Northwest Michigan apple maturity report – September 25, 2013

With good weather in the forecast, apple harvest will be in full swing for most regions of northwest Michigan.

The weather forecast for the week is almost perfect for apple harvest: cool nights and warm days are good for both the fruit and workers. The most striking observation of apple harvest this season is the variability in ripeness among varieties and regions of the northwest. Some blocks of HoneyCrisp in the northern part of the region are ready for harvest compared to the same variety in other orchards much further south. In past seasons, growers typically have a set order for harvest according to variety or block, but this variability has growers hopping from block to block to capture the optimum harvest window for each variety. Overall, quality is looking good and color has really improved in the past week. Labor is a bit on the short side across the region, which is a concern for growers, particularly if they have to move to multiple different blocks in a given time period. Apple harvest will be in full tilt for most farms this week.

Summary of northwest Michigan apple maturity samples taken on Sept. 25, 2013


Color % (range)

Firmness lbs. pressure (range)

Starch (range)

Brix (range)


84 (50 - 100)

19.7 (16.5 – 23)

2.6 (1 - 9)

12.0 (10 – 14)


95 (75 - 100)

16.9 (14 - 23)

3.5 (1 - 6)

12.4 (11 – 15)


71 (25 - 95)

16.0 (12.5 - 19)

4.2 (1 - 6)

12.4 (10.8 – 14)


70 (25 – 100)

18.1 (15 – 23)

2.3 (1 – 8)

13.9 (11.4 – 17)

Golden Delicious

11 (5 – 20)

18.9 (17 – 23)

1.4 (1 – 3)

13.5 (12.2 – 14.5)

Gala. Mature to approaching mature (three samples). Firmness is at 19.7 lbs., holding well. Starch index is at 2.6, up from 2.0 and brix levels are up to 12.0. Color has improved to 84 percent. Galas with a light crop are maturing quicker and coming off faster than blocks with a heavy crop.

McIntosh. Mature to approaching mature (4samples). Firmness is at 16.9 lbs., holding well. Starch index is at 3.5, up from 2.9 and the brix level has increased to 12.4. Color has improved 95 percent. Some Mac harvest has begun in the region, and although the firmness and starch are in the target zone, some fruit still eats fairly green.

HoneyCrisp. Approaching mature (4 samples). Firmness is at 16.0 lbs., down from 16.1 lbs. Starch index is at 4.2, up from 3.6 and the brix level has increased to 12.4. Color has improved to over 70 percent. Background of most apples is still green. Growers on the east side of the Bay are further along with this variety, and HoneyCrisp harvest is underway in this region of NW Michigan. This variety needs multiple pickings over several weeks for premium quality fruit. Watch for the first 2 to 3 apples per tree to color for the first picking.

Jonagold. Approaching mature (3 samples). Firmness is at 18.1 lbs. Starch index is at 2.3, up from 1.6. Brix level is 13.9 and color is 70 percent.

Golden Delicious. Approaching mature (1 sample). Firmness is at 18.9 lbs. Starch index is at 1.4. Brix level is 13.5 and color (blush) is 10 percent. Maturity may vary among blocks as only one sample has been tested.

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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