Studies on herbicidal carbamoyltetrazolinone derivatives: Selection of fentrazamide

Abstract

1‐Phenyl‐5(4H)‐4‐dialkylcarbamoyltetrazolinones represent a new class of herbicides that are active against barnyardgrass (Echinochloa spp.) in paddy fields. To select the most favorable compound as a paddy herbicide, herbicidal activity and selectivity of the carbamoyltetrazolinone compounds to transplanted rice were determined in greenhouse tests. Higher herbicidal activities were associated with the compounds having a 2‐Cl‐ or 2‐Cl‐6‐Me‐substituted or an unsubstituted phenyl ring, and a combination of C2–3 linear alkyl group and a C4 branched‐chain alkyl or a C5–6 cycloalkyl group on the nitrogen atom in the carbamoyl structure. In addition, the compounds carrying a total of seven to nine carbon atoms in the substituents on the carbamoyl nitrogen exhibited a good selectivity between barnyardgrass and transplanted rice plants. From the results of soil thick‐layer chromatography, the good crop compatibility of carbamoyltetrazolinones was correlated to the mobility of the compounds in paddy soil. The investigation resulted in the selection of an excellent compound, 4‐(2‐chlorophenyl)‐N‐cyclohexyl‐N‐ethyl‐4,5‐dihydro‐5‐oxo‐1H‐tetrazole‐1‐carboxamide (common name: fentrazamide), as a rice paddy herbicide for controlling barnyardgrass.

Absorption, translocation, and metabolism of fentrazamide in rice and early watergrass (Echinochloa oryzicola)

“…For effective barnyardgrass control, herbicides with high efficacy to the weed and good selectivity to rice are required. 1-Phenyl-5(4H)-4-dialkylcarbamoyltetrazolinones have exhibited high phytotoxic activity against barnyardgrass in paddy field experiments (Goto et al 2002). Fentrazamide, 4-(2-chlorophenyl)-N-cyclohexyl-N-ethyl-4, 5-dihydro-5-oxo-1H-tetrazole-1-carboxamide, has been developed as a rice paddy herbicide for controlling barnyardgrass.…”

Dissipation studies of fentrazamide (YRC-2388) in soil under anaerobic condition

“…1-Phenyl-5(4H)-4-dialkylcarbamoyltetrazolinones, a new class of herbicide, have exhibited high phytotoxic activity against barnyard grass in paddies, under field experiments. 3 Bayer AG and Nihon Bayer Agro-chem developed fentrazamide [4-(2chlorophenyl)-N-cyclohexyl-N-ethyl-4,5-oxo-1H-tetrazole-1-carboxamide] a new tetrazolinone/amide class herbicide with a novel chemical structure. 4,5 It can be used in low doses (100-300 g a.i.…”

“…in paddy fields and can be used as a pre-emergent herbicide and inhibits seedling growth by inhibiting cell elongation and cell division. 3,[14][15][16][17][18] Very little studies on the fentrazamide residues in soil, crop, plant, animal and multi-residue have been reported. [19][20][21][22][23][24][25][26][27][28][29] No study has yet reported on dissipation of fentrazamide from the hot and humid sub tropical climate and Tarai region soils of Indian conditions.…”

Action of fentrazamide on protein metabolism and cell division in plants

“…1-Phenyl-5(4H)-4-dialkylcarbamoyltetrazolinones exhibited high activity against barnyardgrass in paddy field experiments. 1) Fentrazamide, 4-(2-chlorophenyl)-N-cyclohexyl-Nethyl-4,5-dihydro-5-oxo-1H-tetrazole-1-carboxamide, has been developed as a rice paddy herbicide for controlling barnyardgrass. In Japan and Korea, this compound is applied at the time of rice transplanting due to its long residual activity.…”