Germination Profiles of Introduced Lovegrasses at Six Constant Temperatures

Abstract

Seeds of A-68 Lehmann lovegrass (Eragrostis lehmanniana Nees), cochise lovegrass (Eragrostis Iehmanniana Nees X Eragrostis trichophora Coss & Dur.) and A-84 and Catalina boer lovegrasses (Eragrostis curvula var. conferta Nees) accessions were germinated for 14 days at constant temperatures of 15,18,21,24, 27, and 30" C. Light intensity was 216 p mol m-k-' and photoperiod was 15 h. Germination of Catalina seeds varied from 87 to 96% between 18 and 300 C after 12 days. Germination of cochise seeds was optimum between 21 and 270 C after 12 days. Germhtation of A-68 seeds was optimum at 27" C and A-84 seeds at 30" C. This study indicates that Catalina boer lovegrass and cochise lovegrass will germinate at relatively low temperatures. A-68 and A-84 lovegrasses, in contrast, require higher temperatures for optimum germination. The authors are graduate student, School of Renewable Natural Resources, University of Arizona, Tucson 85721; and range scientist.

Research observation: Nitrogen effects on Arizona cottontop and Lehmann lovegrass seedlings

“…Las plántulas de D. californica produjeron más biomasa por planta (1.09 vs. 0.31g), exhibieron mayor eficiencia en el uso del nitrógeno (63 vs. 39 %), y toleraron mejor condiciones de alto nivel de N. D. californica podría ser un competidor superior por N tanto en condiciones de N limitante como en aquellas de alto nivel de N, mientras que E. lehmanniana podría superar a D. californica en la competencia por N bajo niveles moderados de este nutriente. and Cox 1984); and relative unpalatability compared to natives (Cox et al 1990). Lehmann lovegrass also can use soil water during the winter and early spring, when other warm-season plants are generally considered to be dormant, and is able to extract soil water at very low soil water potential (Frasier and Cox 1994).…”

Research observation: Nitrogen effects on Arizona cottontop and Lehmann lovegrass seedlings

“…and Cox 1984); and relative unpalatability compared to natives (Cox et al 1990). Lehmann lovegrass also can use soil water during the winter and early spring, when other warm-season plants are generally considered to be dormant, and is able to extract soil water at very low soil water potential (Frasier and Cox 1994).…”

Laboratory Germination Responses of 3 Lovegrasses to Temperature in Relation to Seedbed Temperatures

“…is a native perennial lovegrass that is adapted to higher Although Jordan and Haferkamp (1989) presented germination rate data for Cochise and plains lovegrass, little other germination data have been reported for these 2 species. Germination of Cochise lovegrass was much higher than that of Lehmann lovegrass at constant temperatures of 15, 18, and 21" C (Martin and Cox 1984). Germination responses of Cochise and plains lovegrass to alternating temperatures have not been reported but Chirco and Turner (1986) recommended alternating temperatures of 20/ 30° C and 20/ 35" C for testing of Lehmann and plains lovegrass germination, respectively.…”

“…Lehmann lovegrass germination responses to different temperature and other treatments vary greatly depending on collection and seed age. Certain collections of Lehmann lovegrass have exhibited high germination under constant temperatures (Toole 1938;Knipe 1967;Ryan et al 1975a,b;Martin and Cox 1984). Some collections have a strong post-harvest or extended dormancy that may decrease with time, mechanical scarification, exposure to light, prechilling, and various moisture and temperature pretreatments (Knipe and Herbel 1960, Brauen 1967, Wright 1973, Hardegree and Emmerch 1991.…”