MSU Extension

General comments

In the Grand Rapids, Michigan, area, harvest is in full swing for mid-season apple varieties – Gala, Honeycrisp and Macs are being worked on now. The weather has been very conducive for harvest with dry, sunny days. Temperatures are a little too high for good apple color development, but it is coming on slowly. Comments heard in the last week from growers and industry representatives include:

• Picking out a bit longer than expected.
• Adequate labor supply.
• Mixed maturity issues, especially on gala.
• Bruising issues from two weeks ago are lessening.
• Wishing the weather would cool off a bit for better color.
• Can’t remember seeing so much bitter pit in Honeycrisp before.

There is variability from site to site with some testing showing fruits ready for long term CA storage four days ahead of our predicted dates. Growers should be doing in-field maturity testing earlier and more often this season so as not to miss something. If you need guidance on how to do in-field maturity testing, please don’t hesitate to ask.

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

Many operations are undergoing the various audit inspections right now. This is a reminder to all who might be visiting orchards that you need to be especially mindful of these audits and sign in as appropriate before your visit.

Gala are being harvested as time allows. Our maturity testing indicates that fruits are quickly moving through the maturity spectrum for this variety. The very hot weather a few weeks ago probably sped Gala up and the hot weather predicted for the next week could lead to higher incidence of fruit waxiness. Shoulder cracking continues to be reported and in some cases it is quite severe.

McIntosh continue to be harvested on the Ridge where color is good. Ethylene continues to be much lower than expected for McIntosh, but they have made a definite movement upwards with this week’s samples. Pressure readings are still very good for McIntosh. The crop is not overly heavy, and there seems to be low incidence of fruit pushing themselves off this year. Fruit drop is lower than usual, but warm weather and higher ethylene levels could enhance the incidence of drop, so macs need to be picked where not treated with stop drop materials.

Most Honeycrisp blocks have had at least one picking, but some are still untouched. Firmness readings continue to be quite variable, but are still very good at 17.9 pounds pressure. Starch readings have really changed from 3.9 last week to 6.8 this week. Continue to watch Honeycrisp blocks closely for maturity and harvest on time.

This is our third week of sampling Empire on the Ridge. All maturity indices indicate fruits are now in the window for long-term storage. The predicted date for Empire was September 18 and some are beginning to be harvested when time allows. Ethylene levels continue to be on the low side for Empire, with only a few fruits over the 0.2 ppm climacteric.

This is our third week of sampling Jonagold on the Ridge. Our predicted harvest date for Empire is Sept. 29, and now, with three weeks of data, we feel this date is about 4 days too late for any fruits destined for long-term storage. Keep a close eye on Jonagolds as they could quickly move out of condition this year.

This is our second week of sampling Jonathan (RubyJon) on the Ridge. Our predicted harvest date for Jonathan is Sept. 29, and just like Jonagold, this might be a bit on the late side for harvest for optimum, long-term CA storage. Firmness is excellent, but we were surprised by the starch clearing of 3.6 already for Jonathan. Brix levels are pretty good at 12.3 for this early in the season. There is some slight bleeding in the very red strains, but not a concern yet.

This is our first week of sampling Cortland (RedCort). All maturity indices indicate fruit is still immature. This is not a common variety and most harvest them in late September when time allows.

This is our first week of sampling Golden Delicious and they read immature. The predicted harvest date for Goldens is Oct. 3.

Red Delicious were sampled for the first time this week. All maturity tests indicate immaturity for Reds. The predicted harvest date is Oct. 5 for the Ridge.

This is our first week of sampling Ida Red. The predicted harvest date for Ida Red is Oct. 10. Even though the ethylene readings might seem high, this is very typical for Ida Red - for some reason, it always expresses ethylene at higher levels than other varieties.

We added Nova Spy to our sampling this week. Fruits are showing quite high ethylene levels, but low starch levels. The brix are excellent for spies.