Abstract: The pot trials showed that low light intensity decreased the growth of wheat weeds Veronica agrestis and Chorispora tenella, but high nitrogen application rate could make V. agrestis develop more leaves to adapt the weak light condition. Nitrogen application benefited the growth of V. agrestis under high or low light intensity, but had no significant effect on the growth of C. tenella under low light intensity. V. agrestis had a stronger competitive ability than C. tenella when the two weeds grew together on the soil rich in P and K, and the competitive predominance of V. agrestis could not be changed by light intensity and nitrogen application rate.

Key words: Chlorophenols, Aerobic degradation, Anaerobic degradation, Bioderadability, Biotechnology