bluuebunny/crossref_metadata_2025 huggingface dataset:
Ethylene Production as a Drought Stress Response in Cassia corymbosa
Authors: Berumen Salvador , Lownds Norman K.
Published: February 2019

Landscapes in the desert Southwest must be water efficient and utilize drought tolerant plants. Therefore, plants with landscape potential must be evaluated for their level of drought tolerance and drought tolerance mechanisms. Drought tolerance, for some plant species, may be related to the plants ability to produce ethylene as a mechanism for defoliation, thus reducing water use. Cassia corymbosa has potential as a woody shrub for southwestern landscapes because of its dark green foliage and bright yellow flowers. Studies were conducted to determine the effect of leaf dehydration and drought stress on ethylene production in Cassia. Leaf dehydration was examined by excising leaves and placing them at 20, 25, or 30 °C. The time course of ethylene production depended on the temperature (rate of dehydration), but the peak occurred at 18% to 25% fresh weight loss, regardless of dehydration temperature. The effect of irrigation rate was determined by supplying plants with 0%, 40%, 60% and 100% of the daily water consumption (WC) based on pot capacity. Ethylene production depended on irrigation rate. Plants irrigated at 100% of daily WC were not stressed and did not produce ethylene. Irrigation at 60% of daily WC induced peak ethylene production 72 hours after treatment with decreased production as at longer times. Irrigation at 40% or 0% of the daily WC did not induce ethylene production because of the rapid dehydration. Drought-induced ethylene production in Cassia corymbosa appears to be closely related to the rate of dehydration and may provide a drought tolerance mechanism.
A Study to Evaluate Links between Leaf Anatomy and Environmental Stress in Acer saccharum Cultivars
Authors: Osterhaus Greg , Le Duc Alice
Published: February 2019

An anatomical study was conducted to determine and compare the internal leaf surface to volume (S/V) ratio of the spongy mesophyll in selected cultivars of Acer saccharum. A low S/V ratio is one of several selectively advantageous characteristics associated with xerophytic plants. It has been proposed that a correlation exists between certain injuries produced by environmental stress and plant leaf anatomy. The taxa included in the study were Acer saccharum cvs. Green Mountain and Legacy, A. saccaharum Caddo and Wichita Mountain (seedlings of Caddo County and Wichita Mountains, Oklahoma relictual populations respectively), and A. saccharum ssp. nigrum (syn. Acer nigrum). Leaf samples were taken from five different representative trees for each of the five cultivars. The results showed that Caddo, which is highly stress tolerant, had a significantly lower internal S/V ratio than the other four cultivars. `Legacy' which is intermediate in stress tolerance had the next lowest S/V ratio. As expected the highly injury-susceptible selections A. saccharum `Green Mountain' and A. saccharum nigrum had high S/V ratios. However, the Wichita Mountain variety which exhibits a stress tolerance similar to Caddo, also had a high S/V ratio. These results suggest that other factors may be involved in determining environmental stress tolerance.
Seminar Courses—Content to Satisfy the Needs of Future Horticulture Professionals
Authors: Beyl Caula A.
Published: February 2019

In the past, a seminar course was considered effective if the students were trained in oral presentation techniques. Two things have changed since then: 1) the growing popularity of the poster as a form of research communication and 2) new technologies such as the use of computers and LCD projection systems. Familiarity with these techniques then becomes a highly desirable part of a seminar course designed to satisfy today's needs. At Alabama A&M Univ., the undergraduate and graduate seminar courses require students not only to present an oral seminar but to participate in a public poster presentation once each semester. The entire department participates in viewing the posters, questioning the students and assigning scores. This allows students to participate in a simulated professional meeting environment and learn how to interact with other professionals concerning their posters. The seminar course also includes topics such as parts of a seminar, multimedia presentations, computer usage, developing a time sense, dealing with fear of public speaking, public speaking do's and do not's, impromptu talks, handling questions, and poster techniques. Graduate students serve as moderators for the oral seminar sessions thus gaining additional experience. An essential part of the course is peer grading and evaluation. Peer involvement in the process acts to promote a high standard for oral seminars and posters.
Two Tropical Plants as Plant Materials for Teaching Seed Germination
Authors: McConnell J.
Published: February 2019

A local ground orchid, Spathoglottis plicata Blume, and coconut, Cocos nucifera L., were used in the classroom to teach seed germination. S. plicata, a common orchid on Guam, was utilized to demonstrate the aseptic culture of seeds under non-sterile conditions. The procedures were done in the classroom without a laminar air-flow cabinet. Nonsterile seeds were sown on growing media which were prepared without autoclaving, but by incorporating sodium hypochlorite into the media. Students had a high rate of success in germinating the orchid seeds without contamination by spraying sodium hypochlorite on the seeds. Different stages of coconut seed development were presented to students by simply cutting coconut in half. Unique features and botanical terms of coconut seed development can be taught throughout the year. Teaching materials on seed germination of the two tropical plants are being developed by print-on-demand methods.
Economic Analysis of Arizona Ash Sequentially Produced in Copper-treated or Nontreated 0.21-, 2.5-, and 11.8-Liter Containers
Authors: Obst Steven P. , Hall Charles R. , Arnold Michael A.
Published: February 2019

