The use of vegetation as biological indicator of environmental quality has a long History dating back to the miners canary, to the recognition about 100 years ago. Recent studies have shown the feasibility of using natural vegetation for monitoring pollution (Berg, 1973; Brandt, 1974; Vick and Bevan, 1976; Rasmussan, 1977; Navara, Horvath and Kaleta, 1978).

In spite of the very varied approach of study and the extensive work done, the larger number of herbicides being developed in industry and used in agriculture stand only in testimony of the necessity of more work in the field. Herbicides drastically reduced pollen germination as well as tube growth. It was, therefore, important to study the effect of such chemicals on germination as well as tube growth since inhibitory effects of these chemicals will eventually reduce fruit- and seed-set. For the present study Nitrofen or Tok-E25 (2,4-Dichlorophenyl 4-nitrophenyl ether) (25%) very common herbicide was selected.