High grain yields are being forgone by Australian growers because most cereals are still not preceded by a break crop, according to John Angus of CSIRO Plant Industry. Crop statistics show that the annual average 16 million ha of cereals grown in Australia each year far exceeds the 4 million ha of broadleaf (break) crops including pulses and oilseeds, Dr Angus said.

"The adoption of break crops in the past 20 years has triggered the largest increase in yields in the history of the Australian wheat industry," he said at a recent Cropping Research Update supported by the GRDC. Improvements to yields occur through break crops such as pulses boosting soil nitrogen while brassica oilseeds, including canola, provide a biofumigation effect on cereal root diseases.

Dr Angus said the increased sowing of break crops would contribute to further increases in wheat yields and this should occur when better-adapted pulse and oilseed varieties become available; when better, methods of managing these crops are devised; III)d when growers are further assisted in crop sowing decisions. "There is also a need to further measure break crop benefits in different environments and to research the mechanisms of the break crop effects;' he said.

Contact: Dr John Angus 02 6248 4911