Southeast Michigan apple maturity report – October 5, 2016

Red Delicious harvest is underway in the south of the region and getting started to the north, with Golden Delicious being harvested in the rest of the region. Empire harvest is wrapping up.

General apple harvest comments

Most Red Delicious strains are being harvested in the southern parts of the region, however some blocks are still eating a little on the green side. This week’s data shows that many Red Delicious blocks to the north are ready for harvest as well. Golden Delicious harvest has wrapped up in the south and continues for others toward the north. A few Fuji blocks are ready for harvest at this time as well. Northern Spy and Idared are slow to mature and are not ready yet.

This is the fifth apple harvest report for the season; I have collected and analyzed apples for the last six weeks. This week, 10 apple varieties were sampled and tested for maturity, with Cameo being added to the mix. I will not continue sampling Empire, Jonagold or Golden Delicious next week, as they are mature.

Again this week, Brix levels took another nice jump to 12.8 percent when averaged over all varieties tested, even including the five varieties that are still immature. Growers continue seeing mixed apple maturity in the bin, mainly due to the extended bloom period. With cooler weather predicted over the weekend, fruit color should continue to improve. Fruit size is generally improving as we move further into harvest, but due to the drought, is not as large as most years. Harvest labor remains in short supply.

The table with the normal and 2016 peak harvest dates for apple varieties in east Michigan continues to be included at the end of this report. I encourage apple growers to spend some time in the orchard to evaluate the maturity of your apple varieties to make sure you are on top of apple harvest.

Growers are encouraged to be on the lookout for brown marmorated stink bug insects and damaged fruit as apples are being harvested and graded. Increased trap catch continues to be seen, and this week most growers are seeing limited damage to fruit. 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 and more this week. Blister spot is being seen in Crispin.

Apple maturity in east Michigan for apples harvested Oct. 3

Variety

% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness Lbs. (range)

Starch (range)

Brix %

Empire

30 (30-30)

95 (90-97)

16.0 (14.8-20.5)

3.3 (2.0-5.0)

13.6

Jonagold

40 (40-40)

67 (35-80)

15.9 (14.0-19.5)

5.7 (3.0-7.0)

13.6

 

Golden Delicious

23 (0-30)

15 (1-25)

16.8 (15.9-18.0)

4.3 (1.3-6.2)

13.5

Red Delicious

78 (60-100)

95 (91-97)

16.5 (15.6-18.1)

4.7 (3.6-6.4)

12.0

Northern Spy

73 (40-100)

42 (26-65)

21.9 (19.0-25.2)

2.5 (2.1-3.1)

11.7

Crispin

3 (0-10)

11 (4-20)

18.2 (17.4-19.4)

2.1 (1.7-2.4)

12.0

Idared

53 (30-80)

85 (82-88)

15.8 (15.1-16.9)

1.9 (1.5-2.2)

12.5

CandyCrisp

0 (0-0)

22 (10-40)

16.4 (14.3-19.5)

2.3 (2.0-3.0)

12.0

Fuji

43 (0-70)

71 (40-94)

17.6 (16.2-18.4)

4.3 (2.3-5.6)

13.0

Cameo

20 (20-20)

36 (5-70)

18.2 (16.0-21.0)

3.3 (2.0-7.0)

14.0

Individual variety results

Empire was sampled for the fifth week of apple harvest, and this week's sampling was limited to just a few blocks, as most Empire blocks have been harvested. Also, this week’s data is from blocks that have been picked hard for their first picking, and fruit that was left is less mature, mostly from the insides of the tree. Empire matured very slowly this season, last week it reached is peak maturity and thus most have been harvested. The predicted harvest date for Empire was Sept. 14, however I think that for next season I will be adjusting the normal harvest date for Empire to be just ahead of Golden Delicious.

The percentage of fruit with internal ethylene levels greater than 0.2 parts per million (ppm) has stayed nearly the same over the last three weeks, now at 30 percent. Fruit color finally improved to 95 percent, with fruit pressure still firm at 16.0 pounds. The average starch index remained nearly the same at 3.3. Brix has steadily improved as well, this week being at 13.6 percent.

Empire 2016 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 %

Sept. 5

7 (0-20)

53 (39-62)

21.0 (19.8-22.7)

1.8 (1.6-2.0)

10

Sept. 12

3 (0-10)

76 (62-86)

19.4 (19.1-19.5)

1.8 (1.0-2.4)

10.9

Sept. 19

30 (0-100)

79 (71-85)

17.8 (16.8-19.1)

2.5 (1.8-3.4)

11.6

Sept. 26

33 (0-70)

78 (73-84)

15.7 (14.3-16.7)

3.6 (2.2-5.0)

12.0

Oct. 3

30 (30-30)

95 (90-97)

16.0 (14.8-20.5)

3.3 (2.0-5.0)

13.6

Jonagold was sampled for the fourth week of apple harvest and like Empire, sampling was limited as most blocks of Jonagold were harvested early last week. The predicted harvest date for Jonagold was Sept. 24, and I think that date was very close this season. All Jonagold blocks tested this week are over-mature. Jonagold maturity was ahead of Jonathan and Empire this season.

