bluuebunny/crossref_metadata_2025 huggingface dataset:
Economic Evaluation of Mechanized Pruning of Coffee in Hawaii
Authors: Mauri Silvia G. , Bittenbender H.C. , Fleming Kent D. , Gautz Loren D.
Published: December 2018

Marketable coffee (Coffea arabica) yield and cost of production under two systems of mechanized pruning—hedging and stumping— were investigated. Data were collected from 1997 to 2001—a single pruning cycle—on three cultivars on three farms on Kauai, Maui, and Molokai. Treatments were variations of hedging and stumping, including time of pruning, methods of re-growth control, and tree in-row spacing were applied to each coffee cultivar. Economic evaluation was based on a partial budget analysis of the actual costs per year of the different pruning systems used on each farm. Mechanical pruning costs per acre for best hedging and stumping treatments across cultivars were 90% and 83% less, respectively, than the current practice of manual pruning. Response to pruning system varied according to coffee cultivar, tree in-row spacing and farm location. The tall cultivar Mokka had higher yields when hedged at 5 ft (1.5 m) tall and 5 ft wide, and the semi-dwarf cultivar Yellow Catuai had higher yields when stumped at 2 ft (0.6 m) tall. Hedge pruning should be done early in the year, January to February, for the semi-dwarfs, `Yellow Catuai' and `Red Catuai', but can be delayed until May for `Mokka'. Annual topping in the hedging systems should be done January to May for `Yellow Catuai' but maybe delayed until May for `Mokka' and `Red Catuai' without yield loss. The economic evaluation revealed that the cost of stumping was higher than hedging. For `Yellow Catuai' on Kauai the economic evaluation indicated that although the cost of stumping was higher, the accompanying higher yields resulted in a higher gross margin for this system. When stumping, verti- cal branches can be set with a contact herbicide spray to avoid higher hand pruning costs without lowering yields. Stumps should be narrowed after stumping if spaced, 2.5 ft (0.75 m) the current standard in-row spacing for mechanical harvesting. Wide in-row spacing (5 ft) should be considered by growers when planting or re-planting.
Amendment of Muskmelon and Watermelon Transplant Media with Plant Growth-Promoting Rhizobacteria: Effects on Seedling Quality, Disease, and Nematode Resistance
Authors: Kokalis-Burelle Nancy , Vavrina C.S. , Reddy M.S. , Kloepper J.W.
Published: December 2018

Greenhouse and field trials were performed on muskmelon (Cucumis melo) and watermelon (Citrullus lanatus) to evaluate the effects of six formulations of plant growth-promoting rhizobacteria (PGPR) that have previously been shown to increase seedling growth and induce disease resistance on other transplanted vegetables. Formulations of Gram-positive bacterial strains were added to a soilless, peat-based transplant medium before seeding. Several PGPR treatments significantly increased shoot weight, shoot length, and stem diameter of muskmelon and watermelon seedlings and transplants. Root weight of muskmelon seedlings was also increased by PGPR treatment. On watermelon, four PGPR treatments reduced angular leaf spot lesions caused by Pseudomonas syringae pv. lachrymans, and gummy stem blight, caused by Didymella bryoniae, compared to the nontreated and formulation carrier controls. One PGPR treatment reduced angular leaf spot lesions on muskmelon compared to the nontreated and carrier controls. On muskmelon in the field, one PGPR treatment reduced root-knot nematode (Meloidogyne incognita) disease severity compared to all control treatments.
Arbuscular Mycorrhiza and Growth Responses of Several Ornamental Plants Grown in Soilless Peat-based Medium Amended with Coconut Dust (Coir)
Authors: Linderman R.G. , Davis E.A.
Published: December 2018

