• Adoption of Brush Busters: Results of Texas county extension survey

      Kreuter, U. P.; Amestoy, H. E.; Ueckert, D. N.; McGinty, W. A. (Society for Range Management, 2001-11-01)
      Changing landowner demographics and the increasing recognition that some quantity of woody plants is valuable for certain rangeland management objectives has led to increasing interest in selective brush management practices. Brush Busters is a collaborative extension/research program developed in response to this growing interest. A survey of Texas County Extension Agents-Agriculture was conducted in 1999 to determine their perceptions about the interest in and adoption of Brush Busters practices. Using 3 threshold photographs, Extension Agents representing almost 50% of the counties in the 9 Extension Districts surveyed estimated that 44, 34, and 49% of the total area of mesquite, juniper and pricklypear, respectively, could be treated using Brush Busters. They also indicated that over 405,000 ha (78% mesquite) were treated with Brush Busters methods between 1995 and 1998, but that this represented less than 7% of the potentially treatable area. In most Extension Districts, more time was spent disseminating information about Brush Busters methods than any other brush management method since 1995. Extension Agents indicated that Brush Busters has become popular because it is perceived to be an inexpensive, convenient, safe, effective and predictable method for controlling brush, and because user-friendly information is widely available. Our findings suggest that increasing the adoption rates of ecologically sound rangeland management technologies requires: (1) greater emphasis on developing and disseminating user-friendly messages to rangeland managers and Extension Agents; and (2) greater emphasis on short-term efficacy rather than the long term advantages of new technologies.
    • Broom Snakeweed: Effect on Shortgrass Forage Production and Soil Water Depletion

      Ueckert, D. N.; Anderson, D. M.; Kothmann, M. M. (Society for Range Management, 1979-05-01)
      Perennial shortgrasses were delayed in responding to removal of a dense broom snakeweed population (387/m2) because of low initial vigor. However, after 1 year, grass production increased by 107% (1,175 kg/ha) and after 2 years, by 324% (2,201 kg/ha) compared to undisturbed stands. Reducing snakeweed density by 25 or 50% did not affect forage production during the 2-year study. Estimated carrying capacity of the shortgrass rangeland was increased from 1 A.U./26 ha to 1 A.U./6.1 ha by the second year after complete removal of broom snakeweed. Juvenile broom snakeweed plants utilized soil water from the upper 15 to 45 cm. Soil water depletion was increased after perennial grasses regained vigor following complete removal of snakeweeds. Precipitation-use efficiency for production of usable forage was 2.1 and 4.3 times greater on broom snakeweed-free rangeland than on infested rangeland at 1 and 2 years, respectively, following removal of snakeweed.
    • Changes in Redberry Juniper Distribution in Northwest Texas (1948 to 1982)

      Ansley, R. J.; Pinchak, W. E.; Ueckert, D. N. (Society for Range Management, 1995-04-01)
    • Comparative Diets of Rambouillet, Barbado, and Karakul Sheep and Spanish and Angora Goats

      Warren, L. E.; Ueckert, D. N.; Shelton, J. M. (Society for Range Management, 1984-03-01)
      Diets of Rambouillet, Karakul, and Barbado sheep (Ovis aries) and Spanish and Angora goats (Capra hircus) grazing in 3 plant communities in western Texas were determined by microhistological analysis of fecal samples. Grasses were commonly the major foods of all sheep breeds as well as Angora goats. Forbs were major diet items of all breeds of sheep and goats when they were readily available. Spanish goats, and to a lesser extent Angora goats, relied heavily on browse. Barbado sheep consumed more browse than did Rambouillet or Karakul sheep. Diets of Rambouillet and Karakul sheep overlapped considerably, whereas diets of Rambouillet sheep and Spanish goats were quite dissimilar. Barbado sheep appeared to occupy a food niche intermediate between that of the goats and the other sheep breeds. Spanish and Angora goats exhibited the strongest tendency and Karakul sheep exhibited the least tendency to selectively graze. Neither Barbado nor Karakul sheep consumed sufficient amounts of undesirable shrubs to be considered valuable for brush suppression.
    • Control of Bitterweed with Herbicides

