were slow to mature this season. They are eating much better this week. The average starch index rose from 3.8 last week to 4.9 this week. The predicted harvest date for Idared for east Michigan was Oct. 2.

Idared 2017 maturity sampling for the harvest season

Date of sample

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness Lbs. (range)

Starch (range)

Brix %

Sept. 18

40 (40-40)

69 (50-90)

19.0 (16.5-23.0)

1.6 (1.0-3.0)

12.6

Sept. 25

90 (80-100)

73 (63-83)

19.1 (18.2-19.9)

3.6 (2.9-4.3)

13.2

Oct. 2

97 (90-100)

79 (63-92)

18.2 (17.0-19.6)

3.2 (2.9-3.9)

13.7

Oct. 9

85 (70-100)

78 (78-78)

14.5 (14.2-14.6)

3.8 (3.1-4.4)

14.2

Oct. 16

100 (100-100)

88 (80-95)

18.2 (16.0-22.0)

4.9 (4.0-6.0)

14.4

Rome was sampled for the third week of the season. Based on this week’s data, they are ready to harvest. The percentage of fruit with internal ethylene levels over 0.2 ppm moved sharply from 10 percent last week to 80 percent this week. The average starch index is up from 4.0 last week to 5.2 this week. The predicted harvest date for Rome was Oct. 7 for east Michigan, so it is maturing a few days later than this predicted date.

Rome 2017 maturity sampling for the harvest season

Date of sample

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness Lbs. (range)

Starch (range)

Brix %

Oct. 2

15 (10-20)

91 (86-96)

24.0 (22.0-25.0)

3.0 (2.9-3.1)

13.5

Oct. 9

10 (10-10)

80 (65-100)

20.5 (16.0-29.5)

4.0 (4.0-4.0)

13.7

Oct. 16

80 (80-80)

93 (80-100)

23.1 (14.0-29.0)

5.2 (4.0-7.0)

15.0

Winesap was sampled for the third week of the season. While the percentage of fruit with internal ethylene levels greater than 0.2 ppm remains high at 100 percent, the average starch index is slightly changed to 1.6. Based on this third week of testing, it is a ways off and is not ready to harvest. The predicted harvest date for Winesap is Oct. 27.

Winesap 2017 maturity sampling for the harvest season

Date of sample

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness Lbs. (range)

Starch (range)

Brix %

Oct. 2

70 (70-70)

75 (35-90)

18.9 (17.0-21.5)

1.1 (1.0-2.0)

12.0

Oct. 9

90 (90-90)

71 (45-85)

16.3 (16.0-18.0)

1.0 (1.0-1.0)

13.0

Oct. 16

100 (100-100)

85 (75-95)

19.3 (17.0-22.0)

1.6 (1.0-4.0)

12.6

Braeburn was sampled for the second week of the season. Again this week, all of the fruit tested had internal ethylene levels greater than 0.2 ppm, which is typical for Braeburn. The average starch index is about the same as last week at 4.3. Based on two weeks’ worth of data, I am even more confident Braeburn is ready to harvest. The predicted harvest date for Braeburn is Oct. 21, so it is ready several days before this date.

Braeburn 2017 maturity sampling for the harvest season

Date of sample

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness Lbs. (range)

Starch (range)

Brix %

Oct. 9

100 (100-100)

59 (40-70)

22.5 (19.0-25.0)

4.2 (3.0-6.0)

13.8

Oct. 16

100 (100-100)

67 (50-85)

21.2 (19.0-25.0)

4.3 (1.0-6.0)

12.8

Predicted peak fresh market apple harvest dates

Each year we publish predicted harvest dates for three varieties for many locations across the state. This year’s “Predicted 2017 apple harvest dates” were published July 25. The table below has been expanded to include more apple varieties and it lists only one date for the entire east Michigan region, which is hard to do! The information in the “Predicted 2017 apple harvest dates” article lists the bloom and harvest dates for Deerfield and Romeo, Michigan. You can adjust your predicted harvest dates based on your bloom dates or make adjustments to this expanded list based on the typical harvest dates at your farm. These predicted harvest dates are based on a long-established formula using the bloom date and temperatures for 30 days post-bloom.

These dates are an estimate and will be affected by the apple strain, rootstock, crop load, fertility, soil type, and other factors including current weather. I believe our actual harvest dates may be a few days ahead of these predicted harvest dates for most varieties. Keep a close eye on the weekly apple harvest updates for possible revisions of these dates.

Normal and 2017 peak harvest dates for apple varieties in east Michigan

Variety

Normal date

2017 predicted date

Paula Red

8/22

8/17/17

Gingergold

8/23

8/19/17

Gala

9/8

9/3/17

McIntosh

9/13

9/4/17

Early Fuji

9/14

9/7/17

Honeycrisp

9/16

9/12/17

Empire

9/20

9/17/17

Jonathan

9/23

9/18/17

Jonagold

9/23

9/18/16

Cortland

9/25

9/20/17

Golden Delicious

9/29

9/25/17

Red Delicious

10/1

9/28/17

Idared

10/6

10/2/17

Northern Spy

10/8

10/2/17

Crispin

10/9

10/6/17

Rome

10/11

10/7/17

Fuji

10/22

10/18/17

Braeburn

10/23

10/21/16

Goldrush

10/31

10/29/16

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

The East Michigan Apple Harvest Report is produced by Bob Tritten, district fruit educator in Flint, Michigan. Email: .(JavaScript must be enabled to view this email address); Office phone: 810-244-8555; Cell: 810-516-3800; and Fax: 810-341- 1729. Special thanks to the three orchards that allow me to harvest fruit for analysis every Monday during the apple harvest season: Spicer Orchards in Hartland, Erwin Orchards in South Lyon and Hy’s Cider Mill in Romeo. Thanks to so many other orchardists that I collect fruit samples from to include their varieties on more of a random basis. Lastly, thanks to the Post-Harvest Lab in the Department of Horticulture at Michigan State University that provides the quick and very accurate analysis of so many apple samples in the fall. Randy Beaudry and his students do a fantastic job and are a valuable part of our Apple Maturity Team.

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