Coconut fiber dust (coir) is being used as a peat substitute or amendment to potting mixes with varied results. However, its microbial composition and compatibility with beneficial microbes that might be added to growth media in the nursery, such as mycorrhizal fungi, has not been determined. In this study, coir was amended to a peat-based medium (15%, 30%, 45%, and 60% by volume) to determine its effects on growth of several ornamental plants and on the formation and function of the arbuscular mycorrhizal (AM) fungus Glomus intraradices. Mycorrhizae formed as well, and usually better, in all the coir-amended peat treatments as in peat alone. The magnitude of growth enhancement due to mycorrhizae was small for the plants tested in these media compared to that which usually occurs in soil-based media. In this experiment, plant growth responses appeared to be independent of level of mycorrhizal colonization and were plant species dependent. Consistent growth enhancement from mycorrhizae only occurred with marigold (Tagetes patula). With germander (Teucrium fruticans), growth was depressed with mycorrhizal inoculation in the medium composed of 60% coir. Growth of lavender (Lavandula augustifolia) was depressed in all coir-amended media, with or without AM inoculation, compared to the nonamended control. These results confirm previous reports of varied response of plant species to coir, and indicate the lack of any detrimental effects of coir on mycorrhiza formation.
Seasonal Abundance and the Use of an Action Threshold for Western Flower Thrips, in a Cut Carnation Greenhouse
Authors: Cloyd Raymond A. , Sadof Clifford S.
Published: December 2018

A 2-year greenhouse study was conducted to evaluate the seasonal population dynamics and use of an action threshold for western fl ower thrips (Frankliniella occidentalis) in cut carnation (Dianthus caryophyllus). An action threshold of 20 thrips/card/week was adopted to time insecticide applications. The highest numbers of thrips were caught on blue-colored sticky cards from May through September whereas the lowest thrips numbers were present from November through March 1994 and 1995. Thrips numbers based on sticky card counts, from December through March for both years were below the action threshold and as a result, no insecticides were applied. Thrips abundance on blue sticky cards was significantly correlated with both numbers of thrips in fl owers and a subjective ranking of fl ower quality. Seasonal patterns of both insecticide use and numbers of damaged fl ow- ers closely followed patterns of thrips abundance found on blue sticky cards. Our findings are the first to demonstrate, based on a case study over a 2-year period, that routinely scouting for thrips throughout the year can lead to fewer insecticide applications and thus possible cost savings in labor and insecticide purchases. This study suggests that sticky cards can be an effective tool for reducing insecticide applications in regions of the U.S. where there are seasonal fl uctuations of thrips abundance.
Direct Silk Applications of Corn Oil and Bacillus thuringiensis as a Barrier to Corn Earworm Larvae in Sweet Corn
Authors: Cook Rosalind , Carter Anne , Westgate Pam , Hazzard Ruth
Published: December 2018

Field studies were conducted in 2000 and 2001 to rate the efficacy and longevity of four pesticide treatments against corn earworm (Helicoverpa zea) larvae (CEW) in sweet corn (Zea mays). The four treatments used were 1) corn oil, 2) Bacillus thuringiensis ssp. kurstaki (Bt), 3) oil + Bt, and 4) an untreated plot. All treatments were applied on silk day 5. Silk day 1 was the first day that more than 50% of the ears had 2.5 cm (1 inch) or more silks emerging from the husk using a hand-held pump applicator. Two first-instar CEW larvae were placed directly into silk channel of selected ears on 6 different days (days 3, 6, 9, 12, 15, and 18 after first silk). The same six ears were then harvested 4 days later. Untreated ears had more live CEW and higher levels of feeding damage than the other three treatments ears for all harvest days in both years. The number of CEW found per ear was lower when Bt was included in the treatment. The use of corn oil gave the lowest damage ratings on almost all harvest days in both years. Treatments which contained oil had the highest number of marketable ears in both years, but also the highest percentage of underdeveloped kernels at the tip of the ear (6% to 9%). The oil and Bt treatments appeared to control CEW for at least 17 days, from silking through maturity. This treatment regime appears to be a promising alternative for growers to conventional pest management methods.
Profile of the Virginia Commercial Greenhouse Industry
Authors: Scoggins Holly L. , Latimer Joyce G. , Barden Victoria T.
Published: December 2018

A survey was conducted in 2000-01 to provide a comprehensive description of Virginia's commercial greenhouse industry. A total of 274 responses were analyzed. Responses were categorized based on the amount of heated greenhouse space: small, medium, large, or other (including part-time). The survey included questions about growing space, number of employees, education and experience of respondent, crops grown, gross receipts, and target markets. Seventy-five percent of the respondents were owners or owners/growers and respondents reported an average of 15 years experience. Most greenhouse operations were classified as small or less than 10,000 ft2 (929.0 m2). A wide variety of crops were reported, with more than 50% growing bedding plants and nearly 50% growing herbaceous perennials in the greenhouse. Market outlets were about equally divided between wholesale and retail.
The Hawaiian Native Plant Propagation Web Site: Developing a Webbased Information Resource
Authors: Herring Eileen C. , Criley Richard A.
Published: December 2018

