Australian farmers embrace GM cotton

The first full-scale production season for Australia's new Bollgard 2 transgenic cotton cultivars is shaping as an outstanding success, despite continuing drought in areas of NSW and southern Queensland.

With the harvest due to begin in northern regions in late February, Bollgard 2 cultivars will account for some 70 per cent of this season's 310,000 hectares.

CSIRO cotton breeder Dr Greg Constable, of the Cotton Cooperative Research Centre at Narrabri said farms that have planted the new cultivars are likely to do even better than the 86 per cent reduction in synthetic pesticide consumption achieved with last season's first limited-scale plantings of Bollgard 2 cultivars.

And this is in a season that has seen "quite heavy pressure" from destructive Helicoverpa caterpillars, Constable said. Heavy infestations of H. punctigera on conventional, unprotected crops have required farmers to spray repeatedly with synthetic pesticides.

"Essentially, no spraying have been necessary to control Helicoverpa bollworms," Constable said. "The only sprays have been for control of aphids, myrids and mites."

Constable said most growers were achieving further savings by planting Bollgard 2 cultivars that, in addition to carrying the Cry1ac and Cry2Ab insecticidal transgenes from the bacterium Bacillus thuringiensis, also contain Monsanto's improved version of its Roundup Ready (RR) gene, which confers improved resistance to the herbicide Glyphosate.

The previous version of the RR gene could only be used on seedlings up to the four-leaf stage, limiting weed control to the early season. The new variant allows growers to spray at any time in the season - it gives superior weed control and provides further savings by reducing fuel costs for tillage.

Overall, 45 per cent of growers planted Bollgard2/RR varieties, 25 per cent planted Bollgard 2-only, 10 per cent planted Roundup-Ready cultivards, and 20 per cent chose conventional cotton.

In their introductory season, 2003-04, limited seed supplies restricted plantings of Bollgard 2 varieties to only 16 per cent of the crop. Obsolescent Ingard cultivars, which carry only one Bt gene, were limited to 30 per cent of the total crop in 2003-04 in compliance with measures to prevent the emergence of Bt-resistant pests - they were completely phased out this season.

Constable said that, with the rapid uptake of the new varieties this season, conventional cotton would account for only 20 per cent of this year's 310,000 hectare crop.

Severe drought last year limited plantings to only 180,000 hectares, well down on the long-term average of around 400,000 hectares.

The ongoing drought is one reason why Australia has been one of the only nations growing GM crops to go against the worldwide trend towards increasing its GM crop acreage.

Worldwide GM crops up 20 per cent

According to a report this month by the International Service for the Acquisition of Agri-Biotech Applications (ISAAA), an independent agency that monitors GM agriculture, Australia still ranked 10th in total plantings in 2004, behind the US, Argentina, Canada, Brazil, China, Paraguay, India, South Africa and Uruguay.

ISAAA reported that the total global area planted to GM crops in 2004 increased by 20 per cent - a substantial upturn in the 15 per cent annual rate of increase that has been sustained since the first GM crops were planted in 1996.

The rise, coming on top of the already geometric rate of increase, brought the total global area of approved GM crops to 81 million hectares, up from 67.7 million hectares in 2003.

In 2004, according to the ISAAA survey, GM crops accounted for 5 per cent of the 1.5 billion hectares of cultivable cropland worldwide. Some 8.25 million farmers in 17 countries were growing GM crops, up from 7 million in 18 countries in 2003.

The most significant trend, according to ISAAA, was that 90 per cent of the farmers now benefiting from increased income from GM crops were resource-poor farmers from developing nations.