West central Michigan apple maturity report – Aug. 28, 2017

Dave Jones, Michigan State University Extension - August 29, 2017

Early apple harvest is underway. Growers eyeing Gala fields for harvest still have at least a week to wait.

General harvest comments

Harvest of the club variety SweeTango and early cultivars such as Gingergold and Paulared is underway. Growers are starting to eye some early Gala and McIntosh blocks, but the start of harvest is still at least a week away at most sites.

Brown marmorated stink bugs are still very low in the area. Our brown marmorated stink bug traps in west central Michigan did not catch any adults or nymphs in the past seven days.

Significant precipitation fell in the region Sunday and Monday, Aug. 27-28, and more is predicted Tuesday, Aug. 29, and Thursday, Aug. 31. The rainfall will mean that another spray cover will be necessary for many growers.

The normal and estimated 2017 peak harvest dates for apple varieties in Grand Rapids, Michigan, is included at the end of this report. Most growers in west central Michigan can expect to track three to five days behind these dates, depending on site. Data in the following tables are based on samples collected from commercial orchards in Oceana and Mason counties. Firmness and starch ranges are the observed low and high mean values.

Apple maturity for west central Michigan apples harvested Aug. 25
Variety	Firmness lbs. (range)	Starch index (range)	Brix %
Honeycrisp	18.86 (14-22)	1.33 (1-3)	11 (19.5-13.5)
McIntosh	16.81 (13.5-27)	3.3( 1-7)	12.35 (11-14)
Gala	22.14 (18-24)	1.3 (1-4)	11.9 (10.5-14.5)

Individual variety results

Early Fuji was tested for the first time last week. The low starch conversion reading and firmness indicate that early harvest is still at least a few days away. Red color was poor on the sampled fruits, but cool weather may help color up fruits in coming days.

Early Fuji maturity sampling for the harvest season
Sample date	Firmness lbs. (range)	Starch index (range)	Brix %
Aug. 25	18.12 (15.5-25)	2.2 (1-4)	12 (10.5-14.5)

Honeycrisp was sampled for the second time late last week. Target starch index for this variety is 3.5, and the predicted harvest date for the Grand Rapids area is Sept. 15. We expect Honeycrisp in the west central region to track three to five days behind Grand Rapids, depending on site. However, early sites in the region may be in sync with the estimated date for Grand Rapids.

We expect high variability in Honeycrisp during maturity testing, and this week was no exception. Brix, starch index, firmness and color are all highly variable at this time.

Honeycrisp maturity sampling for the harvest season
Sample date	Firmness lbs. (range)	Starch index (range)	Brix %
Aug. 25	18.86 (14-22)	1.33 (1-3)	11 (19.5 - 13.5)

Gala was sampled for the second time this week. It is probably at least a week away from harvest at most sites. Predicted harvest for Grand Rapids is Sept. 5, so we can likely expect to begin picking Galas in the west central region anywhere from Sept. 8 – 10.

Gala maturity sampling for the harvest season
Sample date	Firmness lbs. (range)	Starch index (range)	Brix %
Aug. 25	22.14 (18-24)	1.3 (1-4)	11.9 (10.5-14.5)

McIntosh was also sampled for the second time late last week and is probably at least a week away from harvest. The predicted harvest date for Grand Rapids is Sept. 5. As with Gala, we can likely expect to begin picking McIntosh in west central Michigan anywhere from Sept. 8 – 10. McIntosh that were sampled this week had good red color and displayed very little russeting.

Predicted harvest dates for Grand Rapids
Variety	Normal date	2017 predicted date
Paulared	Aug. 24	Aug. 19
Gingergold	Aug. 26	Aug. 21
Gala	Sept. 10	Sept. 5
McIntosh	Sept. 15	Sept. 5
Honeycrisp	Sept. 18	Sept. 15
Empire	Sept. 26	Sept. 25
Jonathan	Sept. 28	Sept. 27
Jonagold	Sept. 28	Sept. 27
Golden Delicious	Oct. 2	Oct. 1
Red Delicious	Oct. 5	Oct. 4
Idared	Oct. 10	Oct. 9
Rome	Oct. 15	Oct. 14
Fuji	Oct. 25	Oct. 24
Braeburn	Oct. 25	Oct. 24
Goldrush	Nov. 1	Oct. 31

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

This article was published by Michigan State University Extension. For more information, visit https://extension.msu.edu. To have a digest of information delivered straight to your email inbox, visit https://extension.msu.edu/newsletters. To contact an expert in your area, visit https://extension.msu.edu/experts, or call 888-MSUE4MI (888-678-3464).