Arizona ash (Fraxinus velutina Torr.) seedlings were grown in 0.21-L plastic liner containers, half treated with 100 g Cu(OH)2/L latex carrier (formulated as Spin Out), and half nontreated. Seedlings were sequentially transplanted to larger containers, from liners to 2.5-L black plastic containers then to 11.8-L containers resulting in a 2 × 2 × 2 factorial combination of container sizes and Cu-treatments (eight combinations with 30 replicates/treatment). Nursery conditions and production procedures were determined from regional nurseries using a modified Delphi technique. Growth responses (height, caliper, market grade) and costs of production were determined for each treatment combination through marketable size in 11.8-L containers. Significant interactions (P ≤ 0.05) among liner and 2.5-L container treatments occurred for end of season trunk diameter and market ratings. Those seedlings grown in both Cu-treated liners and 2.5-L containers tended to have larger calipers and market ratings than other treatment combinations. Growth increases were not realized when containers were treated at a single stage. Copper-treated containers resulted in a 17-second labor savings per container at transplant from 2.5- to 11.8-L containers. Labor requirements were not significantly (P ≤ 0.05) different among treatments at transplant from 0.21- to 2.5-L containers.
Up from the Ashes: Vegetable Crop Research Capacity Development in Cambodia, 1984–1995
Authors: Rowell Brent
Published: February 2019

Civil war and the hostilities which followed it in Cambodia from 1972 to 1979 resulted in a 20% reduction in the country's population and the near total destruction of its educational and agricultural research infrastructure. As if this were not enough, western governments embargoed humanitarian aid to Cambodia during its most critical period of need from 1981 until multiparty elections were held in 1993. During this period a handful of nongovernmental agencies helped the government begin rebuilding some of its agricultural production capacity. One NGO, together with its government counterparts, established the country's first research station for vegetable crops in 1985 at the request of the Ministry of Agriculture. The Kbal Koh Vegetable Crops Research Station was built and its staff received training from 1985 to 1987. The facility has continued its four-part mission with very limited outside funding and technical support since 1987. Numerous variety and seed production trials have been conducted at the station and in farmers' fields since 1985; practical training programs for agricultural technicians and students began in 1986 and today provide much of the salary and operating budget support for the station. Coinciding with the phase out of NGO assistance in 1995, their are great expectations for continuing support through the newly formed Cambodia–Laos–Vietnam vegetable production and research network, AVRDC, and the Asian Development Bank.
Integrated Approach to an Improved Citrus Production and Marketing System in Benue State of Nigeria
Authors: Smith-Kayode G. , Akbigbe George , Kolade J.A. , Amih C.A.
Published: February 2019

The commercial production and handling systems in Benue State was undertaken under a World Bank assisted project to identify and seek solution to constraints facing citrus farming in some rural parts of Nigeria. Selected areas noted for intensive fruit cultivation like Gbako,Yandev,Katsina-ala, and Aliade was covered in a survey by citrus agronomists and postharvest specialists. The study looked into processes and activities at farmers plots, agriculture department extension plots and nurseries, local markets and processing plants. Key production constraints identified include pest management and weed problems,bush burning, and high labor costs for farm operations. Lack of organized marketing outlets, high transport costs, and fruit decay at collection centers were the main bottlenecks facing the postharvest operations. Local processors face the problems of poor-quality raw material supply and the unstable price regimes every season. Investigation revealed that improved extension linkages that emphasize appropriate orchard management skills, integrated pest management, and careful handling should be introduced.
Using a Research Facility for an Extension Outreach Program Festival of Color
Authors: Steinegger Donald H.
Published: February 2019

Most of Nebraska's population resides in the urban centers of eastern Nebraska. Traditionally, however, the Cooperative Extension Service has catered to the rural populations of the state. Now, it is imperative that the public and the legislative representatives from these urban areas learn that the research and outreach programs of the university also serve them. A Festival of Color was the vehicle for educators and aides, Natural Resource District personnel, and other professionals, including government officials. Both professionals and the general public responded enthusiastically to the Festival's innovative use of the research site. The educational objective was to creatively answer questions on low input landscapes; their design and maintenance. Information was presented by Extension Specialists and Assistants, Master Gardeners, Natural Resource District personnel, Dept. of Environmental Quality, State Energy Office, and Nebraska Association of Nurserymen.
Determining Landscape Tree Knowledge of Fourth to Sixth Graders
Authors: Ruppert Kathleen C. , Davis Gregory L.
Published: February 2019

In his State of the Union Address (1990), President Bush proposed planting a billion trees annually for the next 10 years. Organizations such as Global ReLeaf are planning to plant 400 to 600 million trees by the year 2000. A review of science education periodicals and general information available on tree planting and care reveal little directed to children. Science education tends to focus on the nature, not the handling of trees, and where planting ideas are suggested, they tend to be about growing trees from seed. To determine the level of landscape tree care knowledge of 4th–6th graders, a questionnaire addressing how trees grow, site and tree selection, proper planting, and other areas was administered by 4-H agents and Univ. of Florida students throughout the state during five camps, involving 211 children during the summer of 1995. The questionnaire was revised with additional topics such as irrigation and mulching added and administered during three 4-H camps involving 77 4th–6th graders. Answers to these questionnaires were used to develop materials targeted for this age group and their teachers.
Developmental Stages of Single-stem Cut Rose Production
Authors: Anderson Robert G. , Jia Wenwei
Published: February 2019

