5 pp. / This Extension Bulletin is similar to others previously completed for Tucson, Phoenix, Flagstaff, Prescott and Payson. The bulletin provides information on turfgrass consumptive use for the River Cities (Bullhead, Lake Havasu, etc.) and Kingman areas. Consumptive use is provided for each month of the year in units of inches/month and inches/day for three grass production systems: high quality overseeded turf, acceptable quality overseeded turf and acceptable quality turf with no overseeding. The bulletin concludes with a discussion on how to use incorporate this into turf irrigation management programs.

Master of Science / Department of Horticulture, Forestry, and Recreation Resources / Jared Hoyle / Buffalograss [Buchloe dactyloides (Nutt.) Engelm] is a warm-season turfgrass species that is native to North America and requires minimal maintenance to survive. However, the use of buffalograss on golf courses throughout the transition zone is limited due to its appearance, growth habit, and lack of information available. Buffalograss is more drought tolerant than many other turfgrass species cultivated on golf courses, therefore, its drought resistance can lead to significant water savings. The objectives of these 2014 – 2016 field research studies were to evaluate: 1) buffalograss divot recovery as influenced by nitrogen source and application rate; 2) the influence of nitrogen application rate and simulated golf cart traffic on the wear tolerance of buffalograss; 3) the effect of simulated golf cart traffic on colorant treated buffalograss; and 4) buffalograss recovery from winter trafficking. When compared to untreated turf, divots in buffalograss treated with urea achieved 50% divot recovery 6.3 days faster when 1 lb N/1,000 ft² was applied, which was statistically similar to the 3 lb N/1,000 ft² rate. Applications of a slow-release polymer coated urea did not enhance divot recovery duration when compared to untreated turf. As nitrogen application rate increased in the presence of traffic stress, regardless of traffic rate, the green cover, quality, and color of the turf was enhanced. Percent green cover values for 0, 1, 2, and 3 lb N/1,000 ft² 10 weeks after initiation (WAI), regardless of traffic rate, were 60.2%, 69.0%, 75.5%, and 79.1% respectively. Regardless of nitrogen application rate, buffalograss receiving 16 passes/week of traffic never provided >72% green cover, while buffalograss receiving 0 passes/week had 74% green cover prior to the onset of dormancy. Endurant Premium turfgrass colorant in the presence of wear treatments provided >50% green cover 0 – 5 weeks after treatment in 2014 and 0 – 3 weeks in 2015. In general, as traffic rate increased, turfgrass colorant longevity decreased. Overseeded perennial ryegrass hindered buffalograss recovery after winter trafficking in comparison to untreated turf and colorant applications.

Salinity is a major abiotic stress in plant agriculture which reduces seed germination, vegetative growth, and flowering, and limits crop productivity world-wide. Salinity causes water deficit, ion toxicity, and nutrient deficiency in plants, which can result in cellular damage, growth reduction, and even death. Kentucky bluegrass (Poa pratensis L.) is the most widely used cool-season species in cool-arid climates; however it has relatively poor salt-tolerance. Thus the development of Kentucky bluegrass genotypes with increased salt tolerance is of interest to turf breeders. One impediment to selection towards this goal is finding an efficient and accurate method to evaluate the salt tolerance. The objective of this study was to examine physiological responses to salt stress and to evaluate the genetic diversity among the accessions used in the research. Salt-tolerant accessions PI371768 (768) and PI440603 (603) and salt-sensitive varieties Midnight and Baron were exposed to four levels of salinity imposed by irrigating with salt solutions of 0 dS m-1 (control), 6 dS m-1, 12 dS m-1, and 18 dS m-1 or 24 dS m-1. Soil salinity was measured using Acclima Digital TDT sensors and grass response to the stress was measured using turf quality ratings, stomatal conductance, leaf water potential and electrolyte leakage. In general, turfgrass quality, stomatal conductance, and leaf water potential decreased while electrolyte leakage increased under salinity stress. Midnight and Baron exhibited greater changes in these measurements, indicating more sensitivity compared to 768 and 603. The 6 dS m-1 treatment had little effect on the salt-tolerant accessions. Salt tolerance of 603 and 768 was confirmed and likewise, salt sensitivity of Baron and Midnight was confirmed. The genetic similarity of all cultivars used in this study was very high. All of the evaluation measurements were highly correlated, with water potential and electrolyte leakage being the most reliable and accurate methods due to the low standard deviations. Due to more repeatable methods and less user error, electrolyte leakage and turfgrass quality are recommended methods for screening salt tolerance of turfgrasses.

