East Michigan apple maturity report – Sept. 18, 2019

Gala, second picking of Honeycrisp and Early Fuji are being harvested at most apple orchards across east Michigan. McIntosh harvest has been wrapped up at most farms, except those treated with ReTain.

General apple harvest comments

Apple harvest is in “full steam ahead” mode across the region. This week, growers are harvesting the first picking of Gala, the second picking of Honeycrisp and finishing Early Fuji and McIntosh. The next group of varieties ready to be harvested—Empire, Jonathan Jonagold and Cortland—were tested this week for the first time to get an early read on their maturity. None are ready to begin harvest. Golden Delicious was also tested for the first time and are not ready. I also had one sample of SnowSweet tested this week, but I don’t have much experience or data for SnowSweet to include the maturity numbers in my weekly table of data or individual varieties section. I believe it is ready for harvest.

The brix or sugar level have taken a nice jump in the last week. It is up from an overall average of 12.1% last week to an average of 13.5% this week.  Weather conditions have generally been good for harvest over the last week, with most of the 2 inches of rain coming overnights for most farms. Labor supply for harvest has generally been adequate thus far this season. Cider makers are still scrambling to find a good blend of apples to make cider. With Gala harvest getting underway, cider makers will have a much sweeter variety to add to their blend. Demand for cider has been excellent so far this season.

The third apple harvest report for the 2019 apple harvest season follows with more details on nine varieties, four of which are new this week. Our predicated apple harvest dates for east Michigan are three to four days later than the normal dates. Here is the link for the 2019 Apple Predicted Harvest Dates article that was emailed to area growers as well as being published on our Michigan State University Extension Fruit & Nuts website in August.

Apple maturity in east Michigan for apples harvested Sept. 16

Variety

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Gala

84 (40-100)

81 (60-95)

20.0 (18.5-22.2)

5.0(2.5-7.0)

13.2

McIntosh

20 (0-80)

82(61-98)

15.1(14.4-16.0)

4.9 (4.3-5.6)

13.1

Early Fuji

 

80 (80-80)

75 (71-78)

16.0 (16.0–16.0)

5.9 (5.5-6.2)

13.7

Honeycrisp

87 (60-100)

68 (60-81)

15.7 (13.5 -18.8)

5.7 (5.3-5.9)

14.1

Empire

0 (0-0)

73 (66-82)

20.1 (17.6-22.1)

2.3 (1.8-3.1)

12.6

Jonathan

13 (0-40)

88 (68-98)

20.5 (19.3-22.7)

3.0 (2.3-3.9)

13.5

Jonagold

40 (0-100)

48 (29-78)

19.5 (17.3-21.5)

3.0 (2.4-3.5)

14.4

Cortland

0 (0-0)

73 (63-90)

17.1 (16.1-18.2)

1.2 (1.0-1.5

13.3

Golden Delicious

7 (0-20)

11 (6-14)

18.1 (17.4-18.7)

2.0 (1.0-2.6)

13.4

Individual variety results

Gala

Gala was sampled for the third week of the season, with several strains being tested this week. Gala maturity has pushed ahead quickly in the past week, most strains are now ready for harvest. Until this past week, Gala have been slow to mature this season, with most McIntosh strains maturing ahead of Gala. The predicted harvest date for Gala for the region was Sept. 11.

The percentage of fruit with internal ethylene levels over 0.2 parts per million (ppm) is up from 76% last week to 84% this week. Fruit are still very firm averaging 20.0 pounds pressure and the average starch index is up from 2.8 last week to 5.0 this week. The range of starch clearing is quite broad this week, from a low of 2.5 to a high of 7.0. We usually look for a starch index for Gala to be in the 3 to 4 range. The brix or sugar level jumped from 12.2% last week to 13.2% this week. None of the many Gala samples that I picked on Monday of this week had a greasy feel. Lastly, many cider makers will be glad to have mature Gala availably to add to their cider blend.

