A. Valeragil et L. Garciatorres, ABSORPTION AND TRANSLOCATION OF CARBON 14-GLYPHOSATE APPLIED TO OLIVETREE SUCKERS, Journal of the American Society for Horticultural Science, 119(5), 1994, pp. 1020-1023
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%.