Commercial quality cut-roses were produced in a single-stem production system from single node cuttings. A significant advantage to single-stem rose production is that specific environments can be used for specific developmental stages of rose growth. In stage 1 (propagation), cuttings were treated with a 5-second dip in 500 ppm IBA/250 ppm NAA solution, placed in growing media in 8-cm pots, and placed under intermittent mist (5 second every 5 minutes) with growing medium temperature of 35°C. In stage 2 (axillary budbreak and stem development to visible pea size flower bud), rooted cuttings moved to benches (200 stems/m2) in a greenhouse at 14 to 16°C night, and plants received 12 hours supplemental light at 80 to 100 mol·m–2s–1. In stage 3 (stem elongation and flower bud development), small rose plants (30 to 35 cm tall with a pea-size flower bud) were moved to 100 stems/m2 in a greenhouse at 14 to 16°C night with ambient light. Through seven sequential crops of rose cuttings grown from Feb. through May 1995, rooting required a mean of 16 days, flower buds were visible in 42 days, and flower harvest required a mean of 58 days. Accumulated radiation and average temperatures through the spring had significant effects on the number of days in each developmental stage of rose growth.
A Knowledge-based System for Control of the Environment for Single-stem Roses
Authors: Chao Kuanglin , Gates Richard S. , Anderson Robert G.
Published: February 2019

Knowledge engineering offers substantial opportunities for integrating and managing conflicting demands in greenhouse crop production. A fuzzy inference system was developed to balance conflicting requirements of producing a high-quality, single-stem rose crop while simultaneously controlling production costs of heating and ventilation. An adaptive neuro-fuzzy inference system was built to predict the rose status of `Lady Diana' single-stem roses from nondestructive measurements. The fuzzy inference system was capable of making a critical decision based on the principle of economic optimization. Temperature set points for two greenhouses with similar rose status were treated significantly different by the fuzzy inference system due to differences in greenhouse energy consumption. Moderate reduction in heating energy costs could be realized with the fuzzy inference system.
Silicate Sprays as Effective as Calcium Sprays at Suppressing Bract Necrosis in Poinsettia
Authors: McAvoy Richard , Bible Bernard
Published: February 2019

Bract necrosis (BN) first appears at anthesis, and symptoms become more numerous and severe with time. Previously, we reported that 3.6 mm sodium silicate (Na2SiO3) sprays, applied during bract development, were as effective as 10 mm CaCl2 sprays at suppressing BN on `Supjibi' and `Angelika White', but only for several weeks after initial anthesis. While applying Na2SiO3 during bract development dramatically suppressed BN (7.2% of bracts with BN 46 days after anthesis vs. 33.4% for untreated plants), applying Na2SiO3 after anthesis is ineffective (35.7% BN). In 1995, suppression of BN was evaluated on `Supjibi' plants sprayed with similar concentrations (2 or 4 mm) of Na2SiO3 and CaCl2; treatments were compared to unsprayed poinsettias, or plants sprayed with either deionized (DI) water, 4 mm SrCl2, 4 mm NaCl, 4 mm MgCl2, or a solution of Na2SiO3 plus CaCl2 (1 or 2 mm each). At harvest (38 days after initial anthesis), 40.6% of the bracts on unsprayed plants and 35.8% of the bracts on DI water sprayed plants had BN. In contrasts, only 5.3% of the bracts on the 4 mm CaCl2 treated plants and 5.9% of the bracts on 4 mm Na2SiO3 treated plants had BN. Plants sprayed with 4 mm SrCl2 or the combination of 2 mm Na2SiO3 plus 2 mm CaCl2 developed BN on 7.8% and 9.2% of bracts, respectively. NaCl and MgCl2 sprays (4 mm) were not as effective (29.6 and 26.4% BN) as Ca, Si, or Sr sprays at suppressing BN over the duration of this study.
Greenhouse Evaluation of Poinsettia Cultivars for Colorado
Authors: Succop C. Elizabeth , Newman Steven E.
Published: February 2019

During 1995, 33 poinsettia cultivars were evaluated for Colorado greenhouse production conditions. Plants were supplied by the Paul Ecke Poinsettia Ranch, Fischer Geraniums USA, Oglevee, and Mikkelsens. At the end of the production period, Colorado greenhouse growers were invited to an open house and asked to judge the cultivars for plant, bract, and cyathia quality. As rated by the 24 growers, the best red cultivars in overall performance were `Freedom Red', `Nutcracker Red', `Cortez', and `Bonita', respectively. The best pink cultivars in overall performance were `Nutcracker Pink', `Maren', and `Flirt', respectively. The best white cultivars in overall performance were `Nutcracker White' and `V-17 Angelika White', respectively. The best novelty cultivars in overall performance were `Puebla' and `Monet', respectively.
Biofiltration of Metalaxyl Residue in Recirculating Irrigation Water Using Constructed Wetlands
Authors: MacNeal Erin P. , Berghage Robert D.
Published: February 2019

Recirculating irrigation systems (RISs) conserve water and decrease fertilizer application, providing cost-effective alternatives to other watering methods in greenhouses. However, RISs can potentially become contaminated from spray or drench pesticide applications. In this study, we determined the amount of metalaxyl residues (the active ingredient in Subdue) in RISs over 3 and 6 weeks using HPLC analysis. Also examined was the potential use of constructed wetlands for the remediation of RIS water contaminated with metalaxyl. Metalaxyl was found to persist in a RIS over 6 weeks with no decrease in concentration. After repeated metalaxyl treatments over an 11 month period, a possible breakdown product or chemical modification of metalaxyl was present in the RISs. Drench applications, 150 ml of an 18.8 ppm metalaxyl solution, (recommended dosage) resulted in 0.5 to 3.0 ppm contamination levels in the RISs. Small scale (≈70 L void volume), indoor, constructed wetlands (two planted with Scirpus and Iris, two unvegetated) were treated with 420 mg metalaxyl. Limited breakdown of metalaxyl occurred in the constructed wetlands during the first 30 days after treatment. After 3 months, metalaxyl concentrations in all wetlands had decreased or were below detection levels. This indicates a possible selection of microbial populations capable of metabolizing or degrading metalaxyl.
Efficacy of Ancymidol, Paclobutrazol, and Uniconazole on Growth of Tuberous-rooted Dahlias
Authors: Whipker Brian E. , Hammer P. Allen
Published: February 2019