The percentage of fruit with internal ethylene levels greater than 0.2 ppm is 40 percent, with fruit color improving to 67 percent this week. The pressure is still firm at 15.9 pounds and starch index averaging 5.7.

Jonagold 2016 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 %

Sept. 12

0 (0-0)

23 (16-29)

17.5 (16.7-18.3)

3.9 (1.6-6.1)

11.6

 

Sept. 19

13 (0-40)

56 (38-85)

17.0 (16.1-18.9)

5.1 (2.9-6.3)

13.0

 

Sept. 26

50 (30-70)

59 (32-86)

15.9 (15.4-16.8)

6.2 (4.8-7.2)

13.4

 

Oct. 3

40 (40-40)

67 (35-80)

15.9 (14.0-19.5)

5.7 (3.0-7.0)

13.6

 

Golden Delicious was sampled for the fourth week of apple harvest, with a predicted harvest date of Sept. 30. As with Empire and Jonagold, sampling was more limited this week as many Golden Delicious blocks were spot-picked for color last week, thus the fruit left for me to sample this week is less mature. Golden Delicious matured quickly this season, with the remaining fruit being ready for harvest now.

The percentage of fruit with internal ethylene levels greater than 0.2 ppm moved from 10 percent last week to 23 percent this week, with fruit color or blush remaining the same at 15 percent. The pressure is firm at 16.8 pounds and starch index remained the same at 4.3 this week.

Golden Delicious 2016 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 %

Sept. 12

0 (0-0)

5 (0-10)

18.1 916.4-19.7)

2.8 (1.8-3.8)

11.5

Sept. 19

0 (0-0)

16 (2-36)

18.3 (16.1-19.4)

2.2 (1.0-4.8)

12.7

Sept. 26

10 (0-20)

16 (2-35)

16.5 (15.0-17.2)

4.3 (2.3-6.2)

13.7

Oct. 3

23 (0-30)

15 (1-25)

16.8 (15.9-18.0)

4.3 (1.3-6.2)

13.5

Red Delicious was sampled for the third week of the season. All samples tested are the Redchief strain. The predicted harvest date for Red Delicious was Oct. 1. Most blocks in the south are ready to harvest and in the mid- and northern parts of our region are very close to being ready to harvest. So, this Oct. 1 date was good for the south and a few days later for mid- and northern parts of east Michigan. However, some Red Delicious blocks still eat green.

The percentage of fruit with internal ethylene levels greater than 0.2 ppm rose again from 63 percent last week to 78 percent this week. Color remains good at 95 percent. The pressure remains firm at 16.5 pounds and the starch index rose from 3.0 last week to 4.7 this week, with a few blocks at 6.4.

Red Delicious 2016 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 %

Sept. 19

7 (0-10)

89 (85-95)

17.3 (16.7-17.6)

1.8 (1.7-1.9)

10.4

Sept.26

63 (50-70)

93 (88-98)

16.4 (15.7-17.5)

3.0 (2.0-4.5)

10.8

Oct. 3

78 (60-100)

95 (91-97)

16.5 (15.6-18.1)

4.7 (3.6-6.4)

12.0

Northern Spy was sampled for the third week of apple harvest. They are still immature and eating very green. The percentage of fruit with internal ethylene levels greater than 0.2 ppm rose from 30 percent last week to 73 percent this week. Fruit color improved to 42 percent and pressure remains firm at 21.9 pounds. The starch index is slowly raising, from 1.6 last week to 2.5 this week.

Northern Spy 2016 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 %

Sept. 19

30 (30-30)

13 (5-30)

21.1 (16.0-26.0)

1.2 (1.0-3.0)

11.2

Sept. 26

30 (20-40)

18 (15-21)

18.5 (17.7-19.2)

1.6 (1.5-1.6)

11.0

Oct. 3

73 (40-100)

42 (26-65)

21.9 (19.0-25.2)

2.5 (2.1-3.1)

11.7

Crispin or Mutsu was sampled for the third week of the season. Crispin is still immature and not ready for harvest. Some blister spot symptoms continue to be seen on Crispin. The percentage of fruit with internal ethylene levels greater than 0.2 ppm is still low at 3 percent, with fruit color at 11 percent. The pressure is firm at 18.2 pounds and starch index raising from 1.2 last week to 2.1 this week.

