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Well, as you may expect, the summer drought has left us with fruit maturation that is somewhat different than normal. Starch index values from the eastern part of Massachusetts last week suggested that ripening was pretty much on a normal track. Values for standard McIntosh strains ranged from 1.3 to 1.9, and those from Marshall McIntosh ranged from 1.6 to 3.0. In Belchertown, however, standard strains were about 3.5 and Marshalls were 3.6. Similar values were seen in the Pittsfield area. This week, standard McIntosh in Belchertown are about 4.5, suggesting that harvest should be well underway. Galas have shown a similar variation in ripening, with the eastern part of the state ranging from 1.2 to 2.0 last week, and Belchertown averaging about 4.5. (The Belchertown harvest of Gala also should be underway.)
Drought stress seems also to be having varying effects depending upon cultivar. In Belchertown, some of the new cultivars are as much as two weeks ahead of normal, and others are not nearly as affected.
Retain seems to be holding back ripening well. Most data for McIntosh and Gala suggest that Retain treatments are delaying maturation by about a week.
It is imperative this year to keep a careful eye on maturation. Do not expect that the order of ripening will be normal, and be prepared to harvest some varieties early. The best way to monitor ripening is with the starch-iodine test. It is a simple and reliable method of assessment. Please contact Wes Autio (413-545-2963) if you need more information, charts, or chemicals.
Data for this report were collected by Jim Krupa, Jim Williams, Bob Rondeau, Duane Greene, Rick Bartlett, and Howie Vinton. If you are assessing starch index values in your orchard, it would be very much appreciated if you call those data into Wes Autio (413-545-2963). In your message, please leave your name, the date of sampling, the variety (and strain for McIntosh and Delcious), and whether or not trees received Retain.
Healthy Fruit is written by Dan Cooley, Ron Prokopy, Starker Wright, Wes Autio, and Duane Greene except where other contributors are noted. Edited by Dan Cooley. Publication is funded in part by the UMass Extension Agroecology Program, grower subscriptions, and the University of Massachusetts IPM Program. A text version can be e-mailed to you if you contact Doreen York. Please cite this source if reprinting information.
