Farmers say scientists advised them to mix pesticides with a sugary syrup to control pests, and they found the mixture cheaper and more effective than pure chemicals -- although soft drink makers and scientists dismissed the claims.

N Hamunayya, who has become a celebrity in his village in Andhra Pradesh, said his crop survived an attack of pests which had resisted other remedies.

"We found that all the colas had uniform effect on pests. The pests became numb and fell to ground," he said.

He said the drinks had all the elements they needed: they were cheaper, sticky, fizzy, and attracted ants, which devoured the larvae of the pests.

But Thirupathi Reddy, assistant director of the Regional Agri Research station, Guntur, says tests had refuted such claims.

"We conducted some field trials on cotton crop at our research station. There was no boosting of productivity or eradication of pests," he says.

Statements from Pepsi and Coca-Cola said there was "no scientific basis" for this practice.

But their vendors are enjoying booming sales.

Mantan Wali, who sells soft drinks in 17 villages in the region, said sales fizzed up, thanks to the farmers.

"For the 10 days between August and September I had booming business. Instead of just 30 cases (each containing a dozen one-litre bottles) of cola I started selling almost 200 cases," he said.

"We expected the sales to nosedive after the cacophony over pesticide residues in the cola drinks. Now I have to keep extra stock for the cotton farmers," he said.

In February, a Parliamentary panel upheld a report by an environment group that said beverages made by Coca-Cola Co and PepsiCo Inc contained pesticides and called for tougher safety standards.

The US firms strongly rejected the findings of the New Delhi-based Centre for Science and Environment and said their products were safe.