ABSORPTION, TRANSLOCATION AND METABOLISM OF THE HERBICIDE NAPROANILIDE IN TOBACCO

Naproanilide [2-(2-naphthyloxy)propionanilide] has a high activity aga inst dicotyledonous weeds in rice fields, but is very safe to rice. Th is study was designed to clarify the absorption and translocation of r adiolabelled naproanilide in tobacco plants and the metabolism in toba cco callus. The results indicated that naproanilide is translocated ea sily to the upper part of tobacco plants. Distribution of radioactivit y in tobacco plants at the 7th day was shown to be 0.88, 0.24 and 0.03 %, and at the 14th day 1.71, 1.86 and 2.32% of the total activities of [C-14]naproanilide in root, stem and leaf, respectively. When compare d to earlier results obtained with rice, the translocation rate in tob acco is much higher and might therefore contribute a possible mechanis m of herbicidal selectivity. Metabolites including NOP [2-(2-naphthylo xy)propionic acid], NOPM [methyl 2-(2-naphthyloxy)propionate], 2-napht hol, 2,3-naphthalenediol, 2,6-naphthalenediol, 2,7-naphthalenediol and 2-hydroxy-1,4-naphthoquinone were identified in tobacco callus by co- chromatography.