Breeding summer-dormant grasses for the United States
Summer dormancy can lead to increased drought tolerance and persistence in cool-season grasses. Here we describe efforts to develop summer-dormant cultivars in the United States. Summer-dormant grasses are generally well adapted to the Southern Plains but have poor persistence as well as low productivity east and north of this region because of limited winter hardiness and other factors. This limited geographic adaptation is thought to be due to germplasm background rather than the summer dormancy trait. Depending on the target environment, improved cultivars could be developed by selecting within existing summer-dormant material or by crossing the trait into adaptive germplasm. Difficulties in phenotyping summer dormancy, and in some instances fertility barriers across germplasm sources, will need to be overcome to utilize the latter approach.