Agricultural instructors have been documenting declining enrollments at land-grant institutions for the past few years. Of the students enrolled, those with farm background are decreasing. Some instructors have suggested the use of video tutorials to raise competence levels of these nonfarm-background students. A video tutorial was initiated in the beginning crop science course at the University of Georgia to provide nonfarm-background students (53% of the class) with short, descriptive, video programs on several agronomic practices. Students viewed the video tutorial on a voluntary basis during the fall and winter quarters of 1987 and on a compulsory basis for the spring quarter, 1988. To discern students' attitudes and progress, students took various pretests, surveys, and evaluations throughout the quarter. When offered on a voluntary basis, 15% of the class used the tutorial compared to 87% usage when the tutorial was compulsory. Ninety-five percent of those who used the videos signified varying degrees of improvement in their level of familiarity with agronomic items and practices. Urban, nonfarm-background students' increase in familiarity due to video viewing was significantly higher than those students with a rural, farm background experience. This study suggests that video tutorials are useful supplements to existing lecture and lab portions of a crop science course and can help bridge the gap between farm- and nonfarm-background agricultural students.
With recent advances in N analyzers, the Dumas method becomes more attractive as a replacement for Kjeldahl N. Kjeldahl N (K_N):Dumas N (D_N) ratios were determined for anthurium (A), orchid (O), fern (F) and turf (T). Dry tissues were ground to pass a 20-mesh seive. D_N was determined using 0.2 g of sample and a Leco FP-428. K_N was determined by digesting 0.4 g tissue with a CuO/TiO/K 2 SO 4 catalyst and 10 mL H 2 SO 4 at 450°C for 2 hr. Ammonium in the digest was assayed by colorimetry (Lachat analyzer). Overall (n=397 obs.), D_N was a good estimator of K_N: K_N = 0.90 (p<0.01) D_N + 0.09 (p=0.03) , R 2 =0.93, over the 0.4-6.6 N range. K_N:D_N ratio was significantly (p<0.01) affected by plant type. Ratios of 0.85 for A, 0.92 for T, 0.99 for O, and 1.00 for F may be used to estimate K-N from D-N for the diagnosis of N nutrition, along with existing interpretative data.
Videotapes have been utilized in various crops and soils courses to supplement lecture and laboratory material. Little is known in agronomic education regarding how videotapes compare with more traditional teaching methods and overall student attitudes toward their use. The objectives of this study were to determine: (i) the effectiveness of videotapes compared with other teaching methods; (ii) if videotapes depicting various aspects of turfgrass management could effectively supplement the lecture and laboratory portions of the course; and (iii) student attitudes concerning their self-perceived knowledge improvement and overall acceptance of the use of videotapes as a supplemental teaching aid. During the spring of 1989, six videotapes were utilized to supplement the lecture and laboratory material in an introductory turfgrass management course at the University of Georgia. The video topics included: pesticide handling, equipment calibration, lawn aeration, turf insects, turf weeds, and maintenance of reel mowers. One laboratory section was required to view the videotapes, while another section was not. Although the video users attributed 23 to 36% of their knowledge of various turfgrass topics to the use of the videos, there was no difference in grades between them and the nonuser group. Thirty-nine percent of the video users stated the videotapes should be continued on a mandatory basis, while 44% indicated they should be voluntary. However, students thought the use of other teaching aids, such as live plant specimens and field trips were more effective than videotapes. In general, students perceived the use of videos as a positive supplement to the turfgrass management course, but not as a substitution for traditional teaching methods.
Abstract Information concerning the mineral nutrient composition of various turfgrass species and cultivars is limited. The concentration of nutrients in the turfgrass plant provides an indication of the overall nutrient status and quality of the turf stand. Bermudagrass [Cynodon dactylon (L.) Pers.] is an important turfgrass utilized throughout the Southeastern and Southwestern states and the transition zone of the United States. A study was conducted to determine the effects of different rates of nitrogen (N) and potassium (K) on the macronutrient content of fifteen bermudagrass cultivars. The cultivars utilized were: ‘Ormond’, ‘Texturf 10’, ‘Tiflawn’, ‘Tufcote’, and ‘U‐3'; ‘Everglades’, ‘Midiron’, ‘Midway’, ‘Pee Dee’, ‘Santa Ana’, ‘Tifdwarf’, ‘Tifgreen’, ‘Tifway’, and ‘Tifway II’ [Cynodon dactylon (L.) Pers. x Cynodon transvaalensis Burtt‐Davey]; and ‘Sunturf’ [Cynodon magennisii Hurcombe], Cultivar plots were replicated three times and were divided into four sub‐plots for the application of N and K monthly from July to October, 1996 at rates of 227 g N and K 93 m‐2 (low rates) and 454 g N and K 93 m‐2 (high rates). The four N:K treatments were: (i) high N:high K; (ii) high N:low K; (iii) low N:high K; and (iv) low N:low K. Plant tissue samples were collected in late August and analyzed for N, K, phosphorus (P), calcium (Ca), magnesium (Mg), and sulfur (S). The high N:low K treatment was the only one to result in differences of N content among the cultivars. There were differences in P, K, Ca, Mg, and S content among the cultivars under each of the four treatments. The N, P, and S contents for all cultivars under all treatments were within the sufficiency ranges for these elements while K, Ca, and Mg contents were less than the lower value of the sufficiency range for these three elements for some cultivars under certain treatments. The content of K for most cultivars was toward or below the low end of the sufficiency range regardless of the high or low K rates.
