Northwest Michigan apple maturity report – Oct. 21, 2020

Apple harvest for 2020 is wrapping up on most farms. Quality continues to hold and growers are ready to be finished for the year.

Apples

General apple harvest comments

Apple harvest is winding down for the season. Growers have been happy with their quality and color has been excellent for all varieties. Some growers are still harvesting later varieties, and Northern Spy, IdaRed, Red Delicious are coming off the tree, mainly for processing.

EverCrisp, a newer variety from the Midwest Apple Improvement Association (MAIA), has been planted in recent years by a few growers in the region. This variety remains very firm (still in the low 20s for starch removal), but color has improved over the past week.

We are observing some watercore in our samples this week, which seems to be more common than in past weeks. However, we had a small sample size this week.

Growers are eager to finish up with harvest this year. The harvest season seems to be going a little longer than expected. We did have some weather challenges with a lot of rain, which made it difficult to get into the orchards. We had 14 rain days out of the 21 days in October where we received 2.51 inches of rainfall at the Northwest Michigan Horticulture Research Center. Despite the dreary conditions, the colors on the hardwood trees remain bright—thank goodness for something bright during this cloudy and wet fall.

Apple maturity in northwest Michigan for apples collected on Oct. 20, 2020

Variety

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

Red Delicious

97%

17.2

3.2

11.9

Crispin

32%

19.6

3.6

13.5

Pink Lady

90% (70 - 100)

22.1 (20.5 - 23)

2.9 (2 - 5)

14.1 (13.1 - 15)

EverCrisp

83% (70 - 95)

21.5 (21 - 22)

4 (2 - 6)

15 (14 - 15.7)

Individual variety sampling results

This was the first week of testing Red Delicious and Crispin. Maturity parameters indicate that the Red Delicious and Crispin are ready for harvest.

This was also the first week of testing for Pink Lady, and we tested two samples of Pink Lady. These apples are firm with high brix. There is variability in starch indices, but on average the apples are close to being ready for fresh eating.

Pink Lady maturity sampling for the harvest season

Sample date

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

 

Oct. 20, 2020

90% (83 - 96)

22.1 (22.1 – 22.1)

2.9 (2.5 – 3.2)

14.1 (14 - 14.1)

 

Two samples of EverCrisp were tested this week. We observed improvements in color this week, and overall the apples are still very firm. Like Pink Lady, there is also variability in the starch indices of this variety. Overall, the apples are especially juicy and eating well, particularly with such high Brix.

EverCrisp maturity sampling for the harvest season

Sample date

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %

 

Oct. 13, 2020

80.7% (70 - 95)

22.6 (22 - 23)

2.5 (2 - 3)

14.7 (13.7 - 15.3)

 

Oct. 20, 2020

83% (70 - 95)

21.5 (21 - 22)

4 (2 - 6)

15 (14 - 15.7)

 

 

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

7

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

*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.)

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

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