CSIRO cotton breeders have provided a glimpse of two exciting new Australian-bred varieties set for commercialisation in 2012.
Speaking on CSD’s Web on Wednesday broadcast, CSIRO cotton breeder Dr Warwick Stiller introduced a new high yielding variety with Bollgard II Roundup Ready Flex and a new conventional.
Dr Stiller said Sicot 75BRF was a breakthrough in resistance to the soil-borne disease fusarium wilt which is now present in almost all cotton production areas.
“From the data we have at the moment, the fusarium resistance rank of this variety is 142 which is 10 points higher than our current best variety, Sicala 340BRF – so this is a massive jump in fusarium resistance from what we’ve had in the past.”
“We’ve found it to be slightly more vigorous than Sicot 74BRF – probably a similar degree as Sicot 74BRF is fractionally more vigorous than Sicot 71BRF - so some caution should be taken for the cooler, southern and eastern areas.”
He said, based on the current data, the yield appears to be intermediate between Sicot 71BRF and Sicot 74BRF – so approximately two percent better than Sicot 71BRF.
“I think when we get it out in the field in some of the more central areas – the Namoi, Gwydir, Macintyre and even up onto the Downs, there is the potential there to extract a bit more yield with the right management. It has improved staple length over Sicot 71BRF and even Sicot 74BRF – and the strength and micronaire is roughly similar to what Sicot 74BRF is.”
Dr Stiller said Sicot 75BRF may be the last variety released with Monsanto’s Bollgard II traits – with efforts now being directed to Bollgard III.
“Its’ dependant on whether all the regulatory hurdles that Bollgard III still have to pass can be overcome, but with the timelines we’re currently working on this will be probably be the last BRF variety,” he said.
CSIRO’s attention to conventional varieties is still very strong according to Dr Stiller, despite only comprising less than two percent of the national crop.
He said a new experimental variety, designated CSX9238 had shown a four percent yield improvement over Sicot 71 across three years of experiments.
“It’s quite a broadly adapted variety with a similar sort of growth habit to Sicot 71. Given time, I think there are some areas where it could potentially replace Sicot 71 but I don’t think I’ll make that call just yet. Like Sicot 71, it is a full season variety so we would expect it to do better in the central to full season regions.”
“There are some improvements in staple length – it’s at least a grade better for staple than Sicot 71 and just as importantly, the fusarium wilt resistance is around 110 – 113 so while it’s not the best of the varieties we’ve got, it’s quite an improvement.”
“The conventional breeding program really forms the backbone of our program and that is where the new gains in fibre quality, disease resistance regional adaptation and particularly yield are going to come from.”
“So one of the reasons for bringing new conventional varieties through is to get a better evaluation across larger scale experiments than what we can do in CSIRO. This variety is being moved into the transgenic program and hopefully over the next few years we will see transgenic versions in one form or another.”
Cotton Seed Distributors general manager Steve Ainsworth said both these new varieties would be under commercial evaluation and seed increase in the 2011-12 season – aiming for full commercial release in 2012-13.
He said growers wanting to know more about these new varieties should contact any of the Cotton Seed Distributors extension and development agronomists.
