TRANSLOCATION AND METABOLISM OF A SEED FUNGICIDE, PEFURAZOATE, IN RICE SEEDLINGS

Translocation and metabolism of a fungicide, pefurazoate (pent-4-enyl furfuryl-N-imidazol-1-ylcarbonyl-DL-homoalaninate, Healthied(R), were investigated in rice seedlings after the seeds were treated with thre e different kinds of C-14-labeled pefurazoate. Three weeks after seedi ng in a sand culture medium, the radioactivity in the seeds accounted for 81.3-86.3%, and decreased to 54.1-55.8% during the following two-w eek culture. The decrease,was mostly due to the translocation to the s hoots and the roots. Pefurazoate was so readily metabolized that the p arent molecule was reduced to 49.1-58.2% of the total radioactivity in the seedlings three weeks after seeding. During the following two-wee k culture it was further reduced to 22.6-25.4%, remaining mostly in th e seeds (90.2-93.9%). Major metabolites were 4-pentenyl (RS)-2-furfury laminobutanoate, (RS)-2-furfurylamino-butanoic acid, 1-((RS)-1-carboxy latopropyl)-3-hydroxypyridinium, N-(furan-2-ylcarbonyl)-glycine, (RS)- 2-aminobutanoic acid, imidazole, hydantoin and hydantoic acid. Conjuga ted metabolites were observed in small amounts. The metabolic pathway of pefurazoate in the rice plants was almost similar to that in soil.