Grand Rapids area apple maturity report – Sept. 11, 2019

First harvest of early blocks of Honeycrisp and Gala will begin soon.

Apple storage bins
Photo by Amy Irish-Brown, MSU Extension

General comments

Fruit color has been excellent so far this season due to cool nights and sunny days. Warmer weather and rainy conditions are on tap for this week and next week’s forecast is for much of the same. Rain slows harvest just at a time when several varieties are coming into the harvest window for long-term storage—in the next week or two, it could become harder to stay on top of the best quality parameter to harvest.

In general, internal ethylene levels have been low and will likely get moving with warmer weather. Fruit firmness has been very good this year, on the high side for most varieties tested. Background color seems to be on the lower (less green) side overall.

In the Grand Rapids, Michigan, area, apple maturity seems to be running close to our 2019 predicted apple harvest dates. We are seeing trends in maturity parameters that McIntosh might be three or four days ahead of our predicted dates and Gala perhaps a day earlier than predicted. Keep in mind these predicted dates are for peak harvest, so some fruits might be ready ahead or behind these dates as we move through maturity.

 Normal and 2019 peak harvest dates for varieties for the Grand Rapids area

Variety

Normal date

2019 predicted date

Gala

9/10

9/15

McIntosh

9/15

9/20

Honeycrisp

9/18

9/23

Empire

9/24

9/30

Jonathan

9/26

10/6

Jonagold

9/26

10/6

Golden Delicious

10/2

10/8

Red Delicious

10/5

10/11

Idared

10/10

10/15

Rome

10/15

10/20

Fuji

10/25

10/28

Braeburn

10/25

10/28

Goldrush

11/1

11/3

Variety sampling results

Strains are noted where applicable. We try our best to collect samples from blocks untreated with harvest management products.

Gala

Color is very good to excellent on most Gala strains this year and continues to improve. Size is also good to excellent. With a lack of extreme hot weather in August, it is expected that traditional Gala strains will not be earlier in their maturity by more than a day ahead of our predicted harvest date of Sept. 15. Early Gala cultivars (Wildfire, Foxtrot) are all harvested. Fulford Gala is also being picked. Our samples this week are only from traditional Gala strains. There is some harvest of these strains just beginning this week—next week will be the big week for Gala harvest.

Traditional Gala (Gale, Buckeye, Brookfield) 2019 maturity sampling records

Date of sample

Avg. Ethylene (ppm)

% Fruits with Ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Avg Firmness lbs. pressure (range)

Starch range)

Brix (range)

Aug. 21

NA

NA

49.3 (35-70)

4.8 (3-5)

23.7

1.8 (1-5)

10.8 (10-13.8)

Sept. 3

NA

NA

68.3 (45-90)

3.8 (3-5)

25.6

1.4 (1-3)

11.5 (10.4-12.8)

Sept. 10

0.8690

20

75.7 (50-90)

1

23.4 (21.5-26)

1.7 (1-7)

12 (11.5-12.5)

McIntosh

McIntosh have moved forward in their maturity. They still eat on the starchy side. Internal ethylene levels show about half of the fruits tested have any ethylene present and none over the climacteric of 0.2 ppm. We still believe that macs might come ready three or four days ahead of the predicted harvest date of Sept. 20. They should be behind Gala for 2019.

McIntosh (RubyMac) 2019 maturity sampling records (Linda Mac)

Date of sample

Avg. Ethylene (ppm)

% Fruits with Ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Avg Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Sept. 3

NA

NA

73 (60-90)

5

17.5

NA

12.3 (11.6-13.2)

Sept. 10

0.0150

0

86 (70-100)

1.6 (1-2)

20.8 (13-24.5)

3.2 (3-4)

11.6 (10.5-12.5)

Early Fuji

Early Fuji strains indicate they are nearing harvest maturity ranges and they will fit in right with Macs or even just ahead. Color is not great yet with an average of 48% red color. Forty percent of fruits do have internal ethylene above 0.2 ppm and starch clearing readings are 2s and 3s.

