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P.R. Knight, J.R. Harris and J.K. Fanelli

Year-old seedlings of Acer rubrum L. and Crataegus phaenopyrum (L.f.) Medic. were grown for 1 year in a Groseclose silty clay loam. Seventy-two plant per species were harvested on 15 Dec. 1995 and weighed. Plants were stored at 4°C for 0, 1, 3, 5, 10, or 15 weeks. At the end of each storage period, 12 plants were weighed to determine water loss. Six plants were then sacrificed to determine percent embolism, and six plants were planted in a pine bark media and grown in a glasshouse for 15 weeks to determine the influence of storage on post-transplant growth and embolism recovery. Length of storage had no influence on embolism of Crataegus. Embolism of Acer increased linearly with increasing length of storage. Embolism was greater for Crataegus compared to Acer at each harvest. Water loss for both species increased linearly as time of storage increased.

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P.R. Knight, J.R. Harris and J.K. Fanelli

Two-year-old, bareroot, Corylus colurna seedlings were grown in 7.5-L containers from 15 Mar. to 23 June 1995. Plants were grown in a glasshouse using pine bark media. Temperatures were maintained at 30/20°C. Plants received no fertilization or Osmocote 18–6–12 top-dressed at 14 or 28 g/container. Additionally, plants were pruned to remove 0%, 25%, or 50% of the root system based on root length. Height, diameter, branch number, leaf area, and root and shoot dry weight increased linearly as rate of fertilization increased. Percent embolism was not influenced by rate of fertilization. Plant height, branch number, leaf area, and root and shoot dry weight were not influenced by rate of root pruning. Plant diameter increased linearly as rate of root pruning decreased. Percent embolism increased linearly as rate of root pruning increased.

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P.R. Knight, J.R. Harris, J.K. Fanelli and M.P. Kelting

Two experiments were conducted on Acer rubrum L. to determine the influence of root severance on sap flow, stomatal conductance, leaf water potential (ψ), and stem xylem embolism. Experiment 1 utilized 3-year-old trees, and experiment 2 utilized 2-year-old trees. Sixteenmm sap flow gauges were installed on both groups. Trees for experiment 1 were harvested on 31 May 1996 with a root ball diameter of 30.5 cm. Sap flow was reduced within one day after plants were harvested and was still lower 1 week after harvest. On 7 June 1996, harvested trees had lower stomatal conductance measurements, compared to not-harvested trees, but ψ were similar. A second experiment was initiated on 20 Aug. 1996, using the same protocol as in experiment 1. Sap flow was reduced within 2 h after harvest for harvested trees compared to not-harvested trees. Leaf stomatal conductances were reduced within 4 h of harvest. Leaf water potentials were not influenced on the day that the trees were harvested. Embolism levels were increased by harvest within 24 h. These results indicate that transplant stress begins shortly after harvest and not at the actual time of transplant.

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A.N. Pollard, P.C. Coggins, C.E. Coker and P.R. Knight

There are over 30,000 named daylily cultivars in existence today. Ancient Chinese used the plant for nutritive and medicinal qualities. The Greek name Hemerocallis means beautiful for a day. Daylilies demonstrate potential in food service due to the range of color, fragrance, flavor, and textural varieties. The objective was to quantify by descriptive analysis the attribute descriptors for two edible daylily cultivars, i.e., `Rosie Meyer' and `Siloam Powder Pink' and to provide data indicating optimum month for consumption of these two cultivars of daylilies. Blooms were harvested during early morning hours over 5 months (May to September). Six panelists were trained utilizing Quantitative Descriptive Analysis for 6 months on the sensory attributes of `Rosie Meyer' and `Siloam Powder Pink' cultivars. Training consisted of determining attribute categories as well as intensity ratings for references. Attribute categories included appearance, odor/scent, handfelt texture, oral texture, basic taste(s), flavor, mouth feeling factors, and chew rate. Results showed attribute categories with descriptors for `Siloam Powder Pink' as odor/scent, flavor, mouth feeling factors, and oral texture as having a significant difference (P < 0.05) for the evaluation months. `Rosie Meyer' demonstrated significant differences (P < 0.05) for the evaluation months in attribute categories for appearance, odor/scent, flavor, oral texture, and mouth feeling factors. The optimum month for consumption of `Rosie Meyer' was September (P < 0.05); `Siloam Powder Pink' was July (P < 0.05). These results provide a descriptive language for daylily (Hemerocallis sp.) cultivars `Rosie Meyer' and `Siloam Powder Pink'. The optimum month for consumption to obtain the fullest range of desirable attributes will provide the food and horticultural industry with added information by which to market these cultivars.

