Bumper Aust cotton harvest said to validate GM technology

The harvest of Australia's 2004/05 cotton crop, the first to involve full-scale production of new-generation, pest-resistant Bollgard 2 varieties, is nearing completion.

In the early 1970s, massive pest resistance forced the industry to abandon its former tropical heartland in WA's Ord River Irrigation Scheme and decamp to central-northern NSW. Its resurrection will be complete when growers in the cooler regions of southern NSW bring in their crops in the next few weeks.

The new, doubly-protected transgenic cultivars have delivered a further massive reduction in the industry's use of synthetic pesticides, a hazard both to human health and the environment.

CSIRO cotton breeder Dr Greg Constable, of the Cotton Cooperative Research Centre at Narrabri, said Bollgard 2 varieties this year accounted for about 70 per cent of the total crop area, and with the extended protection provided by two Bt endotoxin genes, average consumption of synthetic pesticides has been cut by 85 per cent.

Constable said the combination of the 85 per cent reduction in synthetic pesticides, and a huge increase in the area of the crop planted to transgenic cotton, from 30 per cent of the total crop last season, to 70 per cent this season, equates to a 60 per cent reduction in pesticide consumption for the average farm, relative to the pre-transgenic era.

Until this year, the industry voluntarily limited the total area of the national crop planted to transgenic cultivars to only 30 per cent, as part of a broad strategy to minimize the risk of pest resistance to now-obsolete, single-gene Ingard cultivars.

After their introduction in season 1995/96, Ingard cultivars reduced pesticide consumption by 50 per cent. But as long as conventional cultivars still accounted for 70 per cent of the crop, the net reduction in pesticide consumption industry-wide was only 15 per cent.

With the advent of Bt-protected cultivars, anti-GM activists and organic farmers protested that widespread planting of Bt-protected cotton would impose selection pressure that would lead to cotton's major pests, the heliothine moths Helicoverpa armigera and H. punctigera, becoming resistant to the 'organic' pesticide Bacillus thuringiensis, a mainstay of organic farming.

The industry's resistance management strategy required Ingard growers to plant small refuge areas of conventional cotton or other crops highly attractive to Helicoverpa larvae. The strategy was based on computer modelling which predicted that the regular influx of wild-type genes should swamp any emergent resistance genes, and it proved watertight.

In the seven years during which Ingard crops have been grown in Australia, no trace of resistance was detected in the field.

In addition to being protected against pests, 53 per cent of this year's total crop area was planted to herbicide-tolerant cultivars, containing Monsanto's Roundup Ready glyphosate-tolerance gene.

The RR gene has reduced the time and energy required to control weeds in the establishment phase of the crop -- Constable said many growers of non-RR cultivars still manually weed their crops.

Constable said that, perhaps as early as 2007, Monsanto will deploy its 'super' Roundup Ready technology. Currently, RR cultivars can only be sprayed up to the six-leaf development stage; thereafter, plants may be damaged by the herbicide. The new, more potent version of the RR gene will allow growers to control weeds through the entire season.

Constable said continuing drought again reduced the total crop area this year, but most growers of Bollgard/RR cultivars would have achieved substantial savings in production costs.

Costs up

The sting in the tail is that, this week, growers will have to pay an extra AUD$50 per hectare -- a 20 per cent increase on season 2004/05 to use Bollgard 2 technology.

Monsanto Australia communications manager Mark Buckingham said the company had been telling growers since 2003 that it believed the appropriate price for the technology was $300 per hectare, plus an extra $51 for Roundup Ready technology.

"Last year's $250 introductory price reflected the fact that growers needed to gain experience with Bollgard 2, and that seed companies had not had sufficient time to produce elite cultivars," Buckingham said.

"Both issues have been substantially addressed over the past season, so we are reverting to the price which, we have consistently been telling growers, reflects the proper value of the technology, and an appropriate sharing of the profits between ourselves and growers."

Buckingham said the company had considered the value in relation to the costs of insect control in conventional crops, both in terms of the expenses involved in purchasing and applying synthetic pesticides, and yield losses due to insect damage.

"The technology provides a wide range of other benefits to the farming system, and we haven't sought to put a value on those," he said.

The company's technology agreement provided for a range of payment options during the season, and rebates if growers chose to remove Bollgard 2 crops before a particular stage of development.