The Hawaiian Native Plant Propagation Web Site (http://pdcs.ctahr.hawaii.edu:591/hawnprop) is a collection of organized propagation information for selected Hawaiian indigenous and endemic plants. It was designed to provide easy access to this information for university extension personnel, researchers, students, conservationists, and nursery and landscape professionals. Journals and newsletters published in Hawaii provided the most relevant data for this Web site. The first prototype was a database-driven Web site that provided sophisticated search capability and dynamically generated Web pages for each plant record. Subsequent testing of the prototype identified a number of usability problems. These problems were corrected by redesigning the Web site using a hybrid databasestatic Web page approach. The database software search features are retained, but each database record is linked to a static Web page containing the propagation information for a specific plant.
The Perceptions and Needs of Volunteers at a University- affiliated Public Garden
Authors: Haynes Cynthia , Trexler Cary J.
Published: December 2018

University-affiliated gardens enhance the teaching, research, and outreach missions of the university. Attracting and retaining volunteers is challenging but important for the success of most public gardens. The objective of this case study was to determine the perceptions and needs of volunteers at a university-affiliated public garden. In a focus group format, participants' responses were analyzed to determine the benefits of volunteering to both the participants and the university. Benefits were categorized into three groups: material, solidarity, and purposive. Material benefits are tangible rewards that are equated with monetary or resource gain. Solidarity benefits are social rewards from being in a group. Purposive benefits are rewards from achieving a goal or mission. This study documents the shift of volunteer motives from deriving purposive to solidarity benefits as the garden grew and expanded. Concomitantly, the goals of the university-affiliated garden shifted from purposive to material benefits. Our results confirm that garden volunteers are like other groups of volunteers in that they expect specific benefits for their participation, and their needs may fluctuate over time. Thus, a public garden may need to adjust reward systems to maximize the positive impact of volunteers. The university would benefit from an efficient support system to help volunteers meet their desire for helping the organization. To retain volunteers the university needs better training programs, a more flexible volunteer work schedule, and more recognition ceremonies. This study has implications for any institution that uses volunteer support to accomplish its mission.
DACUM as a Model for Horticulture Curriculum Development and Revision: A Case Study
Authors: Halbrooks Mary C.
Published: December 2018

DACUM (develop a curriculum) was implemented at Kent State University (KSU) to develop and revise curricular content of an associate degree program in horticulture technology. Initially, at KSU-Salem in 1990, a committee followed a typical DACUM process to develop a skills profile for the horticulture technology worker. The skills profile consisted of terminal and intermediate learning objectives that served as the content of basic data sheets for thirteen new courses in horticulture technology. This associate degree program was initiated at Salem in 1991 and offers three concentration areas: landscape management, turfgrass management, and arboriculture. Later, when a proposed new program offering was considered at KSU-Geauga, a modified DACUM process was implemented to develop a new skills profile that refl ected both general knowledge areas of horticultural and business practices and industry-spe- cific competency areas. Comparison of the two curricula revealed similarities between the two skills profiles. This led to the recommendation that the original curriculum also be offered at KSU-Geauga campus with two differences: 1) omit the arboricul- ture concentration, and 2) consider a new concentration in greenhouse and nursery operations in the future. The associate degree program in horticulture technology at the KSU-Geauga campus began in 1999. The DACUM process, by involving members of the horticultural industry in the curricular development process, provided several long-term benefits and a high level of cooperation between industry leaders and KSU-Geauga.
Effectiveness of Various Iron Sources for Correcting Iron Chlorosis in Dwarf Ixora
Authors: Broschat Timothy K.
Published: December 2018

