Diuron Metabolism in Two Sugarcane(Saccharum officinarum)Cultivars

Abstract

The uptake, distribution, and metabolism of diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] by sugarcane(Saccharum officinarumL.) cultivars ‘PR980’ and ‘PR1048’ were determined 3 and 10 days after root treatment with 18.4 μM14C-ring-labeled diuron. Uptake and distribution did not account for the differential tolerance of the two cultivars to diuron. Concentration of unmetabolized diuron was higher in the shoot and root of susceptible cultivar PR1048 than in tolerant cultivar PR980 at 3 and 10 days after treatment. The predominant metabolic pathway for diuron metabolism in both susceptible and tolerant sugarcane cultivars appeared to be the formation of mono-methyl diuron and its conjugation. The metabolic process was more rapid in PR980 than PR1048, apparently accounting for the tolerance of PR980.