Southwest Michigan apple maturity report – September 11, 2013

Gala harvests are finishing up and Honeycrisp is being spot-picked in southwest Michigan apple harvesting.

General comments

Recent, warm weather is pushing apple softening, but retarding red blush development. Empires continue to be harvested for processing. Golden Supreme, Honeycrisp and Gala harvest is continuing, with some early Fuji varieties ready for harvest. First tests of Jonagold were taken this week. Dry conditions are retarding development of summer diseases. Marmorated stink bug numbers continue to increase around Stevensville, Mich., but none reported in fruit crops.

Summary of Berrien County apple maturity samples taken Sept. 6-10, 2013.

Variety

Date sampled

Firmness lb. pressure (range)

Starch conversion (range)

Brix (range)

Gala

Sept. 6

19.6 (18.0 – 22.3)

3.7 (2.8 – 4.6)

13.1 (11.7 – 14.6)

Honeycrisp

Sept. 9

15.2 (17-14.7)

6.6 (6-7)

13.7 (13.3 - 14.2)

McIntosh

Sept. 9

15.5 (15-16)

5 (4-6.6)

14.2 (13.5 - 15.4)

Early Fuji

Sept. 10

17.7 (17.0-18.7)

3.9 (3.0-5.2)

13.9 (13.2 - 14.4)

Jonagold

Sept. 10

18.7 (18.0-19.4)

3.3 (1.6-5.8)

13.2 (12.0 - 14.4)

Gala

Gala sampled on Sept. 6 averaged 19.6 pounds, about 1 pound less than the Aug. 30 reading. Pressure readings of 18 pounds are considered to be sufficient for long-term controlled atmosphere storage. Starch removal index readings for Sept. 6 averaged 3.7 (mature = 3), compared to the Aug. 30 reading of 2.3. Brix for Sept. 6 averaged 13.1, up from the previous week’s average of 12.4. Background skin color for Gala ranged 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. Excellent firmness in some sites will allow delay of harvest.

Honeycrisp

Firmness averaged 15.2 pounds, suitable for mid-term controlled atmosphere storage with starch conversion index of 6.6 (mature) and brix of 13.7. Growers are spot-picking Honeycrisp to get the more mature fruit of similar appearance. Predicted peak harvest date for 2013 for mid-Berrien County is Sept. 13.

McIntosh

Firmness averaged 15.5 pounds, suitable for mid-term controlled atmosphere storage with starch conversion index of 5 (almost mature) and brix of 14.2. Red-strain McIntosh such as RubyMac are nearly full-colored. Predicted peak harvest date for 2013 for mid-Berrien County is Sept. 11. Like Honeycrisp, growers are concentrating on picking fruit with good coloration.

Early Fuji

This is the first sampling of this group which includes the varieties Auvil, Rising Sun and September Wonder. Firmness averaged 17.7 pounds, suitable for mid-term controlled atmosphere storage with starch conversion index of 3.9 (mature) and brix of 13.9. Early Fuji selections ripen 30 to 45 days before standard Fuji. Mature readings seen in these samples indicate that some early Fuji types could be harvested where skin color is adequate for the market.

Jonagold (three sites sampled Sept. 9)

Samples represent the most advanced fruit that would be harvested in the first picking. Firmness averaged 18.7 pounds, suitable for long-term controlled atmosphere storage with starch conversion index of 3.3 (almost mature) and brix of 13.2. Blush and background are mostly green. Predicted peak harvest date for 2013 for mid-Berrien County is Sept. 22. Internal ripening – pressure and starch conversion – of this variety appears to be ahead of the predicted date, but growers will need to wait for sufficient color.

Pressure and starch conversion target indices for apple maturity for selected varieties.

Variety

Firmness

Starch

Short CA*

Mid-CA

Long CA

Mature

Over mature

Gala

16

17

18

3

6

Honeycrisp

15

16

17

3.2

7

McIntosh

14

15

16

5

7

Fuji

16

17

18

3

7

Jonagold

15

16

17

3.5

5.5

*CA = controlled atmosphere storage

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.

Related Events

Related Articles

Related Resources