`Petite Yellow' dwarf ixoras (Ixora spp.) were grown in an alkaline substrate (3 limestone gravel: 2 coir dust) or a poorly aerated composted seaweed substrate to induce iron (Fe) chlorosis. Chlorotic plants were fertilized every 2 months with soil applications of 0.1 g (0.0035 oz) Fe per 2.4-L (0.63-gal) pot using ferrous sulfate, ferric diethylenetriaminepentaacetic acid (FeDTPA), ferric ethylenediaminedi-o-hydroxyphenylacetic acid (FeEDDHA), Hampshire Iron (FeHEDTA plus FeEDTA), ferric citrate, iron glucoheptonate, or DisperSul Iron (sulfur plus ferrous sulfate). Additional chlorotic ixoras growing in a substrate of 3 sedge peat: 2 cypress sawdust: 1 sand were treated every 2 months with foliar sprays of Fe at 0.8 g·L-1 (0.11 oz/gal) from ferrous sulfate, FeDTPA, FeEDDHA, ferric citrate, or iron glucoheptonate. Only chelated Fe sources significantly improved ixora chlorosis when applied to the soil, regardless of whether the chlorosis was induced by an alkaline substrate or a poorly aerated one. As a foliar spray, only FeDTPA was effective in improving chlorosis in dwarf ixora. Leaf Fe content either showed no relationship to plant color or was negatively correlated with plant chlorosis ratings.
Yield Potential of Selected Medicinal Herbs Grown at Three Plant Spacings in New Mexico
Authors: Kleitz Kathryn M. , Wall Marisa M. , Falk Constance L. , Martin Charles A. , Guldan Steven J. , Remmenga Marta D.
Published: December 2018

Field studies were conducted to determine the production potential of echinacea (Echinacea purpurea), valerian (Valeriana officinalis), mullein (Verbascum thapsus) and yerba mansa (Anemopsis californica) medicinal herbs at two sites in New Mexico. Las Cruces, N.M., is at an elevation of 3,891 ft (1,186 m) and has an average of 220 frost free days per year, whereas Alcalde, N.M., is at an elevation of 5,719 ft (1,743 m) and averages 152 frost-free days per year. In-row plant spacings of 12, 18 and 24 inches (30.5, 45.7, and 61.0 cm) were compared at both locations. The corresponding plant densities for the 12, 18 and 24 inch spacings were 14,520 plants/acre (35,878 plants/ha), 9,680 plants/acre (23,919 plants/ha), and 7,260 plants/acre (17,939 plants/ha), respectively. Data were collected on growth rates, fresh yield, and dry yield for the herbs grown at each site. All crops at both sites had highest plot yields at the 12-inch spacing, suggesting that optimum in-row plant spacings are at or below the 12-inch spacing. Yields of 1.94 ton/acre (4.349 t·ha-1) of dried yerba mansa root, 0.99 ton/acre (2.219 t·ha-1) of dried echinacea root, and 2.30 ton/acre (5.156 t·ha-1) of dried mullein leaves were realized at the 12-inch spacing at Las Cruces in southern New Mexico. Yields of 1.16 ton/acre (2.600 t·ha-1) of dried valerian root, 0.93 ton/acre (2.085 t·ha-1) of dried echinacea root, and 0.51 ton/acre (1.143 t·ha-1) of dried mullein leaves were harvested at the 12-inch spacing at Alcalde in northern New Mexico. Yields of fresh echinacea flowers were 1.56 ton/acre (3.497 t·ha-1) in Las Cruces. Yields of dried mullein flowers were 0.68 ton/acre (1.524 t·ha-1) in Las Cruces and 0.66 ton/acre (1.479 t·ha-1) in Alcalde.
Apple Micrografting Protocol to Establish Transgenic Clones on Field Ready Rootstock
Authors: Lane W. David , Bhagwat Basdeo , Wahlgren Susan , Armstrong John D.
Published: December 2018

A protocol for micrografting shoot tips harvested from in vitro shoot cultures directly to transplanted rootstock plants in the greenhouse was developed. Shoot tips of the apple (Malus domestica) cultivars Golden Delicious, Granny Smith and Fuji clone, Nagafu12, were harvested, stored in a water bath then prepared for grafting by cutting the stem immediately below the tip into a wedge shape leaving the tip approximately 3 mm (0.12 inch) long. The rootstock cultivar, Malling 9 (M.9) (M. domestica), was prepared by cutting into a young fast growing side branch to expose the cambium, creating a pocket into which the shoot tip was inserted. The cut section of the tip was oriented so as to contact the exposed rootstock cambium and was held in place by wrapping with a strip of pliable plastic film. Two weeks later the wrapping was loosened and the grafted branch cut back. Side branches of the rootstock were not removed until later in order to support rootstock growth. The scion shoots developed into nursery whips suitable for transplanting to a screen house or field after 2 months. The protocol proved to be a simple efficient way to rapidly grow nursery trees from tissue culture clones developed in genetic modification experiments and was used to propagate several hundred plants. Grafting success was often 100% but was reduced if quality of shoot tips was poor due to injury indicated by brown tip color. The protocol eliminates the steps of rooting, acclimatizing and growing shoots into plants to serve as a scion wood source.
Soil Depth and Tillage Effects on Dry Bean Production
Authors: Russo V.M.
Published: December 2018