      Ueckert, D. N.; Scifres, C. J.; Whisenant, S. G.; Mutz, J. L. (Society for Range Management, 1980-11-01)
      Herbicide 2,4-D was less effective for bitterweed control when applied at air temperatures below 14 degrees C compared to applications at 22 degrees C even when soil water was adequate for active plant growth. There was no difference in bitterweed control whether the ester or amine formulations of 2,4-D were used. At 22° C air temperature, 1.12 kg/ha of 2,4-D + dicamba (3:1), picloram, or 2,4,5-T + picloram (1:1) did not improve short-term control (36 to 182 days) of bitterweed compared to 2,4-D alone at the same rate. However, at 14 degrees C temperature or when bitterweed were in advanced phenological states (75% with inflorescences), these herbicides provided excellent short-term bitterweed control whereas 2,4-D was inconsistent. Mixtures of dicamba with 2,4-D slightly improved residual bitterweed control, compared to the same rate of 2,4-D alone. Picloram at 0.56 to 1.12 kg/ha controlled 60 to 100% of the bitterweed populations for a year or more following applications in winter or spring. Tebuthiuron at 0.56 to 1.12 kg/ha was not as effective as 2,4-D at 1.12 kg/ha relative to initial bitterweed control, but provided excellent residual control after 1 year following winter application.
    • Cultural Practices for Establishing Fourwing Saltbush within Perennial Grass Stands

      Petersen, J. L.; Ueckert, D. N.; Potter, R. L. (Society for Range Management, 1986-09-01)
      Establishment of fourwing saltbush [Atriplex canescens (Pursh) Nutt.] on rangelands in western Texas could improve forage production and quality. Three experiments were conducted to evaluate establishment and growth of fourwing saltbush in grass stands as affected by width of tilled seedbed, fertilization, and competition from various grasses. Four-month-old seedlings were transplanted on 1.8-m centers and seeds were planted in 10-cm-wide, ripped areas and in 46- or 91-cm-wide, tilled strips within a dense stand of sideoats grama [Bouteloua curtipendula (Michx.) Torr.]. Transplanted seedlings were fertilized with nitrogen (N) (50 kg/ha), phosphorus (P) (50 kg/ha), or N+P (50+50 kg/ha). Survival and size of transplanted seedlings were significantly (P is less than or equal to 0.01) greater after 17 months in tilled than in ripped strips. Standing crops of competing vegetation were about 50% greater in ripped than in tilled areas. Fertilizer did not affect survival of fourwing saltbush seedlings or standing crops of competing vegetation. However, P increased (P is less than or equal to 0.05) mean canopy height and diameter of 17-month-old fourwing saltbush seedlings 50 and 67%, respectively, compared to those of plants receiving no fertilizer or N. Very few seedlings established following direct seeding. Survival and growth of transplanted fourwing saltbush seedlings were significantly (P≤0.05) greater in competition-free plots than in interspaces between rows of various species or short-, mid-, and tall grasses, and survival decreased as height of grasses increased.
    • Diet of Walkingsticks on Sandhill Rangeland in Colorado

      Ueckert, D. N.; Hansen, R. M. (Society for Range Management, 1972-03-01)
      The seasonal dry-weight composition of the diet of walkingstick insects collected on sandhill rangeland in northeastern Colorado was determined by microscopic examination of crop contents. The walkingstick was found to be monophagous and highly selective in its feeding habits. Slimleaf scurfpea comprised essentially 100% of its seasonal diet. Preference indices were calculated from herbage availability data. The frequency of plants in the habitat and the frequency of plants in the diet of the walkingsticks were not correlated. Walkingsticks may compete with cattle for high-protein forage.
    • Ecotypic Variation in Selected Fourwing Saltbush Populations in Western Texas

