West central Michigan apple maturity report – September 16, 2015

Apple maturity sampling is showing many varieties moving quickly to maturity.

General comments

In the Grand Rapids, Michigan, area, mid-season apple varieties are continuing the trend to be running in line with or even slightly ahead of our predicted harvest dates. There is variability from site to site with some testing showing fruits ready for long-term CA storage four days ahead of our predicted dates. Growers should be doing in-field maturity testing earlier and more often this season so as not to miss something. If you need guidance on how to do in-field maturity testing, please don’t hesitate to ask.

Fruit size has been excellent so far this season. Fruit color is good and becoming much better every day. The Ridge is well into Gala harvest. First picking of Honeycrisp is now taking place. It appears that this is a very low ethylene production year – our internal ethylene readings continue to be much lower than average for all varieties samples so far.

For the Hart/Shelby, Michigan, area, growers can expect harvest dates for that area to be behind the Grand Rapids area using this guide: along the lakeshore approximately six days behind Grand Rapids; areas inland about four days behind.

Many operations are undergoing the various audit inspections right now. This is a reminder to all who might be visiting orchards that you need to be especially mindful of these audits and sign in as appropriate before your visit.

We continue to see a higher incidence of water core in early harvested apples so far this season. Given the high amounts of rain that some areas have received in the last four weeks, you should be paying close attention to water core in varieties that are highly susceptible to it this season and harvest accordingly. Special preconditioning treatment prior to storage may be warranted for some lots of fruit with high water core potential.

Hopefully early harvested varieties are not an indication of things to come, but we are seeing higher levels of bruising in some lots than usual. It could be due to the higher amount of rainfall we’ve had recently. Even the most carefully picked fruit might show bruising from just bumping other fruits in the picking bag.

Very high levels of bitter pit are being noticed in Honeycrisp in particular. There doesn’t seem to be a correlation with cropload as is commonly the issue. Again, this is most likely due to the extremes in rainfall as it does seem to be less prominent in irrigated blocks.

Individual variety results

Many Gala are not being harvested and our maturity testing indicates that fruits are quickly moving through the maturity spectrum for this variety. The very hot weather a few weeks ago probably sped Gala up. Shoulder cracking is now being reported and in some cases it is quite severe. We continue to see a slight lesser effect from ReTain in Gala than is typical, so be sure to check your fruits often to harvest at the best timing.

Gala 2015 maturity sampling records

Date of Sample

Avg. ethylene (ppm)

% Fruits with ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Firmness lbs pressure (range)

Starch (range)

Brix (range)

Aug. 24

0.0694

5

80 (50-95)

2.25 (1-5)

22.4 (18.9-26.4)

2.75 (1-7)

10.3 (9-11)

Aug. 31

0.26

30

91 (70-100)

1 (1-2)

16.7 (12.5-18.5)

2 (1-4)

10 (9-11)

Sept. 8

1.364

87

69 (40-85)

3.7 (1-7)

18.9 (10.8-24.3)

3.7 (1-7)

11.8 (10.2-14.5)

Sept. 15

1.737

95

89 (75-95)

1.5 (1-3)

18.7 (14-23.3)

5.5 (1-8)

12.5 (11.5-14)

McIntosh are now being harvested on the Ridge where color is good. The crop is not overly heavy, and there seems to be low incidence of fruit pushing themselves off this year. Ethylene continues to be much lower than expected for McIntosh, but they are changing ever so slightly from week to week. Pressure readings are still very good for McIntosh.

McIntosh 2015 maturity sampling records

Date of sample

Avg. ethylene (ppm)

% Fruits with ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Firmness lbs pressure (range)

Starch (range)

Brix (range)

Aug. 24

0

0

78 (60-95)

2.9 (1-5)

18.5 (15.8-24.2)

2.4 (1-4)

11.5 (10-13)

Aug. 31

0.0084

0

90 (70-98)

1.5 (1-3)

13.7 (11.5-15.5)

3.4 (3-4)

10.9 (10.5-11)

Sept. 8

0.0064

0

84 (70-100)

3.4 (3-4)

17.5 (14-25.3)

4.4 (4-6)

12.2 (12-13)

Sept.15

0.0294

0

90 (70-100)

4

15.2 (13.5-18)

6

12.4 (12-13)

Honeycrisp sampled made another definite leap forward in maturity – particularly in starch clearing and brix levels. Most sites on the Ridge have now begun their first pick for Honeycrisp. Firmness readings are varied, but still very good at 16.7 pounds pressure. Starch readings moved forward from 1.9 last week to 3.9 this week. Brix level has improved from 11.4 to 12. 3 this week and they eat much better. Getting color continues to be a struggle this season for Honeycrisp. Bitter pit is a major problem this season in Honeycrisp with some blocks having as much as 30 percent fruits with bitter pit already. Ideally, you want to harvest your Honeycrisp as soon as you can get the red color, but before the bitter pit shows – if you see it in the orchard, it will only get worse in storage.

