Tall fescue (Lolium arundinaceum) is the principal cool-season species within pastures of the southeastern USA and is known to have a mutualistic relationship with a fungal endophyte (Neotyphodium coenophialum) that produces the ergot alkaloids responsible for tall fescue toxicosis. Management of the reproductive growth of tall fescue is necessary, as the seedheads contain the highest concentrations of ergot alkaloids, and livestock have been documented to selectively graze these tissues. Recently, the herbicide Chaparral™ has been shown to be an effective method to prevent seedhead production in tall fescue pastures while also increasing steer gains at a low stocking rate. The objective of this study was to compare the impact of Chaparral on steer and pasture production under multiple grazing intensities (GI). Chaparral (0 and 140 g ha-1) and two levels of GI (low: 3300±250 kg ha-1 & moderate: 2500±250 kg ha-1) treatments were arranged in a factorial combination as RCBD with three replications. Tall fescue seedhead densities were decreased (P < 0.05) within the Chaparral-treated pastures, but efficiency of the inhibition varied slightly between growing seasons. Chaparral-treated pastures had lower (P < 0.05) forage availabilities and contained forage with higher (P < 0.05) concentrations of crude protein (CP) and in vitro digestible dry matter (IVDDM) during both growing season. Steers within the Chaparral-treated pastures and low GI treatment had higher average daily gains (ADG). Carrying capacities (CC) were lowest and highest within the Chaparral-low GI and control-moderate GI treatments, respectively. Estimates of CC were not different (P > 0.15) between the Chaparral-moderate GI and control-low GI treatments. The higher ADG compensated for the lower CC of the Chaparral and low GI treatments and resulted in no difference (P > 0.60) in total gain per hectare (GPH) between grazing intensities and herbicide treatments in 2011. In 2012, the GPH were higher within the control and moderate GI treatments due to a lessening in the magnitude of difference between the herbicide and GI treatments. The effects of these treatments for alleviating symptoms of tall fescue toxicosis were inconclusive due to the low levels of ergot alkaloids production.

Nineteen bermudagrass (Cynodon dactylon (L.) Pers.) cultivars were evaluated for field emergence, establishment rate, traffic tolerance, post-harvest seed coating, germination velocity, and total germination under varying temperature regimes. Two cultivars were evaluated for thermal modeling, day/night temperature fluctuations, day lengths, and effects of fluridone on speed and percentage of total germination. The effect of cultivar was highly significant for visible field germination, time to 100% cover, and traffic tolerance in both 2010 and 2011. Riviera was the slowest or equivalent to the slowest for visible germination. Casino Royale was the fastest or equivalent to the fastest for visible germination. Yukon was the slowest to reach 100% cover in both years, while Sovereign was the quickest for 2010. Riviera and Sovereign were equivalent for the quickest to cover in 2011. Riviera and Yukon ranked highest and lowest, respectfully, in tolerance to simulated athletic traffic. There were no significant effects (p>0.05) of post-harvest seed coatings. There were highly significant differences among cultivars in germination velocity and total germination when grown under 20-year average day/night temperatures representing data from Lexington, KY on 15 May to 1 August in 15 day intervals. Evaluations for day/night temperature regimes, day length regimes, and effects of fluridone on the germination speed and percentage were also completed on Riviera and Casino Royale. Day/night regimes of 35/20, 35/25, and 40/25 degrees Celsius were evaluated. Significant differences (p<0.05) were observed, 35/20oC producing the fastest and highest percentage of germination across both cultivars. Day length was evaluated for 8, 12, 14, and 16 hours with no significant differences (p<0.05) observed. Fluridone significantly (p<0.05) decreased the germination time and increased the percentage of total germination of Riviera while only significant differences (p<0.05) in germination time observed with Casino Royale.