      Petersen, J. L.; Ueckert, D. N.; Potter, R. L.; Huston, J. E. (Society for Range Management, 1987-07-01)
      Fourwing saltbush [Atriplex canescens (Pursh) Nutt.] seedlings from 4 western Texas tetraploid populations were established in uniform nurseries at San Angelo, Barnhart, and Marfa, Texas, in 1981 to determine relative adaptability to these respective environments. Survival and canopy development of the ecotypes were similar at the site with the most favorable growing conditions (San Angelo), but the ecotype originating nearest the planting site tended to have greatest survival and canopy size where site conditions were less favorable. Additional shrub attributes evaluated at the San Angelo site included: leaf, current year's stem, and wood phytomass, seasonal nutrient concentrations, and floral development and phenotype. Prediction equations utilizing plant canopy measurements were used to estimate weights of plant components. Variation in canopy size and yields among individual plants within ecotypes masked detection of significant (P lesser than or equal to 0.05) differences among ecotypes, but ecotypes from arid environments tended to be larger and to have greater yields than those from more mesic environments. Concentrations of crude protein (CP), phosphorus (P), and digestible organic matter (DOM) of leaves and stems were similar among the 4 ecotypes. Floral development of the ecotype from the most mesic environment progressed at a faster rate than that of ecotypes from more xeric environments. Ecotypes from xeric environments tended to have fewer staminate plants, but more plants with no sex expression than ecotypes from more mesic areas.
    • Effect Of 2,4-D on Hymenoxon Concentration and Toxicity of Bitterweed (Hymenoxys odorata) Force-Fed to Sheep

      Calhoun, M. C.; Ueckert, D. N.; Livingston, C. W.; Camp, B. J. (Society for Range Management, 1982-07-01)
      Bitterweed (Hymenoxys odorata) growing at two locations was sprayed with 2,4-D (1.1 kg acid equivalent/ha) during the spring of 1977. Subsequently, plants were collected, dried, and stored when they showed definite signs of herbicide phytotoxicity (epinasty and turgidity). Hymenoxon concentrations were determined on the dried plant material and it was force-fed to penned sheep, in two experiments, to determine the effect of foliar spraying with 2,4-D on bitterweed toxicity. Bitterweed administration decreased voluntary feed intake and increased serum concentrations of urea nitrogen (UN), creatinine (C) and glutamic-oxalacetic transaminase (GOT). Hymenoxon concentrations (air-dry basis) were 2.33 +/- .18% and 1.64 +/- .05%, for unsprayed and 2,4-D sprayed bitterweed, respectively, in Experiment 1 and 1.24 +/- .02% and 1.08 +/- .05%, respectively, in Experiment 2. Spraying bitterweed did not affect feed intake and serum levels of UN, C and GOT and there were not interactions between bitterweed levels and 2,4-D treatments.
    • Effect of Burning on Infiltration, Sediment, and Other Soil Properties in a Mesquite-Tobosagrass Community

      Ueckert, D. N.; Whigham, T. L.; Spears, B. M. (Society for Range Management, 1978-11-01)
      Burning had a minimal effect on rainfall infiltration and sediment load in runoff from a mesquite-tobosagrass community on slopes less than 1%. Most soil physical properties that affect infiltration on these heavy clay soils were not altered significantly by burning. Potential soil loss in runoff can be minimized by burning under relatively moist conditions. Larger soil aggregates were broken down by burning and had not returned to equilibrium on 5-year-old burns. Trends in levels of soil organic carbon, salinity, sodium, and potassium following burning varied with degree of soil cracking, which is a function of soil moisture.
    • Effect of Desert Termites on Herbage and Litter in a Shortgrass Ecosystem in West Texas

      Bodine, M. C.; Ueckert, D. N. (Society for Range Management, 1975-09-01)
      The desert termite, Gnathamitermes tubiformans, is an important insect on rangelands in the southwestern United States. Population densities of this insect averaged 2139/m2 in the upper 30 cm of soil in a shortgrass community in West Texas over a 3-year period and reached a peak of 9127/m2 The live biomass of termites averaged 5.2 g/m2 and reached a peak of 22.21 g/m2. In a laboratory study, desert termite workers consumed 2.4% of their live body weight/day of dry buffalograss leaves. In field studies, control of desert termites with insecticide resulted in a 22% increase in standing crop of grass and a 50% increase in litter accumulation by the end of the second growing season after control was initiated. Termite-free plots had almost three times more litter than termite-infested plots after four growing seasons. Desert termites accounted for 55% of the disappearance of litter from the soil surface. Ranchers can expect higher population densities of desert termites and hence greater consumption of forage and litter during wet years.
    • Effects of Fire on Texas Wintergrass Communities

