Southeast Michigan apple maturity report – September 4, 2014

Harvest of summer apple varieties was wrapped up several weeks ago at most farms.

General apple harvest comments

This is the first Southeast Michigan apple harvest report for the season. With the lack of a peach crop in eastern Michigan, growers are very anxious to get started with harvest of the first of the fall apple varieties. Growers are looking to begin harvest of early maturing strains of Gala in the next few days and are looking quickly at both McIntosh and Honeycrisp. Most growers have had plenty of moisture this season, thus fruit size is excellent. Fruit color is generally better than average, but was much better a few weeks ago prior to the heat of the last few weeks.

Overall, there is a wider range of maturity within blocks this season compared to most seasons. This maturity variability exists from tree to tree and in some varieties from branch to branch. This will make harvest challenging. Harvest labor is short at most farms as we begin to ramp up apple harvest.

Apple maturity in southeast Michigan for apples harvested on Sept. 2, 2014


% Fruits with ethylene over 0.2 ppm (range)

Color % (range)

Firmness lbs. (range)

Starch (range)

Brix %


85 (80-90)

74 (54-94)

18.4 (18.1-18.6)

3.3 (2.0-4.6)



5 (0-10)

40 (35-45)

16.3 (15.5-17.0)

3.0 (2.6-3.3)



50 (20-80)

36 (34-37)

16.6 (16.5-16.6)

2.10 (1.5-262)


Individual variety results

Gala were sampled for the first week of the fall harvest season. Growers are looking to begin harvest of early maturing strains for long-term and CA storage in the next few days, however Gala does not eat well yet and growers are delaying harvest for fresh sales and midterm storage. Fruit size is excellent this season; for growers that thinned well, this is the largest fruit size ever. I have not seen any stem end cracking. Color is generally fair to good, averaging 74 percent. The fruit remains firm, averaging 18.4 pounds, but there is a wide range of firmness depending on the strain. The starch index averaged 3.3, which is good for long-term and CA storage harvest. One caveat to add is that some Gala blocks have a great deal of variability of starch readings, ranging from 2 to 7.

McIntosh were sampled for the first week of the season and are still eating green. Most blocks had low percentages of fruit with internal ethylene levels greater than 0.2 ppm. The color is generally poor at this time, averaging 40 percent, and the firmness remains excellent at 16.3 pounds. The starch removal is fine at 3.0; recall that McIntosh need to be closer to 5 to be considered mature, higher than any other variety. McIntosh needs at least a week to 10 days to be mature.

Honeycrisp were sampled for the first week of the season. Honeycrisp always have a wide range of fruit maturity, and this season it is typical. Fruit on the outside of the tree are beginning to color well and eat a little better than fruit on the inside of the tree, which is green as grass. Internal ethylene are averaging, 50 percent of the fruit are greater than 0.2 parts per million (ppm). The color of fruit sampled from the outside of the tree is only 36 percent and fruit are firm, averaging 16.6 pounds. The starch removal averaged 2.1 with a brix of 11.7 percent. In my opinion, it is too early to jump the gun by beginning to even spot-pick Honeycrisp.

Predicted apple harvest dates

Each year Michigan State University Extension publishes predicted harvest dates for three varieties for many locations across the state. This year’s dates can be seen at “Predicted 2014 apple harvest dates,” published July 17. The table below lists the bloom and harvest dates for the Michigan cities Deerfield and Romeo. You can adjust your predicted harvest dates based on your bloom dates. The harvest dates are based on a long established formula using the bloom date and temperatures for 30 days post-bloom. These dates are an estimate, and from the data I generated from this week’s samples, I believe these harvest days are going to be fairly close to the actual dates for a variety nearing maturity. Time will tell more of this story over the next few weeks, so keep a close eye on the weekly apple harvest updates for possible revisions of these dates.

Predicted harvest dates for southeast Michigan

Full bloom date

Predicted harvest dates






















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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