Laboratory germination responses of 3 love-grasses to temperature in relation to seedbed temperatures

Measured seedbed temperatures and soil water on two semidesert grassland sites in the US Southwest, and tested germination of Lehmann lovegrass Eragrostis lehmanniana, "Cochise' lovegrass (E. lehmanniana × E. trichophora) and plains lovegrass E. intermedia seed collections associated with natural or artifical revegetation studies on these sites in relation to an array of constant and alternating temperatures. Lehmann and Chochise lovegrass had high germination at temperature alternations similar to wet seedbed temperature extremes in December (0,2/15°C) and these species and plains lovegrass were germinable at moderate temperature alternations representative of wet seedbeds in April (10/30°C)./ Ability to germinate in laboratory tests at these temperatures is not necessarily indicative of germinability in the field for Lehmann lovegrass, which has been observed to germinate in April, not December, in wet seeedbeds. All species had maximum or near maximum germination at a temperature alternation of 20/40°C, similar to wet seedbed temperature extremes during the summer rainy period when these species usually emerge. -from Authors