West central Michigan apple maturity report – Sept. 13, 2017

Gala and McIntosh are ready to go, harvest is complete or ongoing. Early Honeycrisp are being picked now and will dominate the picking in the next several days at many sites.

General harvest comments

Harvest of Gala and McIntosh blocks is now in full swing. Growers are also starting to get through a first pick of Honeycrisp at early sites. In spite of some heavy rain late last week, the quality of the crop continues to look outstanding, although it is picking out on the light side in many locations. Generally, growers who had frost protection during the May 8 frost events are looking at nearly a full crop, while growers without frost protection are looking at some level of reduction. Deciding to pick based on appearance of fruit continues to be tricky right now because color is so good. Many blocks are full of bright red fruit that still have at least a few more days to go before full maturity.

Brown marmorated stink bugs are still very low in the area, though they have been detected in small numbers elsewhere in the state. Our brown marmorated stink bug traps in west central Michigan did not catch any adults or nymphs in the past seven days. Apple maggot catches continue, but are low. Second generation of codling moth is over, and trap counts have dropped down to zero in most blocks. While certain hot spots may still see some adults, numbers are down and damage is generally very low this season. We are not expecting a third generation. We are past peak egg hatch for the last generation of oriental fruit moth for the season. If you catch more than 50 adults in an apple block, a spray is warranted to protect fruits.

The normal and estimated 2017 peak harvest dates for apple varieties in Grand Rapids, Michigan is included at the end of this report. While we have historically assumed that we lag behind the Ridge in the west central region, this does not seem to be so much the case this season in many areas. Gala and McIntosh are either right with or only just behind Ridge harvest maturity measurements. Generally, growers in the Elbridge, Hart, and Shelby areas are tracking consistently with Ridge harvest predictions, while growers near the lake in the Clay Banks and Ludington area are generally about 3-5 days behind. 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.

Individual variety results

Early Fuji was tested for the third time this week. The long-term storage starch index recommendation for this cultivars is 3, and fruits this week again tested just over that mark. Harvest began in a couple of places last week, but more will be picked as this week continues.

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)

Sept. 6

15.25 (11-18.5)

3.2 (1-6)

12.25 (11-14)

Sept. 13

14.98 (11-15.5)

3.2 (2-7)

12.42 (11-13)

Honeycrisp was sampled for the fourth time this week. Target starch index for this variety is 3.5, and the predicted harvest for the Grand Rapids, Michigan, area is Sept. 15. Starch index averages for the west central region are now consistently around the 3.5 mark, so Honeycrisp can be considered mature at many sites in west central Michigan. However, this is still the early side of the season and you do not need to be in a rush to get through just yet. Many sites in Mason County and the Clay-Banks area are still several days off. The Sept. 15 harvest date prediction for Grand Rapids is proving to be a little bit later than what we are actually seeing in the field at a lot of sites this season, here and on the Ridge.

Honeycrisp maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch index (range)

Brix % (range)

Aug. 25

18.86 (14-22)

1.33 (1-3)

11 (19.5 - 13.5)

Sept. 6

16.15 (11.5-19.5)

2.71 (1-6)

11.7 (10-15)

Sept. 13

14.85 (11-19)

3.5 (2-6)

12.06 (9-14)

Gala was sampled for the fourth time this week. Gala is now past the 3.0 starch index mark for long-term storage, and is ready to be picked at most sites. Color on Gala is excellent this year and blocks are yielding well thus far. Gala is one of the cultivars that had good fruit set in many sites in spite of the spring frost events.

Gala maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch index (range)

Brix % (range)

Aug. 25

22.14 (18-24)

1.3 (1-4)

11.5 (10.5-14.5)

Sept. 6

19.612 (16-24.5)

2.49 (1-6)

11.74 (10-13.5)

Sept. 13

18.79 (15.5-23.5)

3.13 (1-6)

12.60 (10-15)

McIntosh was also sampled for the fourth time late this week and is now mature. Harvest is complete or ongoing in most orchards. Color and size are good this year.

McIntosh maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch index (range)

Brix % (range)

Sept. 6

14.9 (12.5-18.5)

3.7 (1-5)

12.55 (11.5-14.5)

Sept. 13

14.80 (11-17)

4 (1-5)

12.87 (11-14.5)

Jonagold was sampled for the second time this week. The target starch index rating for long-term controlled atmosphere (CA) storage is 3.5, so the regional averages indicate we are there. However, Jonagold maturity is very site-dependent right now. Generally, growers in Mason County and the Clay-Banks Township region of Oceana County are one to two weeks away. Color on Jonagold is outstanding this year, but excessive size is an issue in some blocks that are bearing a light crop due to loss from the spring frosts.

Jonagold maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch index (range)

Brix % (range)

Sept. 6

18.51 (16.5-20)

2.83 (1-4)

11.81 (9.5-14)

Sept. 13

17.93 (15.5-19.5)

3.7 (2-4)

12.08 (11-15)

Jonathan was also tested for the second time this week. The starch index target for long-term CA storage is 3.5, and fruit this week all tested well below that mark. Color on Jonathan is outstanding, but some red bleeding into the cortex was observed this week on the redder strains.

Jonathan maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch index (range)

Brix % (range)

Sept. 6

17.55 (15.5-20)

3 (3)

11.34 (10.5-12.5)

Sept. 13

17.89 (16-22)

2.85 (2-3)

13.04 (11.5-15)

Empire was sampled for the second time this week. Size has much improved, though color is still lacking. Fruit still have at least a week or two to go before they reach the target starch index of 3.5.

Empire maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch index (range)

Brix % (range)

Sept. 6

18.25

2.2

10.39

Sept. 13

18.49 (14-23.5)

2.6 (1-3)

11.93 (10.5-13)

Golden Delicious was sampled for the first time this week. Red blushing is proving to be an issue on Golden Delicious this season. Weather for coloring is so good that most Golden Delicious have at least 5-10 percent red blush. Early harvest is a couple of weeks away.

Golden Delicious maturity sampling for the harvest season

Sample date

Firmness lbs. (range)

Starch index (range)

Brix % (range)

Sept. 13

18.07 (15.521.5)

2.4 (2-4)

11.9 (10-13)

 

Predicted harvest dates for Grand Rapids, MI

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.

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