The relationship between CO2 assimilation and the metabolism of bentazone in wheat plants

Summary: The assimilation of CO2 by wheat plants after treatment with various amounts of bentazone was investigated. Maximum inhibition of assimilation always occurred at the same time after treatment irrespective of the amount of bentazone applied. The reduction in CO2 assimilation rate was correlated with the uptake of active ingredient in the leaf tissue. Assimilation increased again, when the concentration of bentazone inside the leaf dropped as the results of metabolism to hydroxybentazones. The toxicity of 6‐ and 8‐hydroxybentazone to sensitive mustard plants was lower than that of the parent compound. It is suggested that hydroxylation is a step in the detoxification of bentazone.