MORPHO-ANATOMICAL CHANGES OF PEQUI LEAVES (Caryocar brasiliense Cambess.) EXPOSED TO SIMULATED DRIFT OF GLYPHOSATE

Abstract

ABSTRACT The goal of this research was to examine phytotoxicity and leaf anatomy of pequi plants (Caryocar brasiliense Cambess.) exposed to simulated drift of glyphosate. The experimental design was randomized blocks with nine replications. Each experimental unit was composed by one 18-L pot with one plant. The treatments consisted of different doses of glyphosate sprayed: 0 (control), 50, 100, 250, 500, 1000 and 1500 g ae ha-1 of glyphosate. Phytotoxicity visual ratings were carried out at 7, 14 and 21 days after spraying (DAS) by scores expressed in a percentage scale, within which zero and one hundred represent no symptom and plant death, respectively. Description of symptoms, changes in leaf anatomy and micromorphometric analysis were performed on leaves taken from plant top and middle third at 23 DAS. Poisoning symptoms were wilting, chlorosis followed by necrosis, winding of top leaves and leaf senescence, being intensified with increasing doses. Leaf anatomical changes were detected from the dose of 250 g ha-1. The observed damages consisted of plasmolized cells, epidermal disruption, distorted cells, hyperplasia, cell collapsing, necrotic tissue and accumulation of phenolic compounds.