Charles E. Johnson and Edward W. Bush
E.W. Bush and J.T. Payne
Container-grown `Formosa' azalea plants were affected by irrigation water quality. Sodium (200 ppm), supplied by NaHCO3 and NaCl, inhibited plant growth and diminished plant quality. Observable symptoms were tip-burn, marginal necrosis, leaf curling, and eventual defoliation. There was a negative relationship between leaf tissue calcium and magnesium and higher rates of sodium from NaHCO3. Leaf tissue Cl levels were higher in the higher NaCl treatments. Sodium treatments inhibited root growth. Plants in NaHCO3 treatments accumulated more Na than did plants in NaCl treatments. Media pH and sodium levels following 12 months of sodic irrigation far exceeded acceptable levels for producing marketable container-grown `Formosa' azalea plants.
E. W. Bush, M. L. Robbins and D. A. Wall
Sodium bicarbonate type irrigation water is detrimental to the growth of Azalea indica `Formosa'. Alkaline irrigation water reduced both top and root growth of `Formosa' azalea. Leaf tissue sodium was significantly greater in azalea plant tissue irrigated with alkaline water. Concentrated sulfuric acid was used to acidify the alkaline water source. Acidification significantly reduced the uptake of sodium into the leaf tissue by 45%. Leaf tissue Ca and Mg levels were significantly greater from plants irrigated wtih deionized water. Azalea plants irrigated with acidified water produced significantly better quality plants. Leaf and root tissue samples were taken after 8 months.
E.W. Bush, D.A. Wall and M.L. Robbins
Calcium and magnesium medium requirements were investigated for the production of container-grown `Formosa' azalea irrigated with filtered and unfiltered deep well water. Four inch `Formosa' azalea plants were planted into 3.8 liter containers filled with an amended 4:1(v,v) pinebark:sand growing medium. Calcium and magnesium treatments were supplied by either dolomitic lime or gypsum + epsom salt at three rates. Plants irrigated with good quality water produced excellent quality plants regardless of Ca/Mg treatment. Alkaline well water containing moderate sodium levels inhibited azalea root growth. Medium amended with gypsum + epsom salt produced significantly better quality plants than did medium with dolomitic lime during 157 days of deep well irrigation. Medium pH and Na levels were significantly higher in the control treatment than in the filtered well water treatment. Growth effects of calcium and magnesium treatments were dependent upon water quality and time length of treatment.
E.T. Pippin, E.W. Bush, D.J. Lee and R.E. Strahan
Weeping lovegrass (Eragrostis curvula) is commonly used in native areas bordering golf courses in the Southeastern United States. These areas do not receive significant levels of maintenance, thus weed encroachment is a problem that can negatively impact the functional and aesthetic values of the golf course. The objectives of this study is to determine which selective postemergent herbicides labeled for use on golf courses can remove weeds from Weeping Lovegrass and to determine the level of phytotoxicity. Herbicides included monosodium methane arsenate (MSMA 6.0) applied at 3.0 lb/acre a.i., sulfosulfuron (Certainty) at 0.047 lb/acre a.i., metribuzin (Sencor 75 DF) at 0.5 lb/acre a.i., and imazaquin (Image 70 DG) at a rate of 0.5 lb/acre a.i.. Treatments were applied on July 20, 2004 to 9.6 × 9.6 plots arranged in a randomized complete block design (RCBD) using Teejet 8005 nozzles at 40 psi calibrated to deliver 40 ga/acre. Plots were monitored daily and data was collected 0, 7, 14, 21, 28, 35, and 42 DAT. Sulfosulfuron and MSMA provided the highest level of weed control 35 DAT. Metribuzin and imazaquin provided limited weed suppression compared to the control. Initial phytotoxic damage to the Lovegrass was observed in all herbicide treatments. The highest level of phytotoxic damage was observed in the MSMA and Metribuzin treatments; however there was no apparent damage at 42 DAT. Herbicide applications of sulfosulfuron and MSMA are effective in reducing weed populations with acceptable levels of phytotoxicity to the Lovegrass.
K.C. Pee, C.E. Johnson, E.W. Bush and E.A. Drummond
Seed of 15 watermelon cultivars were evaluated for germinating ability at sub-optimum temperatures. Seeds of each cultivar were exposed to 12.8, 15.6, 18.3, 21.1, and 30.0°C for 8 days in a germinator in accordance to standard seed testing rules. Radical emergence was evaluated on day 5 and day 8. None of the cultivars germinated at 12.8C after 8 days exposure. At 15.6°C, 'Red-N-Sweet' and `Blackstone' had germinations of 54 and 40 percent respectively on day 5, and both increased to over 80 percent on day 8. At 18.3°C `Red-N-Sweet' and `Blackstone' exhibited at least 90 percent germination after 5 days while the other 14 cultivars ranged from 2.5 to 86 percent. At 21.1°C all cultivars except `Black Diamond' and `Allsweet' had germinations of 80 percent or higher on day 5. Germination increased to 90 percent or above by day 8 except for `Black Diamond' at 83 percent. There were no significant differences among cultivars at the 30°C optimum germinating temperature with cultivars having 89.5 percent or higher germination.
