The threat posed by superweeds on US corn and soya plantations have rekindled the demand of militant farmers and scientists for an end to the cultivation of hybrids.

Less than two months ago, the same groups – Kilusang Magbubukid ng Pilipinas (KMP) and the Magsasaka at Siyentipiko sa Pag-unlad ng Agrikultura (Masipag) – also demanded the dismantling of the International Rice Research Institute (IRRI) in Laguna, which they claimed "did not provide relief from farmers' woes and instead created layers upon layers of burden."

"IRRI's rice technology caters only to a few wealthy farmers, agricultural suppliers and multinational corporations," Dr. Chito Medina, national coordinator of Masipag, said.

With IRRI's encouragement, fertilizer use in Asia rose from only 52 kilos per hectare in 1979 to 138 kilos per hectare in 1999.

Output also declined markedly after the soil was bombarded with chemical inputs and Masipag suspects that this is the culprit for soil sterility.

The annual Asian rice growth rate of 3.4 percent in 1977 slid to only 1.5 percent in 1997.

Medina said Masipag opposes the use of hybrids since these are heavily dependent on chemical inputs, the high costs of which pushed farmers into debt servitude since IRRI's Green Revolution was launched.

The rise of superweeds festering corn and soyabean plantations in the US also showed just how weak the claim of the large US agriculture input company Monsanto that its Roundup Ready corn was genetically designed to tolerate weeds.

While the biotech corn did resist weeds, these weeds developed immunity to glyphosate, a herbicide that Monsanto had propagated and is now used in many US plantations.

Militant farmers and scientists insist that the battle against weeds and pests is a never-ending battle and this has been made even more significant as pests and weeds have mutated and proved to resist the debilitating effects of herbicides and pesticides.