Abstract:
Fusarium wilt was identified on the Darling Downs in the early 1990's and the disease has now been found in most cotton growing areas. The extreme levels of plant death and yield decreases from the disease, coupled with the rapid spread, have seen Fusarium emerge as a major threat to the future of the cotton industry in Australia. Soon after the disease was recognised CSIRO began screening our locally bred lines and numerous introductions from all around the world. Unfortunately we found very little resistance to the disease. The best of our varieties was SiCot 189, but it could not cope with high levels of Fusarium. Some of our varieties such as Siokra 14 were extremely susceptible. There was some correspondence with Verticillium wilt resistance (SiCot 189 and SiCala V-2 have some resistance to both) but not in all cases (Siokra V-16 has some Verticillium resistance but is very susceptible to Fusarium). Amongst the introductions tested only MCU-5, a variety from India, showed significantly better survival. Using the results of the screening nurseries a large crossing and selection program was initiated to tackle Fusarium.