Extension programs across the nation have been given the task of education and outreach to citizens of their respective states. Master Gardener programs have been seen as a way to provide horticultural education, while also providing outreach using the program’s service requirement. Extension professionals have used a variety of training methods throughout the years. These methods include face-to-face workshop trainings, interactive television, and more recently World Wide Web methodologies. This study sought to test the effectiveness of CD-based training materials versus a traditional face-to-face training. Turfgrass management modules chosen for testing in this study included nutrient, water, and pest topics. Participants’ knowledge levels were measured using a pre-test/post-test design. Student satisfaction with the learning materials and their perceptions of lawn care also were measured during the study. Results indicated that CD-based materials were more effective than were face-to- face workshops for teaching difficult turfgrass material to the Master Gardener trainees. Community development is one of the four focus areas for Texas Cooperative Extension. A secondary purpose was to determine if the Master Gardener program affected community development. Descriptive statistics were used to compare participants’ past experiences with their anticipated experiences after completion of the Master Gardener program. Results indicated that community development activities were being completed, but the extent and type of development could not be measured. This study revealed several surprising and far-reaching implications for extension programming. These implications and recommendations for improvement of extension programs are discussed further. Recommendations for additional research also are included.

We compared water deficit responses of 'Tifsport', 'Tifway 419', 'Tifgreen 328', and 'MidIron' bermudagrass (Cynodon dactylon x Cynodon transvaalensis), and 'SeaSpray', 'SeaDwarf', and 'Sea Isle 1' seashore paspalum (Paspalum vaginatum Swartz) under a linear gradient irrigation system in the desert Southwest. Target irrigation levels were 100, 80, 60, and 40% (2009) and 100, 80, 70, 60, and 40% (2010) of standard reference evapotranspiration (ETo). Actual water applied (including rainfall) was 100%, 83%, 66%, and 49% of ETo (2009) and 100%, 83%, 75%, 66%, and 49% (2010). Canopy temperatures increased, and quality and dry matter production declined with reduced irrigation. For optimum turfgrass quality, 75 to 83% ETo replacement was required; for acceptable quality turfgrass, 66 to 75% ETo replacement was needed for bermudagrass, and 75 to 80% ETo for seashore paspalum. Spring green-up was delayed by drought. Bermudagrasses, particularly 'MidIron', performed better than seashore paspalums under water stress conditions.

The North Bosque River watershed of central Texas hosts a large portion of diary production in the state. In recent years, the Texas Commission on Environmental Quality (TCEQ), formerly known as the Texas Natural Resource Conservation Commission (TNRCC), has applied a Total Maximum Daily Load Program for soluble phosphorus to the watershed. Best management practices (BMPs) are now necessary to remedy the issue of excess phosphorus. This thesis explores the application of GIS as an agricultural planning tool in support of a BMP for the region. The suggested BMP calls for the production of turfgrass sod using composted dairy manure; this sod is then transported at a profit from the watershed and provides an economically sustainable means to reduce the nutrient loading in the watershed. Using GIS, a geospatial database was developed with available data from government and institutional sources. As part of the development process, these sites were verified by field technicians and the results were combined in the GIS to refine the database. This database demonstrates the suitability of GIS as a tool for large-scale planning in agriculture.

