In conclusion, dimethoate and UV-B, alone and together lead to
production of free radicals viz. O2
and H2O2 which causes lipid
peroxidation and electrolyte leakage. To reduce its deleterious
effect the activity of CAT, POD and SOD were increased in M.
charantia. Highest concentration of dimethoate (200 ppm)
together with UV-B exhibited maximum stimulation in enzymatic
activity. There could be a possibility of UV-B and dimethoate
interacting with the physiological as well as biochemical
mechanisms of the plant retarding its growth. Result thus showed
the severity of the stresses individually as well as in combination
and point out the importance of antioxidant machinery in reducing
the stress. However, efficient mechanism is needed further to
prevent the generation of free radicals.