EFFECT OF MINERAL-NUTRITION AND HERBICIDE MIXTURES ON THE ABSORPTION AND TRANSLOCATION OF BENSULFURON METHYL IN RICE

Absorption and translocation of bensulfuron methyl {methyl -pyrimidiny l)amino]carbonyl]amino]sulfonyl]methyl] benzoate} in rice (Oryza sativ a L.) as affected by mineral nutrition and herbicide mixtures were det ermined using C-14-labeled herbicide in culture solution. Absorption o f C-14-bensulfuron methyl by roots decreased with increasing concentra tion of bensulfuron methyl. However, increase in the application conce ntration did not affect movement of the C-14-label to shoots. There wa s no difference in total amount of C-14-bensulfuron methyl taken up be tween absorption periods of 12 and 48 hours, whereas C-14-bensulfuron methyl translocated to shoots increased with increasing the absorption period. When mixtures of bensulfuron methyl were applied, butachlor y methyl)-2-chloro-N-(2,6-diethylphenyl)acet-amide] did not affect absor ption and translocation of C-14-bensulfuron methyl. However, quinclora c (3,7-dichloro-8-quinoline carboxylic acid) mixed at a high concentra tion resulted in decrease in absorption and translocation of C-14-bens ulfuron methyl. Nutritional disorder such as deficient or excess suppl y of mineral nutrients caused to depress absorption of C-14 = bensulfu ron methyl. The greatest decrease and delay of C-14-bensulfuron methyl absorption and/or translocation occurred in N-deficiency and S-excess supply conditions.