Turfgrass settings, including lawns, golf courses, and sports fields, support many beneficial invertebrates that provide important ecosystem services. These non-target organisms and their associated predation, decomposition, and pollination services can be disrupted by the use of certain insecticides. I compared the ecotoxicity of representatives from three major turf insecticide groups, the neonicotinoids, premix formulations, and the anthranilic diamides, in lab and field realistic settings in order to inform industry initiatives towards environmental sustainability. In lab and field bioassays clothianidin, a neonicotinoid, and a premix clothianidin/pyrethroid spray were acutely toxic to beneficial insects. Populations of predators, springtails, and earthworms, as well as parasitism, predation, and decomposition rates were all reduced. In contrast, chlorantraniliprole, a novel anthranilic diamide with a similar spectrum of pests controlled, had no apparent impact on natural enemies, decomposers, or ecosystem services. This newer class is a good fit for industry initiatives to use relatively less toxic pesticides, with the caveat that golf course superintendents may see secondary pest outbreaks of ants and earthworms. Bumble bee colonies exposed to clothianidin-treated white clover for two weeks suffered acute effects including increased mortality of workers and decreases in the number of honeypots constructed in the hive. When hives were exposed to clothianidin treated clover for six days and then allowed to develop naturally over six weeks they exhibited delayed weight gain and produced no new queens. Colonies exposed to chlorantraniliprole-treated flowers suffered no observable adverse effects. When treated blooms were mowed, colonies exposed to newly-formed blooms exhibited no ill effects. After a single mowing neonicotinoid residues in clover nectar were reduced from > 2000 ng/g, to < 10 ng/g. Residues of imidacloprid were also short-lived in guttation water. Some 50 species of bees and other pollinators were collected from flowering white clover and dandelions in lawns across an urbanization gradient. Such weeds, an underappreciated resource for urban bees, could play a role in pollinator conservation if tolerated and not over-sprayed with broad-spectrum insecticides. Informing the public about the potential benefits these weeds could have for pollinators may help lead to more environmentally conscious management decisions.

Rhizoctonia zeae is a common pathogen of tall fescue and other turfgrasses in various regions of the United States. Disease caused by R. zeae typically occurs during hot, humid summer months when conditions are ideal for growth of the fungus but less than ideal for growth of tall fescue. While R. zeae has been reported on turfgrasses in several Mid-Atlantic states, there are no records of this pathogen being present in Virginia. Rhizoctonia isolates were obtained from samples of various turfgrasses exhibiting typical Rhizoctonia disease symptoms in Virginia. Additional isolates were obtained from several other states. All were characterized with respect to species characteristics as well as pathogenicity and virulence on two common cultivars of tall fescue. All isolates were pathogenic on tall fescue but there was some variability in virulence. There was consistently slightly less disease present on Crossfire II than on Kentucky 31. Experiments were also conducted to determine the impact of prior exposure to high air temperatures on the severity of disease. Preliminary data showed that one week of exposure to higher air temperatures caused an initial increase in overall turf quality, but as length of exposure increased the quality of turfgrass declined. Tall fescue plants were subjected to 0, 7, and 35 days of heat stress prior to inoculation with several isolates of R. zeae. No relationship was found between predisposing heat stress and disease severity. / Master of Science

Preemergence herbicides are generally considered as a group to negatively affect hybrid bermudagrass (Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy) establishment. However, little is known about the effects upon hybrid bermudagrass root growth, establishment, and sod harvestability. Several research projects were conducted at Mississippi State University to determine the effects of commonly used preemergence herbicides on hybrid bermudagrass sod production. Measured response variables included visually estimated hybrid bermudagrass cover, normalized difference vegetative index (NDVI), ratio vegetative index (RVI), relative chlorophyll concentration (CI-RE), sod tensile strength, root mass, root length, root surface area, average root diameter, and root carbohydrate concentration after application of these herbicides. While several of these preemergence herbicides initially reduced hybrid bermudagrass growth, hybrid bermudagrass was generally able to recover and outgrow the herbicidal effects by the end of the growing season.

No description available.