A one-credit course, Writing in Horticulture, was developed and taught to graduate students in the Dept. of Horticulture at Clemson Univ. The course focused on discussion and explanation of the philosophies and methods of writing in the horticulture field. Discussions included a review of writing mechanics, types of writing and audiences, examples of exemplary writings, editing and reviewing, and examples and methods of professional correspondence. Real-life writing experiences were emphasized. Hands-on activities included writing and reviewing peer manuscripts and grant proposals. Three original written works were completed by the end of the semester: 1) a popular press article, 2) a grant proposal (maximum three pages long), and 3) an abstract for a manuscript published previously in a scientific journal.
Dennis R. Decoteau
The influence of polyethylene (plastic) mulch surface color (white versus black) on leaf area distribution of tomato (Lycopersicon esculentum) was investigated in simulated planting beds at two sampling periods: an early sampling with relatively young plants that had been in the mulch treatment for 22 days and a late sampling with relatively mature plants that had been in the mulch treatments for 50 days. At the early sampling period, tomato plants grown with white mulch had more axillary leaves than plants in the black mulch, resulting in a greater axillary:main leaf area ratio for the plants with white mulch. Leaf area for total leaves (main + axillary) and plant biomass was unaffected by mulch surface color at the early sampling period. Tomato plants grown in black mulch at the early sampling period had significantly more area of main leaves partitioned to node 3, whereas plants grown in white mulch had more area of main leaves in nodes 8 and 9. Plants grown in the white mulch treatment had significantly more axillary leaf area at nodes 1, 2, and 3, whereas plants in black mulch had more axillary leaf area at node 6. At the later sampling period, most of the leaf area from both mulch treatments was recorded in the axillary leaves and there was no effect of mulch surface color on the amount of total leaf area partitioned to main, axillary, or total leaves; to the amount of biomass of the measured top growth; or to the nodal distribution of leaf area among main leaves or axillary leaves. Tomato plants in white mulch had significantly more fruit on plants at the later sampling period than plants in the black mulch. Mulch surface color also affected the plant light environment and soil temperatures. These results suggest that the polyethylene mulch surface color can induce changes in the plant microclimate and affect leaf area distribution of young tomato plants (as recorded at the early sampling) and fruiting of relatively more mature plants (as recorded at the later sampling).
Dennis R. Decoteau
The influence of leaf removal and decapitation (removal of apical bud and top two nodes) of determinate tomato (Lycopersicon esculentum Mill cv. Mountain Pride) plants on canopy development was investigated. Leaf removal and decapitation influenced subsequent leaf development and distribution, and early fruiting of greenhouse-grown tomato plants. `Removal of young axillary leaves increased the size of main (true) leaves in the middle and upper nodes, increased the number of nodes, and increased the number of early fruit produced. Removal of main leaves reduced axillary leaf development at nodes 5 and 9. Decapitation increased axillary leaf development in the middle and upper nodes and delayed early fruit production. These results suggest that cultural practices of tomatoes that remove leaves or apical buds to influence fruiting also affect canopy leaf development and distribution.
Dennis R. Decoteau
The Teaching Portfolio is a factual description of a professor's strengths and accomplishments. It includes documents and materials that collectively suggest the scope and quality of a professor's teaching performance. The Teaching Portfolio is a living, breathing document that changes over time. Items in a Teaching Portfolio include a statement of teaching responsibilities, description of steps to improve teaching, instructional innovations, student and teaching evaluations, awards and honors, and a record of students who have succeeded. I will discuss the steps taken at Clemson University to use the Teaching Portfolio.
Roger Francis and Dennis R. Decoteau
Southernpea and sweet corn can be intercropped effectively. When simultaneously planted, sweet corn appears to be the dominant crop in the mixture, with intercropped southernpea producing a supplemental yield to intercropped sweet corn. Increasing intercrop plant densities increased the amount of sweet corn yield and reduced the amount of southernpea yield. The reduction in light intercepted by southernpea and sweet corn in the intercrop situation probably contributed to the reduction in yield by these component crops as compared to the yield of these crops as monocrops. The total system LER (LERsouthernpea + LERsweetcorn) for the high-population intercropping system, where plant densities for each crop were comparable to the densities of these crops as monocrops, was 1.26. This suggests that intercropping southernpea and sweet corn at this density gave a yield advantage of 26%, or that 26% more land planted in equal proportion of each component crop would be required to produce the same yield as the intercrop. A N application rate of 125 lb/acre (140 kg·ha-1) was optimum for intercropped sweet corn, and there was no advantage of a 2-week delayed planting of sweet corn in this intercrop system.
