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Photosynthetic parameters in glyphosate‐treated sugarbeet ( Beta vulgaris L.)
Author(s) -
MADSEN K. H.,
HEITHOLT J. J.,
DUKE S. O.,
SMEDA R. J.,
STREIBIG J. C.
Publication year - 1995
Publication title -
weed research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.693
H-Index - 74
eISSN - 1365-3180
pISSN - 0043-1737
DOI - 10.1111/j.1365-3180.1995.tb02020.x
Subject(s) - photosynthesis , glyphosate , stomatal conductance , darkness , chemistry , fluorescence , conductance , chlorophyll fluorescence , horticulture , botany , biology , agronomy , physics , quantum mechanics , condensed matter physics
Summary Variable fluorescence and carbon dioxide exchange rate (CER) were measured in intact leaves of glyphosate‐treated sugarbeet plants, to investigate rapid effects on photosynthesis. In one experiment, a significant effect on variable fluorescence and CER was found within 8 h after herbicide application. The effect on stomatal conductance was not significant. In a second experiment, the effects of light or dark conditions during herbicide application and 24 h later were evaluated. Under light conditions glyphosate significantly reduced variable fluorescence after 4 h. However under initial conditions of 24 h darkness, followed by alternating 8 h light/8 h dark, the effect was not significant until 44 h after treatment, by which time the plants had received several hours of light. The eflect on variable fluorescence 8 h after herbidde application correlated positively with plant survival 7 days later.