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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

FORAGE QUALITY OF COOL SEASON PERENNIAL GRASS HORSE PASTURES IN THE TRANSITION ZONE

Riley, AnnMarie Christine 01 January 2019 (has links)
Cool season perennial grasses are the foundation of equine nutrition in the transition zone. The objective of this study was to evaluate forage quality using ADF, NDF, IVTDMD, CP, WSC, and ESC and changes in vegetative swards seasonally, diurnally, across species (Kentucky bluegrass, tall fescue, orchardgrass, and perennial ryegrass) and cultivar. This study was conducted in 2015 and 2017 and plots were maintained vegetatively with two to four week mowing. Morning and afternoon sample collection occurred monthly during the growing season. Samples were flash frozen; freeze dried, ground, and scanned using Near Infrared Reflectance Spectroscopy (NIRS) to predict forage quality. There was a significant year effect; therefore year was analyzed separately. Generally, ADF and NDF were highest for Kentucky bluegrass (30 and 52%), lowest for perennial ryegrass (25 and 46%), and tall fescue and orchardgrass were inconsistent. Crude protein was variable across species and season, ranging 10 to 25%. ADF and NDF concentrations were higher in the morning; IVTDMD, WSC, and ESC were higher in the afternoon; and CP was similar diurnally. In conclusion, forage quality in vegetative cool season grass pastures was sufficient to meet the nutritional needs of most equines, but varied seasonally, diurnally, across species, and cultivar.
122

Evaluation of endophyte-infected tall fescue products, their interaction with Senecio jacobaea in ruminants, and detoxification of alkaloids by ammoniation or ensiling after grinding

Debessai, Woldu T. 26 August 1997 (has links)
Graduation date: 1998
123

Identification of restoration potential on southwestern Oregon rangelands

Barrington, Mack R. 16 December 1994 (has links)
The objectives of this research were to 1) evaluate the establishment and peak standing crop of Berber Orchardgrass (Dactylis glomerata var. "Berber"), Palestine Orchardgrass (Dactylis glomerata var. "Palestine"), and Sheep Fescue (Festuca ovina var. "Covar") ; 2) to assess establishment and production changes resulting from environmental gradients (elevation, slope, aspect, soil texture, precipitation, and resident annual community) across the foothill landscape; 3) develop a mathematical model that predicts site potential for restoration; and 4) evaluate the utility of Geographic Information Systems for creation and analysis of spatial data which identify site production potential. Sixteen sites were chosen which reflect the general character of the foothill rangelands in southwestern Oregon. A Randomized Complete Block design was used to select treatment arrangement on each site. Seeded treatments received both chemical (Glyphosate, Hoelon, and 2,4-D) and mechanical (residue removal) disturbance. Test species were seeded into three replications at each site. Each replication also included a non-treatment control. Standing crop data for test species and resident exotics were collected after three growing seasons. Berber orchardgrass did not establish at most sites and where establishment did take place production was less than 132 kgDM/ha. Palestine orchardgrass established on on a majority of the study sites and produced most aboveground phytomass at mid-elevations where coarser soil textures and deeper soil depths were common. Sheep fescue was the most successful of the three test species and did best on low elevation high clay sites. There was significantly (P=0.001) more phytomass produced by annual exotics on seeded plots than on undisturbed controls at most sites. Both Palestine orchardgrass and sheep fescue treatments significantly suppressed the annual exotics when compared to the Berber treatments. Generally, "Covar" sheep fescue can establish and successfully compete with exotics on heavier textured soils at low elevations. "Palestine orchardgrass is adapted to mid-elevation coarser soils. / Graduation date: 1995
124

Influence of Transplanter Modification and Previous Crop on the Production of No-Till Dark Tobacco

