Germination in Cool‐Season Forage Grasses under a Range of Temperatures

Temperature plays a primary role in seed germination, and germination under a wide range of temperatures can promote early seedling emergence and stand establishment. The objective of this growth chamber experiment was to determine the effects of temperature (5–35°C) on the germination of eight species using 6 annual and 14 perennial cool‐season grass lots. The greatest germination of annual and perennial cool‐season grasses occurred at 20 and 15°C, respectively. Germination of oat (Avena sativa L.) was typically greatest at 10 to 20°C, whereas rye (Secale cereale L.) germination was generally greatest at 5 to 20°C and annual ryegrass (Lolium multiflorum Lam.) germination was greatest at 10 to 30°C. Germination of orchardgrass (Dactylis glomerata L.) and hardinggrass (Phalaris aquatica L.) was greatest at 15 to 20°C. Germination of tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] varied by type: summer‐active tall fescue had optimal germination between 15 and 25°C but summer‐dormant tall fescue had optimal germination between 10 and 20°C, except for ‘NFTF 1800E–’, which was more sensitive to high temperatures (> 5°C). On the basis of these findings, the seeding rates of rye, oat, orchardgrass, hardinggrass, and tall fescue should be increased by ∼30% if planted in early September rather than late September to account for the reduction in germination; summer‐dormant tall fescue should be planted 2 to 3 wk later (1–15 October) than summer‐active types (early September) in the southern Great Plains.