Content and fluorescence of chlorophyll in eucalypt exposed to glyphosate

The objective was to evaluate the response of eucalypt clonal (Eucalyptus urograndis) regarding on chlorophyll content and fluorescence of chlorophyll after glyphosate spraying to verify if the herbicide affects the photochemical process of photosynthesis. Plants of four eucalypt clonal (C219, GG100, I144, and I224), having four expanded leaves, were sprayed with glyphosate in range of doses varying from 0 up to 720 g ae ha-1. We evaluated the chlorophyll content and the relation Fv/Fm during 30 days after spraying glyphosate. The chlorophyll content of the clone C219 reduced by 12% at doses ≥ 360 g ae ha-1. In addition, chlorophyll content was higher (≥ 12%) in all clonal from 7 days after spraying. The relation Fv/Fm did not alter after glyphosate spraying. We concluded that the efficiency of the photosystem II is not influenced by glyphosate in any studied eucalypt clonal, although doses of glyphosate from 360 g ae ha-1 affect the chlorophyll content of the clonal C219