Northwest Michigan apple maturity report – September 17, 2014

Gingergold harvest continues, and many growers are waiting on McIntosh harvest to begin. Apples are coloring nicely with the cool temperatures.

Cool temperatures have hit the northwest region and apple maturity has slowed, but these conditions have been beneficial for coloring up apples. With the overall cool season, insect pest numbers have been low, and as a result, we have little pest damage to fruit. Diseases have also been hard to find and we have observed very little apple scab in orchards, even in blocks where scab was present in 2013. We have reports of hail damage in isolated apple blocks in the middle of Leelanau County.

We have collected apples from many processing blocks where apple size is smaller than in fresh market blocks, as to be expected. Quality is excellent in all orchards, and with the cool weather, apples are really starting to come into their own. Most varieties we have tested still eat a little green, and we expect we will start picking in earnest close to the predicted harvest dates that were set in the spring. 

Summary of northwest Michigan apple maturity samples taken Sept. 16, 2014

Variety

Color % (range)

Firmness lbs. pressure (range)

Starch (range)

Brix (range)

Gala

63.7 (25 – 95)

22.7 (19.0 – 23.5)

1.0 (1 – 2)

10.8 (10.0 – 12.2)

McIntosh

55.0 (20 – 90)

16.9 (14.5 – 22.0)

2.2 (1 – 4)

11.4 (10.0 – 13.2)

Honeycrisp

47.3 (10 – 80)

16.8 (15.0 – 18.0)

1.5 (1 – 3)

12.1 (10.5 – 13.6)

Spartan

81.5 (65 – 95)

17.8 (15.0 – 22.0)

1.3 (1 – 2)

10.8 (10.0 – 12.0)

Empire

65.0 (40 – 95)

19.3 (16.0 – 22.5)

1.6 (1 – 2)

10.9 (10.0 – 11.6)

Cortland

49.2 (25 – 65)

17.1 (15.0 – 20.0)

2.5 (1 – 4)

11.2 (10.2 – 11.6)

Gala. Immature (three samples). Galas are coloring up and holding firmness. Starch levels and low brix indicate Galas are not yet mature.

McIntosh. Immature, possibly mature for long-term storage (five samples). We are seeing orchard-to-orchard variability in percentage of color on McIntosh. Average firmness is comparable to last week. Starch index levels are also variable and brix levels are similar to last week.

Honeycrisp. Immature (two samples). Percentage of color is increasing in Honeycrisp. Firmness is down slightly compared with last week and starch indexes indicate that these apples are starting to ripen. Average brix levels are also up to 12.1 compared with 11.2 last week.

Spartan, Empire, Cortland. Immature (one sample each).

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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