MSU Extension

General comments

On the Ridge, we are past the peak of the harvest season with more than 50 percent of the 2014 apple crop harvested. Gala, Honeycrisp and McIntosh harvest is complete except for those with U-pick operations. Jonathans and Goldens have been coming off in the last week. Jonagold harvest is the major variety being worked on this week.

Below is the table of Grand Rapids, Michigan area predicted harvest dates for remaining apple varieties. We are surprised by how late the maturity is compared to these dates for 2014.

Predicted apple harvest dates for Grand Rapids, Michigan

For the Hart/Shelby, Michigan area, growers can expect harvest dates for that area to be behind the Grand Rapids, Michigan area using this guide: along the lakeshore approximately six days behind Grand Rapids, Michigan; areas inland about four days behind.

All the samples we take for these maturity readings are untreated with any harvest management materials (ReTain, Harvista, Ethryl, etc).

Summary of Grand Rapids, Michigan apple maturity samples measured Oct. 7, 2014

Cortland

Cortland made a giant leap forward in maturity this week. Ethylene increased significantly with 70 percent of fruits now over the 0.2 ppm climacteric. Color is about the same as last week (54 percent) to 55 percent this week. Firmness is good at 14.1 pounds this week compared to 15.1 pounds last week. Starch clearing ratings are still quite variable ranging from 3 to 7, but the average is increased from 2.6 to 5.4 this week. Brix are improved from 10.7 last week to 11.4 this week. Cortland are just at the end of the long-term controlled atmosphere (CA) storage window and will move into the mid-term CA window this weekend on the Ridge.

Jonagold

Jonagold started coming off this week in blocks where color is good. There is no reason to hurry to get Jonagold off with only 20 percent of fruits sampled showing ethylene over the 0.2 ppm climacteric and an average of only 0.1 ethylene. Firmness is the same as last week at 14.9 pounds pressure. Starch clearing is 6.1 compared to 5.4 last week. Brix are also the same as the previous week at 11.6. The predicted harvest date for Jonagold was Oct. 2, which is slightly earlier than they seem to be ripening, most likely due to the much reduced ethylene all apples have expressed so far this year.

Golden Delicious

Ethylene production continues to be very low in Goldens with only 20 percent of fruits sampled this week being over 0.2 ppm. Firmness is down slightly this week to 13.5 pounds compared to 14.7 pounds last week. Brix have improved slightly from 12.3 last week to 12.8 this week. Starch clearing ratings were up greatly to an average of 7 this week compared to 4.6 last week. Golden Delicious is in the window right now for long-term CA storage and many are already harvested for the processing markets.

Red Delicious

This is our second week of sampling of Reds. They still show only 20 percent of fruits sampled with ethylene over 0.2 ppm. Color is excellent on Reds this fall. Fruit firmness is still very good at 16 pounds pressure – similar to last week’s 15.8 pounds. Starch clearing is improved at 2.4 this week compared to 1.6 last week. Brix continue to be on the low side at 10.3 which is similar to last week’s 10.6 and not unusual for Red Delicious. Our predicted harvest date for Red Delicious is October 10 and this seems to be a good target for long-term CA storage for your blocks with adequate red color.

Ida Red

The second week of Ida Red samples and they show an improvement in maturity. Last week, no fruits were over the 0.2 ppm of ethylene; this week, 50 percent are over this climacteric. Color is very nice at 67 percent red color, similar to last week’s samples. Firmness continues to be lower than expected at 13.9 pounds this week compared to 14.7 pounds last week. Starch readings have improved from all ones last week to a range of 1 to 3 this week and an average of 1.8. Brix are improved from 10.7 last week to 11.1 this week. The predicted harvest date for Ida Red on the Ridge is Oct. 14. These early maturity indices suggest that date will be accurate for the first long-term CA harvest.

Rome

Rome was not sampled this week. There is bleeding of red color being reported in some Rome blocks. Harvest Rom as time allows.

Fuji (Aztec)

Our regular (late) Fuji this year is the Aztec strain. Ethylene levels have improved compared to last week. There were no fruits over 0.2 ppm ethylene last week and there are 40 percent of fruits over 0.2 ppm this week. Color is pretty good at an average of 73 percent, compared to 75 percent last week. Fruit are still very hard at 16.9 pounds pressure compared to 17.1 pounds last week. The starch readings average 2.8 with a range of 2 to 4 which is a definite improvement from last week’s 1.4 average. Brix are very good for two to three weeks before anticipated harvest at 12.9, up from 12.6 last week. The predicted Fuji harvest date for the Grand Rapids, Michigan area is Oct. 28, so we are likely to see a great improvement in Fuji maturity indices over the next two weeks.

Cameo

There are not many Cameo planted in Michigan and growers tell me they target harvest for about a week after Rome or maybe in the Fuji window or a little later, but they hang and stay hard for a long time, so you can get to them when time permits. Our first sample of Cameo was this week and the numbers indicate they might be ready ahead of Fuji with 30 percent fruits showing ethylene over 0.2 ppm and a starch level averaging 5.7. Color is OK at 57 percent, but needs improvement. Firmness is excellent at 17.6 pounds. Brix levels are good, but not excellent at 11.9.

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.