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The 2009 ASHS Annual Conference

ReTain Can Increase Nutmeat Yield of Pecan Trees

Saturday, July 25, 2009: 5:15 PM
Jefferson C (Millennium Hotel St. Louis)
Bruce Wood, USDA ARS, Byron, GA
Richard Heerema, New Mexico State Univ, Las Cruces, NM
Excessive fruit-drop limits profitability of certain pecan [Carya illinoinensis (Wangenh.) K. Koch] cultivars.   The present study examined the efficacy of ReTain®, a natural ethylene inhibitor, for reducing fruit-drop.  Four years of field studies on ‘Desirable’ pecan trees found that ReTain® can substantially reduce fruit-drop; thus, increasing crop-load over non-treated trees by as much as 16-38%, with the percentage retention being greatest in trees with a relatively heavy crop load and minimal in trees with a light crop load.  The efficacy of ReTain® for reducing fruit-drop increases with crop load.  Efficacy is also greatest when applied soon after the termination of stigma receptivity.  Two post-bloom applications of ReTain® increased fruit-set in an “on-phase” commercial orchard with an moderately heavy crop by 38%, while not reducing in-shell yield or kernel quality the following year when ReTain® was not used and the orchard possessed a light to moderate crop-load.  Proper usage of ReTain® appears to offer commercial producers of ‘Desirable’ nutmeats a practical tool for reducing fruit-drop and managing crop-load.