Early Fuji (Sept. Wonder) 2019 maturity sampling records

Date of sample

Avg. Ethylene (ppm)

% Fruits with Ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Avg Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Sept. 10

0.2235

40

48 (30-65)

1.9 (1-3)

19.3 (15-22.5)

2.6 (2-3)

11.5 (11-12)

Honeycrisp

Premier Honeycrisp harvest is complete. Traditional and red strains are just starting to be harvested on the Ridge this week as color allows. Our predicted date for traditional Honeycrisp is Sept. 23 for peak harvest, so next week will be a big week for this variety along with Gala. Internal ethylene levels are high as is very common for Honeycrisp. Color is improved over last week, even in the redder strains. Starch clearing jumped from mostly 1s last week to a greater range of readings (1–8) this week with an average of 5. Keep a close eye on Honeycrisp for fruit drop; the warmer the average weather moving in over the next 10 days could enhance fruit drop in Honeycrisp as well as other drop prone cultivars.

Honeycrisp (Firestorm and Royal Red) 2019 maturity sampling records

Date of sample

Avg. Ethylene (ppm)

% Fruits with Ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Avg Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Aug. 28

NA

NA

26 (5-80)

4.7 (3-5)

18

1.7 (1-7)

12.8 (12.2-14.2)

Sept. 10

12.553

100

77 (50-90)

1.9 (1-3)

19.5 (16-28.5)

5 (1-8)

13.4 (12-14.3)

Empire

Empire was tested for the first week and all fruits are immature. Our predicted harvest date is Sept. 30 for Empire and that is likely a good target for peak harvest.

Empire 2019 maturity sampling records

Date of sample

Avg. Ethylene (ppm)

% Fruits with Ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Avg Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Sept. 10

0

0

50 (25-60)

2.2 (2-3)

23.1 (21-25)

1.8 (1-2)

11.3 (10.8-11.8)

Jonathan and Jonagold

We tested Jonathan and Jonagold for the first time and fruits are immature. The predicted harvest date for both Jonathan and Jonagold is Oct. 6. Another week of testing will tell us more. I’ve separated out the data for all samples in the tables below.

Jonathan (RubyJon) 2019 maturity sampling records

Date of sample

Avg. Ethylene (ppm)

% Fruits with Ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Avg Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Sept. 10

0.0169

0

82 (70-90)

1

22.9 (18.5-26.5)

2 (1-3)

11.6 (11-12)

 

Jonagold 2019 maturity sampling records

Date of sample

Avg. Ethylene (ppm)

% Fruits with Ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Avg Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Sept. 10

0.0181

0

32 (10-70)

3

22.1 (20-24)

1.7 (1-2)

12.6 (12-13)

 

Jonastar Jonagold 2019 maturity sampling records

Date of sample

Avg. Ethylene (ppm)

% Fruits with Ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Avg Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Sept. 10

0.0380

0

94 (90-95)

3

21.7 (19.5-24)

1.3 (1-2)

11.6 (11.5-12)

Golden Delicious

The predicted harvest date for Grand Rapids area Golden Delicious is Oct. 8. Our first week of sampling indicated very immature fruit at this time.

Golden Delicious 2019 maturity sampling records

Date of sample

Avg. Ethylene (ppm)

% Fruits with Ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Avg Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Sept. 10

0.0021

0

11.3 (5-15)

3

21.9 (19.5-24)

1

11.5 (11-12)

Nova Spy

Nova Spy is not a common variety and all fruits tested this week are immature. They don’t eat too badly, but they definitely need more time to improve.

Nova Spy 2019 maturity sampling records

Date of sample

Avg. Ethylene (ppm)

% Fruits with Ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Avg Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Sept. 10

0.0267

0

41.5 (25-55)

2.3 (2-3)

22.8 (19.5-26.5)

2.4 (2-3)

11.5 (11-12)

Red Cort

Red Cort was tested for the first time and all fruits are immature.

Red Cort 2019 maturity sampling records

Date of sample

Avg. Ethylene (ppm)

% Fruits with Ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Avg Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Sept. 10

0.0169

0

70 (30-90)

1.6 (1-2)

19.7 (16.5-24)

1

12.2 (12-12.5)

Apple maturity sampling parameters

  • % fruits with internal ethylene over 0.2 ppm = indicates when ethylene begins to influence fruit ripening and it cannot be held back easily after this is reached.
  • Color % = the visual%age of red color from 0 to 100; range is of all fruits tested
  • Background color: 5 = Green, 1 = Yellow; range is of all fruits tested.
  • Firmness in pounds pressure = measured with a Güss Fruit Texture Analyzer; range is of all fruits tested.
  • Starch: 1 = all starch, 8 = No starch; range is of all fruits tested. Using Cornell Starch Iodine Index Chart.
  • Brix = % sugar measured with Atago PAL-1 Pocket Refractometer
 


Michigan State University Michigan State University Close Menu button Menu and Search button Open Close