Penick, William Frazier 01 May 2013 (has links)
Dark tobacco (Nicotiana tabacum L.) has historically been produced usingconventional tillage practices. Soil is cultivated multiple times throughout a growing season leading to an increased incidence of soil erosion. No-till systems have been growing in popularity with the advent of new technology that has enabled the practice to be performed effectively and efficiently. With the recent expansion of no-till practices throughout the agricultural community, many crops have had success in producing comparable yields while reducing input costs and saving soil resources. For this experiment, a traditional tobacco transplanter was modified for use in a no-till environment. All modifications were fabricated without using specialty tools and made possible to be removed if desired or necessary. Frame extensions were designed and built to accommodate row cleaners and coulters. Tillage shanks were also added to aid in optimal furrow formation. Double-disc opening shoes replaced the original round point shoes and the curved edges of the rear drive wheels were removed, creating a flat surface to increase soil contact. Experimental no-till plots in fescue sod and soybean chaff residues were conducted alongside conventional tillage plots at the Western Kentucky University Agricultural Research and Education Complex in summer 2011. Five treatments, one conventionally tilled (Conv) and four no-till, were replicated three times within a randomized complete block design and used to determine the efficacy of transplanter modifications (consistency of depth, furrow closure, observed plant damage), survival of the transplants, and the amount of residue displacement. The four no-till treatments utilized different combinations including: coulter, row cleaner and shank (CRS), row cleaner and shank (RS), coulter and shank (CS), and shank only (S). These treatments demonstrated the functionality of each combination in comparison to conventional treatments. No treatment performed equally well in both residue locations. Plots in fescue residue utilizing a combination of coulter, row cleaner, shank (CRS), exhibited the lowest amount of root exposure, highest survival rate, and comparable cured weight when compared to conventionally tilled treatments. In soybean residue plots, the treatment operating with row cleaners and shanks (RS) had equivalent amounts of furrow closure to conventionally tilled plots. Pairing specific modification combinations with previous crop residue can provide furrow closure, transplant survival, and cured yield equivalent to conventionally tilled dark tobacco.
125

The effect of perennial grass species on forage growth and quality, etiolated growth, animal performance and economics

Ward, Charlotte I. 13 February 2009
A series of experiments were conducted during 2005 and 2006 to evaluate five perennial grass species for forage yield and quality, steer performance and grazing capacity, animal intake, plant energy reserves and economic return under grazed conditions. In 1999, two 0.8 ha replicates each of Paddock meadow bromegrass (<i>Bromus riparius</i>Rehm.), Carlton smooth bromegrass (<i>Bromus inermis</i>Leyss.) and AC Knowles hybrid bromegrass (<i>B. riparius</i> x <i>B. inermis</i>) were seeded. In 2003, two 0.8 ha replicates each of AC Goliath crested wheatgrass (<i>Agropyron cristatum </i> (L.) Gaertn.), hybrid bromegrass, and Courtenay tall fescue (<i>Festuca arundinacea </i> Schreb.) were seeded. A long established stand of crested wheatgrass acted as the control pasture. For 2003 established pastures, AC Goliath crested wheatgrass (7515 kg ha-1) had greater (P<0.05) cumulative dry matter yield than hybrid bromegrass (3136 kg ha-1) during the 2005 grazing season. Average (2005-2006) crude protein (CP) was greatest (P<0.05) for hybrid and smooth bromegrass for 1999 established pastures at start and middle of period one. Control pastures had the greatest (P<0.05) neutral detergent fiber (NDF) mid-grazing period. Over 2 years, smooth bromegrass had greater acid detergent fiber (ADF) (P<0.05) than control pastures at the end of the grazing period one. Average (2005-2006) in vitro organic matter digestibility (IVOMD) was greatest for hybrid and meadow bromegrass (P<0.05) at the start of grazing period one. Control pastures (129 g kg-1) had lower CP levels at the start of the 2005-2006 (average) grazing period 1 (P<0.05) compared to species seeded in 2003. Control and hybrid bromegrass pastures had the greatest NDF and ADF levels at the start of grazing period 1 (2005-2006 average) while tall fescue pastures had the lowest (P<0.05) NDF and ADF levels. Over 2 years, control pastures had the lowest IVOMD at start of grazing (P<0.05). In 2006, hybrid and smooth bromegrass had greater etiolated re-growth than control pastures (P<0.05). In 2006, grazed plants seeded in 1999 had greater (P<0.05) etiolated re-growth than ungrazed plants. For 2003 seeded grasses, crested wheatgrass produced greater (P<0.05) etiolated re-growth than tall fescue and control pastures. Average daily gain was similar (P>0.05) for all 1999 and 2003 seeded grasses. Overall, bromegrasses seeded in 1999 produced greater animal grazing days (AGD) than control pastures (P<0.05). Total beef production (TBP) was greater (P<0.05) for hybrid and meadow bromegrass compared to the control. All species seeded in 2003 produced greater AGD (P<0.05) compared to the control. Crested wheatgrass produced greater (P<0.05) TBP than the control over both years of the study. The C33:C32 alkane ratio estimated greater DMI (P<0.05) for hybrid bromegrass (9.9 kg d-1) and control pastures (9.6 kg d-1) compared to crested wheatgrass (6.8 kg d-1) or tall fescue (6.8 kg d-1) during period 1 in 2006. Over 2 years, net return to labor, equity and personal draw was greater (P<0.05) for hybrid bromegrass ($91.24 ha-1) compared to the control (-$54.32 ha-1). For 2003 seeded pastures, all pastures generated positive returns over 2 years. Crested wheatgrass ($92.49 ha-1) had greater net return than control pastures (-$54.32 ha-1) (P<0.05). Finally, the results of this grazing study indicate beef producers can manage these grasses during the summer grazing season and maintain high levels of animal performance and pasture production. This study has demonstrated that bromegrasses, crested wheatgrass and tall fescue could work well in a complementary grazing system.
126

