Seedbed Requirements for Germination of Sandberg Bluegrass1
- Raymond A. Evans,
- James A. Young and
- Bruce A. Roundy2
Sandberg bluegrass (Poa sandbergii Vasey) is an important range forage species in western North America. If a commercial source of seed were available, Sandberg bluegrass would be a valuable species for revegetating range-lands. Our purpose was to investigate the germination of seeds (caryopses) of Sandberg bluegrass. Seeds were placed in petri dishes and germinated in incubators with constant and alternating temperatures ranging from −6, −4, −2, O, 2, 5 C, and 5-degree increments through 40 C. Each of 85 regimes consisted of 16 hours at cold and 8 hours at all possible warmer temperatures. Germination with and without soil and litter coverage was investigated in clay and sandy loam seedbeds in the greenhouse. Also, the effects of simulated litter on germination was investigated in saturated atmospheres in the laboratory. After a 6 months' afterripening requirement was satisfied, Sandberg bluegrass seeds germinated over a wide range of temperatures from −2 to 35 C. Optimum temperatures for germination, those giving maximum germination and not being significantly different (p = 0.01) from each other, varied among years, but 5, 10, and 15/20 C were consistent in this group. Most rapid germination occurred consistently at 15/15 and 15/25 C. Germination on the soil surface was limited unless coverage was provided. Burial greater than 3 cm inhibited emergence. Seeds of Sandberg bluegrass germinating in a simulated litter environment failed to develop roots although coleoptiles elongated normally. Germination requirements will not limit the usefulness of Sandberg bluegrass as a revegetation species as long as the constraints imposed by afterripening and soil or litter coverage are recognized.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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