Plant growth retardant (PGR) media drench treatments (in mg a.i./pot) of ancymidol at 0.5, 1.0, 2.0, 4.0, or 8.0; paclobutrazol at 1.0, 2.0, 4.0, 8.0, or 16.0; uniconazole at 0.5, 1.0, 2.0, 4.0, or 8.0 were applied to tuberous-rooted dahlias to compare their effectiveness as a chemical height control. All paclobutrazol, ancymidol, and uniconazole rates applied significantly reduced `Red Pigmy' plant height by 21% or greater compared to the nontreated control. Excessively short plants resulted from uniconazole and ancymidol drench rates ≥1.0 mg. `Red Pigmy', a less vigorous cultivar, were acceptable as potted-plants with paclobutrazol rates of 2.0 to 4.0 mg, 0.25 to 0.5 mg of uniconazole, or 0.5 mg of ancymidol. All paclobutrazol, ancymidol, and uniconazole rates significantly reduced `Golden Emblem' plant height by ≥11% when compared to the nontreated plants. Excessively short plants resulted from paclobutrazol drench rates of 16.0 mg, uniconazole rates of 2.0 mg and for ancymidol drenches ≥4.0 mg. `Golden Emblem', the more vigorous cultivar, were acceptable as potted-plants with paclobutrazol rates of 4.0 to 8.0 mg, 0.5 to 1.0 mg of uniconazole, or 2.0 mg of ancymidol.
Using Temperature, Light, and Fungicides to Prolong the Storage Life of Rooted Geranium Cuttings
Authors: Kaczperski Mark P. , Heins Royal D. , Carlson William H.
Published: February 2019

Methods of cold storage for rooted cuttings of three cultivars of Pelargonium ×hortorum Bailey were examined. Cuttings were stored from 0 to 10°C for 7 to 56 days. Treatments included packing the cuttings in ice, storing them under irradiance levels of 0 or 50 μmol·m–2·s–1, applying fungicides, varying cutting developmental stages, and varying the day temperatures. Cuttings packed in ice showed signs of chilling injury within 7 days and died. Applications of etridiazole and thiophanate-methyl or metalaxyl and thiophanate-methyl drenches or fosetyl-Al spray did not improve storage performance of the cuttings. Roots of cuttings held 7 additional days in the propagation area before storage grew faster after storage than those of cuttings with less time in the propagation area, but flowering time was not affected. Maintaining night temperatures at 5°C while allowing day temperatures to rise to 10°C delayed flowering by 6 days compared to maintaining a constant 5°C. Rooted cuttings held at 5°C under 50 μmol·m–2·s–1 irradiance for 9 hours each day could be stored up to 56 days with only a 2-day delay in flowering compared to unstored cuttings. Chemicals used were 5-ethoxy-3-trichloromethyl-1,2,4-thiadiazole (etridiazole); thiophanate-methyl (dimethyl[1,2-phenylene)bis(iminocarbonothioyl)]bis[carbamate]) (thiophanate-methyl); N-(2,6-dimethylphenyl)-N-methoxyacetyl) alanine methyl ester (metalaxyl); aluminum tris (O-ethyl phosphonate) (fosetyl-Al).
Single Basal Fertilization of MEISTER (Polyolefin-coated Urea) to Cyclamen
Authors: Teraoka Y. , Kubo K. , Miyoshi S. , Higashi T.
Published: February 2019

A capillary watering system can easily control water supply to cyclamen and can save nutrient losses by leaching. Introduction of single basal placement using MEISTER will be useful to innovate the traditional cyclamen culture. The conventional cyclamen culture using Nutricote needs double transplanting and double fertilization. In the new cyclamen culture, cyclamen seedlings (sowed on the plug tray in early January) were transplanted to 15-cm pots fertilized with MEISTER in early June. The selected MEISTER was one belonging to the sigmoid dissolution group, which showed delayed release during summer and the maximum release in early September. The new fertilization supplied N to the plants until the end of growing season. The growth of cyclamen plants on two experimental plots were compared at the flowering stage. Numbers and weight of flowers per pot and bulb weight were greater in the new culture than in the conventional culture though the total volume of leaves was less in the former. Regarding the nutrient absorption, the plants of the new culture showed lower concentrations of N and P in the leaves but higher concentrations of Ca and Mg compared to those in the conventional culture. Such nutrient uptake could contribute to preventing the occurrence of tipburn in the new culture.
Effect of Different Substrate on Growth of African Violet (Saintpauila ionantha) Grown in Greenhouse Conditions
Authors: Arias-Gonzalez M. , Farias J. , Guzman S. , Michel A.
Published: February 2019

Our purpose was to evaluate the vegetative growth and flowering of African violet (Saintpauila ionantha) grown in seven soils subtrates under greenhouse conditions. The following were tested: river lime, pine ushers, black clay, oak soil, peatmoss, Canadian peatmoss, and a compost soil. Pots were in a fully randomized experimental design with seven treatments, and four replications was used. A monthly 10N–20P–10K fertilization was applied to potted plants. The study lasted for 135 days, taking data every 15 days on leaf perimeter, length and elasticity of the petiole, plant height, and leaf color. Best vegetative growth was observed with oak and canadian peat moss due to their high capacity to hold water and their very good aeration. Least vegetative growth was observed with black clay, where plants failed to flower. Other substrates did not show differences in plant growth.
Compost Usage for Growing Impatiens `Accent Red'
Authors: Klock Kimberlv A. , Fitzpatrick George
Published: February 2019

