Search Results

You are looking at 11 - 20 of 45 items for

  • Author or Editor: David Williams x
Clear All Modify Search

Abstract

Phaseolus vulgaris L. cv. Contender (green bean) treated with sea salt aerosols, similar to ambient seashore conditions displayed foliar injury from exposures of 8, 168, and 480 hr at sedimentation rates of 27, 5.7 and 1.5 μg/m2/sec, respectively. Sodium and chloride uptake was linear with time. Toxicity symptoms corresponded with a critical leaf tissue level of 2.6% Cl regardless of exposure time or sedimentation rate.

Open Access

The objective of this study was to evaluate the ability of various cultivars of Hosta ovary explants to generate adventitious shoots and obtain variegated plants in vitro. Immature inflorescences along with 8 to 10 cm of scape were harvested from Hosta cultivars. The ovaries were prepared for culture by cutting immature florets before anthesis. The florets were first cut just above the top of the immature ovary to remove the sigma, style, corolla, and anther. Then the calyx and filament bases were also removed. Ovaries were transversely cut into halves and transferred to baby jars containing Hosta initiation medium supplemented with naphthaleneacetic acid (NAA) at 0.5 mg/L and 6-benzylamino purine (BA). The explants produced adventitious shoots from ovary base via organogenesis. The number of shoots regenerated from shoot tips and callus increased linearly with repeatedf subculturing on MS medium. This method would provide an effective alternative to conventional propagation crown division of Hosta, an expensive and slow process. The long-term goal of this project is to improve Hosta.

Free access

Abstract

Picea pungens Englm. trees were treated with a single foliar spray of solutions containing 0, 100, 250, 500, and 1000 mM BA at 4 different times as follows during the growing season: 1) dormant trees, 2) at bud break, 3) during stem elongation, 4) summer hardwood, and 5) summer hardwood combined with a pruning. Treatments of 1000 mM at the time of bud break and to pruned summer hardwood trees resulted in an increase in bud number but not a corresponding increase in branch number the following year.

Open Access

Abstract

Sprays of 4% Off-Shoot-O (45% methyl esters of fatty acids, 4% C6, 56% C8, 38% C10, 2% C12) to container-grown Cotoneaster divaricata Rehd. & Wils., Pyracantha coccinea Roem. cv. Lalandi and Rhododendron carolinianum Rehd. at the beginning of each of 2 growing seasons increased shoots over unpruned plants but reduced fruit clusters of pyracantha. Sprays maintained hedge height of cotoneaster but not Forsythia X intermedia Zobel or privet (Ligustrum ovalifolium Hassk).

Open Access

Shoot tip explants of Algerian Ivy Heder a canariensis were cultured on MS basal medium supplemented with a combination of salt strength and NAA and IBA. More roots per explant developed on full salt strength medium combined with NAA. The most roots per explant were obtained with a combination of IBA and 1/4 MS salt. There was an inverse relationship between an increase in IBA or NAA concentration and root length and number. Shoots proliferated better on full MS salt combined with NAA and IBA. The highest level of NAA (40 uM) and 0.1 uM TDZ produced the most shoots and roots, the longest roots, the highest rooting percentage, the largest plants with the most leaves and the best callus quality per explant. The leaves from in vitro were cultured on MS medium with varying levels of Thidiazuron (TDZ) and NAA in the presence of light produced the highest number of roots.

Free access

Shoot tip explants of Algerian Ivy Heder a canariensis were cultured on MS basal medium supplemented with a combination of salt strength and NAA and IBA. More roots per explant developed on full salt strength medium combined with NAA. The most roots per explant were obtained with a combination of IBA and 1/4 MS salt. There was an inverse relationship between an increase in IBA or NAA concentration and root length and number. Shoots proliferated better on full MS salt combined with NAA and IBA. The highest level of NAA (40 uM) and 0.1 uM TDZ produced the most shoots and roots, the longest roots, the highest rooting percentage, the largest plants with the most leaves and the best callus quality per explant. The leaves from in vitro were cultured on MS medium with varying levels of Thidiazuron (TDZ) and NAA in the presence of light produced the highest number of roots.

Free access

Three node stem cuttings of Algerian Ivy Hedera canariensis were sprayed with growth regulators to incipient runoff under greenhouse conditions. The results demonstrated that the combination of BA + GA4+7, (Promalin) promoted branching of Algerian Ivy better than applications of BA or GA4+7 alone. Plants treated with Atrinal developed more shoots per node than those treated with GA4+7, BA, or Promalin. Increasing concentration of Atrinal from 0 to 3000 ppm, also reduced branch length and leaf number for both pinched and unpinched plants. 2,3,5—triodobenzoic acid (TIBA) significantly increased the branching of Algerian Ivy, although plant shape was not commercially acceptable due to epinasity of the foliage.

Free access

University of Illinois, Department of Horticulture, Plant Science Lab, 1201 S. Dorner, Urbana, IL.

Calli were initiated from immature inflorescences of selected cultivars of Hosta in the light on Hosta initiation medium (Carolina Biological Supply Company, 1986). Three cultivars, Francee, Birchwood Park's Gold, and Wide Brim Sum & Substance, produced microshoots. The calli were compact and green in color. The highest percentage of callus formation occurred with the Francee cultivar. Nakaiana, Golden Edger, Golden Scepter, Obscura, Sum & Substance, and Shade Fanfare produced only calli. The calli were transferred to modified Murashige and Skoog salts. The media containing 5 × 5 factorial combinations of NAA and BA (0.0, 0.1, 0.5, 1.0, or 2.0 mg/l). The results show that media with NAA at 1.0 and 2.0 mg/l in combination with BA from 0.5 to 2.0 mg/l produced the highest number of microshoots per explant.

Free access

Fifty-four taxa of Atlantic white cedar [Chamaecyparis thyoides (L.) B.S.P.] were assembled and maintained. A protocol for propagation of Atlantic white cedar was established. Plants were grown in containers and in a replicated field plot. Height and width data were recorded from container- and field-grown plants and all taxa were evaluated for growth habit, growth rate, and summer and winter color. Color descriptions of foliage are provided based on the Royal Horticultural Society colour chart. Exceptional taxa were identified based on needle color, texture, growth habit, and growth rate. Superior green forms include Dirr Seedlings 1 and 2, `Emily', `Rachel', and `Okefenokee'. The superior variegated form is `Webb Gold'. Superior blue forms include `Blue Sport', `Glauca Pendula', and `Twombly Blue', and superior slow-growing forms include `Andelyensis', `Meth Dwarf', `Red Star', and `Heatherbun'. These taxa are recommended to growers, landscapers, and gardeners for production and use.

Free access

Strong academic abilities and practical work experience are important to employers of horticulture graduates. In greatest demand are students with competent personal and leadership abilities and technical skills. Increased class size and increased university core curriculum requirements hinder our capacity to develop these added skills within our curriculum. However, through extracurricular offerings we can offer students ways to develop skills that are not fully expressed in the academic arena. Student interaction in the traditional horticulture club requires practicing interpersonal relation and often conflict resolution skills. Students learn to work as a team to accomplish goals that they have set for themselves as a group. The Associate¥ Landscape Contractors of America (ALCA) Student Career Days experience offers a highly effective means for reinforcing cognitive skills gained in the classroom and laboratory, as well as supplementing academic learning opportunities with technical activities beyond those offered in the curriculum.

Free access