1379 Integrated Disease Management for Fusarium Wilt of Cotton in Australia

Fusarium wilt of cotton, caused by F. oxysporum f sp.vasinfectum, was first recognized in Australia in 1993. The pathogen can be seed borne and it can also be dispersed in soil and crop residues attached to vehicles and machinery and carried in irrigation and flood water. Infection is favored by cool, wet spring conditions and shallow development of roots. The rapid increase in the distribution of the disease prompted a comprehensive response by the Australian cotton industry. A free central diagnostic service was funded by industry to confirm and record new outbreaks; major plant breeding programs were established to identify better host plant resistance; a protocol was established to provide growers with a quantitative ranking of cotton cultivars based on host plant resistance; fungicide seed treatments were tested for efficacy against seed borne inoculum; a seed production protocol was developed to minimise the chance of dispersing the pathogen in planting seed; cotton extension personnel and local grower associations promoted the importance of farm hygiene and wash-down facilities for vehicles and machinery; a research program was established to determine the origins of the pathogen in Australia and the potential for further adaptation. At the farm level, an extensive research program has evaluated a large number of strategies that could be incorporated into an Integrated Disease Management plan. The resulting plan includes the following recommendations to cotton growers: 1. Sow a resistant cultivar with Bion seed treatment, 2. Delay sowing to the end of October, 3. Avoid cultivating with knives, 4. Retain cotton residues on the surface for 60 d, 5. Bare fallow rotation is best, 6. If using a cereal rotation, then burn, bury, or bale residues, 7. Minimise run-off of excess irrigation water, 8.Always practice good farm hygiene, 9. Flood in summer (if possible) to reduce the inoculum in soil.