Southeast Michigan apple maturity report – September 30, 2015

by Bob Tritten, Michigan State University

This is a delicious bit of applied science:

With good weather over the last two weeks, most growers report they are at the midpoint of apple harvest. Growers have finished up Jonathan and Cortland harvest and have moved on to Jonagold, Empire and early maturing Golden Delicious blocks. Northern Spy and some early maturing Red Delicious blocks are mature at some farms as well.


This week, 10 apple varieties were sampled and tested for maturity. Fuji, CandyCrisp, Cameo and Crispen were added to the sampling this week to get an early read on their maturity. I did not sample Cortland or Jonathan this week as both are mature. Harvest dates for most varieties are running a few days ahead of the predicted harvest dates.


Fruit firmness or pressure has maintained about the same over the past week, and brix has improved in most varieties. Fruit size remains good this season, with the possible exception of some Red Delicious blocks that were not thinned well. Bitter pit is a problem in many Jonagold blocks and blister spot is being found in many Crispen blocks. Woolly apple aphid populations are very high in many apple blocks.


I continue to get reports about how easily fruit is bruising this season. It is mostly showing up a few days after harvest when fruit has been in storage. This bruising is most likely the result of the abundant rains that most growers have had over the past few months.


The East Michigan Apple Harvest Report is produced by Bob Tritten, district fruit educator, Flint, MI, email This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it., office phone 810-244-8555, cell 810-516-3800 and fax 810-341-1729. Special thanks to four orchards that allow me to harvest fruit for analysis from their farm every Monday during the apple harvest season, these farms include: Spicer Orchards in Hartland, Erwin Orchards in South Lyon, Westview Orchards in Romeo and Hy’s Cider Mill in Romeo. Thanks to so many other orchardists that I collect fruit samples from their farms to include their varieties on more of a random basis. Lastly, thanks to the Post-Harvest Lab in the Department of Horticulture at Michigan State University that provides the quick and very accurate analysis of so many apple samples in the fall. Dr. Randy Beaudry and his students do a fantastic job and are a valuable part of our Apple Maturity Team.