Southeast Michigan apple maturity report – Aug. 30, 2017

Growers are starting to do a light spot-picking of early maturing strains and sites of McIntosh and Honeycrisp. Apple maturity appears to be ahead of the normal for long-term storage.

General apple harvest comments

Based on apples that were harvested Monday, Aug. 28, and analyzed yesterday, Aug. 29, some McIntosh and Honeycrisp strains and early maturing sites are ready for a light first picking. Galas are maturing behind McIntosh this season, which is unusual, as Galas tend to be ahead of McIntosh in warm seasons, but not this year.

While this is the first Michigan State University Extension apple harvest report for the season, I have collected and analyzed apples for the last two weeks. This week, four apple varieties were sampled and tested for maturity, with Early Fuji added to the mix.

Our bloom period was early and extended for three to four weeks. Further, our growing season has been running three to six days ahead of normal for most of the summer. Thus, the predicted harvest dates reflect these factors. However, based on the maturity of Gala, McIntosh, Honeycrisp and Early Fuji, our harvest windows are tending to run a few days earlier than the predicted harvest dates, listed at the end of this article. Spend time in your orchard soon to evaluate the maturity of your apple varieties.

Again, apple bloom was very long this spring, meaning apples were not pollinated over a typical short time period of a few days. Thus, we have individual apples on the tree that vary greatly in their maturity. This spread in maturity will be hard to work around this fall. Growers will find that some apples in the bin will be over-mature and others will be green.

Fruit color has been generally better than average for most varieties for the last four weeks. Harvest labor is short at most farms as we begin to ramp up apple harvest.

There are increased numbers of brown marmorated stink bug insects in traps as well as limited amounts of fruit damage at many apple farms I have visited over the last few weeks. Continue to look out for insects feeding in orchards, particularly on warm afternoons, and damaged fruit as apples are being harvested and graded. Black rot on fruit remains a problem at several farms, much worse in many blocks than the last few seasons. Sooty blotch and flyspeck are showing up more on later maturing varieties.

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 in east Michigan for apples harvested Aug. 28

Variety

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness Lbs. (range)

Starch (range)

Brix %

Gala

73 (40-100)

66 (24-90)

21.0 (19.7-22.8)

1.9.0 (1.0-2.4)

12.3

 

McIntosh

20 (0-60)

54 (30-95)

15.8 (15.6-16.1)

3.6 (2.6-4.7)

12.8

Honeycrisp

60 (00-1000)

34 (29-42)

16.2 (14.8-17.3)

3.3 (2.8-3.9)

13.1

Early Fuji

20 (20-20)

39 (10-50)

15.7 (13.3-18.8)

5.6 (4.0-7.0)

11.8

Individual variety results

Gala was sampled for the second week of the season, with several strains tested each week. The predicted harvest date for Gala is Sept. 3, but based on this week’s data I think it will actually be a few days later. Fruit are still firm at 21.0 pounds and the starch index has moved from 1.1 last week to 1.9 this week. Dry conditions in many areas slowed fruit sizing, but color is generally good to very good. Do a block-by-block sampling to determine which are mature, and in most cases a spot-picking to get the earliest maturing fruit off the tree.

Gala 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

%

Aug. 21

100 (100-100)

74 (27-93)

23.2 (22.5-24.8)

1.1 (1.0-2.4)

12.4

Aug. 28

73 (40-100)

66 (24-90)

21.0 (19.7-22.8)

1.9 (1.0-2.4)

12.3

McIntosh was sampled for the second week of the season. The predicted harvest date for McIntosh is Sept. 4, but based on this week’s data and how it is eating, I see it is maturing earlier than this date. Some growers have started to spot-pick Macs in the last few days. Early maturing strains and sites are testing that it is mature. Do a block-by-block sampling to determine which are mature, and in most cases a spot-picking to get the earliest maturing fruit off the tree. There has been some fruit drop in McIntosh, but most of the fruit has been pushed off the limb from growth rather than dropped on its own accord. The starch index has risen from 1.6 last week to 3.6 this week.

McIntosh 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 %

Aug. 21

100 (100-100)

38 (30-46)

18.1(17.92-18.5)

1.6(1.5-1.6)

12.8

Aug. 28

20 (0-60)

54 (30-95)

15.8 (15.6-16.1)

3.6 (2.3-4.7)

12.8

Honeycrisp was sampled for the second week of the season. Recall that when we take a sample of any variety, we take the most mature fruit. So in the case of Honeycrisp, this is the few fruit per tree that have a bright red color (what I call “stop light” color) with the background color changing to yellow. The predicted harvest date for Honeycrisp is Sept. 12, but based on this week’s data and eating a lot of them, it has moved nicely in the past week. Here again, do a block-by-block sampling to determine which strains and sites are mature, and do a very light first picking to get the earliest maturing 5 to 20 percent of the stop light colored fruit off the tree. Honeycrisp always require three to four pickings. The fruit that is ready is eating well.

Honeycrisp 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 %

Aug. 21

60 (20-100)

36 (21-51)

18.2 (17.8-18.5)

3.2 (2.0-5.0)

11.9

Aug. 28

60 (0-100)

34 (29-42)

16.2 (14.8-17.3)

3.3 (2.8-3.9)

13.1

Early Fuji was sampled for the first week of the season and based on these one-week results, a few blocks are ready to be picked, but most still need a bit more time to mature. The average starch index is 5.6. The predicted harvest date for Early Fuji is Sept. 7 for east Michigan, so the date appears to be much earlier than this.

Early Fuji 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 %

Aug. 28

20 (20-20)

39 (10-50)

15.7 (13.3-18.8)

5.6 (4.0-7.0)

11.8

Predicted 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. 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

Aug. 22

Aug. 17

Gingergold

Aug. 23

Aug. 19

Gala

Sept. 8

Sept. 3

McIntosh

Sept. 13

Sept. 4

Early Fuji

Sept. 14

Sept. 7

Honeycrisp

Sept. 16

Sept. 12

Empire

Sept. 20

Sept. 17

Jonathan

Sept. 23

Sept. 18

Jonagold

Sept. 23

Sept. 18

Cortland

Sept. 25

Sept. 20

Golden Delicious

Sept. 29

Sept. 25

Red Delicious

Oct. 1

Sept. 28

Ida Red

Oct. 6

Oct. 2

Rome

Oct. 11

Oct. 7

Fuji

Oct. 22

Oct. 18

Braeburn

Oct. 23

Oct. 21

Goldrush

Oct. 31

Oct. 29

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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