ReTain® (Valent USA) - For increasing fruit set of apple, cherry, European pear. APPLE: Apply one pouch of ReTain per acre, as a single application from pink stage to full bloom. Applications made prior to pink stage or after full bloom will significantly reduce efficacy of the treatment. Do not apply after petal fall. CHERRY: Apply one to two pouches of ReTain per acre during bloom. Retain may be applied as a single application of up to two pouches, or as sequential applications of one pouch per application. Applications between popcorn stage (balloon stage) to first bloom are more effective than earlier or later applications. Do not apply after petal fall. EUROPEAN PEAR: Apply one pouch of ReTain per acre, as a single application from white bud stage to full bloom. Applications made prior to white bud stage or after full bloom will significantly reduce efficacy of the treatment. Do not apply after petal fall. Can also be applied to European pear at 10 mm fruit size at a rate of one pouch of ReTain at 10 mm fruit size to increase fruit set.
Promalin® or Maxcel® (Valent USA) and Perlan® or Exilis 9.5SC (Fine Americas), latex paint application FOR INCREASING BRANCHING AND FEATHERING OF NON-BEARING APPLE, PEAR AND CHERRY TREES. Such an application improves tree structure by improving branch angles and increasing bud break and shoot growth in nursery stock and young trees. At the location where branching is desired, apply a uniform application in latex paint mix at a rate of 5,000-7,500 ppm (0.8-1.2 fl. oz./pint of latex paint). The latex paint mix should be applied using a brush or sponge to achieve thorough coverage of the bark surface. Application should only be made to one year old wood in the spring once terminal buds begin to swell but before shoots emerge. Applications made following shoot emergence may result in injury to the young shoots. DO NOT apply latex paint mix after bud break. Doing so may cause injury to shoot tips and reduce the effectiveness of the application for shoot growth. One-year pre-harvest interval. See F-140 Branching Young Apple Trees with Plant Growth Regulators.
Protone® is registered as a defoliant to stimulate leaf drop in the fall. It may be used on nursery trees or on trees in the orchard carrying green leaves into the fall. A good nonionic surfactant should be used with this and at a rate between 250 and 1000 ppm. (16.5 - 66.1 ounces per acre.) Application on trees in the orchard is meant to speed leaf abscission and speed the development of dormancy. (May be particularly handy on non-cropping younger trees still actively growing later into the fall.)
kudos 27.5 WDG (Fine Americas, Inc.) has an updated label (2023) to include pears. (Kudos only, not Apogee.) In addition to growth control, Kudos may result in fire blight suppression. Updated label rate is 6 to 12 oz. per acre between petal fall and pear “turndown” with a second application 6 weeks after the first (if necessary), and don’t apply when daytime temperatures are predicted to exceed 90 degrees F. Note that kudos application to pears can result in an "off" crop the following year.