Mechanism of quizalofop-ethyl selectivity in monocotyledonous and dicotyledonous species
Cucumber (Cucumis sativus L.) susceptibility to quizalofop-ethyl herbicide was investigated under field and greenhouse conditions. Yield of cucumber cultivars was significantly reduced under field conditions with a single or repeat application of the ethyl ester of quizalofop at 0.14 or 0.28 kg ai/ha. Under greenhouse conditions, quialofop-ethyl significantly suppressed cucumber plant fresh weight with or without the presence of an adjuvant. Enhancement of herbicide activity was directly related to concentration of adjuvant. Microliter droplet application of quizalofop-ethyl at a 10/sup -3/ M concentration, inhibited the relative growth (RGR) and net assimilation rate (NAR) of the treated cucumber leaf 45% and 52%, respectively. Expression of herbicidal injury was localized on the treated leaf with no visible symptoms observed on adjacent leaves. Radiolabeled /sup 14/C-quizalofop-ethyl was applied to leaves of cucumber and corn (Zea mays L.) to compare translocation patterns between two susceptible plant species and relate this information to the observed selectivity of the herbicide. Cucumber autoradiographs showed minimal translocation of /sup 14/C-quizalofop-ethyl 192 hours after treatment. In contrast, corn autoradiographs showed both apoplastic and symplastic transport of quizalofop-ethyl 3 and 24 hours after treatment. Quantification of /sup 14/C in cucumber revealed 96% of absorbed /sup 14/C was confined to the treated leaf after 192h of exposure.
- Research Organization:
- Ohio State Univ., Columbus (USA)
- OSTI ID:
- 6545859
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
60 APPLIED LIFE SCIENCES
AUTORADIOGRAPHY
CARBON 14 COMPOUNDS
CEREALS
COMPARATIVE EVALUATIONS
CUCUMBERS
FOOD
GRASS
GROWTH
HERBICIDES
LABELLED COMPOUNDS
MAIZE
MEMBRANE TRANSPORT
PESTICIDES
PLANT GROWTH
PLANTS
PRODUCTIVITY
TOXICITY
VEGETABLES