Grand Rapids area apple maturity report – September 5, 2013

Gala and Macs are close with Honeycrisp coming soon.

General comments

In the Grand Rapids, Mich., area, apple maturity seems to be running just about right in line with Michigan State University Extension’s predicted harvest dates. Some warm or sandy sites have been slightly ahead of our dates by a day or two. Paula Red and Gingergold harvest was completed on the Ridge last week with good quality reported. Fruit color, flavor and finish have been outstanding so far this season. There is some general variability in maturity being seen and it’s a bit strange – tree-to-tree differences in maturity and even some limbs on trees with noticeable differences.

Gala will be the next major variety for harvest for long-term CA storage in the Grand Rapids, Mich., area. Macs and Honeycrisp are seven to 10 days away from major harvest. For the Hart/Shelby, Mich., area, growers can expect harvest dates for that area to be behind around Grand Rapids, Mich., using this guide: along the lakeshore approximately six days behind Grand Rapids; areas inland about four days behind.

This is the first Grand Rapids Area Apple Harvest Report for the season. Statewide reports will be available on the Michigan State University Extension Apple maturity program and reports page every week.

Summary of Grand Rapids apple maturity samples taken September 3, 2013.


Avg. Ethylene (ppm)

% Fruits with Ethylene over 0.2 ppm

Color % (range)

Firmness lbs pressure (range)

Starch (range)

Brix (range)




90% (75 - 95%)

20.6 (18 - 23.2)

2.5 (1 - 5)

10.9 (10 - 11.5)

Ruby Mac



70% (60 - 85%)

16.9 (14.8 - 18.6)

2.7 (2 -3)

12.4 (11.5 - 13.5)




22% (5 - 40)

16.7 (14.5 - 19)

1.8 (1 - 3)

9.6 (9 - 10)


Color is good on most Gala strains this year, but size could use a little improvement. Gala have moved towards maturity from early sampling last week and growers should watch their individual blocks very carefully. Our predicted harvest date for Gala was Sept. 10 and some sites might be slightly ahead of that date this year. Some earlier strains of Gala should be at the stage for long-term CA storage very soon, with the majority of strains in that window early next week. Blondee maturity is similar to Buckeye Gala and both are expected to be at optimum long-term CA condition by the middle or late next week.


They are not quite there yet in the general Grand Rapids, Mich., area, although some eat pretty well. Ethylene is lower than expected with no fruits being over 0.2 ppm. Pressure readings are indicating excellent firmness at an average of nearly 17 pounds of pressure. Color is excellent of course on Ruby Mac and very good in other Mac strains and improving every day. Brix reading is pretty good at 12.4, but is expected to improve in the next few days. Harvest for long-term storage of Macs can begin at any time color is right, with the majority of harvest coming in seven to 10 days. Be watchful in blocks with a heavy fruits set as drop could occur from fruits pushing themselves off. Macs appear to be one to two days ahead of Honeycrisp.


Honeycrisp are moving toward maturity, but still immature overall. There are some fruits that appear ready and eat well, but the majority of Honeycrisp are not physiologically ready for harvest in the Grand Rapids, Mich., area; being economically ready is a different story, with a bitter ending if done too soon. Firmness readings are excellent at 16.7 pounds pressure on average, indicating immaturity. Starch readings are very low and also indicate immaturity. Brix level is very low at 9.6. Initial first picking of Honeycrisp for fresh sales is recommended seven to 10 days from now around Grand Rapids, Mich.

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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