Three compost products [biosolids (SYT), refuse derived fuel residues (RYT), and municipal solid waste (MSW)] were compared to a commercial bedding plant medium of 60% Sphagnum peat: 25% shredded bark: 15% aerolite to support Impatiens wallerana `Accent Red' growth. The treatments consisted of 100% compost as a stand alone medium plus blends in which compost was combined with control medium components at 60% compost or 30% compost. Shoot dry mass of plants grown in 100% SYT and RYT was greater than shoot dry mass of Impatiens plants grown in 100% MSW. Plants grown in SYT showed an increase in shoot dry mass from 1.29 to 1.64 g as the percentage of compost in the mix increased from 0% to 100%, while plants grown in MSW showed a linear decrease in. shoot dry mass from 1.29 to 0.18 g. Shoot dry mass of plants grown in RYT did not differ significantly from 0% to 100% compost in the media.
Growth of Euphorbia pulcherrima and Pelargonium ×hortorum in Shredded Rubber-containing Substrates
Authors: Evans Michael R. , Waber Andrew A.
Published: February 2019

Euphorbia pulcherrima `Freedom' (poinsettia) and Pelargonium ×hortorum `Pink Elite' (geranium) were grown in 75:25:0, 50:50:0, 27:75:0, 75:0:25 50:0:50, 25:0:75 (v/v sphagnum peat: 0.25-grade rubber: 0.10-grade rubber) substrates or in a 50 sphagnum peat: 30 perlite: 20 loam (v/v) standard greenhouse substrate. Geranium root and shoot fresh weights, height, and number of axillary shoots were reduced when grown in rubber-containing substrates compared to plants grown in the standard control. As the proportion of either grade of rubber increased, root and shoot fresh weights, height, and number of axillary shoots decreased. Flowering in geranium was delayed and the number of inflorescences reduced as the proportion of the 0.10-grade rubber increased. Plants grown in the 0.25-grade rubber failed to flower by the termination of the experiment. Poinsettia plants grown in rubber-containing substrates had reduced shoot fresh weight, height, number of bracts, and bract area compared to plants grown in the standard control. As the proportion of either grade of rubber increased, height, shoot fresh weight, number of bracts, and bract area decreased. Number of axillary branches was reduced in substrates containing 50% and 75% of the 0.10-grade rubber. Days to anthesis was unaffected by substrate.
Inflorescence Color Manipulation in Hydrangea Forced in Media Containing Coal Bottom Ash and Mine Soil
Authors: Pitchay Dharmalingam S. , Sherratt Mark D. , Bearce Bradford C.
Published: February 2019

Dormant budded plants of Hydrangea macrophylla (Thunb.) cvs. Blaumeise Blue and Pink were planted on 29 Jan. 1996 in 15-cm azaleas pots containing media with topsoil, peat, perlite, coal bottom ash, and mine soil, mixed in varying proportions. Media pH levels were initially adjusted with dolomitic limestone to a range of 6.0 to 6.1 for pink inflorescences and with ammonium sulfate to a range of 4.4 to 5.9 for blue inflorescences. Plants of Blaumeise Blue and Blaumeise Pink in low pH media were drenched on 29 Feb. with a solution of aluminum sulfate at 6 g·L–1. Number of shoots per plant were reduced in media with the highest proportion of coal bottom ash (40%, v/v) plus 30% mine soil. Plant diameter was affected very little by type of media. Tallest plants were `Blaumeise Pink' growing in media containing at least 20% top soil or mine soil plus 20% coal bottom ash. These mixes also contained 20% or 40% perlite. Inflorescence diameters ranged from 10.88 to 17.43 cm. and were mostly unaffected by media type. Inflorescence number per plant appeared to be reduced in `Blaumeise Blue' regardless of media. Inflorescence color brightness ranged from L = 55.26 to 61.38 and was affected very little by media type in both cultivars. Bluest inflorescences occurred on `Blaumeise Blue' plants growing in a combination of zero top soil, 40% peat, 30% perlite, 20% coal bottom ash, and 10% mine soil with no lime, and`Blaumeise Pink' plants growing in media with zero topsoil, 40% peat, and 20% mine soil. Blue color did not develop well in media containing top soil and no mine soil. This study demonstrated that florists' hydrangea can be satisfactorily forced in media containing substantial amounts of coal bottom ash and mine soil and that color regulation is also possible in some of these media.
An Irrigation Management Method to Reduce the Nitrogen Content of Effluent from Nursery Containers
Authors: Walden Ronald F. , Niemiera Alex X.
Published: February 2019

Container nurseries often irrigate daily with a fixed amount of water that exceeds the water-holding capacity of the container substrate, thus, leaching a portion of the applied water and nutrients. We compared the influence of daily container irrigation based on substrate moisture tension (SMT) to that of daily irrigation with a set amount on irrigation volume, container effluent volume, total effluent N content, and plant growth. Rhododendron, Ilex, and Juniperus were grown outdoors in 11.3-L containers in a pine bark-based substrate at four rates of fertilization with a controlled-release fertilizer. Drip irrigation was applied each morning until an electronic tensiometer signaled an irrigation controller that SMT was less than a set value corresponding to container capacity. Irrigation at 1.5 cm·d–1 served as the control. Irrigation treatment had little influence on growth and no influence on growth response to fertilizer rate. Irrigation volume, effluent volume, and total effluent N content were lower for each species when irrigation was based on SMT. For Juniperus, irrigation volume, effluent volume, and total effluent N content were 62%, 69%, and 60% less, respectively, for tension-based irrigation than for irrigation with a set amount.
Growth Index and Disease Ratings of 55 Crape Myrtle Cultivars in Tennessee
Authors: Witte W.T. , Windham M.T. , Sauve R.J. , Flanagan P.C.
Published: February 2019

