The Persistence and Movement of Fluorodifen in Soils and Plants

1971

Weed Research

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Summary. Autoradiographs and liquid scintillation counts of cucumber (Cucumis sativus L. cv. Ashley) seedlings indicated rapid absorption and translocation of radioactivity from fluorodifen‐1′‐14C (p‐nitrophenyl‐α,α,α‐trifluoro‐2‐nitro‐p‐tolyl ether labelled with 14C in the 1 position of the p‐nitrophenyl ring). After 24 h in 1 mg/1 of fluoro‐difen‐1′‐14C, 25% of the absorbed radioactivity was translocated from the roots. Cucumber seedlings degraded fluorodifen‐1′‐14C via a pathway similar to that reported for peanut seedlings but at a slower rate. The major degradation products were p‐nitrophenol and an unidentified polar compound (Unknown I). More rapid absorption and translocation coupled with slower degradation by cucumber as compared with peanut seedlings are factors which may contribute to the susceptibility of cucumber to fluorodifen.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

MOVEMENT AND FATE OF FLUORODIFEN‐1′‐¹⁴C IN CUCUMBER SEEDLINGS

1971

Weed Research

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“…Long Green) (Rogers, 1969), morning glory {Ipomoea hederacea (L.) Iaeq.) (Walter et al, 1970), peanut (Eastin, 1969b;Walter et al, 1970), sorghum {Sorghum vulgare Pers.) (Waher et al, 1970) and soybean (Rogers, 1969;Geissbuhler, 1970;Walter e^fl/., 1970).…”

Section: Introductionmentioning

confidence: 99%

DEGRADATION OF FLUORODIFEN‐1′‐¹⁴C BY PEANUT SEEDLING ROOTS

1971

Weed Research

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Summary. Degradation of p‐nitrophenyl‐α,α,α:‐trifluoro‐2‐nitro‐p‐tolyl ether (fluorodifen) labelled with 14C in the 1 position of the p‐nitrophenyl ring (1′‐14C) proceeded rapidly in peanut (Arachis hypogaea L. cv. Starr) seedling roots. All degradation products were present after only 2 h. The major degradation products for fluorodifen‐1′‐14C were the water‐soluble compounds p‐nitrophenol and Unknown I, a polar compound or complex which remained on the origin during thin‐layer chromatography. Minor products included p‐nitrophenyl‐α,α,α‐trifluoro‐2‐amino‐p‐tolyl ether, p‐aminophenyl‐α,α,α‐trifluoro‐2‐nitro‐p‐tolyl ether and traces of p‐aminophenol. No p‐aminophenyl‐α,α,α‐trinuoro‐2‐amino‐p‐tolyl ether was detected. The p‐aminophenol previously reported [PL Physiol., Lancaster, 44,1397‐1401 (1969)] was not p‐aminophenol, but primarily Unknown I with a possible trace of p‐aminophenol. Fluorodifen continued to be absorbed throughout the 72‐h treatment period.

“…Walter et al (7) stated that very little translocation of p-nitrophenyl-a,a,a-trifluoro-2-nitrop-tolyl ether (C-6989) was However, more C-6989 was translocated following root application than foliar application. Rogers (5) reported limited translocation of C-6989 to the shoots of soybean or cucumber (Cucumis sativus L., var.…”

mentioning

confidence: 99%

Movement and Fate of p-Nitrophenyl-α,α,α-Trifluoro-2-Nitro-p Tolyl Ether-1′-¹⁴C in Peanut Seedlings

1969

Plant Physiol.

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Abstract. Autoradiographs and liquid scintillation counts of peanut (Arachie hypogaea L., var. Starr) seedlings indicate that p-nitrophenyl-acy,a.trifluoro-2-nitro.p.tolyl ether-l'-14C (C-6989) is rapidly absorbed from nutrient solution but only 6.5 % of the radioactivity absorbed is translocated to the shoot after 144 hr, with the acropetal movement being confined to the stem and petiole.Metabolism of C-6989 by peanut seedlings proceeds rapidly, the major pathway being hydrolysis of the ether linkage and reduction of the 4-nitrophenol formed to 4-aminophenol. After 48 hr 4-aminophenol, C-6989 and 4-nitrophenol comprised 67.8, 17.4, and 13.5 % of the total radioactivity recovered, respectively. After 144 hr these compounds comprised 94.3, 4.0, and 0.9 % of the radioactivity, respectively.Reduction of one of the nitro groups of C-6989 followed by hydrolysis of the ether linkage is a minor pathway of metabolism in peanut seedlings. Small amounts (less than 1.0 % of the total radioactivity) of both P-nitrophenyl-a,a,a-trifluoro-2-amino-p-tolyl ether and p-aminophenyl-a,a,a-trifluoro-2-nitro-ptolyl ether were present but no p-aminophenyl-a,a,c-trifluoro-2-amino-p-tolyl ether was detected. Two very minor metabolites (less than 0.1% of the radioactivity) were detected which were not identified. These metabolites were possibly conjugates of the phenol derivatives with natural plant constituents. or products of substitutionl on, or ring cleavage of, the phenols. Approximately 50 % of the radioactivity persisted as C-6989, whereas p-aminophenyl-a,a,a-trifluoro-2-amino-p-tolvl ether (p,2-diamino-C-6989) was also detected in both species.Williams (9)