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Title: EFFECT OF SELECTED DRIFT CONTROL AGENTS ON THE EFFICACY OF DEF-6 PLUS PREP DEFOLIANT MIXTURES

Author
item JONES, E - DREC
item Hanks, James
item WILLS, GENE - DREC
item MACK, R - HELENA CHEMICAL CO.

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/6/2003
Publication Date: 6/5/2003
Citation: JONES, E.J., HANKS, J.E., WILLS, G.D., MACK, R.E. EFFECT OF SELECTED DRIFT CONTROL AGENTS ON THE EFFICACY OF DEF-6 PLUS PREP DEFOLIANT MIXTURES. NATIONAL COTTON COUNCIL BELTWIDE COTTON CONFERENCE. 2003. CD-ROM

Interpretive Summary:

Technical Abstract: A field study was conducted in 2002 to compare the effects of the combination of Def®-6 cotton defoliant and Prep boll opener as applied alone and in combination with each of five selected drift control agents. These mixtures were applied to cotton var. 'Delta Pine 451 B/R' at 65 to 70% open bolls. Treatments were applied in water at 10 gallons per acre (gpa) to cotton in plots of four rows each, spaced 40 inches apart, 40 feet long, arranged in randomized complete block designs, and replicated three times. Visual ratings were made of the percent defoliation at 7 and 14 days after treatment (DAT), whereby, 0 = no defoliation and 100% = complete defoliation and of the percent shoot regrowth at 21 DAT, whereby 0 = no shoot regrowth and 100% = complete regrowth of the cotton shoot. Def-6 was applied at 10 oz/A, which was below the recommended rate of 16 oz/A, in order to detect any increase or decrease in the effect on defoliation or shoot regrowth as caused by the addition of a drift control agent. The percent cotton defoliation at each 7 and 14 DAT with the combination of Def-6 and Prep without a drift control agent was 77 and 78%, respectively. The percent defoliation was significantly increased to 83 and 85%, respectively, by the addition of HM 2005-B. Defoliation was not significantly affected by the addition of HM 2007 (73 and 73%) and was reduced by the addition of HM 2052 to 70 and 70%, HM 2006 to 62 and 68% and HM 9752 to 37 and 37% at 7 and 14 DAT, respectively. The percent shoot regrowth was significantly greater with the addition of HM 9752 (40%) and HM 2006 (40%) than with the Def-6 and Prep mixture without a drift control agent (27%) or in combination with HM 2005-B (22%), HM 2007 (27%), or HM 2052 (20%).