Gala maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 2

58 (0-90)

73 (33-90)

19.2 (18.8-25.0)

1.4(1.0-2.1)

12.1

Sept. 9

76 (10-100)

79 (75-85)

21.4 (18.2-23.2)

2.8(1.6-5.0)

12.2

Sept. 16

84 (40-100)

81 (60-95)

20.0 (18.5-22.2)

5.0(2.5-7.0)

13.2

McIntosh

McIntosh was sampled for the third week of the season. Many strains of McIntosh were ready to begin harvest last week, and this week most other later maturing strains are now ready for harvest. Most McIntosh have been harvested already. The predicted harvest date for McIntosh was Sept. 16, so it matured a few days ahead of the predicted harvest date.

Fruit color is improved this week, up from 74% last week to 82% this week. Understand that two of the four McIntosh samples for this week are RubyMac strain, which is a highly colored Mac strain. Thus, these two blocks had close to 100% color, raising my average of 82%. Only 20% of the fruit tested showed internal ethylene levels over 0.2 ppm. The average starch index is up from 4.1 last week to 4.9 this week. We usually look for a starch index for McIntosh to be around 5. The brix level also jumped nearly 1 percentage point to 13.1% this week.

McIntosh maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 2

0 (0-0)

58(25-98)

19.1 (16.8-23.0)

2.3 (1.7-3.5)

12.7

Sept 9

Sept. 9

13 (0-40)

74(59-99)

18.0 (16.3-19.6)

4.1 (3.2-5.1)

12.2

Sept. 16

20 (0-80)

82(61-98)

15.1(14.4-16.0)

4.9 (4.3-5.6)

13.1

Early Fuji

Early Fuji was sampled for the second week of the season. Based on this week’s data, Early Fuji are mature to a bit over mature at this time. Growers have been harvesting Early Fuji over the last week. The predicted harvest date for Early Fuji is Sept. 17. Fruit color is generally much better thus week, averaging 75%. Eighty percent of fruit tested showed internal ethylene levels over 0.2 ppm. The average starch index is 5.9 this week, up from 4.1 last week.

Early Fuji maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 9

30 (0-60)

50 (47-52)

17.9 (17.9–17.9)

4.1 (3.8-4.4)

12.0

Sept. 16

80 (80-80)

75 (71-78)

16.0 (16.0–16.0)

5.9 (5.5-6.2)

13.7

Honeycrisp

Honeycrisp was sampled for the second week of the season. Honeycrisp were ready to begin harvest last week for the first light picking. Most growers started harvesting Honeycrisp in the last week. Most of the fruit that was sampled this week is from blocks that have been picked once already. The predicted harvest date for Honeycrisp is Sept. 20. Based on this week’s data, Honeycrisp is ready for a second picking. Some growers are waiting for better color development to pick some of the remaining fruit. The crop load and maturity are extremely variable in Honeycrisp this season in almost all blocks.

Fruit size is excellent this year for Honeycrisp, maybe even too big. Some bitter pit is being seen in Honeycrisp, but not as much as I expected to see. Fruit color is generally good, averaging 68%, which is not bad as the most highly colored fruit has been harvested in the last week. The average starch index is 5.7 this week, up from 4.2 last week. As I shared last week, in a good Honeycrisp season, this variety is not grower-friendly, but this season it has been a very challenging variety to grow!

Honeycrisp maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 9

88 (50-100)

63 (37-90)

18.3 (14.9-20.2)

4.2 (3.6-5.1)

12.9

 

Sept. 16

87 (60-100)

68 (60-81)

15.7 (13.5 -18.8)

5.7 (5.3-5.9)

14.1

Empire

Empire was sampled for the first week of the season to get an early read on its maturity. Based on one week’s worth of data, Empire are not ready to begin harvest. The predicted harvest date for Empire is Sept. 24, but I believe it will not be mature by this date. None of fruit tested had internal ethylene levels over 0.2 ppm and the pressure is 20.1 pounds. The average starch index is 2.3 this week.

