Iranian Society of Weed Science Iranian Journal of Weed Science 1735-3548 13 2 2017 12 22 Study on the Effect of Salicylic Acid (SA) Mixture with Some Herbicides on Chlorophyll a Fluoresce and some Morphological Traits of Common Lambesquarts (Chenopodium album) Study on the Effect of Salicylic Acid (SA) Mixture with Some Herbicides on Chlorophyll a Fluoresce and some Morphological Traits of Common Lambesquarts (Chenopodium album) 175 191 115886 10.22092/ijws.2017.1302.07 FA Soheila Porheidar Ghafarbi Department of Agronomy and Plant Breading, Faculty of agriculture, University of Tehran Hamid Rahimian Department of Agronomy and Plant breading, University of Tehran Hassan Alizadeh Department of Agronomy and Plant breading, University of Tehran Sirous Hassannejad Associate of Weed Science, Department of Plant Eco-Physiology, Faculty of Agriculture, University of Tabriz Journal Article 2017 12 04 Photosynthesis in plants is strongly influenced by stress. Evaluation of chlorophyll <em>a</em> fluoresce is one of the methods for assessment the different stresses effects such as herbicide on photosynthesis. Application of plant growth regulators like salicylic acid (SA), is one of the strategies to overcome for physiological disorders in plant. Therefore, to study the effect of SA mixture with Bentason, Bromoxynil+MCPA and 2,4-D+MCPA herbicides on physiological behavior of Common lambesquarts (<em>Chenopodium album</em> L.), a greenhouse experiment was conducted in randomized complete block design with three replications in Agricultural faculty of University of Tabriz in 2016. The results indicated a reduction in maximum fluorescence (Fm), variable fluorescence (Fv), maximum quantum yield of photochemistry (Fv/Fm), efficiency of the water-splitting complex on the donor side of PSII (Fv/Fo), and performance index (PI_ABS), and an increase in minimum fluorescence (Fo) and photosystem II antenna (Fo/Fm) of Common lambesquarts subjected to Bentason and Bromoxynil+MCPA. Dry weight and chlorophyll index in control treatment (without SA) increased 4.3% and 2.1% respectively, but in Bentason and Bromoxynil+MCPA and 2,4-D+MCPA treatments, these two indexes reduced 41.6%, 13.7%, 13.6% and 32.2%, 36.4%, 18.7%, respectively. SA not only did not reduce the Bentason and Bromoxynil+MCPA efficiency, but also increased efficiency of these two herbicides. Photosynthesis in plants is strongly influenced by stress. Evaluation of chlorophyll <em>a</em> fluoresce is one of the methods for assessment the different stresses effects such as herbicide on photosynthesis. Application of plant growth regulators like salicylic acid (SA), is one of the strategies to overcome for physiological disorders in plant. Therefore, to study the effect of SA mixture with Bentason, Bromoxynil+MCPA and 2,4-D+MCPA herbicides on physiological behavior of Common lambesquarts (<em>Chenopodium album</em> L.), a greenhouse experiment was conducted in randomized complete block design with three replications in Agricultural faculty of University of Tabriz in 2016. The results indicated a reduction in maximum fluorescence (Fm), variable fluorescence (Fv), maximum quantum yield of photochemistry (Fv/Fm), efficiency of the water-splitting complex on the donor side of PSII (Fv/Fo), and performance index (PI_ABS), and an increase in minimum fluorescence (Fo) and photosystem II antenna (Fo/Fm) of Common lambesquarts subjected to Bentason and Bromoxynil+MCPA. Dry weight and chlorophyll index in control treatment (without SA) increased 4.3% and 2.1% respectively, but in Bentason and Bromoxynil+MCPA and 2,4-D+MCPA treatments, these two indexes reduced 41.6%, 13.7%, 13.6% and 32.2%, 36.4%, 18.7%, respectively. SA not only did not reduce the Bentason and Bromoxynil+MCPA efficiency, but also increased efficiency of these two herbicides. https://ijws.areeo.ac.ir/article_115886_7e34c46f746ebf39acad6c04aca015fc.pdf