Fifty-five accessions of commercially available crape myrtle cultivars were established with 10 single-plant replications during Fall 1993 and Spring 1994. Drip irrigation began on a regular basis May 1994 and plants were fertilized regularly. In contrast to the 1994 growing season with heavy powdery mildew infestation, little powdery mildew occurred in 1995. Mean growth index (GI = centimeter height + centimeter mean width) was calculated for each cultivar in Fall 1994 and 1995. Fastest growth occurred in `Tuskegee' and `Biloxi' (GI = 276, 246, respectively), followed by a group including `Tonto', `Comanche', `Choctaw', `Hardy Lavender', `Natchez', `Potomac', and `Tuscarora' (GI = 185 to 227). Slowest growth occurred in the group including `Pecos', `Seminole', `Baton Rouge', `Petite Orchid', `Bourbon Street', `Cherokee', `Monink Pink', `Moned Red', `Delta Blush', `Low Flame', `New Orleans', `Monow', and `World's Fair' (GI = 5 to 53). Data will be presented on powdery mildew ratings and physiological injury sustained during Winter 1995–96.
Fastest Growing Oaks in Species/Cultivars Trials at TSU-NCRS, McMinnville, Tenn.
Authors: Witte W.T. , Sauve R.J. , Flanagan P.C.
Published: February 2019

Eighty-one accessions of oak species, hybrids, and cultivars from commercially available sources were established at TSU-NCRS in Fall 1993 and Spring 1994, using 10 single-plant replications in a randomized complete block. Drip irrigation was begun on a regular basis May 1994, and plants were fertilized regularly. Height and diameter was recorded Fall 1994 and 1995. Fastest growing oaks in order of cm height growth increment over the two growing seasons were nigra, phellos, texana nuttalli, cerris, macrocarpa, falcata pagodaefolia, macrocarpa `Maximus', acutissima, austrina, shumardii, muehlenbergi, falcata, robur fastigiata, lyrata, virginiana, palustris, acutissima `Gobbler', glandulifera, macrocarpa `Ashworth', gambelli ×macrocarpa, alba. Most evergeen oaks did not survive Winter 1995–96, and data will be reported on winterkill.
Effect of Cold Storage and Pretransplant Desiccation on Root Growth Potential and Budbreak of Washington Hawthorn and Norway Maple
Authors: Bates Rick M. , Niemiera Alexander X.
Published: February 2019

Two-year-old Washington hawthorn (Crataegus phaenopyrum Med.) and Norway maple (Acer platanoides L.) seedlings were subjected to varying cold storage durations and four storage treatments: whole plant covered in polyethylene bags, shoots exposed, roots exposed, and whole plant exposed. After storage, half the seedlings were immediately plant and half received a 12-hour desiccation treatment before transplanting. Root growth potential (RGP), time to budbreak, and marketability were measured. With the root covered treatments, Norway maple RGP increased while Washington hawthorn RGP decreased with increased cold storage duration. RGP for both species remained low throughout storage for treatments exposing roots. The 12-hour desiccation treatment reduced RGP for both species with hawthorn being more affected than maple. Days to budbreak for both species decreased with increased storage time for whole plant covered treatments but increased for both species when stored with exposed roots. Maple marketability for root covered treatments was high for most storage durations. Hawthorn marketability was generally low except for the whole plant covered treatment during the first 6 weeks of storage. For the respective storage durations, hawthorn RGP, time to budbreak and marketability values for the shoots exposed treatment were similar to the root exposed treatments. In contrast, values for the shoots exposed treatment were similar to the whole plant covered treatment for maple. There was a high positive correlation between RGP and marketability for both species.
Effect of Postfrost Pruning on Winter Hardiness of Selected Garden Chrysanthemums
Authors: Iles Jeffery K.
Published: February 2019

Pruning aboveground tissues back to the plant crown in preparation for winter is a common cultural practice for garden chrysanthemums [Dendranthema grandiflorum (Ramat.) Kitamura]. But some landscape managers suggest pruning immediately before the onset of low temperatures may be responsible for predisposing plants to winter injury. To evaluate the effect of pruning garden chrysanthemums in November and December on winter survival, rooted cuttings of 19 chrysanthemum cultivars were obtained from Yoder Brothers and were field-planted in a randomized complete-block design with five replications. Pruning treatments were 1) plants pruned to 2 cm above the crown on 1 Nov., 2) plants pruned to 2 cm above the crown on 1 Dec., and 3) plants not pruned. Survival and regrowth data were gathered the following summer. Cultivars differed in their response to the treatments, but in general, survival percentages and regrowth shoot dry weights were greater for plants that were not pruned.
Effectiveness of Ethephon Treatments in Reducing Seed Set in Kalmia latifolia L.
Authors: Kiyomoto Richard K.
Published: February 2019

