Search Results

You are looking at 1 - 9 of 9 items for

  • Author or Editor: D.W. Williams x
Clear All Modify Search
Free access

James D. Williams and D.W. Kretchman

Transplants of `Ohio 8245' tomato grown in 48-cell plastic trays received 5 potassium chloride concentrations and were stressed by withholding water during the 6th week of growth. Gravimetric water loss differed between treatments with decreased water loss associated with increased potassium chloride concentration. As water was withheld, incidence of wilt was greater and more evident at an earlier stage with plants supplied with lowering KCL concentrations. Root and shoot dry weights, plant height and leaf area were not affected by treatments. This indicates an apparent increase in water use efficiency in tomato transplants supplied with KCL at greater concentrations than supplied under standard fertilizer regimes.

Free access

D.W. Williams and P.B. Burrus

Perennial ryegrass (PR) (Lolium perenne L.) is often used as a low-mowed turf in the transition climatic zone. However, control of the fungal disease gray leaf spot (Pyricularia grisea (Cooke) Sacc.) has drastically increased the cost of PR management. Seeded bermudagrasses (SB) [Cynodon dactylon (L.) Pers.] are viable options for turfgrass management operations with limited pesticide budgets. Field trials in 2000 and 2001 tested the effects of two herbicides and several plant growth regulators (PGR) during renovation of mature PR to either of two cultivars of SB. The herbicides glyphosate and pronamide, and the PGR's trinexapac-ethyl, ethephon, paclobutrazol, and flurprimidol were applied at label rates to mature stands of PR. `Mirage' and `Yukon' SB were seeded separately either 1 or 7 days after applications (DAA) of chemicals. SB establishment, first-winter survival, and turfgrass quality (TQ) were rated and compared to an untreated control. Results indicated that only applications of glyphosate resulted in acceptable renovation of PR to SB, but also resulted in significantly lower (P< 0.05) TQ during the transition. Applications of pronamide resulted in significantly less (P < 0.05) SB transition than did applications of glyphosate, but pronamide plots maintained higher TQ. None of the PRG treatements had a significant effect (P < 0.05) on SB transition. There were no consistent significant effects (P < 0.05) due to DAA among any of the chemicals evaluated. First-winter survival was significantly higher (P < 0.05) with `Yukon' than with `Mirage' in both years. We conclude that among the chemicals tested, only applications of glyphosate resulted in acceptable transition of PR to SB, but a significant reduction of TQ should be expected during the transition. Chemical names used: [N-(phosphonomethyl) glycine] (glyphosate); [3.5-dichloro-N-(1,1-dimethyl-2-propynyl)-benzamide] (pronamide); [(2-chloroethyl) phosphonic acid] (ethephon); [4-(cyclopropyl-α-hydroxy-methylene)-3,5-dioxo-cyclohexane-cabroxylic acid ethyl ester] (trinexapac-ethyl); [(±)-(R*R*)β-[(4-chlorophenyl)-methyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol] (paclobutrazol); [α-(1-methylethyl)-α-[4-(trifluromethoxy)phenyl]-5-pyrmidinemethanol] (flurprimidol).

Free access

J.L. Sibley, J.D. Williams, L. Waters and W. Lu

International experiences enhance opportunities for future employment in that many companies, and particularly government agencies desire graduates that comprehend the global economy of our world. Traditional and emerging opportunities with ports of entry, Homeland Security, and international companies are increasing. There are seven primary avenues to an International Experience for Auburn Horticulture students. In recent months, some students have been deployed to military assignments. Through the IPPS we have been able to facilitate student exchange programs. Several graduate students have accompanied faculty on plant expeditions or in agricultural development or research efforts. However, these three types of opportunities are not long-term or sustainable. The E.T. and Vam York Endowment provides monetary support, often equal to air fare, to faculty and graduate students for short duration trips. A similar endowment created by Bill and Margaret Stallworth provides monetary awards for airfare and other incidentals to undergraduates on international internships six months or longer in duration. The Henry P. Orr Fund for Excellence commemorates out-of-the-classroom experiences championed by Orr for almost 40 years at Auburn. The purpose of the Orr Endowment is to provide short-term study tours of gardens of the world for students and faculty. In Summer 2005 we begin our first Horticulture Study Abroad Program operated on a cost recovery basis providing 13 semester hours of academic credit at a cost similar to taking the same course load on campus. Altogether, our current goal is to involve about 10% of our students annually in international opportunities.

Full access

A.W. Fleener, C.W. Robinson, J.D. Williams and M. Kraska

Children's gardens have recently been shown to increase life skills. The purpose of this study was to assess the effects that gardening/plant activities from the Junior Master Gardener curriculum, Literature in the Garden, have on children's life skills. The life skills examined were leadership, teamwork, self-understanding, decision-making skills, and communication skills. About 130 third-grade students from a Lee County, AL, school participated in the study. Students were equally divided into control and experimental groups, and each student was given the youth life skills inventory (YLSI) as a pre- and posttest. The experimental group participated in eight gardening/plant activities after the pretest, whereas the control group did not complete the activities. No significant differences were found between pretests and posttests for teamwork, self-understanding, decision making, communication, and overall life skills. Significant decreases from pretest to posttest were found on leadership skills for the experimental group. Several trends were observed with students who read more for fun, read more each week, and read more garden books generally increasing in life skills.