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A.N. Pollard, P. Coggins, P.R. Knight and C.E. Coker

There are >52,000 cultivars of daylilies (Hemerocallis spp.), some of which the ancient Chinese used for nutritional and medicinal purposes. Daylilies have tremendous potential in foodservice due to the range of color, fragrance, flavor, and textural varieties. The objective was to quantify by descriptive analysis the attribute descriptors for two edible daylily cultivars; that is, `Rosie Meyer' and `Siloam Powder Pink,' and to provide data indicating the optimum month for consumption of these two cultivars of daylilies. Blooms were harvested during early morning hours over 5 months (May through September). Six panelists were trained to use Quantitative Descriptive Analysis for 6 months on the sensory attributes of `Rosie Meyer' and `Siloam Powder Pink' cultivars. Training consisted of determining attribute categories as well as intensity ratings for references. Attribute categories included appearance, odor/scent, handfelt texture, oral texture, basic taste(s), flavor, mouthfeel factors, and chew rate. Results showed attribute categories with descriptors for `Siloam Powder Pink' as odor/scent, flavor, mouthfeel factors, and oral texture as having a significant difference (P < 0.05) for the evaluation months. `Rosie Meyer' demonstrated significant differences (P < 0.05) for the evaluation months in attribute categories for appearance, odor/scent, flavor, oral texture, and mouthfeel factors. The optimum month for consumption of `Rosie Meyer] was September (P < 0.05); for `Siloam Powder Pink,' it was July (P < 0.05). These results provide a descriptive language for daylily cultivars `Rosie Meyer' and `Siloam Powder Pink.' The optimum month for consumption to obtain the fullest range of desirable attributes will provide the food and horticultural industries with added information by which to market these cultivars.

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S.L. File, P.A. Knight, C.G. Gilliam, D.B. Reynolds and R.L. Harkess

Non-target herbicide losses pose environmental concerns for nurseries. Therefore, the objective of this research was to determine the ability of each alternative mulch to suppress weed growth when compared to traditional chemical methods. Uniform quart liners of Lagersroemia indica × faurei `Natchez' were planted in 15-gal containers 15 June 1999, on a gravel container pad using overhead irrigation. Weed pressure was uniform. Treatments include Regal 0-0 3 G (3 lb ai/a) as a broadcast or individual container application, recycled newspaper pellets (1 inch thick), Spin-out coated recycled newspaper pellets (1 inch thick) geotextile disks (Spin-out coated), kenaf mulch, waste tire crumbles, wheat straw (2 inches thick), oat straw (2 inches thick), cereal rye straw (2 inches thick), paper mill sludge (2 inches thick), a handweeded control, and a weedy control. Treatments were organized in a RCBD consisting of eight single-plant replicates. The geotextile disks, newspaper pellets treated with spin-out, and shredded rubber tire treatments all had better than 80% weed control from 30 to 180 DAT. These alternative weed control methods can provide a good alternative to conventional weed control practices in large container-grown ornamental.