      Whisenant, S. G.; Ueckert, D. N.; Scifres, C. J. (Society for Range Management, 1984-09-01)
      The effect of season of burning on standing crop, point frequency, density, and reproductive vigor of Texas wintergrass (Stipa leucotricha Trin. & Rupr.) communities was measured in this study. Additional information on the effects of fire on Texas wintergrass will aid resource managers plan the use of fire in these communities. Burning or clipping Texas wintergrass did not significantly affect the number of reproductive culms per plant in the northern Edwards Plateau region of Texas. Burning, regardless of season, reduced standing crops for 1 year and burning in January or March reduced Texas wintergrass point frequency for 1 year. Burning where annual cool-season grasses were abundant in the southern Rolling Plains tended to increase Texas wintergrass density, point frequency, and standing crop, apparently a result of reduced competition from annual plants. Increases in Texas wintergrass point frequency and standing crop were greater following burning in the fall than following burning in the spring. Prescribed burning in Texas wintergrass communities generally killed annual grasses and forbs if burning occurred subsequent to seedling emergence. However, soil reserves of seed and/or subsequent seed immigration into burned areas appeared to be sufficient to reestablish populations of annual plants during the second year following burning. Annual grass populations consistently tended to be higher in the second year after burning than on unburned rangeland.
    • Effects of Leaf-Footed Bugs on Mesquite Reproduction

      Ueckert, D. N. (Society for Range Management, 1973-05-01)
      Leaf-footed bugs, Mozena obtusa Uhler, were observed feeding on immature mesquite pods in the Rolling Plains of Texas. A sleeve cage study, using various population densities of these insects, showed that their feeding significantly increased the abortion of immature mesquite pods while decreasing the dry weight of pods and seeds and the germination percentage of seeds. Seedlings from seeds fed upon by this insect were significantly smaller and less vigorous than those from bug-free seeds. This insect may limit the reproduction of mesquite and may offer a possibility for the utilization of a native insect for the control of a native weed.
    • Emergence and Survival of Honey Mesquite Seedlings on Several Soils in West Texas

      Ueckert, D. N.; Smith, L. L.; Allen, B. L. (Society for Range Management, 1979-07-01)
      Results from field and laboratory studies indicated that germination and emergence was adequate on soils that supported heavy densities, low densities, or no mesquite for establishment of dense populations of honey mesquite. Absence of honey mesquite or low densities of this species on soils where seeds are readily deposited by natural mechanisms could not be explained by soil chemical or physical properties that might inhibit seed germination or emergence of seedlings. In field studies, seedling emergence was not related to the density of honey mesquite presently growing on six range sites. At the end of the first growing season and at 1 year after planting, seedling survival was inversely related to density of honey mesquite. Two years after planting, seedling survival was not related to density of mesquite supported by the six soils. In this short-term study, competition with associated herbaceous vegetation overshadowed the effects of soil properties on survival of honey mesquite seedlings.
    • Factors Influencing Bitterweed Seed Germination

      Whisenant, S. G.; Ueckert, D. N. (Society for Range Management, 1982-03-01)
      Bitterweed seed germination exceeded 90% at constant temperatures between 20 degrees and 25 degrees C and more than 65% between 15 degrees and 30 degrees C in a controlled environment chamber. Seeds germinated equally well in light and dark conditions. Germination percentages of seeds in aqueous media with a pH range of 5 to 9 were significantly different, but the range of germination (91 to 97%) probably is not sufficient to affect distribution. However, a decrease in water availability significantly decreased bitterweed seed germination. Viability of bitterweed seed did not change significantly after 39 months dry storage at room temperature, but was significantly reduced at 47 months.
    • Foodniche of Coyotes in the Rolling Plains of Texas

