Influence of herbicides on cellulolytic, proteolytic and phosphate solubilising bacteria.

Accepted : February, 2010 The present day agriculture depends upon high yielding varieties, inorganic fertilizers and pesticides to achieve the increased food production required to keep pace with the increasing population. The progressive modernization of irrigated rice cultivation in India, using the above technologies has led to tremendous increase in rice production, which has more than doubled over the last 35 years, mainly driven by 85% increase in productivity. In India, herbicides constituted only 15per cent of the total consumption of pesticides, compared to the worldwide consumption of 47.5 per cent. The herbicide consumption is expected to increase dramatically in future as the use of herbicides has been expanding more rapidly than that of the other pesticides (Bhan and Mishra, 2001). Herbicide usage, which was earlier confined to plantation crops, has now expanded to crops like wheat (42 per cent of the total consumption of herbicides) and rice (30 per cent) with the states of Punjab, Uttar Pradesh, Tamil Nadu and Andhra Pradesh leading in the consumption of more herbicides. Since the herbicides are used when the crop is either absent as pre-emergence or at its early stage of growth as post-emergence, a high proportion of the herbicide reaches the soil and accumulates in the microbiologically active