New Delhi, March 5
Monsanto has confirmed that its first-generation Bt (‘Bollgard-I') cotton has developed susceptibility to pink bollworm insect pests in the Saurashtra belt of Gujarat.
During field monitoring of the 2009 crop, scientists from Monsanto and Mahyco (its 26 per cent-owned local partner) detected “unusual survival” of pink bollworm in Bollgard-I cotton in four districts of Gujarat (Amreli, Bhavnagar, Junagadh and Rajkot), a company release issued on Friday said.
Bollgard-I cotton harbours the Cry1Ac gene, isolated from a soil bacterium, Bacillus thuringiensis (Bt).
The protein synthesised by this foreign gene is supposed to be toxic against various bollworm insect pests, thereby conferring ‘in-built' plant resistance and minimising spraying of chemical insecticides.
However, in its statement, Monsanto has admitted to the Cry1Ac protein's limited efficacy against pink bollworm, even though this has been confirmed only in the four said districts of Gujarat.
Push to new variant
At the same time, the single-protein Bollgard-I cotton continues to “deliver value” by controlling other bollworms, including the dreaded Helicoverpa armigera or American bollworm.
Some analysts view Monsanto's latest statement as a means to push its second-generation ‘Bollgard-II' gene construct technology, incorporating two Bt genes: Cry1Ac and Cry2Ab.
“No instance of insect resistance in any of India's cotton-growing States, including the four districts in Gujarat, has been observed with Bollgard-II”, the statement claimed.
During 2009, an estimated 250 lakh packets of Bollgard seed packets were sold in the country.
Of these, Bollgard-II (fetching prices ranging from Rs 750 to Rs 925 a packet) accounted for 55 per cent, with Bollgard-I making up the balance 45 per cent (at Rs 650-750 a packet).
According to Monsanto, approximately 80 per cent of all Indian cotton farmers are expected to plant Bollgard-II in the coming 2010 season.
Even in Gujarat, over 65 per cent farmers chose Bollgard-II in 2009, with pre-season bookings indicating that this proportion would cross 90 per cent in 2010, the statement added.
Why the resistance
Monsanto attributed the development of pink bollworm resistance to Cry1Ac protein in Gujarat to inadequate planting of non-Bt refuge and planting of unauthorised Bt hybrids prior to 2002 (when the Genetic Engineering Approval Committee had not accorded commercial clearance to Bt cotton).
The early use of unauthorised Bt cotton, having lower levels of protein expression, would have facilitated development of resistance.Related Stories:
Bollgard Bt cotton acreage may swell to 172 lakh acres
‘28% of area under cotton in Gujarat using illegal seeds’