The effects of soil depth on yields of dry bean (Phaseolus vulgaris) produced under different types of tillage is not well understood. Black and pinto bean yields were evaluated under conventional and reduced-tillage for 2 years in a 3.24-ha (8-acre) commercial field in southeastern Oklahoma. Before planting, a grid pattern was laid out on the field with points at every 13.7 m (45.0 ft) north to south and 6.1 m (20.0 ft) east to west. Samples were taken at each intersection of the grid lines (496 sites) to determine pH, and the amounts of nitrogen, phosphorus, and potassium present in soil. Depth to an impervious clay pan was determined at these sites, and were grouped as being one of the following: <25 cm (9.8 inches), >25 to 50 cm (19.7 inches), >50 to 75 cm (29.5 inches) and >75 cm. Irrigation was supplied, if needed, at 50% flowering and, in both years, at 50% pod set. There was no significant effect on yield due to year. Black bean yields from conventional tillage averaged 1166 kg·ha-1 (1040.4 lb/acre) across soil depths and were better than yields from reduced-tillage which averaged 136 kg·ha-1 (121.3 lb/acre). Pinto bean yields from conventional tillage were 611 kg·ha-1 (545.2 lb/acre) across soil depths and were better than for reduced tillage, which averaged 403 kg·ha-1 (359.6 lb/acre). Yields generally were reduced as soil depth increased regardless of tillage type. The reduction in input for reduced-tillage would not compensate for the reduced yields for plants grown on the most productive soil depths.
Peel Injury on `Marsh' Grapefruit from Quaternary Ammonia
Authors: Ritenour Mark A. , Ng-Sanchez Teofilo , Kelsey D. Frank
Published: December 2018

Quaternary ammonia (QA) has been used on equipment and fruit bins in Florida to reduce the risk of spreading citrus canker. This study was initiated to understand the cause of a previously unknown peel injury believed to be associated with QA residues. Symptoms of QA injury on `Marsh' grapefruit (Citrus paradisi) usually developed within 24 to 36 h of contact with QA and ranged in severity from very slight discoloration to severe, dark brown, necrotic peel tissue that collapsed to form large sunken areas. Placing fruit in 10 mL (0.34 floz) of ≥100 mg·L-1 (ppm) fresh QA solution caused moderate to severe peel injury. Drying the QA solutions on polystyrene petri dishes and then redissolving the residue with 10 mL deionized water before fruit contact resulted in essentially the same degree of peel injury as contact with fresh QA solutions. Peel injury on early (November) or late-season (April) grapefruit also occurred when fruit were placed on a thin film of QA solution left on polystyrene petri dishes after dipping the dishes in ≥300 mg·L-1 QA solutions or if fruit themselves were dipped in QA solutions ≥500 mg·L-1. No significant peel injury occurred when dipping solutions contained only water with 200 mg·L-1 chlorine, 0.025% (v/v) Triton N-101, or a combination of both.
Effect of Humic Acids on Growth of Annual Ornamental Seedling Plugs
Authors: Evans M.R. , Li G.
Published: December 2018

