On 24 Apr. 2003, 3-gallon (11.4-liter) Quercus shumardii were potted into 13.2-gallon (50-liter) containers using a standard nursery mix. Treatment design was a 3 × 2 × 2 factorial with two fertilizer placements, three irrigation methods, and two herbicide rates. Controlled-release fertilizer 17N–2.9P–9.8K was dibbled (placed 10.2 cm below the surface of the container media at potting) or top-dressed at a rate of 280 grams per container. Irrigation was applied using one of three methods: 1) a spray stake attached to a 3-gallon- (11.4-L-) per-hour pressure compensating drip emitter; 2) a surface-applied pressure-compensating drip ring delivering water at a rate of 2.3 gallons (8.9-L) per hour; and 3) the same drip ring placed 4 inches (10.2 cm) below the container substrate surface. A granular preemergent herbicide (oxyfluorfen + oryzalin) was applied at 2.0 + 1.0 lb/acre (2.24 + 1.12 kg·ha-1). At 75 days after treatment (DAT), containers with no herbicide and top-dressed fertilizer had a percent weed coverage of 46% compared to 18% for dibbled containers with no herbicide. At 180 DAT weed top dry weight was greater for top-dressed containers compared to dibbled. None of the treatments in the study had any effect on height increase. At 240 DAT, trees irrigated with drip rings at the surface had a 28% greater caliper increase among the dibbled fertilizer-treated containers. Trees irrigated with the drip ring placed below the surface and fertilizer top-dressed had the smallest caliper increase. Irrigation method had no effect on weed control in this study; however, a repeat fall application showed a significantly greater weed control with the drip ring below surface compared to the spray stake.
Glenn B. Fain and Patricia R. Knight
Patricia R. Knight, James R. Harris and Jody Fanelli
Bareroot Corylus colurna were grown in 7.5-liter containers from 11 Apr. until 27 June 1994. The growing medium was fritted clay. Fertility levels included no fertilization, 100 ppm N, or 200 ppm N. Plants were root pruned to remove none or one-quarter to one-half of the primary roots. Root pruning at any level resulted in decreased height, shoot, and root dry weights and number and length of new shoots. One-quarter primary root removal resulted in lower root: shoot ratios compared to plants that were unpruned. One-half primary root removal further reduced root: shoot ratios. One-half primary root removal also reduced total leaf area compared to unpruned controls. Fertilization at 200 ppm N increased leaf numbers and total leaf areas compared to plants receiving no fertilization.
Ashley N. Pollard*, Patti C. Coggins and Patricia R. Knight
Flowers are traditionally used to flavor and garnish dishes. There are many different varieties of edible flowers such as daylilies (Hemerocallis sp.). Daylilies come in many varieties and colors. Their blooms and buds are tasty and nutritious. The objective of this study was to indicate most preferred to least preferred among 15 daylily cultivars (Gentle Shepherd, Lavender Doll, Siloam Powder Pink, Aztec Gold, Rosie Meyers, Catherine Woodberry, Pink Charm, Virginia Henson, Lemon Yellow, Joan Senior, Along the Way, Border Baby, Bonanza, Pandora's Box, and Apricot Beauty). A consumer panel was conducted evaluating the taste preference of fifteen participants to an assortment of daylilies. Panelists were associated with Mississippi State Univ.. Each panelist received 15 different daylily blooms. The ranking methods and analysis of variance were used to determine the preference. The questionnaire for ranking given to each panelist stated to “Please taste each numbered sample and rank in order of preference with the first being most preferred and last being least preferred and to provide comments.” Among the 15 daylilies tested, Rosie Meyer was the most preferred, followed by a second group that consisted of Lavender Doll, Jones Senior, and Aztec Gold. The third most preferred group consisted of two, Gentle Shepherd and Along the Way. The preference for the remainder tapered off with the last two samples, Bonanza and Border Baby. These results suggest that of the 15 daylily varieties, Border Baby and Bonanza were statistically non-preferred with no daylily being statistically preferred.
Patricia R. Knight, John M. Anderson and Ralph A. Parks
The influence of media on plant growth was investigated for five annual species. Uniform 164-cm3 liners of Tagetes erecta `Discovery Orange', Impatiens wallerana `Accent Orange', Melampodium paludosum `Showstar', Scaevola aemula `New Wonder', and Petunia axillaris `Surfinia White' were planted into 2.8-L containers on 4 Apr. 1997. The experiment was terminated after 90 days. Media included Metro-Mix 366 peat or coir, Metro-mix 700 peat or coir, and 4 pine bark : 1 sand (by volume, amended with 1.2 kg.m-3 dolomitic limestone). Plants were top-dressed with 9 g Osmocote Plus 15-9-11. Substituting coconut coir for peat moss in commercial media reduced Petunia 90 DAT foliar color ratings, Impatiens shoot dry masses, and Melampodium and Scaevola root ratings. Utilization of pine bark did not influence foliar color ratings of Tagetes, Melampodium, Petunia, or Scaevola 90 DAT. Utilization of pine bark reduced shoot dry masses of Impatiens, Melampodium, and Scaevola, and root ratings of Melampodium and Tagetes.
