MSU Extension

General comments

Growers are moving very quickly through harvest this season and it seems that our predicted harvest dates are on target for most cultivars. For all varieties tested by the MSU apple maturity team in 2012, the brix levels are very high, most likely due to the lighter cropload and the very sunny summer weather.

We continue to hear of unexpected fruit drop in all areas of the state. The surprise is Gala, which usually does not exhibit much drop, but is this year. This is most likely due to the unusual 2012 growing season and the fact that much of the Gala fruit was set on 1-year-old wood this season with low to no seed counts.

Southwest Michigan - Bill Shane, Michigan State University Extension

Honeycrisp harvest is mostly done. Tests of Golden Delicious ‘Smoothee’ picked on September 11 at the Southwest Michigan Research and Extension Center showed average firmness of 18 lbs. compared to 19.4 for last week. The target firmness for long-term controlled atmosphere storage for Golden Delicious is 17 lbs. Starch conversion index for this site was 3.0 (mature) compared to 1.2 for last week. Skin color of Golden Delicious was breaking on a few, from uniform green to light green with a hint of yellowish-green. Brix tested at 16.1 compared to 15.2 for last week.

Red Delicious ‘Red Chief’ strain, also from SWMREC on September 11, tested 17 lbs. flesh firmness – about the same as last week – and starch conversion of 4.4 compared to 2.8 for last week and currently with brix of 11.5. Approximately 20 percent of the Red Delicious fruit had moldy core. Target firmness for Red Delicious for long-term controlled atmosphere storage is 18 lbs. The presence of moldy core in the Red Delicious may have pushed maturity earlier. Predicted peak harvest date for 2012 Red Delicious for Berrien County was September 8. 

Southeast Michigan - Bob Tritten, Michigan State University Extension

Apple harvest is moving along quickly this season for the few apple growers with a crop to harvest. Honeycrisp are being harvested for their final pick with quality an issue on many of these remaining fruit. Many are over-mature. Empire and Jonathon have been harvested and growers are working on finishing up Jonagold harvest.

Drop continues to be an issue at many farms. Golden Delicious skin color is beginning to break to a lighter green or even a few yellow. They will be next in line to harvest. Growers are looking at Red Delicious maturity; the predicted harvest date for the region is September 19 for Deerfield, Mich., and September 21 for Romeo, Mich. I am seeing a fair number of Red Delicious with moldy core as was reported in southwest Michigan.

West Central Michigan - Phil Schwallier and Amy Irish-Brown, Michigan State University Extension

Honeycrisp, Gala and McIntosh are harvested now, for the most part. If you still have Honeycrisp to harvest, it’s time to get them off the tree; they are testing out with starch clearing at 8 and very high ethylene levels. Pressure and brix are still good for Honeycrisp, but don’t wait too long to finish them up or they will drop. Non-harvested Galas continue to drop at excessive amounts; for example, in our untreated trees (no Retain or NAA), we had 15 percent fruit drop last week and another 15 percent drop this week. This is very unusual for Gala especially, and is likely due to the weather of 2012 in some way.

Jonathan, Jonagold and Golden Delicious are now entering the harvest window; ethylene levels are low, but changing and firmness is 13 to 17 pounds, which is a little lower than expected. Next week, Red Delicious and Empire should be harvested. Red Delicious samples are starting to show some internal ethylene and the predicted harvest date of late September appears to be accurate for the Ridge.

Fruit brix levels continue to be excellent. Color is good to very good, especially on red strains. Firmness is less than expected on nearly every variety tested. Moldy core is present in Red Delicious.

Northwest Michigan – Nikki Rothwell, Michigan State University Extension

Apples throughout the region have colored up in the past week with the cooler nights. Growers are starting to harvest the different strains of McIntosh. This variety still eats a little green, but we have seen some drop of McIntosh in the past few days and growers are trying to get the fruit off in those blocks. Galas have been improving in size despite the dry conditions, but are still firm and need more color.

Honeycrisp starch indexes are variable, but the fruit eat pretty well at this time. Honeycrisp harvest is anticipated to begin with spot-picking next week. Jonagolds still have time before they are harvested; firmness levels and starch indexes suggest a week and a half to two weeks before harvest. Golden Delicious firmness is lower than expected at this time.

Apple post-harvest laboratory comments – Randy Beaudry, MSU Department of Horticulture

We are noticing some variability with the Red Delicious samples that are coming in from the Ridge/Belding, Mich., area. This is perhaps due to the various maturity levels with individual fruits on the same tree this year.

 Go to the 2012 MSU apple maturity program and reports.