ICOP 2009-International Conference on Optics and Photonics Chandigarh,India,30 Oct.-1 Nov.2009 LIF SPECTRA OF DIMETHOATE TREATED CAJANUS CAJAN L

The effect of dimethoate on the photosynthetic activity and pigments content on Cajanus cajan L. is determined by laser induced chlorophyll fluorescence (LICF) and fluorescence induction kinetics (FIK) of leaves. The LICF spectra is recorded in the region of 650-780 nm by using 405 nm violet diode laser and FIK curves are recorded at 685 and 730 nm by using 635 nm red diode laser as the excitation source and PMT as a detector. The fluorescence intensity ratio (FIR) of control and as well as dimethoate treated C. cajan L plants are calculated by evaluating curve-fitted parameters using Gaussian spectral function. Vitality index is calculated by FIK curve. All these parameters along with photosynthetic pigments content are used to analyze the effect of dimethoate on C. cajan L. treated with different conc. of dimethoate (20, 40 and 80 ppm). It is found that dimethoate inhibits the plant growth even at very low concentration of 20 ppm.