Patricia R. Knight, John M. Anderson, Wayne McLaurin and Christine Coker
Lagerstroemia indica ×fauriei `Tonto' and `Sioux' were planted in Mar. 1995. All other cultivars were planted in Oct. 1985. Plants were planted into a Ruston sandy loam on a 12 × 12 ft (3.7 × 3.7 m) spacing. Trees were pruned to develop multiple trunks. Trees are pruned annually in winter to remove any limbs smaller than 0.6 cm in diameter. Pruning cuts are made 6–8 in (15.2–20.3 cm) above prior cuts. Severe pruning is performed every 5 years. Trees were evaluated at 2-week intervals during the flowering season to determine total length of flowering and duration of good to superior flowering. Growth indices (height + width + perpendicular width)/3 were recorded after plants were dormant. Total days of flowering and floral display (0–5 with 0 representing no flowers and 5 representing superior flowering) were rated. `Muskogee' had the greatest growth index after the 2004 growing season. `Seminole' had the least. However, `Seminole' had the greatest number of flowering days. `Biloxi' had the fewest flowering days. `Tonto' had the most good to superior flowering days, while `Tuskegee' and `Muskogee' had the fewest. In 2005, `Muskogee' again had the greatest growth index, while `Sioux' had the least. `Yuma' and `Seminole' had the greatest number of flowering days, and `Biloxi' again had the fewest. `Tonto' again had the most good to superior flowering days, while `Biloxi' and `Acoma' had the fewest.
Patricia R. Knight, D. Joseph Eakes and Charles H. Gilliam
Two inch caliper Acer rubrum, Quercus phellos, and Platanus occidentalis were planted March 26, 1990, into 8' × 8' planting holes that were lined with either Typar Biobarrier, Dewitt Pro-5 Weed Barrier or left unlined as a control. There has been little or no root penetration beyond the Biobarrier for the 3 tree species during the first 3 years of this study. At the end of 1990, the control and the Dewitt Pro-5 had similar root penetration numbers. By the end of 1991, the Dewitt Pro-5 had greater root penetration than did the control for A. rubrun. Root penetration of Dewitt Pro-5 and the control treatment was similar for Q. phellos and P. occidentalis. There were no differences in root penetration for Dewitt Pro-5 and the control in 1992 for any species. There were no differences in height for any tree species following the 1990 or 1991 growing seasons and no difference following the 1992 growing season for A. rubrum and Q. phellos. The control treatment had the grearest height for P. occidentalis in 1992. There were no differences in caliper due to root control treatment for the 3 species during the first 3 years of this study.
Christine E. Coker, Patricia R. Knight and John M. Anderson
Sun coleus (Solenostenum scutellarioides) are commonly used in the southern landscape. However, with the introduction of new cultivars, producers and consumers may be unaware of the selection and landscape performance of sun coleus. Sun coleus cultivars were trialed under landscape conditions at the South Mississippi Branch Station in Poplarville, Miss., in 2000 and 2001. The objective of this study was to evaluate sun coleus cultivars based on landscape performance criteria including flowering, durability, vigor, uniqueness, and insect and disease resistance. Cultivars performing well over both years included `Ducksfoot Red,' `Ducksfoot Tricolor', `Ducksfoot Yellow', `Sunflower Red', `Pineapple', Mardi Gras', and `Saturn'.
Patricia R. Knight, John M. Anderson, Wayne McLaurin and Christine Coker
Lagerstroemia indica x fauriei `Tonto' and `Sioux' were planted in March, 1995. All other cultivars were planted in October, 1985. Plants were planted into a Ruston sandy loam on a 12 × 12 ft (3.7 × 3.7 m) spacing. Trees were pruned to develop multiple trunks. Trees are pruned annually in winter to remove any limbs smaller than ¼ in (0.6 cm) in diameter. Pruning cuts are made 6–8 in (15.2–20.3 cm) above prior cuts. Severe pruning is performed every five years. Trees were evaluated at 2-week intervals during the flowering season to determine total length of flowering and duration of good to superior flowering. Growth indices (height + width + perpendicular width)/3 were recorded after plants were dormant. Total days of flowering and floral display (0–5 with 0 representing no flowers and 5 representing superior flowering) were rated. `Muskogee' had the greatest growth index after the 2004 growing season. `Seminole' had the least. However, `Seminole' did have the greatest number of flowering days. `Biloxi' had the fewest flowering days. `Tonto' had the most good to superior flowering days while `Tuskegee' and `Muskogee' had the fewest.
Patricia R. Knight, J. Roger Harris and Jody K. Fanelli
Root severance during field harvesting alters the water status of a tree, resulting in water stress and reduced post-transplant growth. Two experiments, using Acer rubrum L. (red maple), determined the influence of root severance at harvest on sap flow and xylem embolism. Trees 1.5–1.8 m tall (4 years old) were utilized in the first experiment, and trees 1.2–1.5 m tall (2 years old) were utilized in the second. Sap flow sensors were installed on the 4-year-old trees prior to root severance and remained on the trees until 1 week after harvest. Within 1 day after root severance sap flow was reduced and remained lower than nontransplanted (control) trees for the remainder of the experiment. Leaf stomatal conductance (Cs) of transplanted trees 1 week after root severance was lower than that of control trees, but leaf water potentials (ψ) were similar. In the second experiment, sap flow was reduced relative to control trees within 2 h after root severance. Although Cs was reduced 4 hours after root severance, ψ was not. Embolism increased within 24 hours of root severance. These results indicate that root severance quickly induces increased levels of embolism, which is associated with reduced sap flow.
Patricia R. Knight, D. Joseph Eakes, Charles H. Gilliam and Harry G. Ponder
Seed geranium (Pelargonium × hortorum Bailey `Scarlet Elite') were grown in subirrigation troughs in 10-cm pots from 25 June to 3 August 1993. Production medium was a 1 pine bark:3 peat moss:1 perlite (v:v:v) mixture. Plants were irrigated using fresh or recycled solutions and fertilized using Peter's Geranium Special 15N-6.5P-12.5K or Osmocote 14N-6.1P-11.6K. Controlled release fertilizer produced greater shoot dry weights and foliar color ratings than plants receiving water soluble fertilizer. Plants receiving a controlled release fertilizer had lower shoot N concentrations than plants receiving water soluble fertilizer. Recycled irrigation solutions reduced plant quality regardless of method of fertilization.