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Cynthia B. McKenney

Writing Across the Curriculum (WAC) programs are viewed as a plausible solution to poor student communication skills. These programs are further justified on the premise that writing fosters and reinforces learning in any discipline.

WAC programs integrate easily into horticulture. Traditional writing opportunities frequently utilized in horticulture include essays, papers, presentation critiques, lab reports, field trip summaries, business proposals, and cropping schedules. New opportunities might include microthemes and target audience writings.

WAC programs have their own share of pitfalls: increased grading time, reduced course content, ill-equipped faculty to teach language arts, and unrecognized objectives. Ultimately, the success or failure of a WAC program hinges on the commitment of faculty in the discipline who should have the best understanding of the language and style needed to communicate effectively in their field.

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Cynthia B. McKenney and Ellen B. Peffley

Proponents of distance education encourage the migration of courses and entire degree programs onto the web. To this end, vast amounts of time, energy, and funds are directed to the development of new courses as well as the enhancement of traditionally taught courses. The question now begs to be asked, “Are we getting what we truly want from distance education?” Using a web platform provides a framework with excellent options to develop audio and visually rich courses. Distance programs also provide access to students not able to participate in traditional on-campus degree plans, providing the potential for a boost in enrollment. However, there are serious considerations that need to be balanced, including student satisfaction/dissatisfaction, enrollment management, faculty time commitment, and technical support. In this presentation, some of the benefits and liabilities of web courses will be discussed and program management suggestions will be explored.

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Cynthia B. McKenney and Ellen B. Peffley

Teaching at a distance has many rewards and challenges inherent in its delivery. Interactive video conferencing has the advantages of having audio and visual contact with students during a set class period while having the disadvantages of scheduling multiple locations and keeping the equipment functioning at peak performance. Likewise, using a web platform such as WebCT provides a framework with excellent options to develop a course that is both audio and visually rich. This solution also presents its own difficulties as required textbooks change and the platform version may be upgraded. In this presentation, the advantages and disadvantages of both formats will be reviewed. In addition, helpful hints for blending these two teaching methods together to create a custom course will be discussed.

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Peter A. Dotray and Cynthia B. McKenney

Experiments were conducted to evaluate established and seeded buffalograss [Buchloe dactyloides (Nutt.) Engelm.] tolerance to herbicides applied preemergence at labeled use rates. Established buffalograss tolerated benefin, benefin plus oryzalin, benefin plus trifluralin, DCPA, dithiopyr, isoxaben, oryzalin, pendimethalin, and prodiamine. For established buffalograss treated with atrazine, diuron, or metolachlor, the injury rating was 27% to 71% at 6 weeks after treatment (WAT) and 22% to 84% at 15 WAT. Buffalograss tolerated cyanazine, metsulfuron, propazine, and pyrithiobac applied in the seedbed. Seeded buffalograss stands were reduced by alachlor, atrazine, dicamba, linuron, metolachlor, metribuzin, oryzalin, pendimethalin, and quinclorac. Stand reductions by dicamba (a preplant and postemergence herbicide), up to 100% at 4 WAT and up to 85% at 16 WAT, were those most severe. Seeded and established buffalograss showed excellent tolerance to a few preemergence herbicides that could be used effectively and safely to control weeds during establishment and maintenance of buffalograss. Chemical names used: 2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl) acetamide (alachlor); 6-chloro-N-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine (atrazine); N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl)benzenamine (benefin); 2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino]-2-methylpropanenitrile (cyanazine); dimethyl 2,3,5,6-tetrachloro-1,4-benzenedicarboxylate (DCPA); 3,6-dichloro-2-methoxybenzoic acid (dicamba); S,S-dimethyl 2-(difluoromethyl)-4-(2-methylpropyl)-6-(trifluoromethyl)-3,5-pyridinedicarbothioate (dithiopyr); N′-(3,4-dichlorophenyl)-N,N-dimethylurea (diuron); N-[3-(1-ethyl-1-methylpropyl)-5-isoxazolyl]-2,6-dimethoxybenzamide (isoxaben); N′-(3,4-dichlorophenyl)-N-methoxy-N-methylurea (linuron); 2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide (metolachlor); 4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one (metribuzin); 2-[[[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]amino]sulfonyl]benzoic acid (metsulfuron); 4-(dipropylamino)-3,5-dinitrobenzenesulfonamide (oryzalin); N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine (pendimethalin); N 3,N 3-di-n-propyl-2,4-dinitro-6-(trifluoromethyl)-m-phenylenediamine (prodiamine); 6-chloro-N,N′-bis(1-methylethyl)-1,3,5-triazine-2,4-diamine (propazine); 2-chloro-6-[(4,6-dimethoxy-2-pyrimidinyl) thio]benzoic acid (pyrithiobac); 3,7-dichloro-8-quinolinecarboxylic acid (quinclorac); Team™ [premix of 1.33% benefin and 0.67% 2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine] (trifluralin).

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Cynthia B. McKenney and Marihelen Kamp-Glass

The effectiveness of antitranspirant type and concentration on the leaf water relations of Saliva splendens F. `Firebird and Petunia × hybrida Juss. `Comanche'. Two film-forming antitranspirants, Cloud Cover and Folicote, were tested at three different concentrations in two different environments. The leaf water potential, stomatal conductance, and relative water content were evaluated. Transpiration per unit vapor pressure deficit and stomatal conductance for both crops decrease slightly but there was no trend with respect to the film type, environment or concentration rate. The leaf water potentials and relative water content did not show significant difference after antitranspirant application. In order for antitranspirant application to be of benefit to the growth of herbaceous plants, a more durable coating that remains semipermeable would have to be utilized.

