Northwest Michigan apple maturity report – October 4, 2023

Growers are moving through harvest and Honeycrisp and Gala are the main priorities at this time. Fruit seems to be maturing quickly this season.

Gala apples in tree
Gala at the Northwest Michigan Horticulture Research Center, Oct. 4, 2023. Photo by Karen Powers, MSU Extension.

This is the fifth apple maturity report for 2023 for northwest Michigan. Reports are sent out every week (usually on Wednesdays) following the Michigan State University Extension fruit team apple maturity calls on Wednesday morning.

Growers are moving through harvest, and most varieties are mature. Growers are still picking Honeycrisp, and some growers are on the second or third pick of this variety. Growers are also harvesting Gala now, and color on this fruit is good in most blocks. Gala size is variable, and some fruit is small where the trees did not have irrigation. Growers are also going after processing fruit if they have a home for it. Jonagold harvest is happening in some blocks, and we visited two orchards to pick for maturity testing yesterday, and both were already harvest. Jonagold Brix are excellent, but color is variable. In one orchard where we collected samples, the crop load on Jonagold trees is high. We have also seen some dying trees in a Jonagold orchard this week.

Weather

This weather seems more like summer than fall, but wait until the weekend, and we will see a shift. Daytime temperatures have been in the 70s degrees Fahrenheit and topping out in the low 80s F this week. We have also had sunshine. Today, Oct. 4, is predicted to be cloudy but back to sunny tomorrow but cooler daytime temperatures. Nighttime temperatures are also predicted to cool, but there are no freezing temperatures in the forecast; lows will be in the mid-40s F for next week. Next week is also predicted to be cooler, in the 60s F, for daytime highs.

How to read maturity tables

Each week, we test apple varieties that are nearing maturity in northwest Michigan. We are reporting average values for several samples for each variety. Maximum and minimum values are included for the highest and lowest individual fruits evaluated for each, to give a full spectrum of maturity. All samples included in the reports have been untreated with ReTain or Harvista, unless otherwise noted.

Apple maturity in northwest Michigan for apples collected on Oct. 3, 2023

Variety

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Evercrisp

44% (15-70)

22.8 (21.5-23)

2.8 (2-7)

13.95 (13.5-14.7)

Jonagold

78% (one sample)

17.5

5.3

12.9

Jonagold

We only tested on orchard of Jonagold this week because all other blocks have been harvested. The firmness is still good in this one sample, and starch is testing an average of 5.3. Brix was also good in the one sample.

Evercrisp

We decided to test the variety Evercrisp this week, and we were surprised to note how far along this variety seems to be for the beginning of October. In most years, we harvest Evercrisp at the end of the month and even into November in some years. We saw variability in starch removal, but the majority of the fruit was testing in the two range; we did have some outlier fruit that were testing at 7, but these were only a few fruits in the sample. Color is not good in one block of Evercrisp, but the cooler weather should help improve the color. Brix is excellent in this variety, and we had fruit that tested in the high 14s. Growers should keep an eye on this variety as it is surprisingly more mature than anticipated for this time of the season.

Apple maturity sampling parameters

  • Ethylene (% 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 percentage of red color from 0 to 100; range is of all fruits tested. Indicates surface area covered in red and intensity of red color.
  • 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

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

Suggested firmness and starch index levels for long-term and shorter-term controlled atmosphere (CA) storage by variety.

Variety

Firmness (pounds)*

Starch Index*

Short CA

Mid-CA

Long CA

Mature

Over mature

McIntosh

14

15

16

5

7

Gala

16

17

18

3

6

Honeycrisp

15

16

17

3.5

6

Empire

14

15

16

3.5

6

Early Fuji

16

17

18

3

7

Jonagold

15

16

17

3.5

5.5

Jonathan

14

15

16

3.5

5.5

Golden Delicious

15

16

17

3

6.5

Red Delicious

16

17

18

2.5

6

Idared

14

15

16

3.5

6

Fuji

16

17

18

3

7

Rome

15

16

18

3

5.5

Did you find this article useful?