Effect of fertilizers and adjuvants on quizalofop, sethoxydim, and thiameturon foliar uptake and weed control

Combinations of urea ammonium nitrate (UAN), ammonium polyphosphate (APP), ammonium sulfate (AS), petroleum oil concentrate (POC), and non-ionic surfactant (SURF) were evaluated as postemergence spray additives to improve giant foxtail (Setaria faberi Herrm.) and volunteer corn (Zea mays L.) control by 28 g ai/ha of the ethyl ester of quizalofop $\{({\pm})$-2- (4 ((6-chloro-2-quinoxalinyl)oxy) phenoxy) propanoic acid$\}$ or 56 g/ha sethoxydim $\{$2- (1-(ethoxyimino)butyl) -5- (2-(ethylthio)propyl) -3-hydroxy-2-cyclohexen-1-one$\}$. UAN (9.4 L/ha), APP (9.4 L/ha), and AS (2.8 kg/ha), in general, did not affect grass control. Compared to no adjuvant, SURF (0.25%) and POC (2.3 L/ha) improved grass control; however, POC typically provided more consistent and greater weed control than SURF. The effects of the additives on $\sp{14}$C-quizalofop uptake into corn leaves at 8 h after treatment (HAT) were also determined. Greatest $\sp{14}$C uptake was found with POC (80% uptake) and SURF (18%) additions, while less uptake was observed with treatments containing either no additive, UAN, APP, or AS (8 to 13%).The effect of ammonium and methylammonium on the foliar uptake of (0.31mM) $\sp{14}$C-thiameturon $\{$3-(((((4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino) carbonyl) amino) sulfonyl) -2-thiophenecarboxylic acid$\}$ into velvetleaf (Abutilon theophrasti Medik.) was also determined. All treatment solutions contained 0.2% SURF. Total $\sp{14}$C uptake into velvetleaf tissues at 24 HAT was only 15%, but the addition of 0.32 M NH$\sb4$Cl, UAN (0.32 M NH$\sb4\sp+$), or 0.32 M CH$\sb3$NH$\sb2$HCl increased total $\sp{14}$C uptake to 31, 38, or 59%, respectively. Total $\sp{14}$C uptake at 24 HAT averaged 68% when CH$\sb3$NH$\sb2$HCl was added at 0.16, 0.24, and 0.32M, but only 51% uptake was observed with 0.08M CH$\sb3$NH$\sb2$HCl.U of I OnlyRestricted to the U of I community indefinitely during batch ingest of legacy ETD