Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 30, 1993
Publication Date: N/A
Interpretive Summary: Native vegetation in the sagebrush-bunchgrass vegetation type of the Great Basin has been replaced over large areas by cheatgrass, an alien weedy grass. Cheatgrass invasion lowers natural levels of biodiversity, severely limits forage availability in dry years, and significantly increases fire frequency on public and private rangelands. Cheatgrass is able to germinate eat relatively low temperatures early in the spring and establish a root system more quickly than native perennial grasses. A pre-sowing seed treatment currently under development by ARS scientists was used to enhance low temperature germination response of seven perennial grasses native to the Great Basin region of the U.S. This seed treatment, called matric-priming, was found to increase germination rate of native perennial grasses by up to eight days at cold temperature. Three of the native species could be induced to germinate as rapidly as cheatgrass. Matric-priming is especially well suited for rangeland applicationsbecause of the relatively low cost of treating large quantities of seeds once optimal priming conditions are determined in the laboratory.
Technical Abstract: Cheatgrass (Bromus tectorum) germinates at relatively low temperature in the spring and is able to establish a root system more quickly than Great Basin native perennial grasses. A matric seed priming technique was used to enhance low temperature germination rate of seven perennial grasses native to the intermountain west: bluebunch wheatgrass (Pseudoroegneria spicata), thickspike wheatgrass (Agropyron dasystachyum), basin wildrye (Leymus cinereus), sheep fescue (Festuca ovina), canby bluegrass (Poa canbyi), Sandberg bluegrass (Poa sandbergii) and bottlebrush squirreltail (Sitanion hystrix). Seeds primed at both 10 and 25 C were evaluated for germination response at both 10 and 25 C. The maximum reduction in median germination time for seeds germinated at 10 C was between about 4 and 8 days for all species. Germination rate at the colder temperature was generally higher when the seeds were primed at 25 C except for basin wildrye. Priming increased cold temperature germination rate of bluebunch wheatgrass, thickspike wheatgrass and sheep fescue to a level comparable to cheatgrass.