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United States Department of Agriculture

Agricultural Research Service


Location: Fruit and Nut Research

Title: Retain can increase nutmeat yield of pecan trees

item Wood, Bruce
item Heerema, Richard

Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: 5/30/2009
Publication Date: 7/20/2009
Citation: Wood, B.W., Heerema, R. 2009. Retain can increase nutmeat yield of pecan trees. HortScience. 44(4):1012.

Interpretive Summary: The profitability of commercial pecan orchards is often limited by excessive fruit-drop occurring during early June (i.e., June-drop). ReTain, a commercial fruit-set inducing growth regulator derived from a natural product was shown to possess efficacy for increasing fruit-set via reducing June-drop. Adaptation of ReTain to pecan offers a new horticultural tool for managing crop-load and increasing yield of commercial pecan orchards.

Technical Abstract: Insufficient fruit-set can limit profitability of specific pecan [Carya illinoinensis (Wangenh.) K. Koch] cultivars. The present study examined efficacy of ReTain® (Valent BioSciences, Libertyville, IL), a natural ethylene inhibitor, for increasing fruit-set in pecan trees grown at three distinct locations within the U.S. pecan-belt. Up to four years of field studies found that timely post-pollination ReTain® sprays [132 mg•L-1 a.i. (11.7 oz./acre)] to canopies could increase fruit-set of ‘Desirable’, and, accordingly, increase crop yield by 16-38% in trees carrying a “moderate to heavy” crop; nevertheless, was ineffective for increasing fruit-set on trees carrying a “light” crop-load. The ReTain®-associated increase in yield did not necessarily decrease yield the following crop year. Proper usage of ReTain® appears to offer commercial producers of ‘Desirable’ nutmeats a practical tool for managing crop-load via regulation of Stage-II drop (i.e., June-drop).

Last Modified: 10/16/2017
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