Summer Dormancy in Australian Perennial Grasses : Historical Background, a Simulation Study, and Current Research

The need for summer-dormant, perennial, temperate grass cultivars in Australia has increased since European-style agriculture arrived and began to push further inland into the drier pastoral zones. Early attempts to breed cultivars for marginal environments resulted in a few notable successes, but many failures resulted due to poor marketing, a lack of understanding of the environment, and economic downturns. A new spur to summer-dormant cultivar development is climate change with predictions of lower and more erratic rainfall and higher temperatures. This paper discusses briefly the history of temperate perennial grass breeding as it relates to summer-dormant cultivar development. Two case studies are presented. Simulations of higher input summer-dormant grass pastures vs. unimproved annual grass pastures are examined for long-term production and profitability under current and predicted climate scenarios. The current orchardgrass (syn. cocksfoot, Dactylis glomerata L.) and tall fescue [Lolium arundinaceum (Schreb.) Darbysh. = Schedonorus arundinaceus (Schreb.) Dumort.] breeding and commercialization programs are described.