Regrowth of <i>Festuca hallii</i> (Vasey Piper) and <i>Stipa curtiseta</i> [(A.S. Hitch.) Barkworth] following defoliation on a hummocky landscape in Central Saskatchewan

Pantel, Andrew William 20 December 2006
A 4-year study was conducted on the Missouri Coteau in the Mixed Grassland Ecoregion of Saskatchewan to determine the effects of mowing to a 7.5 cm stubble height on the growth of <i>Festuca hallii</i> (Vasey) Piper and <i>Stipa curtiseta</i> (A.S. Hitch.) Barkworth. Green standing crop (GSC), dead standing crop (DSC) and above ground net primary production (ANPP) were compared to an unmowed control after a single mowing in April, May, June, July, August, September, October or November on 5 landforms including north aspect-concave-slope, north aspect-convex-slope, south aspect-concave-slope, south aspect-convex-slope and level upland. Mowing reduced GSC, DSC and ANPP with reductions varying among months of mowing and among landforms. Green standing crop, DSC and ANPP of <i>F. hallii</i> were greatest on the north aspects and least on south aspect-convex slope and ranged from 2 to 122 g m-2, 3 to 121 g m-2, and 8 to 122 g m-2, respectively. Mowing reduced GSC of <i>F. hallii</i> for 1 to 11 growing season months and DSC for 1 to >11 growing season months. Mowing in May or November reduced ANPP of <i>F. hallii</i> for 1 growing season, while mowing in other months reduced ANPP for 2 growing seasons. Green standing crop of <i>S. curtiseta</i>, ranging from 3 g m-2 to 55 g m-2, was least on the north aspects and greatest on the south aspect-convex slope and was reduced 1 to 5 growing season months following mowing. Mowing after June reduced DSC of <i>S. curtiseta</i>(5 to 58 g m-2) for 1 to 10 growing season months, and ANPP (6 to 64 g m-2) for 1 growing season. Generally, mowing reduced GSC, DSC and ANPP of <i>F. hallii</i> longer than <i>S. curtiseta</i>. Production of <i>F. hallii</i>- and <i>S. curtiseta</i>-dominated plant communities in the Northern Mixed Prairie will be maintained by providing rest periods between defoliation events based on the number of growing season months for <i>F. hallii</i> to recover production.
127

Regrowth of <i>Festuca hallii</i> (Vasey Piper) and <i>Stipa curtiseta</i> [(A.S. Hitch.) Barkworth] following defoliation on a hummocky landscape in Central Saskatchewan

