Fusarium Wilt returns to haunt cotton

03 December, 2002

___An unfortunate dividend of the cool, wet start to the cotton growing season has been an expansion of fusarium wilt._

According to the QDPI Fusarium Diagnostic Service, two new outbreaks have been confirmed in NSW: on the Darling River in Western NSW, and in the Macquarie Valley near Warren. The disease has also been seen in Pima cotton for the first time.

Fusarium Wilt (pictured) is also suspected on three more farms in the Gwydir, Macquarie and Darling River regions, but these outbreaks have yet to be confirmed.

The good news is that there are still no confirmed reports of fusarium in the Emerald, Lower Namoi, Tandou or Hillston cotton growing areas.

__Cotton Seed Distributors Pathology team leader, Dr Stephen Allen, said that in severely infested areas, up to 80 per cent of seedlings had died. In areas where fusarium has been established for several seasons, seasonal conditions even over-powered and diluted the performance of resistant cultivars.

Dr Allen said cotton pathologists are developing an Integrated Disease Management Strategy for fusarium based on the use of more resistant cultivars, crop management and disease control practices.

He said the CSD pathology team was contributing to this effort with approximately 30 field experiments over five sites this season, which will be showcased via field days and farm visits over the next couple of months.

Treatments being evaluated include cultivation, pre-emergent herbicides, fertilisers, animal manure, products that induce resistance, soil fumigants, rotation crops, crop residue management options, seed treatments, and several biological and organic products, as well as cultivars.

The industry is also expected to benefit from a February visit by United States fusarium expert, Dr Pat Colyer, from the Red River Research Station in Bossier City, Louisiana, who has worked on fusarium wilt in the USA for several years.

Dr Colyer will visit trial sites and affected farms, and meet with farmers, cotton breeders, pathologists and biotechnologists.

His visit is being sponsored by the Australian Cotton CRC, the Cotton Research and Development Corporation, and FUSCOM (the CRC’s “Fusarium Wilt of Cotton Research and Extension Coordination Committee’).

__Dr Allen said disease problems appeared to be more observable now the crop had started to mature, but there is still some evidence that fusarium is being confused with verticillium wilt.

“QDPI has confirmed that last season, about 80 per cent of all samples submitted for fusarium confirmation, tested negative for fusarium. “Growers have nothing to fear, so If in doubt -Check it Out,” Dr Allen said.

Further Information: *"Robert Eveleigh**, John Marshall, Greg Kauter or Craig McDonald":showstaff.asp?staff=1

or Dr Stephen Allen