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Minor PGR uses on apples

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Written by: 
Jon Clements

Always look at the label before making application of any PGR’s as there are further use directions and warnings on the label which may not be included here.

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® (Valent USA) and Perlan® (Fine Americas) to increase fruit set in APPLE following frost by stimulating the development of parthenocarpic fruit. Make a single application at a rate of 1-2 pints in 50-200 gallons of water per acre prior to or within 24 hours following a frost or freeze event, when the majority of the crop is between early bloom and full bloom. Do not apply to frozen foliage, blossoms or developing fruit, allow trees to completely thaw prior to application. Do not use a surfactant. Do not apply more than 2 times for this use.

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