Nursery production of Mountain Laurel (Kalmia latifolia L.) often involves manual disbudding or deadheading flower clusters immediately after flowering, to stimulate the formation of one or several new shoots. Experiments were initiated on populations of K. latifolia `Angel' (41 plants), `Snowdrift' (17 plants), and `Hoffman's Pink' (37 plants) to test the effectiveness of single applications of 0 (water control), 500, 1000, and 2000 ppm ethephon in reducing seed set and stimulating new shoot formation. Ethephon was applied on 9 June 1995 when an average of 52.9%, 53.4%, and 27.3% of the flowers were open in each flowering cluster of `Angel', `Snowdrift', and `Hoffman's Pink', respectively. On 17 to 19 July 1995, data were collected for numbers of green seed capsules per flower cluster and the number of new shoots per plant. One way analysis of variance showed the treatments had highly significant effects on seed capsule numbers per flower cluster and in stimulating the production of new shoots per plant in the three cultivars. The average number of green capsules per flower cluster and new shoots per plant for each cultivar treated with 2000 ppm ethephon were: 2.2 capsules and 57.2 shoots in `Angel', 1.1 capsule and 40 shoots in `Snowdrift', and 6.6 capsules and 39.3 shoots in `Hoffman's Pink'. In contrast, the controls had 20.1 capsules and 2.8 shoots in `Angel', 22.9 capsules and 8 shoots in `Snowdrift', and 27.3 capsules and 2 shoots in `Hoffman's Pink'.
Herbicide Injury Symptoms on Landscape Plants; A Photo CD-ROM Image File
Authors: Dana Michael , Kemery Ricky , Lerner Rosie , Throssell Clark , Carpenter Philip , Kerper Michael , Putnam Melody
Published: February 2019

Damage caused by misapplication of herbicides in landscape management or drift from agricultural fields on to nearby landscape plantings is often difficult to diagnose. Symptoms may vary with herbicide, species that is damaged, and other factors. To address this need, a photo CD-ROM has been developed to help plant damage diagnosticians determine if damage has been caused by herbicides. Fourteen herbicides or herbicide combinations commonly used in turfgrass, landscape, or field crop production applications were applied to 21 taxa of landscape trees, shrubs, groundcovers, or herbaceous perennials. More than 800 photographic transparencies of damage symptoms (representing all 21 taxa and 12 herbicides) were taken, and 457 were selected for storage in the digitized photo CD format for rapid retrieval. In all cases, as damage symptoms were observed, they were photographically recorded using a Nikon FM camera with a 55-mm micro-NIKKOR lens and Fujichrome Velvia transparency film under ambient, sunlit conditions. Species and plant taxa lists are displayed and the CD-ROM is demonstrated.
Severity and Timing of Mechanical Rejuvenation Pruning Affects Vegetative and Reproductive Growth of Blueberry
Authors: Williamson J.G. , Darnell R.L.
Published: February 2019

Mature `Sharpblue' southern highbush and `Beckyblue' rabbiteye blueberry plants were mechanically pruned at two heights on three dates after fruit harvest during the 1994 growing season. No pruning had occurred for at least 3 years (`Sharpblue') or 5 years (`Beckyblue') before initiating experiment. Pruning heights were 45 and 85 cm and nonpruned for `Sharpblue' and 45 and 95 cm and nonpruned for `Beckyblue'. Pruning dates were 3, 6, and 9 weeks after peak harvest for each cultivar. Regrowth was measured in Mar. 1995 before initiation of spring growth. Pruning `Sharpblue' bushes to 45 cm increased new shoot number and mean and total shoot length but decreased fruit yield compared to the 90-cm pruning treatment. No difference in yield occurred between the 90-cm pruning treatment and the nonpruned control. As time between fruit harvest and pruning increased, new shoot number, mean and total shoot length, plant height, canopy volume, and fruit yield decreased. There was no difference in yield between the earliest pruning treatment and the control. For `Beckyblue', mean and total shoot length of regrowth and flower bud density decreased with increasing time from harvest to pruning. Yield data for `Beckyblue' were not collected in 1995 because of gall midge infestation.
Nitrate Reductase Activity in Leaves and Roots of Two Blueberry Species
Authors: Merhaut Donald J. , Darnell Rebecca L.
Published: February 2019

Commercial blueberry production is limited primarily to soils where ammonium, rather than nitrate, is the predominant N form. However, Vaccinium arboreum, a species native to northern Florida, often is found growing in soils where nitrate is the major N form. This species may serve as a breeding source or rootstock for commercial blueberries, expanding the potential soil types that may be used for blueberry cultivation. In our study, in vivo nitrate reductase activity (NRA) was measured in roots and leaves of 2-year-old seedlings of V. arboreum and a commercial cultivar, V. corymbosum `Sharpblue'. Plants were grown hydroponically in sand culture and fertilized with a modified Hoagland's solution containing N as either ammonium, ammonium nitrate, or nitrate. Vaccinium arboreum averaged nitrite at 200, 60, and 20 nmol/g fresh weight per h for nitrate, ammonium nitrate, and ammonium fertilized plants, respectively. `Sharpblue' root NRA was significantly lower, averaging nitrite 50, 38, and 8 nmol/g fresh weight per h for nitrate, ammonium nitrate, and ammonium fertilized plants, respectively. NRA was much lower in leaves than roots of V. arboreum, averaging nitrite at ≈15 nmol nmol/g fresh weight per h across N treatments. No NRA was detected in the leaves of `Sharpblue', regardless of N treatment. These data suggest that V. arboreum may be used as a rootstock or breeding source to expand blueberry production into soil types that are higher in nitrate than the soils typically used for blueberry production.
Cranberry Crop Manager Computer Software Package
Authors: Roper T.R. , Mahr D.L. , Kaarakka P.
Published: February 2019