The potential of Barsoy barley (Hordeum vulgare L.) as a silage crop was studied at Western Kentucky University in 1970-1971. The field study was conducted at two locations. Barley was seeded at the rate of 107.5 kg/ha in a Pembroke silt loam soil at both locations in September, 1970. At the time of planting the soil was fertilized with 7.5, 32.4 and 33.1 kg/ha of nitrogen, phosphorus, and potassium, respectively. Plants at location 2 received an additional 23.7 kg/ha of nitrogen in February, 1971. Whole barley plants were harvested at weekly intervals from March 11 through June 3 at Location 1 and from April 22 through June 3 at Location 2. Based upon the results for dry matter yield, chemical composition, and dry matter percentage, the dough stage of maturity was found to be the most desirable stage for ensiling barley plants. At this stage dry matter yields were 5.4 and 12.4 metric tons per hectare for Locations 1 and 2, respectively. Dry matter percentages were 32.5 for plants at Location 1 and 33.0 for plant at Location 2. Chemical composition percentages for plants at Location 1 were: crude protein 8.3, crude fiber 28.8 nitrogen free extract 54.7, ether extract 1.1, and ash 7.1. Chemical composition percentages for plants at Location 2 were: crude protein 11.5, crude fiber 33.8, nitrogen free extract 47.0, either extract 0.5, and ash 7.2.

The demand for locally sourced hops from Northeastern microbreweries began the recent resurgence in local hop production. The farming community has increased acreage and improved the quality of hops grown and processed in the Northeast region over the past five years. There was a sharp increase in the number of Northeast hop producers from six in 2009 to over 175 in 2014. Hop growers in the Northeast are new to the crop and have limited experience with pest identification and management. This dissertation encompasses three research projects that were conducted over the 2012-2014 growing seasons. These projects were the first critical steps taken to develop arthropod integrated pest management (IPM) tactics for Northeastern hop growers. First, the arthropod community in seven Vermont hop yards was evaluated. The objectives of Chapter 2 are to 1) present current hop pest biology and management strategies, 2) report the phenology of arthropod pests observed over three growing seasons, 3) report abundance and peak date for each pest, and 4) document natural enemy abundance in Vermont hop yards. The survey indicates that in cool, wet seasons hop aphid (Phorodon humuli Schrank) is expected to be a pest of concern. Two-spotted spider mite (Tetranychus urticae Koch) is expected to be a pest of concern in hot, dry conditions. Potato leafhopper (Empoasca fabae Harris) is an unpredictable pest of special concern for first year hop plants. When hop aphid or potato leafhopper are sprayed for with broad-spectrum insecticide, two-spotted spider mite secondary outbreak can be expected. Second, the abundance of major arthropod pests and their natural enemy groups were evaluated under drive row flowering cover crop treatments. The objectives of this study were to 1) measure the effect of cover crops on natural enemy group abundance, 2) measure the effect of cover crops on the three major Northeastern hop pests, and 3) measure the effect of cover crop presence on hop yield and quality. Natural enemy groups and pests were positively correlated yet cover crop treatments had no significant effect on natural enemy abundance. Red clover cover crop treatments served as a trap crop for potato leafhopper. No significant difference in hop yield or quality was observed between flowering cover crop treatments. Finally, potato leafhopper is a documented but understudied regional pest of hops. The objectives of this study were to 1) measure the physiological response of eight hop cultivars to adult potato leafhopper feeding and 2) measure hop leaf recovery from potato leafhopper injury. Gas exchange (net photosynthesis and transpiration) and chlorophyll content were measured to quantify injury by adult potato leafhopper to first year hop leaves in field and greenhouse studies. Cultivars did not vary significantly in their physiological response to potato leafhopper feeding. Injury significantly reduced gas exchange measures in the field (P < 0.05) and greenhouse (P < 0.05) and when leafhoppers were removed, gas exchange was restored.

It is surprising to know the small amount of work that has been done on alternate freezing and thawing of seeds. Many experiments, however, have been conducted to see the effect of very low temperatures on seeds and to notice the effect it had on their vitality. Some experimenters subjected seeds to temperatures as low as liquid hydrogen with very interesting results but in very few cases, if any, was the effect of alternate freezing and thawing studied. The work that follows deals directly with the effects of alternate freezing and thawing on impermeable seeds of alfalfa and of dodder. It is known that this seed does not germinate readily; therefore it often lays over winter in the soil. Does this natural freezing and thawing aid or hinder this impermeable seed in it's later germination? this has been the main question kept in mind throughout this experiment.

