A replicated, fully phased, field trial was conducted in Tamworth, New South Wales, Australia, to determine the effects of the most common winter and summer break crops on crown rot (caused by Fusarium pseudograminearum) in wheat. The experiment was established in 2000 by sowing F. pseudograminearum-colonized ryegrass seed with wheat cv. Janz into plots. In 2001, rape, chickpea, faba bean, sorghum or wheat cv. Janz were grown under a no-till system. In 2002, wheat cv. Sunstate was planted across the winter break crop plots. All four rotation crops proved effective breaks for crown rot. They encouraged breakdown of the 2000 Janz residue. Stubble ground cover in May 2002 was 15% for sorghum, 28% for faba beans, 30% for rape, and 41% for chickpea compared with 88% for continuous no-till wheat (and 60% long fallow). The rotation crops also reduced survival of the pathogen with recovery of F. pseudograminearum ranging from 7-13% in crowns to 10-15% in stubble following break crops compared with 33% in crowns and 49% in stubble for continuous no-till wheat. These effects carried through to the 2002 wheat crop where infection of Sunstate plants at tillering ranged from 25% for wheat after rape to 39% for continuous wheat.
