Testing of North American barley cultivars for a sub-tropical environment

Selecting cultivars or breeding lines suited for new productionareas is a difficult task because most accessions lack one or more traitsessential for successful production in the new environment. Expansion ofbarley, Hordeum vulgare, production into the subtropical parts ofQueensland is an example of such an undertaking. Key traits involved inadaptation appear to be resistance to spot blotch (Bipolaris sorokiniana)and stay-green, a tolerance to post-anthesis heat and drought stress. MostAustralian cultivars lack one or both of these traits. The economics of seedproduction and distribution require successful introductions to haveadvantages in adjacent production areas where several leaf diseases cancause losses. The diseases include powdery mildew (Blumeria graminis f.sp. hordei), leaf rust (Puccinia hordei), net and spot forms of net blotch(Pyrenophora teres f. teres and maculata), scald (Rhynchosporiumsecalis), stem rust (Puccini graminis f. sp. tritici), crown rot (Fusariumpseudograminearum), and common root rot (B. sorokiniana). Years oftesting barley accessions from North America have identified a sister lineof the North Dakota cultivar ‘Rawson’ as having many of the desirableattributes. Although ND19119-5 does not have higher yields, its largekernel size and the stay-green trait could make it attractive to barleygrowers in Queensland and northern New South Wales. Since locallydeveloped cultivars have shown yield advantages, there is an opportunityfor using attributes of North American introductions to breed cultivars thathave higher yields and better combinations of maturity genes, agronomictraits, and disease resistances.