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)

Photosynthesis in plants is strongly influenced by stress. Evaluation of chlorophyll a 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〣 and 2,4-D〣 herbicides on physiological behavior of Common lambesquarts (Chenopodium album 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 (PIABS), and an increase in minimum fluorescence (Fo) and photosystem II antenna (Fo/Fm) of Common lambesquarts subjected to Bentason and Bromoxynil〣. Dry weight and chlorophyll index in control treatment (without SA) increased 4.3% and 2.1% respectively, but in Bentason and Bromoxynil〣 and 2,4-D〣 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〣 efficiency, but also increased efficiency of these two herbicides.