Unleached root-zones represent an environmental ideal by eliminating wasteful leaching of nutrients and water. NASA grows plants in space in unleached root-zones, incorporating polymer-coated fertilizer (PCF) into a ceramic media (Turface or Profile). However, lack of growth productivity in space has led to the need for research to improve the nutritional and physical environment of the root-zone, which is the objective of this research. PCF types are diverse in release characteristics and the effects of temperature and substrate water content have not been well characterized. In spite of widespread use, studies on chemical properties and applied studies to verify soil physical models of ceramic media have been limited. We quantified the release rate of three widely-used types of PCF (Polyon, Nutricote, and Osmocote) in water and in sand over a wide range of temperature (5, 15, 20, 30, and 40ºC). Results indicated that substrate water content had a minimal effect on release rates. Nutricote fertilizers were the most consistent in releasing individual nutrients with temperature and over time. Polyon fertilizers had the slowest release rates relative to the manufacturer's specifications, but a relatively linear response to temperature. Osmocote fertilizers rapidly released nutrients at all temperatures. For more efficient PCF use, we present a comprehensive model that couples models to predict plant growth and PCF nutrient release rates. This model is based on phosphorus release, the nutrient found to be limiting to PCF-fertilized plants. The efficacy of the model to accurately predict PCF application rates was verified with a growth trial. In ceramic media, relative media-sorbed nutrient concentrations were highly variable from bag to bag. Excesses of manganese, boron, magnesium, and sulfur in the media induced nutrient imbalances in plant tissues. Rinsing and soaking procedures on the media helped mitigate these nutrient imbalances. Ceramic media also interacted with added fertilizer ions. Copper, phosphorus, and zinc ions were largely removed from solution by these interactions. We also used plants to extract water from root-zones of ceramic media to characterize plant-available water and water supply dynamics. The results suggest that soil physical models may be used to predict plant-available water in ceramic media.

A soils infiltration rate (IR) is the measured rate that soil is able to absorb water, either from precipitation or irrigation. A low IR can cause damage to crops if the necessary amount of water cannot penetrate to the plant roots in the time needed. The damage can be common in permanent plantings such as almond and pistachio orchards where regular tillage is avoided. This indicates a physical aspect to the problem because tillage increases IR. However, there is also an electrochemical side to infiltration problems because certain calcium surfactant treatments can increase IR. Various other methods have been used to increase IR such as using cover crops and increasing organic matter. Despite these different approaches to the problem, the specific cause of low IR is often unknown. This study was conducted to determine what physical properties of soils from a site in California cause low IR. This research shows the relationship of these properties to low IR. It was assumed that high amounts of mica in the very fine sand and coarse silt fraction of soils in Northwestern Kern County, California may interact with other physical and chemical properties to reduce IR. Fourteen sites were sampled in the area near the towns of Wasco and Shafter. The soils sampled represented the typical agricultural soils of the area and exhibited three levels of infiltration, Good (no amendments), Moderate (requires gypsum), and Poor (gypsum application is insufficient). Mica percentages in the very fine sand and coarse silt were calculated using a petrographic microscope and compared to the overall IR of the fields. Mica was shown to be significant factor at all three levels of IR.

One of the big problems encountered in experimental yield trials of field crops is the variation that occurs in yield estimates regardless of how the trial is handled with respect to variety or treatment. This so-called "natural" variation is the result of such factors as heredity, human error, and environment.

The purpose of this study was to evaluate three coverings for overwintering twelve varieties of container grown herbaceous perennials under Kentucky conditions. The twelve perennial varieties were started from seed in the spring and had been moved to one gallon containers by fall. In the first week of December, three blocks of containers were covered with one of the following: one layer of 4 mil, milky copolymer; one layer of quarter inch microfoam and one layer of milky copolymer; a sandwich of two layers of milky copolymer with 6 inches of wheat straw between them; the remaining block was left uncovered as a check. The perennials were uncovered in the spring, observed, and evaluated. The single layer of copolymer and the microfoam and copolymer treatments had the most new growth. The growth under the copolymer and straw sandwich method was elongated and white. Only three containers in the uncovered treatment showed signs of regrowth. The microfoam and copolymer and the single layer of milky copolymer proved to be the best coverings for the over - wintering container grown herbaceous perennials in Kentucky.