Cranberry Crop Manager is a predictive software package for commercial cranberry growers. The package consists of linked modules. Predictive models for insect, disease, and weed development are the most important features. With appropriate weather and scouting information the models will make control or no control recommendations. To support the predictive models the program will maintain weather records of air temperatures, evapotranspiration, irrigation, and rainfall. Data can be imported or entered by hand. The program will maintain bed records including pesticide applicators, pesticide and fertilizer applications, and scouting reports. Output options include screen or printed reports or data export. An electronic encyclopedia of cranberry disease, insect and weed pests on CD will accompany the package. Minimum computer requirements are 486 CPU, 6 MB RAM, 6 MB hard drive space.
Growth of Sour Orange in Response to Mesic or Xeric Geographic Isolates of Glomus intraradices under Two Irrigation Frequency Regimens
Authors: Martin Chris A. , Stutz Jean C.
Published: February 2019

Sour orange (Citrus aurannum L.) seedlings were inoculated with geographic isolates of an endomycorrhizal fungus, Glomus intraradices Smith and Schneck, from a xeric (New Mexico) or mesic (Florida) climate or not inoculated as controls, and were grown for 5 months under high (soil water potential more than or equal to –0.1 MPa, irrigated once every 3 days) or low (more than or equal to –1.0 MPa, irrigated once every 12 to 15 days) irrigation frequency regimens. Similar leaf P concentrations were achieved in all plants by giving more P fertilizer to nonmycorrhizal plants than mycorrhizal plants. Plants inoculated with the xeric isolate had more arbuscules and fewer vesicles than those inoculated with the mesic isolate. Mycorrhizal fungi had little affect on plant growth under high irrigation frequency. Low irrigation frequency reduced plant growth compared with high irrigation frequency. Under low irrigation frequency, shoot and root growth increased for mycorrhizal plants; however, the magnitude of increase of shoot growth was greatest for plants inoculated with the xeric isolate. Additionally, low irrigation frequency was associated with a dramatic decrease in vesicle formation in roots inoculated with the mesic isolate. This study showed that sour orange plants especially benefited from inoculation with an isolate from a xeric climate under low irrigation frequency, independent of P nutrition.
Perennial Peanut Establishment and Potential Environmental Benefits to Citrus
Authors: Rouse Robert E. , Mullahey J. Jeffrey
Published: February 2019

A 2-year establishment study of perennial peanut (Arachis glabrata Benth.) planted in row middles of a 1-year-old citrus grove was initiated in southwest Florida. The effect of herbicide and fertilizer treatment combinations on perennial peanut density was measured. Treatments were Fluazifop-p-butyl (Fusilade 2000 1E) herbicide, K-Mag fertilizer, Fluazifop-p-butyl + K-Mag + N, and a nontreated control. Four replications were arranged in a randomized complete-block design. After 2 years, there were no significant differences in plant density between treatments (96% cover) and the control (89% cover). Applications of Fluazifop-p-butyl in years one and two were effective in controlling grassy weeds such as common bermudagrass [Cynodon dactylon (L.) Pers]. In this experiment. initiated 1 year after planting, perennial peanut without inputs (herbicide, fertilizer) was able to suppress common bermudagrass and to obtain a high level (89%) ground cover in 3 years (1991–94).
Evaluation of Four Pistachio Rootstocks in California's Central Valley
Authors: Ferguson Louise , Epstein Lynne , Beede Robert H.
Published: February 2019

Four pistachio rootstocks, Pistacia atlantica, P. integerrima, and two selections of the same interspecific hybridization, P. atlantica, P. atlantica × P. integerrima (A.K.A. PGII and UCB #1) budded with P.vera, P. vera cv. Kerman females have been evaluated since 1989 in three locations in California's central San Joaquin Valley. Thus far, Atlantica is the most cold tolerant, followed by the interspecific hybrids and Integerrima. Integerrima and UCB no. 1 have produced significantly more clusters and nuts per tree, but all rootstocks have produced the same numbers of nuts per cluster. Trees on no.1 and Integerrima rootstocks also have produced significantly more kilograms of nuts per trunk cross sectional area than Atlantica and PGII. UCB #1 and Integerrima also are significantly more tolerant of the soilborne fungus Verticillium dahl. All rootstocks are equally infected with three species vesicular–arbuscular mycorrhizzae. Two seasons of irrigation with water up to 8.00 dS·m–2, have not affected rootstock performance or yield. UCB #1, Integerrima, and PGII all require supplemental boron, zinc, and copper nutrition for good production. Thus far, Integerrima is the best rootstock for soils with verticillium infestations unless winter temperatures are frequently below freezing. UCB #1 is the best rootstock for locations with cold winters.
Estimating Leaf Area of Macadamia and Coffee
Authors: Kobayashi Kent , Liu Guofan
Published: February 2019

One hundred mature leaves of macadamia (Macadamia integrifolia) were selected from 10 trees in a commercial orchard in Papaikou on the island of Hawaii. Length (L), width (W), and area (A) of each leaf were taken. L and W were significantly correlated (r = 0.93), L and A (r = 0.98), W and A (r = 0.94), and (L × W) and A (r = 0.99). L and W showed curvilinear relationships with A. Seventy-five mature leaves of coffee (Coffea arabica `Guatemalan') were selected from five trees at the Waimanalo Expt. Station on the island of Oahu. Leaf L, W, and A were measured. L and W were significantly correlated (r = 0.72), L and A (r = 0.89), W and A (r = 0.93), and (L × W) and A (r = 0.98). L and W showed curvilinear relationships with A. For both macadamia and coffee, although using L × W as a term in linear equations resulted in higher adjusted R2s, the use of these equations would involve taking an additional measurement in the field. A quadratic equation using width (for coffee) or length (for macadamia) best described the relationship between these measurements and area and provide a quick method for estimating leaf area in the field.