Mexican farming communities accused German auto giant Volkswagen on Tuesday of "arbitrarily" provoking a drought in the central state of Puebla to protect its newly manufactured cars from hail.

Volkswagen, which has a major plant in Puebla, has been using "hail cannons" - sonic devises that purport to disrupt the formation of hail in the atmosphere - to disperse storm clouds menacing the thousands of new cars parked on its lots.

But farmers in Cuautlancingo, the rural municipality where the plant is located, say the controversial technique is causing a drought that has made them lose 2,000 hectares (nearly 5,000 acres) of crops.

Scientists are skeptical over whether hail cannons actually work.

But local farmers say the cannons work so well they have dispersed not only hail storms but all precipitation since May - what was supposed to be the start of the rainy season.

The farmers are reportedly seeking more than 70 million pesos (nearly $4 million) in compensation from the automaker.

Volkswagen tried to defuse the conflict this week by announcing it was taking the cannons off automatic mode and would only fire them when potential hail storms approached.

It also pledged to invest in protective mesh to serve as its first line of defense against hail.