A comparison of the relationship of fermentation to chemical composition was made for forages which were wilted and ensiled at 35 to 45 percent dry matter. Trial I consisted of three forages ensiled in October, 1981: interseeded soybeans and grain sorghum. whole plant corn with added anhydrous ammonia, and whole plant corn with shelled corn added at a rate of 150 kg/t of fresh forage. Trial II consisted of two forages ensiled in 1982: interseeded soybeans and pearlmillet, and wheat. Temperatures of fermentation were collected, and chemical composition during the first 25 days of fermentation analyzed. Production data were also collected in Trial I. The cash expenses and yields do not indicate a significant advantage to either crop in this study in terms of yields and return over variables. In terms of plant nutrient content there was an advantage for soybean/grain sorgum silage in protein yield of 854 kilograms per hectare as compared to whole plant corn silage. Temperature data collected on the forages in Trial I covered 57 days from October 8 through December 4. The maximum recorded temperatures for soybean/grain sorghum, corn silage with added anhydrous ammonia and the corn silage control were 37, 37, and 24 degrees Celcius. achieved by day 11, 4, and 11 of ensilement respectively. The rapid temperature increase for material treated with anhydrous ammonia confirmed previous reports. Small fluctuations occurred in silage temperatures but these were not correlated to ambient temperature. Temperatures declined very slowly in all forages, with the lowest reading for silages by day 57 recorded at 19 C for soybean/grain sorghum silage. Ambient temperature was not reached in the ensiled mass during the 57 day period in which data were recorded. The soybean/pearlmillet ensiled in Trial II quickly reached a high peak temperature of 44 C at 4 days of ensilement, gradually decreasing over a 57 day period to 35 degrees on October 19. The silage did not reach a desireable pH. Initial forage pH was high, 7.4, dropped rapidly to 5.1 on day 5, but did not decline further in succeeding samples. Samples were low in lactic acid and high in acetic acid content. Initial buffering capacities for both of the soybean mixture forages were considerably higher than the other forage materials. Buffering capacities at day 0 for whole plant corn, whole plant corn treated with anhydrous ammonia, soybean/grain sorghum, soybean/pearlmillet and wheat forages IA ere 19.4, 20.0, 35.3, 35.3. 38.6 and 22.2 milliequivalents/100 g of dry matter respectively. Increases in buffering capacities during fermentation were smaller for soybean/grain sorgum and soybean/pearlmillet . Buffering capacity increases for the forages were 133.5, 290.5, 69.1, 64.2 and 87.4%. High ammonia nitrogen levels were found in samples of whole plant corn silage with added anhydrous ammonia obtained on days 10 and 20 of ensilement. These contained .282 and .351% ammonia-nitrogen and tested 18.0 and 20.1% crude protein. The increase in buffering capacity which occurrs with addition of anhydrous ammonia was confirmed by the higher acetic acid and pH levels, with corresponding decreases in lactic acid from samples taken days 10 and 25. Crude protein levels were 17.9 and 17.4 percent while the other samples contained only 10-12% crude protein. It appeared that application of anhydrous ammonia was not uniform throughout the silage. Where high concentrations of ammonia occurred fermentation was prolonged as indicated by excessive amounts of lactic and acetic acids and a high pH in these samples. Values for L(+) lactic acid ranged from .2 to .523 in fresh forage to 5.66% of dry matter on day 25. Concentrations of ammonia-nitrogen in the other silages ranged from .061 to .131%. The low buffering capacity of whole plant corn silage was reflected by normal concentrations of lactate and acetate but a more acidic pH when compared to the other forages. Lactic and acetic acid production for soybean/grain sorghum silage was similar to that of the corn silage control. Corn silage pH was lower, however, throughout fermentation and reached a stable pH by day 5 of fermentation. The wheat silage went through a gradual fermentation with low lactic acid production, and an intermediary ending pH of 4.0. Fermentation was essentially complete by day 10 in all silages as indicated by pH, buffering capacity, and lactic acid production: however, there was a tendency for buffering capacity and acetic acid content to increase in all of the ensiled materials throughout the 25 day collection period.