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J.O. Glenn, C.H. Gilliam, J.H. Edwards, G.J. Keever, J. Olive and P.R. Knight

Recycled paper pellets in the bottom of containers were evaluated for retention of N from container leachate. `Formosa' azalea were transplanted on 15 Apr. in 2.8-L containers in a pine bark/peat substrate (3:1; v/v). Treatments included paper (0 or 2.5 cm depth) in the bottom of containers and two rates of Osmocote 18–6–12 (0.68 kg or 1.36 kg N/yd3). Immediately after transplanting, plants were topdressed with 3.2 g of 12–4–6 fertilizer. Data collected included leachate samples every 2 weeks for NO3-N and NH4-N levels and destructive sampling every 4 weeks for shoot dry weight, foliar N, and total paper N. Nitrate-N and NH4-N leachate concentrations were reduced with the 0.68 kg N/yd3 fertilizer rate and with paper. For example, 28 days after planting (DAP) NO3-N leachate concentrations were reduced 36% with the 0.68 kg N/yd3 fertilizer rate and 46% with paper in the bottom of containers. NH4-N in the leachates was reduced 53% with the 0.68 kg N/yd3 fertilizer rate and 59% with paper. Azalea shoot dry weight was not affected by paper or fertilizer rate up to 112 DAP; however, as the study progressed, plants with paper in the bottom of containers grew larger than plants in no paper treatments (29% at 168 DAP, 31% at 196 DAP). Total N absorbed by paper was not affected by fertilizer rate, and peaked at 168 DAP [980 (0.68 kg N/yd3) to 1066 (1.36 kg N/yd3) mg per container, or 41% – 28% of applied N], after which it began to decline. This decline in paper N was associated with greater growth of azalea with paper.

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J.S. Glenn, C.H. Gilliam, J.H. Edwards, G.J. Keever, P.R. Knight and J.W. Olive

Two experiments were conducted to evaluate recycled newspaper products as nutrient filters in the bottom of containers. In Expt. 1 with poinsettia, Euphorbia pulcherrima Willd. ex Klotzsch `Glory', three paper products were evaluated: ground paper, paper crumble, and paper pellets; each placed 2 or 3 cm deep in the bottom of containers, so that drainage holes were covered. Leachate samples were collected at the first irrigation after each liquid fertilization. Nitrate (NO3 --N) and ammonium (NH4 +-N) leachate concentrations were reduced up to 84% with recycled paper pellets, compared to the control (no paper). Recycled paper retained up to 732 mg of nitrogen (N) per container (paper pellets 3 cm deep). Shoot dry weight was reduced with paper pellets but was not affected by ground paper or paper crumble. In Expt. 2, `Freedom Red' poinsettias were grown with either single weekly applications of 500 mg·L-1 N from Peter's 20N-4.3P-16.6K, or 200 mg·L-1 N at each irrigation (2 or 3 times a week, as needed). Recycled paper treatments included paper crumble or paper pellets placed 2.5 cm deep in the bottom of containers, and a control without paper. Leachate NO3 --N and NH4 +-N concentrations were reduced up to 100% and 94%, respectively, 6 days after planting (DAP), and up to 57% and 50%, respectively, 25 DAP with paper crumble compared to nonpaper control. Paper pellets in the bottom of containers retained up to 776 mg N per container. Poinsettia shoot dry weight was lowest with paper pellets in the bottom of containers and continuous fertilization.

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W.C. Dunwell, D. Fare, M.A. Arnold, K. Tilt, G. Knox, W. Witte, P. Knight, M. Pooler, W. Klingeman, A. Niemiera, J. Ruter, T. Yeager, T. Ranney, R. Beeson, J. Lindstrom, E. Bush, A. Owings and M. Schnelle

The Southern Extension and Research Activities/Information Exchange Group-27 (SERA/IEG-27) is sponsored by the Southern Association of Agricultural Experiment Station Directors. Thirteen universities and the U.S. National Arboretum cooperate with official representatives from extension and research programs. The objective of the group is to identify, evaluate, select, and disseminate information on superior, environmentally sustainable, landscape plants for nursery crop production and landscape systems in the southeastern U.S. Plants are distributed to members responding to a request from cooperators for plant evaluation. Those who agree to cooperate are expected to grow the selected liner to landscape size, then transplant it in a landscape setting. The plant is rated for insect, disease, and cold damage, heat stress, growth rate, ornamental flowering and fruiting, fall color, commercial production potential, landscape potential, invasiveness potential, and insect disease transmission potential. Growth rate is evaluated annually by recording plant height and width. Initial bloom date is reported followed by bloom duration in days. Following evaluation, the group collectively and individually disseminates information gained from the plant evaluation system to a wide variety of audiences.