Quizalofop and Sethoxydim Activity as Affected by Adjuvants and Ammonium Fertilizers

• Published in: Weed science 1992-03, Vol.40 (1), p.12-19
• Main Authors: Beckett, Thomas H., Stoller, Edward W., Bode, Loren E.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Chemical control; Fertilizers; Fundamental and applied biological sciences. Psychology; Herbicides; Interfacial tension; Nozzles; Parasitic plants. Weeds; Petroleum; Physiology, Chemistry, and Biochemistry; Phytopathology. Animal pests. Plant and forest protection; Plants; Quaternary ammonium compounds; Sulfates; Surfactants; Weeds
• ISSN: 0043-1745; 1550-2759
• DOI: 10.1017/S0043174500056873

Ammonium fertilizers, petroleum oil concentrate, and nonionic surfactant were evaluated as postemergence spray additives to improve giant foxtail and volunteer corn control by 28 g ai ha−1 of the ethyl ester of quizalofop or 56 g ha−1 sethoxydim. Additions of 0.25% by vol nonionic surfactant or 2.5% petroleum oil concentrate improved grass control, but additions of 10% urea ammonium nitrate (28-0-0), 10% ammonium polyphosphate (10-34-0), or 0.1M ammonium sulfate (21-0-0-24S) did not consistently affect grass control. In laboratory studies with corn, greatest 14C absorption from leaf-applied 14C-quizalofop (8 h after treatment) was found with additions of petroleum oil concentrate (80% absorbed) or nonionic surfactant (18% absorbed), while less absorption was observed with treatments containing either no additive, urea ammonium nitrate, ammonium polyphosphate, or ammonium sulfate (8 to 13% absorbed). Surface tension and droplet size of spray solutions were affected primarily by additions of nonionic surfactant, petroleum oil concentrate, and the formulated herbicides. Solution density, solute potential, pH, and buffering capacity were primarily affected by fertilizer additions.