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Research was conducted to evaluate the effects of presowing seed treatments and temperature on germination of seeds of Engelmann daisy (Ertgelmannia pinnatifida) and western indigo (Indigofera miniata var. leptosepala). The seeds were imbibed in controlled environmental conditions for 14 days with night/day temperatures of 5/15, 10/20, 15125, or 20/?O°C and a ll-hour photoperiod corresponding with the high temperature. Seed treatments prior to imbibition included: mechanical scarification, immersion in hot water (SO’C) for 3 min., acid scarification by immersion in concentrated sulfuric acid for 17 min., and an untreated control. Percent germination was affected by both temperature and presowing seed treatments. Maximum germination (43%) of Engelmann daisy was attained by untreated seeds at 20/30° C. Presowing seed treatments did not significantly increase germination of Engelmann daisy at any temperature. Western indigo seeds which were mechanically or acid scarified germinated over 90% in the 10/20, 15/25 and 20/30°C temperature regimes. Seeds immersed in hot water germinated from 59-68%, and untreated seeds germinated from 17-4270 in the same environmental conditions. Selection of adapted species for revegetation of deteriorated rangeland and surface mined lands is a very important consideration in a revegetation project. The revegetation specialist must often choose between introduced or native species of grasses, forbs, or woody plants to be planted in monocultures or mixtures. Presently, perennial warm-season grasses are used most frequently in revegetation of rangelands or surface mines in central Texas. Planting mixtures of grassesand forbs in the western United States has been found to expedite the natural sequence of plant succession. Mixtures in contrast to a monoculture provide a greaier variety for animals to graze, utilize the total soil profile more efficiently, and are generally better adapted to variable canopy, soil, terrain, and climatic conditions (Vallentine 197 I). Lack of available seed has been a deterrent to use of native mixtures in range seedings or reclamation projects in many areas (Eddlemann 1979, Sutton 1975). The USDA Soil Conservation Service in cooperation with the Texas Agricultural Experiment Station and the Texas Parks and Wildlife Department are continually seeking new plant varieties. Two of the native forb species being evaluated are Engelmann daisy (Engelmannia pinnatifida) The authors are graduate research assistant and assistant professor, Texas Agricultural Exoeriment Station. (Department of Range Science), Texas A&M University, College Station 77843. . This reoort is aoaroved for oublication bv the Director. Texas Anricultuml Exoeriment Staiion, as *Tech. Art& No. . The authors greatfully acknowledge the Center for Energy and Mineral Resources at Texas A&M University for funding the project, the USDA-SC& Plant Materials Center. Knox City, Texas, for providing seeds used in the study, and Mr. Don Shelton for assistance in the statistical analysis. Manuscript received April 13, 1981. and western indigo (Indigofera miniata var. leptosepah) (USDA Soil Conservation Service 1978). Engelmann daisy, a perennial cool-season forb, is native toall of Texas except the Piney Woods (Gould 1975). This species produces high quality, palatable forage. Western indigo is a perennial warm-season legume that has the potential to improve soil fertility through nitrogen fixation. This species grows in the eastern twothirds of Texas. Kneebone (1959) reported western indigo plants in Oklahoma were utilized by grazing animals and that nodule production was good. The species also rated fair in seeding habits, establishment potential, and first year’s growth. Both species have the potential to be used in seeding mixtures for revegetation of deteriorated rangelands or surface mines in central Texas. However, as with many forb species, we are lacking detailed information relative to the environmental requirements for seed germination and seedling growth and the potential for improving seed germination with presowing seed treatments. This information is vital if managers are to successfully establish these species in plant mixtures for revegetation projects. Preliminary trials in our laboratory have indicated germination (radical longer than 5 mm) percentages of 49 and 37 after 14 days in an 18/24’C temperature regime for Engelmann daisy