ABSORPTION AND TRANSLOCATION OF CARBON 14-GLYPHOSATE APPLIED TO OLIVETREE SUCKERS

Field and laboratory studies were conducted in Cordoba, Spain, on oliv e (Oleae europeae L.) trees to determine the absorption and translocat ion of C-14-glyphosate applied to suckers at different growth stages a nd different times of the growing season. Absorption of C-14-glyphosat e by olive sucker leaves was very low, almost-equal-to 3% to 5% of the total C-14 recovered. Absorption and accumulation of C-14-glyphosate decreased if suckers were more developed when herbicides were applied. This explains the greater susceptibility to herbicides of smaller oli ve shoots compared to larger ones. Translocation of C-14-glyphosate in the early season application (May) was predominantly acropetal, where as it was basipetal in the last application (September). Therefore, he rbicide-applied early in the season has a lower risk of translocating to other parts of the tree. The concentration of C-14-glyphosate in di fferent parts of the olive tree varied with time. From 10 to 30 days a fter herbicide treatment, its concentration decreased by 41% in the wo ody basal parts and by 33% in the fruit. In the same period, it accumu lated in the leaves, increasing in concentration by 30%.