Heather Hatt, Arne Sæbø, and Dennis R. Decoteau
Treatment of young watermelon (Citrullus lanatus cv. Sugar Baby) plants with individual and multiple FR light (15 min) treatments during the dark phase of the photoperiod influenced plant growth and development (i.e., petiole elongation, internode elongation, and reduced petiole angles) as compared to plants not treated with FR signals. The timing for the most effective light signal for inducing a growth response was when the signal was delivered immediately after the plant entered into the dark phase of the photoperiod. Decreasing growth responses to FR signals were observed as the signals were delayed after the plant entered into the dark phase. Multiple FR signals during the dark phase slightly increased growth responses as compared to plants that received the signal immediately after the light period. Young watermelon plant growth responses to FR light signals do not appear to be photoperiodic as plants similarly treated with a white light signal did not generate growth responses. Tissue analysis of petioles, leaves, stems, and cotyledons from plants treated with individual and multiple FR signals suggested that carbohydrate composition, distribution, and diurnal fluctuation were affected by the light quality treatments.
Sandra B. Wilson and Dennis R. Decoteau
Similarities exist between the effects of phytochrome and cytokinins on plant growth and development (e.g., chloroplast development, amaranthin synthesis, seed germination). It is unclear, however, if and how these two systems interact. The coaction between phytochrome and cytokinins was investigated by using Nicotiana plumbaginifolia plants transformed with the isopentenyl transferase (ipt) cytokinin gene and treated with end-of-day (EOD) red (R) and far-red (FR) light. The ipt gene was under control of either a constitutive cauliflower mosaic virus promoter (35S-plants) or an inducible, heat shock promoter (HS-plants). When treated with EOD FR light, whole plants were characterized by decreased chlorophyll concentrations and increased fresh weights. When treated with EOD R light, 35S-plants contained high concentrations of zeatin riboside (ZR) compared to plants treated with EOD FR light. When treated with EOD FR light, HS-plants contained high concentrations of ZR compared to plants treated with EOD R light. Both cytokinin responses were photoreversible. The reasons for the differences between the 35S- and HS-plant responses are not known. Results appear to implicate interactions between phytochrome and cytokinins in plant growth and development.
Heather A. Hatt Graham and Dennis R. Decoteau
The influence of end-of-day (EOD), supplemental, cool-white fluorescent light on pepper (Capsicum annuum L. cv. Keystone Resistant Giant No. 3) seedling growth and fruit production after transplanting to the field was investigated. Seedlings were exposed to this light source, which is high in the red wavebands, from one (1988) or two bulbs (1989) for 1 hour before the end of the natural photoperiod. Each year control plants were exposed to ambient light and received no supplemental fluorescent light. Before transplanting to the field, seedlings exposed to two bulbs were shorter and had smaller leaves than plants in the control treatment. Supplemental fluorescent light treatment, regardless of number of bulbs, reduced plant height, leaf area, fruit weight, and fruit count at the first harvest. Total fruit production was not affected by supplemental light, suggesting no residual effect of the light treatment during transplant production on total subsequent fruit production.
Dennis R. Decoteau and T. Ross Wilkinson
Public scrutiny about faculty time commitment have brought professor accountability to the front page of the daily newspapers. Many faculty in agricultural colleges at Land Grant Universities have split appointments in either research, teaching or extension. Effectiveness has been traditionally demonstrated in research by listing of publications, grants, graduate students. and presentations; but these measures are not necessarily appropriate measures for teaching. The need to better document teaching is imperative and a simple listing of classes taught and number of student contact hours can no longer be sole measures of teaching effectiveness. The Teaching Portfolio is a factual description of a professor's strengths and accomplishments. It includes documents and materials that collectively suggest the scope and quality of a professor's teaching performance. The Teaching Portfolio is an important tool for all Land Grant faculty, regardless of their teaching responsibilities. As pan of a ESCOP/ACOP Leadership Program at Clemson University, we have been reevaluating how university faculty are evaluated. We will discuss our experiences in introducing and using the Teaching Portfolio as part of a new evaluation process.