THE COTTON industry is set to take the fight against heliothis pests to a new level in the 2015-16 season when the three-gene, insect-resistant Bollgard III lines of cotton are due for commercial release.
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Bollgard III will take over from the highly successful, two-gene Bollgard II.
The introduction of genetically-modified, insect-resistant cottons – which started with Ingard in 1996 and Bollgard II in 2004 - is credited with reducing insecticide application rates in the industry by 80 percent.
Monsanto technical development team lead Tony May said the aim of taking the next step of introducing Bollgard III was to make sure the Bt technology would remain an effective tool for controlling heliothis well into the future.
“Bollgard II has two Bt proteins. It is working really well and we get great control of the heliothis pest,” he said.
“But insects have a good ability to develop resistance so we and the industry have been doing a lot of resistance monitoring and making sure the two species, armidgera and punctigera, don’t develop resistance to those two toxins in the plant.”
Mr May said adding a third protein, Vip3A, to the plant made it much more difficult for insects to develop resistance.
“They are all independent proteins so if an insect has some resistance to one protein it will be controlled by the other two,” he said.
“There is enough killing power within a plant to overcome any insects that are resistant.”
Mr May said the industry had been working on developing submissions to the Office of the Gene Technology Regulator (OGTR) and Australian Pesticides and Veterinary Medicines Association (APVMA) to gain regulatory approval for the new lines.
“We hope to have all domestic regulatory approvals in place by the 2015/2016 season,” he said.
“They are the timelines we are working towards, but it will be up to the regulators.
“If it comes to be, it will be the opportunity to have the first Bollgard III into the market in that year.”
Mr May said a Bollgard III resistance management plan would be developed for when the lines were introduced.
He said there might be opportunity to ease some of the constraints that were applied to Bollgard II.
Under the resistance management requirements for Bollgard II, growers have to grow refuge crops of pigeon peas or unsprayed cotton and sow their crops within strict planting windows.
The refuges provide a supply of insects that haven’t been exposed to Bt cotton and which mate with any potentially resistant moths that come out of the Bt cotton, thereby diluting any resistance genes that are there.
The planting windows limit the number of generations of heliothis that are exposed to Bt.
“There may be some opportunities to make it easier for farmers growing Bollgard III on the resistance management plan. We may be able to reduce some of the requirements a little bit,” Mr May said.
“We wouldn’t want to compromise any longevity, but there may be opportunities to help out.”