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Samuel C. Hill* and Cynthia B. McKenney

Given the regularity of periods of drought in the southwestern U.S., concern over an ample supply of high quality water is always an issue. With a diminishing water supply, higher quality water will likely be diverted to higher priority uses; therefore, concern arises over the availability and quality of water for landscape use. This project was designed to screen representative cultivars from several of the major garden rose categories (China, Tea, Polyantha, Hybrid Tea, and Found Roses) for tolerance to saline irrigation water. Roses were placed in a completely randomized design with four replications in a container holding area. Salinity treatments were designed to be a 2:1 molar ratio of NaCl:CaCl2. The treatments consisted of 0, 6.25, 12.5, 25, and 50 mmol NaCl. The volume of solution applied to each treatment was adjusted at every irrigation event to meet ET and produce a 30% leaching-fraction. At the conclusion of the study, the China rose retained the best foliage while one of the hybrid tea roses maintained flowering throughout the study at all treatment levels. It appears that the roses with the smallest leaflets were able to tolerate salinity better than those with larger leaflets. Results of the tissue sample, leachate, spad and media analyses will also be presented.

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Cynthia B. McKenney, Ellen B. Peffley and Igino Teolis

Increasingly more collegiate courses are offered through a variety of distance formats. Course management platforms have reduced the faculty time required to create and deliver distance courses while enhancing asynchronous communication. In this study, the transactional distance theory was used to evaluate the different communication levels found between faculty and students in web-facilitated, online, and interactive video courses. A comparison of the online course sections to the web-facilitated course sections determined that there were significantly more asynchronous contacts with the online sections than with the web-facilitated sections. In addition, the total instructor time invested to administer the online course sections was significantly less than for the web-facilitated course sections. The interactive video conferencing sections could not be compared directly to the other teaching modes because the course content differed; however, mean time intervals for teaching and administrative activities are provided.

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Amber N. Bates, Gerald M. Henry and Cynthia B. McKenney

No research has investigated the phytotoxic response of hooker’s evening primrose (Oenothera elata) plug transplants to preemergence herbicides. Varied phytotoxic responses of common evening primrose (Oenothera biennis) to preemergence herbicides suggest that options may exist for the safe control of weeds present within hooker’s evening primrose when grown as an agronomic field crop. Enhanced weed control during early establishment may reduce competition for water and nutrients as well as increase seed yield and oil content. Therefore, the objective of this research was to determine the phytotoxic effect of preemergence herbicides on hooker’s evening primrose plug transplants grown in the greenhouse. Research was conducted in 2010 and 2011 at the Plant and Soil Science greenhouse complex at Texas Tech University in Lubbock, TX. Herbicide treatments were applied on 13 July 2010 and 5 Apr. 2011 and consisted of oxadiazon at 3 lb/acre, isoxaben at 0.5 lb/acre, oryzalin at 2 lb/acre, prodiamine at 1.5 lb/acre, dithiopyr at 0.5 lb/acre, s-metolachlor at 1.8 lb/acre, pendimethalin at 0.6 lb/acre, and isoxaben + trifluralin at 2.5 lb/acre. One 4-month-old hooker’s evening primrose plug (2 inches wide) was transplanted into each pot (3 gal) 2 days after treatment (DAT). Dithiopyr and s-metolachlor treatments exhibited similar lack of phytotoxicity as the untreated control 7 DAT. Phytotoxicity ≥13% was observed for trifluralin + isoxaben, pendimethalin, prodiamine, oryzalin, isoxaben, and oxadiazon 7 DAT, with the highest level of phytotoxicity (24%) exhibited by trifluralin + isoxaben treatments. Hooker’s evening primrose phytotoxicity decreased (plants grew out of the damage) for all treatments except trifluralin + isoxaben, pendimethalin, and oryzalin 28 DAT. Oryzalin (16%) and trifluralin + isoxaben (60%) were the only two treatments that did not exhibit similar phytotoxicity to the untreated control 28 DAT. There were no significant differences in aboveground or belowground biomass nor plant growth index (PGI) of any of the treatments when compared with the untreated control 28 DAT. Based upon the results of this trial, pendimethalin, prodiamine, dithiopyr, s-metolachlor, oryzalin, isoxaben, and oxadiazon may be used for preemergence weed control in hooker’s evening primrose without causing excessive phytotoxicity (>20%), potential yield loss, or both. Trifluralin + isoxaben treatments exhibited 60% hooker’s evening primrose phytotoxicity 28 DAT, which resulted in too low of an initial plant stand to warrant use.

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Cynthia B. McKenney, Amber Bates, Kaylee Decker and Ursula K. Schuch

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Sandra A. Balch, Cynthia B. McKenney and Dick L. Auld

Geographically referenced information is an important aspect in the collection of wild plant species. It provides detailed information about the collection site as well as a method of relocating plant populations. In one project, native plants were collected and analyzed for the presence of gamma-linolenic acid, a valuable fatty acid used in medicinal products. In a second project, native wild-flowers were collected and evaluated for potential use as drought-tolerant ornamental landscape plants. All native plants were initially tagged in the spring while in bloom. Each collection site was revisited later for seed collection. Due to a lack of landmarks in the collection area, a GeoExplorer Global Positioning System (GPS) unit was used to capture coordinate data of latitude, longitude, and altitude. This was added to the passport file of each collection site. Differential correction was used to increase accuracy of GPS data to within a range of 10 m. ARC/INFO software was used to assemble, store, and display collection data in map form. This method has been used to document over 300 accessions and identify areas with a high frequency of plants possessing desired characteristics.