The annual bedding plants `Dazzler Rose Star' impatiens (Impatiens wallerana), `Cooler Blush' vinca (Catharanthus roseus), `Orbit Cardinal' geranium (Pelargonium × hotorum), `Janie Bright Yellow' marigold (Tagetes patula) and `Bingo Azure' pansy (Viola tricolor) were grown on germination papers treated with deionized water (DI), 2500 or 5000 mg·L-1 (ppm) humic acid (HA) or nutrient control (NC) solutions. Seedlings grown on HA-treated germination papers had higher dry root weights than those grown on DI or NC-treated germination papers. Except for impatiens, seedlings germinated on HA-treated germination papers had higher lateral root numbers and higher total lateral root lengths than those grown on DI and NC-treated germination papers. Impatiens grown on NC-treated germination papers had higher lateral root numbers than those grown on DI or HA-treated germination papers. Overall, lateral root numbers for impatiens were higher for seedlings germinated on HA-treated papers than DI or NC-treated papers and highest lateral root numbers occurred on those impatiens germinated on papers treated with 5000 mg·L-1 HA. Except for geranium, seedlings grown in HA-amended sphagnum-peat-based substrates had similar dry root and dry shoot weights as those grown in unamended substrates. Geranium seedlings grown in HA-amended sphagnum peat-based substrates had significantly higher dry root weights than those grown in unamended substrates. However, dry shoot weights of geranium grown in HA-amended sphagnum peat-based substrates were similar to those grown in unamended substrates.
Biodegradable Mulch Films for Weed Suppression in the Establishment Year of Matted-row Strawberries
Authors: Weber C.A.
Published: December 2018

Adequate weed control in the establishment year of matted-row strawberries (Fragaria × ananassa) is crucial for the long-term viability of plantings. Suppression of weed growth until the new strawberry plants are established and runners rooted is an effective strategy in new plantings. Three biodegradable mulch films were compared to standard weed control for establishing matted-row strawberries. Two films were test products using a biodegradable polymer, either clear or black, covering brown 40-lb kraft paper (IP40 Clear and IP40 Black, respectively). The third material was Planters paper, a black paper mulch. The films were evaluated for weed suppression, rate of degradation and effects on runner production and fruit yield. Additionally, the ability of runners that were formed to root as the film degraded was also observed. The IP40 Black mulch reduced the number of weeds compared to the standard control but did not degrade quickly enough for runners to root. The Planters paper also had fewer weeds, but it degraded quickly along the edges where it was covered by soil. This allowed the wind to tear it and blow large pieces off the plots. The IP40 Clear degraded in a timely manner and allowed runner rooting, but it was not acceptable as a weed suppression material. The IP40 Black and Planters paper mulches were effective for weed control in the establishment year, but rate of degradation was too slow in the former case and too fast in the latter. Runner production and fruit yield were not affected by any of the mulch materials compared to standard control.
Managing Orchard Floor Vegetation in Flood-irrigated Citrus Groves
Authors: Wright Glenn C. , McCloskey William B. , Taylor Kathryn C.
Published: December 2018

Several orchard floor management strategies were evaluated beginning in Fall 1993 in a `Limoneira 8A Lisbon' lemon (Citrus limon) grove on the Yuma Mesa in Yuma, Ariz. and in a `Valencia' orange (Citrus sinensis) grove at the University of Arizona Citrus Agricultural Center, Waddell, Ariz. At Yuma, disking provided acceptable weed control except underneath the tree canopies where bermudagrass (Cynodon dactylon), purple nutsedge (Cyperus rotundus), and other weed species survived. Mowing the orchard floor suppressed broadleaf weed species allowing the spread of grasses, primarily bermudagrass. Preemergence (norflurazon and oryzalin) and postemergence (glyphosate and sethoxydim) herbicides were used to control weeds in the clean culture treatment in Yuma. After three harvest seasons (1994-95 through 1996-97), the cumulative yield of the clean culture treatment was 385 kg (848.8 lb) per tree, which was significantly greater than the 332 kg (731.9 lb) and 320 kg (705.5 lb) per tree harvested in the disking and mowing treatments, respectively. In addition, the clean culture treatment had a significantly greater percentage of fruit in the 115 and larger size category at the first harvest of the 1995-96 season than either the disk or mow treatments. At Waddell, the management strategies compared were clean culture (at this location only postemergence herbicides were used), mowing of resident weeds with a vegetation-free strip in the tree row, and a `Salina' strawberry clover (Trifolium fragiferum) cover crop with a vegetation-free strip. The cumulative 3-year yield (1994-95 through 1996-97) of the clean culture treatment was 131 kg (288.8 lb) per tree, which was significantly greater then the 110 kg (242.5 lb) per tree yield of the mowed resident weed treatment. The yield of the strawberry clover treatment, 115 kg (253.5 lb) of oranges per tree, was not significantly different from the other two treatments. The presence of cover crops or weeds on the orchard floor was found to have beneficial effects on soil nitrogen and soil organic matter content, but no effect on orange leaf nutrient content. The decrease in yield in the disked or mowed resident weed treatments compared to the clean culture treatment in both locations was attributed to competition for water.
Exploring the Impact of Outdoor Environmental Activities on Children Using a Qualitative Text Data Analysis System
Authors: Waliczek T.M. , Logan P. , Zajicek J.M.
Published: December 2018

