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PHYTOTOXICITY AND BEHAVIOR OF THREE SELECTIVE POSTEMERGENCE GRASS HERBICIDES IN PLANTS AND CELL CULTURES
Abstract
Phytotoxicity of fluazifop-butyl {butyl 2-{4-{(5-trifluoromethyl)-2-pyridinyl)oxy}phenoxy}propanoate}, haloxyfopmethyl {methyl 2-{4-{(3-chloro-5-(trifluoromethyl)-2-pyridinyl)oxy}phenoxy}propanoate}, and sethoxydim {2-{1-(ethoxyimino)-butyl}-5-{2-(ethylthio)propyl}-3-hydroxy-2-cyclohexen-1-one} increased as carrier volume was decreased from 570 to 24 L/ha. Addition of crop oil concentrate to the spray solution increased phytotoxicity. When plants were treated with single droplets, smaller concentrated droplets were more phytotoxic than larger more dilute droplets. Application site of single herbicide droplets also influenced phytotoxicity. Fluazifop-butyl, haloxyfop-methyl and sethoxydim exhibited soil herbicidal activity in greenhouse and field experiments. When grass seeds were planted at the soil surface control was greater with all three herbicides than when planted 2, 4, or 6 cm deep. Imbibition of the herbicides by grass and soybean {Glycine max (L.) Merr.} seed did not reduce germination at concentrations of 10('-3) M or below. All three herbicides were more readily absorbed from the soil by seedling roots than shoots. Haloxyfop-methyl exhibited the longest soil residual in the field followed by fluazifop-butyl and sethoxydim. Haloxyfop-methyl and fluazifop-butyl controlled shattercane {Sorghum bicolor (L.) Moench} in soybeans with preemergence and early postemergence applications; whereas, control from similar applications of sethoxydim was limited and variable. Behavior of ('14)C-haloxyfop-methyl was examined in soybean, shattercane, and yellow foxtail {Setaria lutescens (Weigel) Hubb.} intact plants and soybean and yellow foxtail cell cultures. Foliar absorption of ('14)C-haloxyfop-methyl was rapid and almost complete within 48 h. Significant translocation occurred within 48 h of treatment with soybean and shattercane plants translocating more ('14)C than yellow foxtail. Metabolism of ('14)C-haloxyfop-methyl in intact plants was similar among the three species. Soybean cells contained greater levels of ('14)C than did yellow foxtail cells. Most of the ('14)C in soybean cells was haloxyfop-methyl, while yellow foxtail contained mostly haloxyfop.
Subject Area
Agronomy
Recommended Citation
BUHLER, DOUGLAS D, "PHYTOTOXICITY AND BEHAVIOR OF THREE SELECTIVE POSTEMERGENCE GRASS HERBICIDES IN PLANTS AND CELL CULTURES" (1984). ETD collection for University of Nebraska-Lincoln. AAI8423765.
https://digitalcommons.unl.edu/dissertations/AAI8423765