Northwest Michigan apple maturity report – October 9, 2013

With the predicted dry and seasonable weather in the forecast, apple harvest is in full swing in northwest Michigan.

Apple harvest continues in northwest Michigan after a lull in picking with the past few days of wet conditions. At the Northwest Michigan Horticultural Research Center (NWMHRC), we received 2.8 inches of rain, but some growers reported substantially more rain at area farms. The rain really slowed harvest this past week and the predicted forecast of warm and seasonable conditions will be welcomed following the soggy weekend. Growers are finishing up Honeycrisp and moving to Jonagold and some are starting to move to Goldens and Reds for long-term storage. Some farms are light on labor and some pickers are new to apples, which has slowed the 2013 harvest.

Summary of northwest Michigan apple maturity samples taken Oct. 8, 2013


Color % (range)

Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Red Delicious

100 (100)

17.2 (15 - 21)

3.3 (2 - 7)

12.9 (12 – 14.2)


86 (70 – 100)

15.8 (13 – 19)

6.2 (2 – 9)

14.7 (12.6 – 16.2)

Golden Delicious

28 (5 – 50)

18.2 (15.5 – 20.5)

3.8 (2 – 7)

15.5 (14.6 – 16.6)

Ida Red

87 (60 – 100)

17.3 (15 – 23)

4.0 (3 – 7)

13.8 (12 – 16.8)

Honeycrisp. Mature (no samples). Many Honeycrisp blocks have been harvested while some growers are on their third picking. Overall, this variety looked very good this season. Some bitter pit has been seen in orchards with light crops, but growers have been pleased with color and yield.

Jonagold. Mature mid-term CA (three samples). Firmness is at 15.8 pounds, down from 16.6 pounds. Starch index is at 6.2, up from 4.2. Brix level is 14.7 and color is 86 percent, both up from last week. Color has really advanced and apples are starting to eat better this week.

Golden Delicious. Mature long-term CA (two samples). Firmness is at 18.2 pounds this week. Starch index is at 3.8, up from 1.6. Brix level is 15.5 and color (blush) is at 28 percent.

Red Delicious. Mature long-term CA (two samples). Firmness is at 17.2 pounds with the starch index at 3.3. Brix level is at 12.9 and the color is at 100 percent.

Ida Red. Mature long-term CA (two samples). Firmness is at 17.3 pounds, down from 17.8 pounds. Starch index is at 4.0 up from 2.7. Brix level is at 13.8 and the color is at 87 percent.

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.

Dr. Rothwell’s work is funded in part by MSU’s AgBioResearch.

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