USE OF TOMATO (LYCOPERSICON-ESCULENTUM) SEEDLINGS TO DETECT BENSULFURON AND QUINCLORAC RESIDUES IN WATER

During 1990, injury to tomatoes grown on the narrow land between the A lbufera Lake (Spain) and the Mediterranean Sea was attributed to use o f irrigation water coming from adjacent rice fields containing bensulf uron and quinclorac. A tomato root bioassay was developed to detect th e herbicides in 10 ml of water. The assay was more sensitive to bensul furon (0.5 ng ml-1) than quinclorac (100 ng ml-1). Only 30 ml of the a ffected water are necessary to conduct the test. Albufera water, sampl ed at three sites during 1991 and one during 1992 in the irrigation ne twork canals caused different tomato main root length responses.