Honeycrisp 2015 maturity sampling records

Date of sample

Avg. ethylene (ppm)

% Fruits with ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Firmness lbs pressure (range)

Starch (range)

Brix (range)

Aug. 24

0.0472

0

30 (5-80)

4.4 (2-5)

21.3 (18-27.1)

1(1-1)

11.1 (10.2-12)

Aug. 31

0.1425

20

67 (40-80)

1.5 (1-3)

17.7 (15.5-22.5)

1(1-1)

11.7(11-12)

Sept. 8

0.2464

70

32 (10-45)

2.6 (2-3)

17.7 (14.3-22.1)

1.9(1-4)

11.4 (10.9-12)

Sept.15

3.0168

100

53.3 (20-90)

2.4 (1-4)

16.7 (13.5-19.8)

3.9(1-7)

12.3(11-13)

This is our first week of sampling September Wonder, an early Fuji strain – we should have sampled it last week. All maturity indices indicate fruit is in the range for harvest. Early Fuji are expected to move quickly to a level of over-mature, so get to them as soon as you can.

Early Fuji 2015 maturity sampling records

Date of sample

Avg. ethylene (ppm)

% Fruits with ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Firmness lbs pressure (range)

Starch (range)

Brix (range)

Sept. 15

0.348

40

51 (35-70)

2 (1-3)

15.9 (13-17.5)

5.1 (3-6)

12.1(11.5-14)

This is our second week of sampling Empire on the Ridge. All maturity indices indicate immaturity, but there is steady forward movement and the Sept. 18 predicted harvest date for Empire will be a good target for long-term storage. Ethylene levels are very low for Empire – similar to what we are seeing with other varieties this season.

Empire 2015 maturity sampling records

Date of sample

Avg. ethylene (ppm)

% Fruits with ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Firmness lbs pressure (range)

Starch (range)

Brix (range)

Sept. 8

0.0278

0

45 (15-75)

2.8 (1-4)

19.2 (16.3-23.5)

1.5 (1-3)

10.1 (9.2-11)

Sept.15

0.0553

1

66(30-98)

2.8 (2-4)

18.6 (14.9-22)

2.4 (1-4)

11.2 (10-12.5)

This is our second week of sampling Jonagold on the Ridge. Our predicted harvest date for Empire is Sept. 29, and now, with two weeks of data, it is starting to look like this date might be a bit late. All maturity numbers indicate immaturity, but starch clearing on untreated fruits made a rather giant leap forward this week compared to last. Keep a close eye on Jonagolds as they could quickly move out of condition this year.

Jonagold 2015 maturity sampling records

Date of sample

Avg. ethylene (ppm)

% Fruits with ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Firmness lbs pressure (range)

Starch (range)

Brix (range)

Sept. 8

0.03

0

22 (5-45)

3.7 (3-4)

18.4 (14.8-21.2)

1.3 (1-2)

11.7 (11.1-12.4)

Sept.15

0.046

0

53 (30-80)

2.8 (2-3)

18.6 (15-21.6)

3.2 (1-7)

12.5 (11.5-14)

This is our first week of sampling Jonathan on the Ridge. Our predicted harvest date for Jonathan is Sept. 29, and just like Jonagold, this might be a bit on the late side for harvest for optimum, long-term CA storage. Firmness is excellent, but we were surprised by the starch clearing of 3.6 already for Jonathan. Brix levels are pretty good at 12.3 for this early in the season. There is some slight bleeding in the very red strains, but not a concern yet.

Jonathan 2015 maturity sampling records

Date of sample

Avg. ethylene (ppm)

% Fruits with ethylene over 0.2 ppm

Red color % (range)

Background color (range)

Firmness lbs pressure (range)

Starch (range)

Brix (range)

Sept. 15

0.167

27%

86 (70-100)

2.5 (1-4)

17.5 (14-21.9)

3.6 (1-7)

12.3 (11-14)

 

Normal and 2015 peak harvest dates for varieties for the Grand Rapids area

Variety

Normal date

2015 predicted date

Gala

9/10/15

9/6/15

McIntosh

9/15/15

9/11/15

Honeycrisp

9/18/15

9/14/15

Empire

9/22/15

9/18/15

Jonathan

9/28/15

9/29/15

Jonagold

9/28/15

9/29/15

Golden Delicious

10/2/15

10/3/15

Red Delicious

10/5/15

10/5/15

Idared

10/10/15

10/10/15

Rome

10/15/15

10/15/15

Fuji

10/25/15

10/25/15

Braeburn

10/25/15

10/25/15

Goldrush

11/1/15

11/1/15

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

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