Northwest Michigan apple maturity report – October 5, 2016

Fruit color has improved drastically in the last week and overall quality is looking good in later season varieties.

General apple harvest comments

Several apple blocks have been harvested, and in particular, Gala and Honeycrisp harvest is nearing the end for some growers in the region. Most of the blocks we have traditionally tested for maturity have been harvested at this time, and as a result, several of this week’s samples were submitted by growers. Color has continued to improve in the last week and the apples that remain on the trees are very apparent. Most varieties are holding their firmness and Brix are slowly improving across the board.

We have received isolated reports of damage on apples and we are investigating the cause of the damage in more depth. Our current hypothesis is the apples were injured by spray material earlier this season. Similar injury has been reported in other parts of the state.

Grape and hop harvest has coincided with apple harvest, resulting in shortages of harvest crews in these crops.

Apple maturity in northwest Michigan for apples harvested Oct. 4

Variety

Color % (range)

Firmness Lbs. (range)

Starch (range)

Brix %

Jonagold

96 (NA)

16.9

4.2

14.4

McIntosh

98 (NA)

16.1

2.9

11.3

Ida Red

86 (86)

17.3 (16.6-17.9)

2.8 (2.6-2.9)

12.9

Red Delicious

99 (NA)

16.6

3.0

10.5

Northern Spy

56 (NA)

21.4

3.1

11.6

Mutsu/Crispin

9 (NA)

19.5

2.2

11.6

Individual variety results

Jonagold has developed quickly in the last week. Firmness dropped slightly from last week in the two samples that were tested. Starch indices jumped up to 4.2, indicating this variety is ready to eat. Brix also increased to 14.4 and color has improved drastically since last week.

Jonagold 2016 maturity sampling for the harvest season

Date of sample

Color % (range)

Firmness Lbs. (range)

Starch (range)

Brix %

Sept. 27

74 (65-92)

17.4 (16.9-18.5)

2.9 (2.6-3.3)

13.2

Oct. 4

96 (NA)

16.9

4.2

14.4

McIntosh harvest is ongoing in the region and several of the earlier McIntosh varieties have been harvested. Most notably, we have observed a good deal of improvement in color this week. Firmness and Brix are holding steady since last week and this week’s starch index indicates this later McIntosh variety is continuing to ripen.

McIntosh 2016 maturity sampling for the harvest season

Date of sample

Color % (range)

Firmness Lbs. (range)

Starch (range)

Brix %

Sept. 13

69 (54-91)

15.9 (14.2-17.6)

2.2 (1.0-3.0)

11.6

Sept. 20

83 (62-100)

15.6 (13.6-17.0)

3.1 (1.4-5.1)

11.3

Sept. 27

89 (88-91)

15.7 (15.2-16.1)

2.7 (1.7-3.7)

11.9

Oct. 4

98 (NA)

16.1

2.9

11.3

 This was the second week of maturity testing for Ida Red. Like last week, samples were collected from two blocks. Similar to other apple varieties, color has also improved on Ida Reds, but they still have some time before color is optimal. Firmness is consistent with last week at an average of 17.3. This week’s starch index is also consistent at an average of 2.8. These apples are still eating green, but Brix have improved slightly since last week.

Ida Red 2016 maturity sampling for the harvest season

Date of sample

Color % (range)

Firmness Lbs. (range)

Starch (range)

Brix %

Sept. 27

68 (61-76)

17.5 (17.1-17.8)

2.8 (1.4-4.2)

12.0

Oct. 4

86 (86)

17.3 (16.6-17.9)

2.8 (2.6-2.9)

12.9

This was the first week of sampling Red Delicious.

Red Delicious 2016 maturity sampling for the harvest season

Date of sample

Color % (range)

Firmness Lbs. (range)

Starch (range)

Brix %

Oct. 4

99 (NA)

16.6

3.0

10.5

This was the first week of sampling Northern Spy.

Northern Spy 2016 maturity sampling for the harvest season

Date of sample

Color % (range)

Firmness Lbs. (range)

Starch (range)

Brix %

Oct. 4

56 (NA)

21.4

3.1

11.6

This was the second week of Mutsu/Crispin sampling. We had one sample per week for this variety and maturity tests indicate this variety is not yet mature. Brix are improving and firmness has remained consistent.

Mutsu/Crispin 2016 maturity sampling for the harvest season

Date of sample

Color % (range)

Firmness Lbs. (range)

Starch (range)

Brix %

Sept. 27

10.1 (NA)

18.2

2.6

10.1

Oct. 4

9 (NA)

19.5

2.2

11.6

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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