Evaluation of Retain~R Plant Growth Regulator on Pecan Production

摘要

Insufficient fruit-set and retention can significantly reduce profitability in some pecan cultivars such as 'Desirable'. Foliar applications of ReTain~R Plant Growth Regulator (aminoethoxyvinylglycine) were evaluated for improving pecan nut retentionin 2009-2010. In 2009, 'Desirable' pecan cultivar was tested at two locations; and 'Oconee' and 'Schley' tested at single locations. 'Desirable' was tested in 3 locations in 2010; and 'Oconee' and 'Success' tested in single locations. Selected trees received foliar applications of ReTain~R growth regulator at 7 and 21 days after the cessation of pistillate receptivity. Nut clusters were evaluated prior to harvest and the data used to calculate the percentage of fruiting terminals per tree and the average number of nuts per cluster. The harvested nuts were dried prior to postharvest analysis and the collected data used to calculate, nut size, shellout, and yield. In Louisiana, tests involving small tree numbers have suggested trends toward higher production per hectare following ReTain~R application, but did not result in statistically significant increases in 'Desirable' pecan yield in 2009 or 2010. However, a large scale demonstration test on 'Desirable' resulted in over a 40% increase in productionfollowing 2 applications of ReTain~R plant growth regulator. Additionally, initial tests on 'Oconee' in 2009 provided positive increases in nut production without any significant decreases in nut size or quality, but produced no significant increases in2010. Proper usage of ReTain~R still appears to offer growers of pecan cultivars with stigmatic receptivity as late or later than 'Desirable' a cultural management tool to improve nut production.