BANGALORE, India - Farmers are defying the government to grow genetically modified cotton in northern India, where authorities have barred it from being planted, the federal textile minister said Thursday.

Authorities have not yet allowed companies to sell seeds of modified cotton - called Bt cotton - in the northern agricultural states such as Punjab and Haryana. So farmers there have found ways around it, Shankarsinh Vaghela told reporters in the southern city of Bangalore.

"Farmers in Punjab and Haryana also want to grow Bt cotton. They go all the way to Gujarat to buy the seeds," Vaghela said, referring to the western desert state. "I don't know if it is illegal. You have to ask the agriculture ministry."

Bt stands for bacillus thuringiensis, a bacterium whose gene is injected to cotton seeds to give them resistance against bollworms, a major concern for farmers in India, where the economy is driven by agriculture.

Bt cotton developed by agricultural biotech giant Monsanto Co., based in St. Louis, is the only bioengineered crop allowed in India. But so far, it is permitted only in six southern and western states.

The fertile plains of the north that include Punjab and Haryana have been kept out of genetic engineering. Last year, the government's regulatory body for the sector, the Genetic Engineering Approval Committee, refused a strain of Bt cotton for use in the north, finding that it was vulnerable to another pest, known as the leaf-curl virus.

Advocates of genetic modification say it helps fight plant diseases, increase yield and improves nutritive value of food crops.

Critics counter that the adverse effects of the technology have not been studied adequately. They say genetically modified seeds are environmentally hazardous and could contaminate the genes of native varieties through cross pollination, eventually making farmers poorer.

Environmental group Greenpeace said Bt cotton cultivation in unapproved regions is an indication that genetic modification in agriculture cannot be regulated effectively.

"One problem is the government's inaction and inability to regulate the cultivation of BT cotton," said Divya Raghunandan, a Greenpeace campaigner in Bangalore. "The other problem is the inherent nature of the technology, which cannot be regulated. It keeps spreading across fields."

Meanwhile, Monsanto said Bt cotton cultivation in the north was beyond the company's control.

"We do not sell the seeds there. If somebody buys from where it is approved and takes it to the north, it is not in our control," Ranjana Smetacek, Monsanto's Indian spokeswoman, said from Bombay.