Free access

W.G. Foshee, W.D. Goff, K.M. Tilt, J.D. Williams, J.S. Bannon and J.B. Witt

Organic mulches (leaves, pine nuggets, pine straw, grass clippings, and chipped limbs) were applied at depths of 10, 20, or 30 cm in a 3 × 3-m area around young pecan [Carya illinoinensis (Wangenh.) K. Koch] trees. These treatments were compared to an unmulched herbicide treatment and a common bermudagrass [Cynodon dactylon (L.) Pers.] sod. Trunk cross-sectional areas (TCSAs) of the mulched trees were larger than those of trees in the sod or unmulched plots and increased linearly as mulch depth increased. All mulches influenced TCSA similarly. Mean TCSA for mulched trees increased 14-fold compared to an increase of 8-fold for the unmulched trees and the sod in this 3-year study. Thus, common yard-waste mulches can be used effectively to increase growth of young pecan trees.

Free access

D.R. Williams, C.R. Andersen, S.E. Eaton and L.W. Martin

A fresh-market tomato trial was conducted in 2003 at two locations in Arkansas (Fayetteville and Kibler) to evaluate new and old tomato varieties of interest to home gardeners and farmers' markets. The observational trial consisted of 43 varieties, indeterminates and determinates. Heirloom tomatoes comprised a large portion of the trial due to increasing popularity. Heirlooms are unique and can be very eye-catching. There is immense variety in shape, size, and color. They can be large or small, many times the shape is irregular, and the fruits flawed (cracking, cat-facing, green shoulders). The fruit may not store or ship well; most are grown and sold locally. Some heirlooms are better than others. A few of the varieties that stood out in the trial were Costoluto Genovese, Abraham Lincoln, Dona, and Persimmon. Costoluto Genovese, a uniquely ruffled red tomato, was the highest yielding variety at the Kibler location. Fruit quality remained high even in the highest temperatures. One of the most promising was a orange variety called Persimmon, it produced large fruit and the plants provided excellent cover. Dona and Abraham Lincoln, both reds, yielded well and had good flavor. San Marzano and Arkansas 7985 were the best paste types. Arkansas varieties such as Bradley, Ozark Pink, and Arkansas Traveler 76 also did well. Brandywine varieties had low yields and lesser quality fruit. Green zebra, a green striped fruit with good flavor, yielded less due to Blossom End Rot. Cherokee Purple and Carbon were two from the purple/black category that did not do well; yields were low and the fruit cracked.

Free access

D.A Grantz, W.A. Retzlaff, L.E. Williams and T.M. DeJong

Models indicate that ozone inhibits carbon assimilation largely in the upper canopy, due to light and ozone gradients. We document yield reductions and ozone gradients in Casselman plum in open-top ozone fumigation chambers. Ambient air (12 hr mean ozone = 0.050 ppm), charcoal filtered air (0.034 ppm) and ambient air plus added ozone (0.094 ppm) were circulated in the chambers. Additional trees grew outside the chambers (0.058 ppm). Outside the chambers large vertical and horizontal gradients in ozone within the canopy were documented, but these were absent in the chambers. Ozone decreased leaf photosynthesis by 31% and 58%, and fruit yield by 20% and 66%, in the ambient and ozone enriched relative to filtered chambers. Despite altered gradients, yield and photosynthesis of exposed leaves were similar inside and outside the chambers in ambient air. Compensatory changes in leaf function may be involved.

Free access

Ken Tilt, William D. Goff, David Williams, Ronald L. Shumack and John W. Olive

Pecan [Carya illinoinensis (Wangenh.) C. Koch `Melrose'] and pear (Pyrus calleryana Decne. `Bradford') trees in the nursery grew more in containers designed to hold water in the lower portion. The water-holding reservoir was obtained either by placing 76-liter containers in a frame holding water to a depth of 6 cm or by using containers with drainage holes 6 cm from the bottom. Continuous waterlogging at the bottom of containers resulted in root pruning and root death in the lower portion of the containers, but roots grew well above the constantly wet zone. Fresh weight of plant tops and trunk diameters were greater after two growing seasons in the containers with water reservoirs compared to those grown in similar containers with no water reservoirs. Total root dry weight was unaffected.

Free access

Eli D. Moore, Gary W. Williams, Marco A. Palma and Leonardo Lombardini

The Texas Pecan Board was established in 1998 to administer the Texas Pecan Checkoff Program and is financed through a half cent per pound assessment on grower pecan sales. The Board spends the assessment collections on a variety of advertising campaigns in an attempt to expand demand for Texas pecans and to increase the welfare of Texas pecan growers. This article presents an evaluation of the economic effectiveness of the Texas Pecan Checkoff Program in expanding sales of Texas pecans. First, the effects of Texas Pecan Board promotion on sales of all Texas pecans are determined using the ordinary least squares estimator followed by a test for differential effects of Texas Pecan Board promotion activities on sales of improved and native Texas pecan varieties using the seemingly unrelated regression estimator. The analysis indicates that the Texas Pecan Checkoff Program has effectively increased sales of improved varieties of Texas pecans but has had no statistically measurable impact on sales of native varieties of Texas pecans. A benefit–cost analysis determines that $35.0 in additional sales revenues are generated for every dollar invested in promotion, indicating that the Texas pecan promotion program has been financially successful. The per unit return is large but on a very few dollars available for investment in promotion implying the need for more investment for more meaningful returns.