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• Farm level data were used to compare yields of cereals and break crops with wheat. • Wheat was the highest yielding and least variable crop. • All break -crops were more sensitive to low yielding environments than wheat. • Canola was the most consistent broadleaf break crop. • In order to increase species diversity yields need to be improved relative to wheat. Typically dryland rain fed cropping systems in much of the world (Australia, North America, Europe and the Middle East) are dominated by cereals, such as wheat, even though the rotational benefits of other crops are well documented. Presumably farmers see an advantage to wheat and this paper tested the hypothesis that on-farm break-crop yields are lower compared to wheat, and more variable. Farm level yields for wheat, barley, hay, oats, triticale, canola, lupin, chickpea, and field pea were taken from a survey of Western Australian grain farms (180–302 farms per year). In general, the yield of broad leaf crops was less than cereals and more variable. Additional data were sourced from published experiments and then yields were compared with wheat using linear regression with wheat as the x-axis and break crop as the y-axis. All break -crops were more sensitive to low yielding environments than wheat, as indicated by a positive intercept with the x-axis. Barley and wheat yields were closely related (R2 = 0.63), but in environments where yield was less than 1.25 t/ha wheat tended to yield more, while barley out yielded wheat when yields were greater than 1.25 t/ha. There was a poor relationship between either oat grain (R2 = 0.26) or hay (R2 = 0.10) yields and wheat indicating that these maybe potential income diversification options. Canola was the least variable (R2 = 0.54) broadleaf crop compared to wheat, with an intercept of 0.15 t/ha and for every 1 t/ha increase in wheat yield, canola yield increased by 0.56 t/ha. If increased diversity of crop species on-farm is the objective, then varieties and management packages that increase the yield and reliability of broadleaf crops relative to wheat will need to be developed. [ABSTRACT FROM AUTHOR]