Empire maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 16

0 (0-0)

73 (66-82)

20.1 (17.6-22.1)

2.3 (1.8-3.1)

12.6

Jonathan

Jonathan was sampled for the second week of the season, and I expanded the number of blocks tested this week. Based on two weeks’ worth of data, Jonathan are not ready to begin harvest. The predicted harvest date for Jonathan is Sept. 27; I believe it will be mature by this date. Thirteen percent of fruit tested had internal ethylene levels over 0.2 ppm. Fruit color is generally good at 88%. The average starch index is up from 1.8 last week to 3.0 this week. We usually look for a starch index for Jonathan to be around 3.5.

Jonathan maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 9

0 (0-0)

86 (86-86)

20.5 (20.5-20.5)

1.8 (1.8-1.8)

12.2

Sept. 16

13 (0-40)

88 (68-98)

20.5 (19.3-22.7)

3.0 (2.3-3.9)

13.5

Jonagold

Jonagold was sampled for the first week of the season to get an early read on its maturity. Based on one week’s worth of data, Jonagold are not ready to begin harvest. The predicted harvest date for Jonagold is Sept. 27; I believe it will be mature by or close to this date. Forty percent of fruit tested had internal ethylene levels over 0.2 ppm and the pressure is 19.5 pounds. The average starch index is 3.0 this week. We usually look for a starch index for Jonagold to be around 3.5.

Jonagold maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 16

40 (0-100)

48 (29-78)

19.5 (17.3-21.5)

3.0 (2.4-3.5)

14.4

Cortland

Cortland was sampled for the first week of the season to get an early read on its maturity. Based on one week’s worth of data, Cortland are not ready to begin harvest. The predicted harvest date for Cortland is Sept. 29; I do not believe that it will be mature by this date. None of fruit tested had internal ethylene levels over 0.2 ppm and the pressure is 17.1 pounds. The average starch index is 1.2 this week.

Cortland maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 16

0 (0-0)

73 (63-90)

17.1 (16.1-18.2)

1.2 (1.0-1.5

13.3

Golden Delicious

Golden Delicious was sampled for the first week of the season to get an early read on its maturity. Based on one week’s worth of data, Golden Delicious are not ready to begin harvest. The predicted harvest date for Golden Delicious is Oct. 3. Seven percent of fruit tested had internal ethylene levels over 0.2 ppm and the pressure is 18.1 pounds. The average starch index is 2.0 this week.

Golden Delicious maturity sampling for the harvest season

Sample date

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Sept. 16

7 (0-20)

11 (6-14)

18.1 (17.4-18.7)

2.0 (1.0-2.6)

13.4

Predicted peak fresh market apple harvest dates for east Michigan

Each year we publish predicted harvest dates for many locations across the state. These predicted harvest dates are based on a long-established formula using the bloom date and temperatures for 30 days post-bloom.

The following table has predicted apple harvest dates for east Michigan. It has been expanded to include more apple varieties and lists only one date for the entire east Michigan region, which is hard to do! You can adjust these predicted harvest dates based on your actual bloom dates or on the typical harvest dates at your farm.

These dates are an estimate and will be affected by the apple strain, rootstock, crop load, fertility, soil type, and other factors including weather this season. Keep a close eye on these weekly Apple Harvest Updates for possible revisions of these dates.


Normal and 2019 peak harvest dates for apple varieties for East Michigan

Variety

Normal date

2019 predicted date

Paula Red

8/22

8/25

Zestar

8/22

8/22

Gingergold

8/23

9/26

Gala

9/8

9/11

McIntosh

9/13

9/16

Early Fiji

9/14

9/17

Honeycrisp

9/16

9/20

Empire

9/20

9/24

Jonathan

9/23

9/27

Jonagold

9/23

9/27

Cortland

9/25

9/29

Golden Delicious

9/29

10/3

Red Delicious

10/1

10/5

CandyCrisp

10/5

10/10

Idared

10/6

10/11

Northern Spy

10/8

10/12

Crispin (Mutsu)

10/9

10/13

Rome

10/11

10/15

Autumn Gala

10/17

10/21

EverCrisp

10/19

10/23

Fuji

10/22

10/26

Braeburn

10/23

10/28

Winesap

10/26

10/30

Goldrush

10/31

11/4

*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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