EFFECTS OF SIMAZINE AND GLYPHOSATE ON OLIVE TREES
Both herbicides were used, applied to the leaves, and simazine was also applied to olive tree soil. The levels of chlorophyll fluorescence and leaf chorophyll content were measured only with simazine, and longitudinal growth was measured for each herbicide.
As a result of the simazine applied to the soil, the olive tree showed an increase in the level of fluorescence in those leaves present before the treatment, for doses of 2, 4 and 6 kg ai ha-1. When the leaves that developed after application were measured, it was found that the level of fluorescence had decreased which could have been due to loss of pigment rather than inactivation of the herbicide. In the treatment applied to the leaves, lower levels of fluorescence were found in the adult leaves than in the young leaves. This seems to indicate a tolerance of the olive tree to this herbicide through a lack of penetration of the adult structures. Simazine applied in preemergence was more effective on A. blitoides than on L. rigidum.
When the herbicide glyphosate was applied to the leaves of the olive tree, this stopped growth at concentrations of 2, 4 and 6 kg ai ha-1. There was also a defoliating action which was greater at higher concentrations. Glyphosate applied in post-emergence showed a total control of both weeds.