Accel- is a newer material that works as a mild thinner but has the ability to increase fruit size over
and above the thinning response. It is valuable for use on small fruited cultivars like Empire. It is best
applied PF to 8MM and used at the maximum rate which is
30 gms/A. It is best used in combination with other materials for effective thinning. Sevin or Vydate
are our two choices for combination.
Caution Notes:Do not use Accel on any trees treated with NAA or NAD this year, they are not
compatible. Avoid drift on threes that have been treated with either NAA or NAD. Avoid the
combination of Accel plus Sevin on Gala Strains. It appears thaton Gala this combinationis a very
aggressive treatmentand under the right weather conditions (cloudydays following application) can
cause over thinning.
Sevinis a carbamate insecticide that is a standard thinner for apples.Only Sevin XLR-Plus
should be used. It has been reported to be safer on bees and to have less toxicity to mite predators. It
has the same concentration of active ingredient as Sevin 50W and thins the same way. Sevin is a mild
thinner at the full rate 1 quart/acre. It can be used at PF till 20 mm and is best used in combination with
other thinners (NAA or Accel) with most varieties. When used alone it may underthin some cultivars in
NJ. (Do not use Vydate in combination with Sevin.
Vydate L is a carbamate insecticide that works the same way as Sevin. it has had a state label in NJ
since 1996 based on our research trials in North Jersey. It too is a mild thinner like Sevin and should
be used in combination with another thinner for best results (NAA or Accel). At 1-2 pints per 100
gallons it should be applied dilute between PF/5MM and 20MM. Up to two applications can be made
per season. Vydate may be less toxic to mite predators than Sevin and at the 1-2 pint /100 rate has
activity on spotted tentiform leafminers if present and white apple leafhopper at the thinning timing.
Ethephon 2 or Ethrel are both labeled for apple thinning. Manufactured by Microflo and Rhone-
Poulenc respectively, their labels are slightly different. Ethephon is used extensively throughout
Europe to help bring non bearing apples into production as well. This use is on both labels as well.
Refer to page 85 of the 1999 NJ Commercial Tree Fruit Guide for a complete program or refer to the
online edition of the Fruit Guide available through