Pantel, Andrew William 20 December 2006 (has links)
A 4-year study was conducted on the Missouri Coteau in the Mixed Grassland Ecoregion of Saskatchewan to determine the effects of mowing to a 7.5 cm stubble height on the growth of <i>Festuca hallii</i> (Vasey) Piper and <i>Stipa curtiseta</i> (A.S. Hitch.) Barkworth. Green standing crop (GSC), dead standing crop (DSC) and above ground net primary production (ANPP) were compared to an unmowed control after a single mowing in April, May, June, July, August, September, October or November on 5 landforms including north aspect-concave-slope, north aspect-convex-slope, south aspect-concave-slope, south aspect-convex-slope and level upland. Mowing reduced GSC, DSC and ANPP with reductions varying among months of mowing and among landforms. Green standing crop, DSC and ANPP of <i>F. hallii</i> were greatest on the north aspects and least on south aspect-convex slope and ranged from 2 to 122 g m-2, 3 to 121 g m-2, and 8 to 122 g m-2, respectively. Mowing reduced GSC of <i>F. hallii</i> for 1 to 11 growing season months and DSC for 1 to >11 growing season months. Mowing in May or November reduced ANPP of <i>F. hallii</i> for 1 growing season, while mowing in other months reduced ANPP for 2 growing seasons. Green standing crop of <i>S. curtiseta</i>, ranging from 3 g m-2 to 55 g m-2, was least on the north aspects and greatest on the south aspect-convex slope and was reduced 1 to 5 growing season months following mowing. Mowing after June reduced DSC of <i>S. curtiseta</i>(5 to 58 g m-2) for 1 to 10 growing season months, and ANPP (6 to 64 g m-2) for 1 growing season. Generally, mowing reduced GSC, DSC and ANPP of <i>F. hallii</i> longer than <i>S. curtiseta</i>. Production of <i>F. hallii</i>- and <i>S. curtiseta</i>-dominated plant communities in the Northern Mixed Prairie will be maintained by providing rest periods between defoliation events based on the number of growing season months for <i>F. hallii</i> to recover production.
128

The effect of perennial grass species on forage growth and quality, etiolated growth, animal performance and economics

Ward, Charlotte I. 13 February 2009 (has links)
A series of experiments were conducted during 2005 and 2006 to evaluate five perennial grass species for forage yield and quality, steer performance and grazing capacity, animal intake, plant energy reserves and economic return under grazed conditions. In 1999, two 0.8 ha replicates each of Paddock meadow bromegrass (<i>Bromus riparius</i>Rehm.), Carlton smooth bromegrass (<i>Bromus inermis</i>Leyss.) and AC Knowles hybrid bromegrass (<i>B. riparius</i> x <i>B. inermis</i>) were seeded. In 2003, two 0.8 ha replicates each of AC Goliath crested wheatgrass (<i>Agropyron cristatum </i> (L.) Gaertn.), hybrid bromegrass, and Courtenay tall fescue (<i>Festuca arundinacea </i> Schreb.) were seeded. A long established stand of crested wheatgrass acted as the control pasture. For 2003 established pastures, AC Goliath crested wheatgrass (7515 kg ha-1) had greater (P<0.05) cumulative dry matter yield than hybrid bromegrass (3136 kg ha-1) during the 2005 grazing season. Average (2005-2006) crude protein (CP) was greatest (P<0.05) for hybrid and smooth bromegrass for 1999 established pastures at start and middle of period one. Control pastures had the greatest (P<0.05) neutral detergent fiber (NDF) mid-grazing period. Over 2 years, smooth bromegrass had greater acid detergent fiber (ADF) (P<0.05) than control pastures at the end of the grazing period one. Average (2005-2006) in vitro organic matter digestibility (IVOMD) was greatest for hybrid and meadow bromegrass (P<0.05) at the start of grazing period one. Control pastures (129 g kg-1) had lower CP levels at the start of the 2005-2006 (average) grazing period 1 (P<0.05) compared to species seeded in 2003. Control and hybrid bromegrass pastures had the greatest NDF and ADF levels at the start of grazing period 1 (2005-2006 average) while tall fescue pastures had the lowest (P<0.05) NDF and ADF levels. Over 2 years, control pastures had the lowest IVOMD at start of grazing (P<0.05). In 2006, hybrid and smooth bromegrass had greater etiolated re-growth than control pastures (P<0.05). In 2006, grazed plants seeded in 1999 had greater (P<0.05) etiolated re-growth than ungrazed plants. For 2003 seeded grasses, crested wheatgrass produced greater (P<0.05) etiolated re-growth than tall fescue and control pastures. Average daily gain was similar (P>0.05) for all 1999 and 2003 seeded grasses. Overall, bromegrasses seeded in 1999 produced greater animal grazing days (AGD) than control pastures (P<0.05). Total beef production (TBP) was greater (P<0.05) for hybrid and meadow bromegrass compared to the control. All species seeded in 2003 produced greater AGD (P<0.05) compared to the control. Crested wheatgrass produced greater (P<0.05) TBP than the control over both years of the study. The C33:C32 alkane ratio estimated greater DMI (P<0.05) for hybrid bromegrass (9.9 kg d-1) and control pastures (9.6 kg d-1) compared to crested wheatgrass (6.8 kg d-1) or tall fescue (6.8 kg d-1) during period 1 in 2006. Over 2 years, net return to labor, equity and personal draw was greater (P<0.05) for hybrid bromegrass ($91.24 ha-1) compared to the control (-$54.32 ha-1). For 2003 seeded pastures, all pastures generated positive returns over 2 years. Crested wheatgrass ($92.49 ha-1) had greater net return than control pastures (-$54.32 ha-1) (P<0.05). Finally, the results of this grazing study indicate beef producers can manage these grasses during the summer grazing season and maintain high levels of animal performance and pasture production. This study has demonstrated that bromegrasses, crested wheatgrass and tall fescue could work well in a complementary grazing system.
129

