Physiological responses of Eucalyptus x urograndis to glyphosate are dependent on the genotype

Authors: CARVALHO, LEONARDO - Universidade Estadual Paulista (UNESP); Duke, Stephen; ALVES, PEDRO - Universidade Estadual Paulista (UNESP)

Submitted to: Scientia Forestalis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/9/2017
Publication Date: 6/1/2018
Publication URL: https://handle.nal.usda.gov/10113/6961198
Citation: Carvalho, L.B., Duke, S.O., Alves, P. 2018. Physiological responses of Eucalyptus x urograndis to glyphosate are dependent on the genotype. Scientia Forestalis. 46(118): 177-187.

Interpretive Summary: Little research has been conducted on the effects of the herbicide glyphosate on woody plants. Two genotypes of Eucalyptus were found to be differentially sensitive to glyphosate. The differences in sensitivity were related to differences in effects on CO2 assimilation and to glyphosate uptake and other factors.

Technical Abstract: Two experiments were conducted to evaluate the response of Eucalyptus urograndis genotypes (C219 and GG100) to glyphosate in growth chambers. As glyphosate dose increased (18 up to 720 g ae ha-1), CO2 assimilation rate, transpiration rate, and stomatal conductance decreased fastest and strongest in the GG100 compared to the C219 genotype. Shikimic acid accumulated at highest levels in the GG100 genotype, at 1 and 2 days after spraying glyphosate at a single dose of 180 g ae ha-1. No significant differences occurred between genotypes in glyphosate content, leaf thickness, and stomatal index. Aminomethylphosphonic acid was not detected in neither genotype. Gas exchange alteration due to glyphosate exposure is dependent on eucalyptus genotype.