and western indigo seeds, respectively. Our hypothesis is that Engelmann daisy and western indigo seeds germinate well over a narrow temperature range and their seed germination may be improved with presowing seed treatments. The study objective was to evaluate the effect of temperature and presowing seed treatments on seed germination. Materials and Methods Seed of PMT-874 Engelmann daisy and PMT-I051 western indigo were obtained from the USDA Plant Materials Center, SCS Knox City, Texas. Germination trials were conducted with 3-year old seeds which were uniformly large-sized, fully developed, and undamaged. Western indigo seeds were sorted by air; Engelmann daisy seeds (achenes) were removed from their bracts. Presowing seed treatments included mechanical scarification by cutting the seed coat with a razor blade (Latting 1961, Martin et al. 1975), immersion of seeds in hot water (800 C) for 3 minutes (Halls et al. 1970, Latting 1961), and acid scarification by immersion of seeds in concentrated sulfuric acid (HzS04)for 17 minutes (Latting 1961). Samples of 50 seeds previously dusted with a fungicide (Captan)!, were imbibed on 2 pieces of Whatman’ No. 1 filter paper in a IOO-mm diameter petri dish. The paper was supported by a 5-mm thick piece of polyurethane foam with a cotton wick in the center IMention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the Texas Agricultural Experiment StatIon and does not imply approval to the exclusion of other products that may aIs0 be suitable. 94 JOURNAL OF RANGE MANAGEMENT 36(l), January 1963 (Haferkamp et al. 1977). The filter paper was kept moist with sterile distilled water (pH 6). One piece of moistened filter paper was placed beneath the dish cover to improve moisture availability. Germination trials were conducted in a controlled environmental chamber. Night/day temperatures were set at S/ 15, 10/20, 15/25, or 20/3oOC with 1Zhour photoperiods during the high temperature periods. These temperature ranges were selected to coincide with normal monthly mean temperaturesincentralTexas (December, January, and February-S/ 15’C; March and November-10/2O”C; April and 0ctober-15/25°C; and May and September-20/300 C). All experiments were conducted in a light regime of 237 pe rn-’ set-’ photosynthetic active solar radiation, during the high temperature periods. One trial wasconducted at each temperature, and 3 replications per seed treatment were arranged in a randomized complete block design. Germinated seeds were counted daily for 14 days. The germination criteria were based on the Association of Official Seed Analysts (Crosier 1970) definition of germination, i.e. that the seed embryo must develop the essential structures to produce a normal plant in favorable conditions. The two major criteria for germination were: 1) Normal-at least one cotyledon exposed and a radical greater than or equal to 5 mm in length. 2) Abnormal-neither cotyledon exposed or a radical less than 5 mm in length. Statistical analyses were conducted with the ANOVA procedure of the Statistical Analysis System (Barr and Goodnight 1972), to determine if significant differences @rO.OS) in germination existed between presowing treatments within temperatures. Differences among means were compared using Duncan’s multiple range test. Counts were transformed prior to analysis using the following relationship: xl = Jxarc sin dv n+3/4 where the proportion (germinated seeds/ total number of seeds) is f/n. Presowing Seed Treatments Engelmann Daisy Untreated Engelmann daisy seeds germinated better than those subjected to presowing seed treatments. Mechanical scarification, acid scarification, and soaking in hot water did not enhance the germination of Engelmann daisy seeds (Table I). The water and acid scarification treatments inhibited germination in the 20/300 C and 18/24’C regimes (data not reported). Seed germination after mechanical scarification sometimes equaled germination of untreated seeds, but germination of mechanically scarified seeds in the 20/3oOC regime was 40% less than germination of untreated Table 1. Percent germination of untreated Engehnann daisy seeds and seeds treated with presowing seed treatments of acid scarification (acid), soaking in hot water (water), or mechankal scarification (mechanical), and imbibed in 4 alternating temperature regimes.

Presowing Seed Treatment and Temperature Effects on Germination of Engelmannia pinnatifida and Indigofera miniata var. leptosepala