Articles
PEACH FLOWER BUDS THINNED WITH DORMANT APPLICATIONS OF VEGETOIL® ADJUVANT PLUS ETHEPHON
Article number
903_115
Pages
827 – 832
Language
English
Abstract
Early removal of flower buds, flowers or small fruitlets increases peach fruit size and value at harvest.
Due to the scarcity of labeled or consistent thinning chemicals, peach growers generally wait ~30 days after full bloom before hand-thinning fruit, which limits potential fruit size.
Experiments were conducted near Clemson, South Carolina to determine the efficacy of combining Vegetoil® (VO), an emulsified soybean oil adjuvant (93% soybean oil), with Ethephon (Ethrel® a.i. 21.7%) for pre-bloom flower bud thinning of peach cultivars. Contender, Cresthaven and Rubyprince peach were sprayed in January 2006, 2007 and 2008 with 10% VO except for Rubyprince in 2006 (8% VO). Ethephon concentrations used varied by year and were 25, 50, 75, 100, or 150 ppm.
Dormant oil (DO) at 3% and VO at 10% were the control treatments in 2006+2008 and 2007 respectively.
VO (10%) plus Ethephon at 100 and/or 150 ppm significantly delayed bloom in Contender and Cresthaven in 2006 and in Cresthaven and Rubyprince in 2007. In 2006 and 2008, VO (10%) significantly reduced the number of flower buds alive at bloom for Contender, Cresthaven, and Rubyprince (only 2008), and the addition of Ethephon to the VO spray significantly increased flower bud mortality when compared to the 10% VO application.
There were no differences among the Rubyprince treatments in 2006, but the addition of ethephon slightly increased flower bud death in 2007 and significantly more in 2008. Basal flower buds on marked shoots had significantly lower survival than the distal or terminal flower buds in the VO treatments in all years and all cultivars except Cresthaven in 2006. Generally, Rubyprince is easier to flower bud thin with soybean oil than Cresthaven, but the opposite was observed in this study when using the Vegetoil® soybean oil product.
Due to the scarcity of labeled or consistent thinning chemicals, peach growers generally wait ~30 days after full bloom before hand-thinning fruit, which limits potential fruit size.
Experiments were conducted near Clemson, South Carolina to determine the efficacy of combining Vegetoil® (VO), an emulsified soybean oil adjuvant (93% soybean oil), with Ethephon (Ethrel® a.i. 21.7%) for pre-bloom flower bud thinning of peach cultivars. Contender, Cresthaven and Rubyprince peach were sprayed in January 2006, 2007 and 2008 with 10% VO except for Rubyprince in 2006 (8% VO). Ethephon concentrations used varied by year and were 25, 50, 75, 100, or 150 ppm.
Dormant oil (DO) at 3% and VO at 10% were the control treatments in 2006+2008 and 2007 respectively.
VO (10%) plus Ethephon at 100 and/or 150 ppm significantly delayed bloom in Contender and Cresthaven in 2006 and in Cresthaven and Rubyprince in 2007. In 2006 and 2008, VO (10%) significantly reduced the number of flower buds alive at bloom for Contender, Cresthaven, and Rubyprince (only 2008), and the addition of Ethephon to the VO spray significantly increased flower bud mortality when compared to the 10% VO application.
There were no differences among the Rubyprince treatments in 2006, but the addition of ethephon slightly increased flower bud death in 2007 and significantly more in 2008. Basal flower buds on marked shoots had significantly lower survival than the distal or terminal flower buds in the VO treatments in all years and all cultivars except Cresthaven in 2006. Generally, Rubyprince is easier to flower bud thin with soybean oil than Cresthaven, but the opposite was observed in this study when using the Vegetoil® soybean oil product.
Publication
Authors
G.L. Reighard, D. Ouellette, K. Brock
Keywords
Prunus persica, soybean oil, crop load
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