Abstract

This study investigated characters that contribute to high grain yield in the recently released Australian winter wheat, cv. Currawong. Currawong was released as a feed grade wheat for south-central New South Wales, with a 10% yield advantage over the highest yielding milling wheat with winter habit, Rosella. When expressed as a percentage of the grain yield of Rosella, Currawong was found to perform best at sites with low soil pH and high grain yield. These sites corresponded to the wetter eastern margin of the wheatbelt in south-central New South Wales. While part of the yield advantage of Currawong is due to its tolerance of soil acidity, there remains an ability to yield particularly well in environments conducive to high yield. In yield component studies that were conducted over 2 seasons at Temora, the yield advantage of Currawong appeared to be associated with its grainfilling characters. Currawong had a more rapid rate of grainfill, and/or a longer duration of grainfilling than other high-yielding winter wheats, leading to significantly heavier grain.

From a plant breeding perspective, the high yield of Currawong is significant for demonstrating rapid genetic gain for yield in Australian winter wheats. The yield of Currawong also demonstrates the possibility of combining high grain yield with the Sr26 stem rust resistance. Characters that confer high yield in Currawong may be of limited benefit in environments where drought stress limits the duration of grainfilling in wheat.