عنوان مقاله [English]
In order to study on the effect of combined castor oil with different doses of Lumax (Mesotrion + S-metolacholor + Terbuthylazine) on physiological behavior of common cocklebure (Xanthium strumarium L.), a greenhouse factorial experiment was conducted in randomized complete block design with 3 replications in agricultural faculty of University of Tabriz in 2017. Results showed that by increasing the herbicide doses, area above the OJIP curve between minimum and maximum fluorescence, maximum Fluorescence, variable fluorescence, maximum quantum yield of photochemistry (Fv/Fm), water-splitting complex on the donor side of PSII and maximum electron transport ﬂux per PSII reaction center, decreased 35, 15/6, 23/6, 11, 43 and 83 percentage, respectively and minimum fluorescence and thermal dissipation quantum yield increased 14 and 60 percentage, respectively. Castor oil had synergistic effect on Lomax, enhanced its efficacy on X. strumarium. In this research, a good relationship were observed between Fv/Fm parameter evaluated 2 days after herbicide spraying (DAHS) with dry weight measured 28 DAHS. The finding of this study showed that evaluating chlorophyll a fluorescence is a good, non-destructive, and fast method for survey the effect of Lomax little time after spraying and before the visual symptoms appear in treated weed species.