2001 Healthy Fruit is written by Jon Clements, Ron Prokopy, Dan Cooley, Arthur Tuttle, Gerald Lafleur, Wes Autio, Bill Coli, Duane Greene, Bill Bramlage, and Sarah Weis and is presented with the cooperation of New England Fruit Consultants and Polaris Orchard Management. 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 . Ethephon controls growth by releasing the naturally occurring plant hormone, ethylene.
Ethylene has many side effects on tree growth too, so use it judiciously.
One month after application check your re-growth, and if more control is needed, a second application at 1 pint per 100 gallons is recommended. We have encouraged growers to started thinning early with a petal-fall spray. In blocks where bee activity was good and there is no visible frost injury, we still feel that this is a good approach that should be initiated now. In these orchards, it is appropriate to assess the extent of injury thoroughly before deciding on any thinning action. Many flowers should be cut to look for black or brown centers in the receptacle tissue.