The fungal disease Verticillium wilt has been of sporadic importance in irrigated cotton for many years. It has traditionally been most serious in cool seasons in parts of the Macquarie valley, around Wee Waa and on the Darling Downs. Crop rotation (particularly with cereals) and other cultural practices help to prevent buildup of the disease. After a period of relatively low Verticillium levels for much of the 80s, the disease has made a pronounced comeback in recent seasons. During the 1988/89 season the disease was common in almost all areas from Warren to Biloela. Last season Dr Stephen Allen even found quite severe outbreaks at Bourke where, because of the very hot summers, the disease would not be expected to flourish.