Southwest Michigan apple maturity report – September 5, 2013

The MSU apple maturity program for southwest Michigan is showing Gala, Honeycrisp and McIntosh harvests are coming up soon.

This is the first of weekly apple maturity report from for southwest Michigan from now until mid-October. The samples for these reports are collected primarily in Berrien and Van Buren counties – the maturity is only a broad indication of trends for this area. Contact Bill Shane at the Southwest Michigan Research and Extension Center (SWMREC) 269-944-1477 ext. 205, or 269-208-1652 if you would like to have samples from your farm tested for maturity. Statewide reports will be available on the Michigan State University Extension Apple maturity program and reports page by Wednesday afternoon each week.

General comments

The 2013 apple crop is moderate to heavy, depending on local effects of spring frosts and success in thinning. Hot weather is maturing some apples earlier than expected as predicted by the Michigan apple maturity predicted harvest dates. Well-exposed fruit, light-colored varieties are expected to show sunburn and lenticel disorders due to recent hot and sunny days. The south end of the southwest region is behind in rainfall. Small number of nymphs of marmorated stink bug has been reported so far this season.

Gala – (five sample sites from Watervliet to Eau Claire area)

Gala sampled on Aug. 30 are testing very firm in the 20.1 to 21.5 pound range, average 20.5 pounds. Starch removal index readings range from 1.4 to 2.8 with an average of 2.3. Brix ranges from 11.1 to 13.4 with average brix of 12.4. A small number of individual fruit had starch conversion tests above 4, usually fruit well-exposed to direct sunlight and perhaps affected by sunburn.

A wide range of red skin coloring is being seen in the area depending on the strain of Gala grown, site and crop load. Background skin color for Gala also differs significantly from site to site, ranging from slight green to cream white.

The general predicted Gala harvest date for southwest Michigan for 2013 is Sept. 6. The long-term normal harvest date for Gala in Berrien County is Sept. 8. Gala have a wide range of starch conversion this year, with some orchards having significant number of fruit testing mature for starch conversion.

Gala maturity summary for Berrien County, August 30, 2013

Site

Firmness (lbs.)

Starch conversion

Brix

1

20.6

2.8

13.2

2

20.1

2.4

11.1

3

20.1

1.4

11.3

4

21.5

2.2

13.4

5

20.3

2.8

13.1

Average

20.52

2.32

12.42

Honeycrisp – (three sites sampled Sept. 4)

Samples represent the most advanced fruit that would be harvested in the first picking. Firmness averaged 15.8 pounds (suitable for mid-term controlled atmosphere storage) with starch conversion index of 4.3 (mature), and brix of 12.9. Some Honeycrisp can be spot-picked by color, according to these tests. Predicted peak harvest date for 2013 for mid-Berrien County is Sept. 13.

Honeycrisp maturity summary for Berrien County, Sept 4. 2013.

Site

Firmness (lbs.)

Starch conversion

Brix

1

16.8

5.6

13.8

2

15.2

4.4

12.9

3

15.5

3.0

12.1

Average

15.8

4.3

12.9

McIntosh – (three sites sampled Sept. 4)

Samples represent the most advanced fruit that would be harvested in the first picking. Firmness averaged 15.6 pounds (suitable for mid-term controlled atmosphere storage) with starch conversion index of 4.3 (almost mature), and brix of 13.1. Red strain McIntosh such as Rubymac are nearly full colored. Predicted peak harvest date for 2013 for mid Berrien County is Sept. 11.

McIntosh maturity summary for Berrien County, Sept 4. 2013.

Site

Firmness (lbs.)

Starch conversion

Brix

1

15.8

5.7

12.8

2

15.8

3.4

13.3

3

15.2

4.0

13.3

Average

15.6

4.3

13.1


Pressure and starch conversion index for apple maturity for controlled atmosphere storage.

Variety

Firmness

Starch

Starch

% Clearing of Flesh

% Clearing of Core

Short CA

Mid CA

Long CA

Mature

Over M.

Mature

Mature

Gala

16

17

18

3

6

0

100

Honeycrisp

15

16

17

3.2

7

5?

80

McIntosh

14

15

16

5

7

40

100

The Southwest Michigan Apple Maturity Report is produced by: Bill Shane, MSU district Extension educator for fruit and marketing, Benton Harbor, 269-944-1477 ext. 205, fax 269-944-310; Diane Brown, Berrien County Extension educator, Benton Harbor, 269-944-4126; and Mark Longstroth, district Extension educator for fruit and marketing, Paw Paw.

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

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