      Meinzer, W. P.; Ueckert, D. N.; Flinders, J. T. (Society for Range Management, 1975-01-01)
      Coyote diets were determined from scat and stomach analyses over a two-year period in an area centered in the Rolling Plains region of Texas. Fruit from 9 species of native plants were the most important food for coyotes, making up 46% of the annual diet. Honey mesquite pods alone contributed 15.6% of the annual diet. Rodents contributed 24.5% of the coyote's annual diet, while leporids made up just 10.5%. The foodniche of coyotes varied seasonally as well as annually. The coyote's role as an agent of seed dispersal appears minimal since digestion of some seeds by coyotes significantly reduces percent germination. Late evening and pre-dawn hours seem the normal feeding period for most coyotes, and moon phase did not affect the timing of this activity. In this study there was no evidence of coyote predation on cattle.
    • Germination of Fourwing Saltbush Seeds: Interaction of Temperature, Osmotic Potential, and pH

      Potter, R. L.; Ueckert, D. N.; Petersen, J. L.; McFarland, M. L. (Society for Range Management, 1986-01-01)
      Establishment of shrubs and other forage plants on arid and semiarid rangelands and salt-contaminated sites may be enhanced if ecotypes with ability to germinate and establish under moisture stress and high temperatures can be identified. The interactive effects of temperature, osmotic potential, and pH on germination were evaluated with seed from 4 populations of fourwing saltbush [Atriplex canescens (Pursh) Nutt.] from western Texas. Predicted optimum temperature (15 to 18 degrees C) from osmotic potential by temperature response surfaces for germination of 3 populations (Valentine, Grandfalls, and San Angelo) were similar to those reported for populations of fourwing saltbush from other western states. Germination of seed collected near Texon, Texas was significantly (P<0.01) affected by media pH range 6 to 9. Seed from the Texon population germinated under lower osmotic potentials compared to the other 3 populations. Total germination of all four populations was enhanced by osmotic potentials lower than 0 MPa. Seed from the Texon population may possess germination characteristics more suitable for arid-land seeding than those from populations near Valentine, Grandfalls, and San Angelo, Texas.
    • Germination Responses of Esyenhardtia texana and Leucaeena retusa

      Whisenant, S. G.; Ueckert, D. N. (Society for Range Management, 1982-11-01)
      Germination and radicle growth of kidneywood and little-leaf leadtree were greatest at 30°C but occurred under a wide range of temperatures. Germination and radicle growth of kidneywood seed did not differ over the pH range of 5 to 9. Germination of little-leaf leadtree was lower at pH 5 and 6 than at pH 7 to 9. Decreased water availability reduced germination and radicle length of both species; however, kidneywood seed germination was more tolerant of moisture stress than little-leaf leadtree. Seeds of both species maintained high viability for at least 42 months after collection. An impervious seedcoat prevents germination of little-leaf leadtree seeds until it is scarified. Results from these experiments indicated no significant germination problems will be encountered in attempts to establish these plants under field conditions.
    • Herbicidal control of pricklypear cactus in western Texas

      Petersen, J. L.; Ueckert, D. N.; Potter, R. L. (Society for Range Management, 1988-07-01)
      The recommended practice for pricklypear (Opuntia spp.) control in western Texas has been aerial spraying with a 1:1 mixture of 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid] and picloram (4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid) at 0.56 kg/ha in late spring-early summer. This practice did not consistently control pricklypear. Experiments were conducted at 2 locations to determine if efficacy of the herbicide mixture could be improved by increasing the rate or by spraying at night. The herbicide mixture was applied at 0.56 and 1.12 kg/ha to dense pricklypear stands in morning and near midnight in December, June, August, and October. The high rate killed more Lindheimer pricklypear (O. lindheimeri) and Edwards pricklypear (O. edwardsii) growing on clay loam soils compared to the low rate during most seasons. The higher rate did not increase control of hybrid pricklypear growing on clay soils sufficiently to justify the added treatment cost or to satisfy the management objectives of most ranchers. Night treatments killed significantly more pricklypear than daytime treatments only during late spring-early summer. The pricklypear species and hybrids were most susceptible to herbicide applications in late summer and early autumn and least susceptible to those in late spring-early summer. The efficacy of early winter treatments was intermediate.
    • Herbicide Control of Poisonous Plants

      Ralphs, M. H.; Whitson, T. D.; Ueckert, D. N. (Society for Range Management, 1991-04-01)