C.E. Johnson, J.T. Payne, W.A. Young and E.W. Bush
Daniel E. Wells, Jeffrey S. Beasley, Lewis A. Gaston, Edward W. Bush and Maureen E. Thiessen
Phosphorus (P) fertilizers with high water-solubility are often applied in excessive amounts to porous horticultural substrates to produce high-quality plants. As a result, high P losses during containerized plant production have presented an environmental challenge to responsible growers. Poultry litter ash (PLA), a byproduct of bioenergy production, contains P concentrations comparable to conventional P fertilizers but is characterized as having lower water-solubility. Therefore, a series of experiments were conducted to characterize effects of PLA on container-plant growth and P leaching. PLA was compared with superphosphate (SP), a highly water-soluble P source, in ratios of 0:100, 25:75, 50:50, 75:25, and 100:0 (SP:PLA) in the production of Lantana camara L. ‘New Gold’. In 2011, lantana fertilized with higher ratios of PLA exhibited slower growth with lower shoot and root biomasses compared with 100% SP-fertilized lantana. However, in 2012, differences in fertilizer treatments lessened, with 100% PLA-fertilized lantana exhibiting 14% less shoot biomass and no differences in root biomass compared with 100% SP-fertilized lantana. Measurement of shoot:root biomass, a common indicator of P deficiency, was not different between any P treatments in 2011 or 2012. This indicates root growth was most likely the driving factor in P-treatment effects on shoot biomass in each year of the experiment. During a postproduction field trial, no differences in growth or biomass were observed between lantana previously fertilized with P, regardless of source. However, application of PLA as the single P source reduced dissolved reactive P (DRP) concentrations in leachate >90% and total P (TP) mass losses 69% compared with 100% SP-fertilized lantana during container production, with P treatments reducing DRP and TP losses as PLA ratios increased. Therefore, the benefit of P-loss reduction during container production achieved through PLA application may warrant the acceptance of slightly smaller plants or extending production cycles.
Allen D. Owings, Gordon E. Holcomb, Anthony L. Witcher, C. Allen Broyles and Edward W. Bush
Performance evaluations of numerous annual and perennial herbaceous ornamentals were conducted in landscape settings in 2004 at the LSU AgCenter in Baton Rouge. A mid-summer through fall evaluation of Kong coleus found no difference in flowering performance and visual quality ratings of the five available cultivars. In a sun/shade study, Kong coleus cultivars in 60% shade were about 50% shorter than those in sun. Other impressive coleus have been Aurora Black Cherry and Mississippi Summer Sun. The Stained Glassworks series of coleus have been average performers. The Son series of lantanas (Sonrise, Sonset, Samson, Sonshine) have been top performers in terms of visual quality and continual bloom. All-America daylilies most prevalent to rust symptoms have included Judith, Leebea Orange Crush, Starstruck, Lady Lucille, and Chorus Line. Some rust has also been noted on Plum Perfect and Frankly Scarlet. Profusion Apricot and Profusion White have been less susceptible to Xanthomonas bacterial petal blight than Profusion Fire, Profusion Cherry, and Profusion Orange. Earth Kind roses, being promoted by Texas A&M, are being evaluated for landscape performance along with black spot and powdery mildew susceptibility. Most problematic cultivars thus far have included Georgetown Tea, Clotilde Soupert, Nacogdoches, Reve d'Or, New Dawn, Souvenir de St. Anne's, Spice, Lamarque, Puerto Rico, Sarah Jones, Ducher, and Louis Philippe. Lady Bird cosmos have been good late summer/early fall landscape performers.
Allen D. Owings, Gordon E. Holcomb, Anthony L. Witcher, C. Allen Broyles and Edward W. Bush
All-American daylily cultivars named from 1994-2004 were evaluated for landscape performance and daylily rust (Puccinia hemerocallidis) susceptibility during 2003 and 2004. Cultivars included `Black-Eyed Stella', `Bitsy', `Leebea Orange Crush', `Plum Perfect', `Judith', `Starstruck', `Frankly Scarlet', `Lullaby Baby', `Lady Lucille', and `Chorus Line'. Bareroot plants were planted in raised beds composed of an Olivier silt loam soil in full sun and received irrigation as needed to prevent stress. Visual quality ratings were made weekly from 19 Apr. to 25 Oct. 2003 and 15 Mar. to 20 Sept. 2004. Included in the visual quality ratings were growth habit and flowering with favorable growth habit being compactness, foliage color, uniformity, and overall aesthetics, and favorable flowering being longevity and visual appeal. Flower observations were made in regard to time in bud and peak blooming periods over the same time frames. Daylily rust ratings were taken in September and November 2003 and in August and November 2004. Flowering observations indicated that Black Eyed Stella and Bitsy were the only cultivars showing reliable repeat bloom potential. Among the other cultivars, Judith was the earliest to bud and bloom but also had a blooming period of only 2 to 3 weeks compared to 4 to 5 weeks of bloom for other cultivars. Rust was most prevalent on Judith, Leebea Orange Crush, Starstruck and Lady Lucille. Judith and Leebea Orange Crush have rust symptoms earlier than other cultivars. `Plum Perfect', `Frankly Scarlet', `Bitsy', `Black Eyed Stella', and `Lullaby Baby' were least susceptible to daylily rust.