EVALUATING A NOVEL ENDOPHYTIC GRASS FOR ITS POTENTIAL TO REDUCE INVERTEBRATE POPULATIONS AND ASSOCIATED BIRD STRIKE RISK AT AIRPORTS

Miller, Diana M 01 January 2015 (has links)
Aircraft strikes are a significant safety hazard on airports worldwide. Wildlife management at airfields is the most effective tactic to reduce airstrike risk – to modify the habitat to be undesirable to animals. Tall fescue grasses containing a fungal symbiont may serve that purpose. They produce alkaloids that convey resistance to some grass-feeding invertebrates, which might in turn reduce incidence of insectivorous birds. A commercial endophytic grass (Avanex™) consisting of ‘Jackal’ tall fescue infected with a unique endophyte (AR 601) is purported to contain especially high levels of alkaloids and to reduce bird populations if planted at airports. I evaluated it against the common KY31 tall fescue with its wild-type endophyte for invertebrate and vertebrate deterrence. Invertebrate abundance, survival, growth, and development were generally similar on Jackal E+ or KY31 E+. Spanish goats and wild birds showed no avoidance of Jackal E+, nor did Jackal E+ contain significantly higher levels of alkaloids than did KY31 E+. The Avanex™ tall fescue was not any better than KY31 in deterring herbivores but the concept is sound. However, better understanding of the relationship between grass, endophyte, alkaloid, and herbivore is needed to inform how such grasses might be used to reduce bird strike hazard.
130

RESTORATION OF TALL FESCUE PASTURES TO NATIVE WARM SEASON GRASSLANDS: DOES A FUNGAL ENDOPHYTE SYMBIOSIS PLAY A ROLE IN RESTORATION SUCCESS?

Hall, Sarah Lynn 01 January 2011 (has links)
Tall fescue, a cool-season grass native to Europe, central Asia, and northern Africa, has been widely distributed throughout the U.S. for use as turf and forage. Following its widespread planting, its ability to associate with a toxic fungal endophyte, Neotyphodium coenophialum, was discovered. Research has linked this fescue-endophyte association with increased biotic and abiotic stress resistance in endophyte-infected (E+) versus endophyte-free (E-) plants, and these differences may affect the ability of land managers to eradicate tall fescue and restore native grasslands. I conducted three studies to examine whether E+ tall fescue plants respond differently to management than E- plants, and whether the success of planted native species might be impacted via indirect soil effects. My overall hypotheses were that E+ plants would recover from restoration/eradication efforts better than E- plants, and that E+ fescue would reduce microbial symbionts in the soil needed by planted native species. I first conducted a field study of a tall fescue pasture consisting of four sub-units being restored with different combinations of prescribed burns and/or herbicide applications, as well as an unmanaged control. I found no evidence of E+ plants preferentially surviving restoration management; however this field had unusually low endophyte infection rates to begin with. The second study was a greenhouse experiment in which I measured growth of E+ and E- plants exposed to different watering regimes (wet, dry) and prescribed burn treatments (none, one, or two burns). Watering regime significantly affected all measured growth parameters (wet>dry), but few endophyte effects were found and when present were opposite the hypothesis (E->E+). All burned plants quickly re-grew tiller lengths comparable to the unburned control, with recovery occurring faster following the second burn compared to the first. My final study examined growth and arbuscular mycorrhizal colonization of native species planted by seed into soil from beneath E+ and E- tall fescue. I observed few differences in mycorrhizal colonization or biomass for seedlings between soil from E+ and E- tall fescue. Taken together, my results indicate endophyte status of tall fescue pastures being restored to native grassland species may not be important in governing restoration success.

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