Root crops are important in developing countries, where food supplies are frequently marginal. Increases in atmospheric CO 2 usually lead to increases in plant growth and yield, but little is known about the response of root crops to CO 2 enrichment under field conditions. This experiment was conducted to investigate the effects of CO 2 enrichment on growth and yield of field‐grown sweetpotato [ Ipomoea batatas (L.) Lam.]. Plants were grown in open‐top chambers in the field at four CO 2 levels ranging from 354 (ambient) to 665 μmol mol −1 two growing seasons. Shoot growth was not affected significantly by elevated CO 2 . Yield of storage roots increased 46 and 75% at the highest CO 2 level in the 2 yr. The yield enhancement occurred through increases in the number of storage roots in the first year and through increases in both the number and size of the storage roots in the second year. Storage‐root/shoot ratios increased 44% and leaf nitrogen concentrations decreased by 24% at the highest CO 2 level. A comparison of plants grown in the open field to plants grown in open‐top chambers at ambient CO 2 concentrations indicated that open‐top chambers reduced shoot growth in the first year and storage‐root yield in both years. These results are consistent with the majority of CO 2 ‐enrichment studies done on pot‐grown sweetpotato.
Multiple use of water through integrating aquaculture and irrigated crop production could minimize the cost of rearing fish and irrigating crops. Aquaculture effluent was tested for irrigation of four turfgrass species and Elderica pine seedlings. Plants were irrigated with fish effluent or city water, with or without supplemental fertilization from Osmocote® or Milorganite®. Turfgrass irrigated with effluent gained more biomass and had better color than grass watered with city water. Treatment with supplemental fertilizer resulted in significantly more biomass gain than in untreated turf. A Minolta CR-200 chroma meter was used to determine L, a, b color coordinates and leaf chlorophyll was extracted in DMF (dimethylformamide) and measured with a spectrophotometer. Color coordinate data were correlated with leaf clorophyll content and both were correlated with biomass gain.
The Introduction to Horticulture course in the Department of Agriculture at Southeast Missouri State Univ. provides an overview of the principles of various horticulture crops. It is a lower-level course comprised primarily of freshmen and sophomores. Although many of the students that take the course are majors in the horticulture option, there are some students taking the course that are not horticulture majors, since the course is a requirement for all majors in the department. The objective of this study was to have students assess their knowledge of various types of horticultural plants before and after the course. During the first day of class, a pre-course student profile and survey was given to each student in order to determine their background and to assess their knowledge of certain horticultural plants. They were asked their knowledge of these topics; and, they rated their knowledge as follows: excellent, good, average, fair, or poor. Throughout the semester, these topics and plants were discussed or demonstrated in either the lecture or the laboratory. At the end of the semester, students were given a post-course survey to assess their knowledge of the same topics and horticultural plants which they rated their knowledge of the first day of class. Comparisons between pre- and post-course student assessment of their knowledge of topics and plants will be discussed.
During a special session on turfgrass education at the 1988 ASA annual meetings, discussion focused on the future of graduate education in turfgrass science. It soon became apparent that a better understanding of the current programs in turfgrass education was needed. On that basis, a study was initiated in 1989 with the objective of assessing the educational background, practical experience, research areas, and career goals of graduate students in turfgrass science. Questionnaires were sent to 67 turfgrass teaching-research-extension faculty at 30 universities to be completed by their graduate student(s). Questions were divided into four categories: (i) student profile, (ii) educational background and current degree program, (iii) prior work experience, and (iv) career goals. Thirty-six surveys were returned from 18 universities. Forty-two percent of the respondents were pursuing the M.S. degree while 58% were working on their doctorate. The average age of all students was 30 yr. Most students held an undergraduate degree in either agronomy or horticulture. Areas of graduate turfgrass research included more traditional areas such as fertility-nutrition, general management (cultural systems), and physiology. There was little research in the areas of biotechnology or molecular biology. Although most students had prior experience in turfgrass maintenance practices, many felt that they needed more practical turfgrass experience. Few turfgrass programs offered advanced undergraduate or graduate-level courses. There is a need for more advanced courses to be offered so that turfgrass graduate students can acquire more formal training in turfgrass science and learn about such topics as the environment and soils as they relate to turfgrass. Generally, students stated that the education they were receiving was adequate in meeting their career goals. Although most students expressed a concern for environmental issues related to the turfgrass industry, few students were addressing this issue in their research.
Abstract St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] is utilized in Louisiana and other Southern states for home lawns, and to a lesser extent for commercial lawns. Under moderate management, it provides an adequate stand of turf but when maintained at a higher level it will provide a denser, greener, and better quality stand of turf. There is limited information on the nutrient content of St. Augustinegrass. The objective of this study was to evaluate the responses of both Palmetto and Raleigh St. Augustinegrass under high (H) and low (L) combinations of the following factors: 2 mowing heights (5.0 and 7.5 cm); 2 nitrogen (N) levels (227 and 454 g N 93 m−2 month−1; and 2 potassium (K) levels (227 and 454 g K 93 m−2 month−1). The treatment combinations were (mowing, N, and K), HHH, HHL, HLH, HLL, LHH, LHL, LLH, and LLL. Plots received a micronutrient fertilizer in 06 and 08 and were irrigated as needed. Color, density, texture, uniformity, and quality were determined monthly (04–10). Plant tissue samples were collected and analyzed for macronutrient and micronutrient contents. There were treatment differences for both macronutrients and micronutrients for both cultivars under all treatments.