Crispin 2016 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 %

Sept. 19

0 (0-0)

12 (5-20)

19.0 (17.0-22.0)

1.2 (1.0-2.0)

11.8

Sept. 26

0 (0-0)

14 (12-15)

18.4 (18.0-18.7)

1.2 (1.0-1.4)

12.0

Oct. 3

3 (0-10)

11 (4-20)

18.2 (17.4-19.4)

2.1 (1.7-2.4)

12.0

Idared was sampled for the second week of the season. The predicted harvest date for Idared is Oct. 6, or tomorrow. Idared is still very immature, not ready for harvest and maturing well after the predicted harvest date of Oct. 6. The percentage of fruit with internal ethylene levels greater than 0.2 ppm is 53 percent, with fruit color improving to 85 percent. The pressure is 15.8 pounds and starch index at 1.9.

Idared 2016 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 %

Sept. 26

50 (10-90)

68 (60-77)

16.5 (14.8-19.2)

1.8 (1.3-2.3)

12.1

Oct. 3

53 (30-80)

85 (82-88)

15.8 (15.1-16.9)

1.9 (1.5-2.2)

12.5

CandyCrisp was sampled for the second time this apple harvest. CandyCrisp is still immature and not ready for harvest. The percentage of fruit with internal ethylene levels greater than 0.2 ppm is 0 percent or none, with fruit color at 22 percent. The pressure has dropped over 2 pounds to 16.4 pounds and starch index up one point to 2.3.

CandyCrisp 2016 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 %

Sept. 26

11 (11-11)

27 (20-30)

18.5 (15.5-22.0)

1.3 (1.0-2.0)

12.0

Oct. 3

0 (0-0)

22 (10-40)

16.4 (14.3-19.5)

2.3 (2.0-3.0)

12.0

Fuji was sampled for the second time this season. Fuji maturity has moved quickly over the last week, with a few blocks ready to harvest and some still immature and not ready for harvest. Fuji growers should keep an eye on its maturity. The percentage of fruit with internal ethylene levels greater than 0.2 ppm has risen from 0 percent or none last week to 43 percent this week. Fruit color is relatively unchanged at 71 percent. The pressure is firm at 17.6 pounds, dropping a pound over the last week, with starch index averaging 4.3, and some blocks as high as 5.6.

Fuji 2016 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 %

Sept. 26

0 (0-0)

68 (35-90)

18.6 (16.0-21.7)

2.5 (1.0-5.0)

12.3

Oct. 3

43 (0-70)

71 (40-94)

17.6 (16.2-18.4)

4.3 (2.3-5.6)

13.0

Cameo was sampled for the first time this season, mainly to get an early read on its maturity. Cameo is still immature and not ready for harvest, but much closer than I thought it would be. A week from now it should be ready. The percentage of fruit with internal ethylene levels greater than 0.2 ppm is 20 percent, with fruit color at 36 percent. The pressure is firm at 18.2 pounds and starch index at 3.3.

Cameo 2016 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 %

Oct. 3

20 (20-20)

36 (5-70)

18.2 (16.0-21.0)

3.3 (2.0-7.0)

14.0

Predicted apple harvest dates

Each year we publish predicted harvest dates for three varieties for many locations across the state. This year's “Predicted 2016 apple harvest dates” were published July 11. The table below has been expanded to include more apple varieties and it lists only one date for the entire region, which is hard to do. The information in the “Predicted 2016 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 2016 peak harvest dates for apple varieties in east Michigan

Variety

Normal date

2016 predicted date

Paula Red

8/22/16

8/17/16

Gingergold

8/23/16

8/18/16

Gala

9/8/16

9/5/16

McIntosh

9/13/16

9/7/16

Early Fuji

9/14/16

9/10/16

Honeycrisp

9/16/16

9/11/16

Empire

9/20/16

9/14/16

Jonathan

9/23/16

9/24/16

Jonagold

9/23/16

9/24/16

Cortland

9/25/16

9/24/16

Golden Delicious

9/29/16

9/30/16

Red Delicious

10/1/16

10/1/16

Ida Red

10/6/16

10/6/16

Rome

10/11/16

10/11/16

Fuji

10/22/16

10/22/16

Braeburn

10/23/16

10/23/16

Goldrush

10/31/16

10/31/16

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: tritten@msu.edu; Office phone: 810-244-8555; Cell: 810-516-3800; and Fax: 810-341- 1729. Special thanks to the four 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, Westview Orchards in Romeo 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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