Advantages and Limitations of Biopesticides and Chemical Pesticides

	Advantages and Limitations of Biopesticides and Chemical Pesticides - The interest in biopesticides is based in the disadvantages associated with chemical pesticides, some of which are as follows: (i) extensive pollution of the environment, (ii) serious health hazard due to the presence of their residues in food, fiber and fodder, and (iii) increasing cases of insects developing resistance, e.g., Helicoverpa has become resistant to most of the insecticides. In contrast, biopesticides
(i) do not leave harmful residues, (ii) do not destroy nontarget species, and (iii) are often cheaper than chemical pesticides. Their chief disadvantages are, (i) very high specificity, which will require an exact identification of the pest/pathogen and may require multiple pesticides to be used, and (ii) often variable efficacy due to the influences of various biotic and abiotic factors (since biopesticides are usually living organisms, which bring about pest/pathogen control by multiplying within the target insect pest/pathogen)
The total world production of biopesticides is over 3,000 tons/yr, which is increasing at a rapid rate. India has a vast potential for biopesticides as it utilizes more than 100,000 tons (1992-93) of pesticides annually. Most (80%) of the pesticides are used on cotton (45%), rice (30%) and vegetables (5%), the remaining crops receiving only 20% as share.