East Michigan apple maturity report – Sept. 11, 2019

McIntosh and Honeycrisp are being harvested at most apple orchards across east Michigan. Gala are slow to mature this fall and need more time on the tree to ripen.

General apple harvest comments

Based on two weeks’ worth of apple maturity data, both McIntosh and Honeycrisp are ready to begin harvest at this time. Early Fuji, tested for the first time this week, is also mature and ready to harvest. This weeks’ data confirms McIntosh and Honeycrisp are ahead of Gala maturity this season.

Monday, Sept. 9, was the second week to collect apple samples from a number of orchards in east Michigan. I expanded the list of varieties being tested from two last week to six this week. Early Fuji, Honeycrisp, Jonathan and Golden Supreme were added to the list of varieties tested this week. Apple samples harvested and delivered on Monday of this week were then analyzed at the Michigan State University Department of Horticulture Post Harvest Lab yesterday, Sept. 10. Last night, I analyzed the data and this morning prepared this report.

Remember that our bloom period this spring was extended for close to three weeks for some varieties. This long bloom period usually results in a longer harvest season for each variety, as the bloom that was pollinated early in the bloom period will be mature before blossoms were pollinated late in the bloom period. The net result for apple growers is the need for multiple picks for many varieties. So far this season it appears there is a widespread of maturity of individual apples on the tree. This may change once we get into harvest further. Fruit size is generally excellent this season.

Cider makers have been scrambling to find a good blend of apples to make cider. I suggest that McIntosh are a good choice, but growers need to harvest from early strains and sites and only pick the ripest fruit at this time that will be used for cider. Demand for cider has been excellent for this early in the season.

The second apple harvest report for the 2019 apple harvest season follows. I encourage apple growers to spend time in the orchard soon to evaluate the maturity of apple varieties.

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 MSU Extension News for Fruit & Nuts webpage in August.

Apple maturity in east Michigan for apples harvested Sept. 9

Variety

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Gala

76 (10-100)

79 (75-85)

21.4 (18.2-23.2)

2.8(1.6-5.0)

12.2

McIntosh

13 (0-40)

74(59-99)

18.0 (16.3-19.6)

4.1 (3.2-5.1)

12.2

Early Fuji

 

30 (0-60)

50 (47-52)

17.9 (17.9–17.9)

4.1 (3.8-4.4)

12.0

Honeycrisp

88 (50-100)

63 (37-90)

18.3 (14.9-20.2)

4.2 (3.6-5.1)

12.9

Jonathan

0 (0-0)

86 (86-86)

20.5 (20.5-20.5)

1.8 (1.8-1.8)

12.2

Golden Supreme

70 (70-70)

4 (4-4)

15.5 (15.5-15.5)

2.4 (2.4-2.4)

11.3

Individual variety results

Gala

Gala was sampled for the second week of the season with several strains tested. The predicted harvest date for Gala for the region is today, Sept. 11. Based on this week’s data, Gala are close to being ready to harvest, but not quite there yet. I expect that by this weekend or early next week they will be ready to begin harvest. Gala is a variety that tends to mature early in hot growing seasons, later in cooler seasons.

The percentage of fruit with internal ethylene levels over 0.2 parts per million (ppm) is up from 58% last week to 76% this week. Fruit are still very firm, averaging 21.4 pounds pressure and the average starch index is up from 1.4 last week to 2.8 this week. The range of starch clearing is quite broad this week. We usually look for a starch index for Gala to be in the 3 to 4 range.

Dry conditions in many areas may have fruit that is more advanced. While growers have heard about different Gala strains maturing over several weeks, my experience is that most strains (with the exception of Autumn Gala) mature in about the same window and within just a few days of each other. Gala that I tasted Monday of this week were very firm, very juicy and on the sweet side, but still eat green.

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

McIntosh

McIntosh was sampled for the second week of the season. Based on this weeks’ data, McIntosh are ready to begin harvest. This being said, they will need a few pickings this season, as fruit on the inside of the tree need more time to develop better color. So, the fruit that is mature at this time are in the tops of the tree and outer shell. The predicted harvest date for McIntosh is Sept. 16, so it is maturing a few days ahead of the predicted harvest date.

Fruit color is generally improved this week, up from 52% last week to 74% this week. Understand that two of the six 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 74%. Only 13% of the fruit tested showed internal ethylene levels over 0.2 ppm. The average starch index is up from 2.3 last week to 4.1 this week. We usually look for a starch index for McIntosh to be around 5.

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

Early Fuji

Early Fuji was sampled for the first week of the season. Based on one weeks’ worth of data, Early Fuji are ready to begin harvest. The predicted harvest date for Early Fuji is Sept. 17. Fruit color is generally OK at 50%. Thirty percent of fruit tested showed internal ethylene levels over 0.2 ppm. The average starch index is 4.1 this 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

Honeycrisp

Honeycrisp was sampled for the first week of the season. Based on one weeks’ worth of data and adding several caveats, Honeycrisp are ready to begin harvest with a very light picking. The predicted harvest date for Honeycrisp is Sept. 20. First, understand that when I harvest a sample of any apple variety for testing for this apple maturity project, I always harvest the ripest fruit I can find, and for Honeycrisp this season, that means that only 5 to 10% of the fruit is mature at this time. So, one caveat is to harvest only the fruit that is highly colored for this first picking, or 5 to 10% of the fruit.

Additionally, on Honeycrisp harvest, the crop load and maturity are extremely variable on this variety this season in almost all Honeycrisp blocks. So, most trees only have a few apples that are ripe at this time. Then again, you will come upon a tree that has a high percentage of apples that are brightly colored and mature fruit that is ready now for harvest. Fruit size is excellent this year for Honeycrisp, maybe even too big. On Monday when I was harvesting my Honeycrisp samples, I had a fair number of other apples that wanted to drop as I was trying ever so hard to gently harvest my samples, so some green fruit will end up in the apple bin. This is frustrating for such a valuable apple variety to see this much drop. The next and mostly heavier picking of Honeycrisp will be in five to seven days.

Lastly, I am starting to see some bitter pit in Honeycrisp. Fruit color is generally OK, averaging 63% and not surprisingly, 88% of the fruit tested had internal ethylene levels over 0.2 ppm. Honeycrisp are always high producers of internal ethylene. The average starch index is 4.2 this week. In a good Honeycrisp season, this variety in not grower friendly, but this season it is 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

Jonathan

Jonathan was sampled for the first week of the season, and I only tested one block to get an early read on its maturity. Based on one weeks’ worth of data, Jonathan are not ready to begin harvest. The predicted harvest date for Jonathan is Sept. 27. Fruit color is generally good at 86%. No fruit tested had internal ethylene levels over 0.2 ppm. The average starch index is only 1.8 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

Golden Supreme

Golden Supreme was sampled for the first week of the season. This variety is not a strain or sport of Golden Delicious and is not widely planted. Based on one weeks’ worth of data, Golden Supreme are not ready to begin harvest. I do not have a predicted harvest date for Golden Supreme, but I believe it falls early into the Empire/Jonagold harvest window. When mature, the skin color is generally yellow with a pink blush. Seventy percent of fruit tested had internal ethylene levels over 0.2 ppm. The average starch index is 2.4 this week.

Golden Supreme 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

70 (70-70)

4 (4-4)

15.5 (15.5-15.5)

2.4 (2.4-2.4)

11.3

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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