The main objective of this study was to investigate the impact of an outdoor environmental program, Math and Science in the Outdoor Classroom, on elementary grade students' creative and critical thinking, and attitudes toward math and science. Math and Science in the Outdoor Classroom is an on-campus nature program in Santa Fe, N.M. Students participated in half-day programs focusing on topics such as water, insects, soil, and weather. Twenty-one teachers from five schools volunteered 175 second through sixth graders to participate in the program and research study. Surveys were administered to students, teachers, and volunteers after completion of the program. Interview data was analyzed using QSR NUD*IST (Nonnumerical Unstructured Data Indexing Searching and Theory-building) computer-assisted qualitative data analysis system to examine respondents' perceptions of the program using Bloom's taxonomy as a theoretical framework. Results indicated that students not only learned math and science at the lower levels of Bloom's taxonomy, but were also thinking at the higher levels of synthesis and evaluation within the framework.
Influence of Seed Germination Percentage and Number of Seeds Sown per Cell on Expected Numbers of Seedlings in Plug Trays
Authors: Boyle Thomas H.
Published: December 2018

Binomial probability distributions were used to determine the effects of percent seed germination and number of seeds sown per cell on expected numbers of seedlings in plug trays. Expected numbers of empty cells in five types of plug trays (128, 273, 338, 406, and 512 cells/tray) were calculated for cases where one to seven seeds were sown per cell and seed germination ranged from 50% to 95%. Generally, one additional seed was required per plug cell for each 10% decrease in the germination percentage in order to attain the same number of filled cells per plug tray. Expected frequencies were calculated for the number of seedlings in plug trays when one to five seeds were sown per cell and seed germination ranged from 50% to 95%. When the number of seeds sown per cell remained constant, uniformity in seedling number per cell increased as the germination percentage increased. When percent seed germination remained constant and the number of seeds sown per cell was increased, the percentage of cells with at least one seedling increased, whereas the uniformity in seedling number per cell decreased. Additional examples are presented in the article on the utility of binomial distributions in determining expected number of seedlings.
Economic Analysis of Aldicarb on Citrus in the Indian River Area in Southeastern Florida
Authors: Blakeley Lindsey , Weldon Richard , Fairchild Gary
Published: December 2018

Aldicarb is a pesticide used on several crops to control citrus rust mite (Phyllocoptruta oleivors), citrus nematode (Tylenchulus semipenetrans) and other citrus pests. Analysis of previous research experiments indicates that this pesticide is beneficial to both orange (Citrus sinensis) and grapefruit (Citrus parasisi) production and that both cost savings and higher yields can be experienced in many types of groves. Actual grove data shows that net returns for mature grapefruit that receive aldicarb can be $500/acre ($1235/ha) greater than net returns for identical acreage that uses other pest control options. Also, based on grove reset data, it is shown that with an application of aldicarb the resulting increased yields for 3-year-old trees more than cover the additional cost of applying the aldicarb.
Freeze Damage to North American Ginseng
Authors: Schooley Jan , Proctor John T.A.
Published: December 2018

The Lake Erie counties of southern Ontario, Canada are the major producers of ginseng (Panax quinquefolius) in North America. In this area there is about 1740 ha (4299.5 acres) of ginseng and an annual production of 1455 t (1603.8 tons). Spring freeze damage to the crop is rare as the mean date of last freeze in spring is 12 May. On 21 May 2002, following three to six nights when air temperatures dropped below freezing, extensive damage to the crop was evident. A survey by the Ontario Ginseng Growers Association showed that 78% of growers had gardens showing freeze damage. The extent of the damage was variable across the growing area, and on individual farms. Most damage to plants occurred in low-lying areas where heavy cold air collected. Recently germinated seedlings that were exposed above the straw mulch were severely damaged, and many did not survive because they did not have leaves and no perennating bud was formed. Damage to 2-year-old plants was expressed as leaves wilting and turning black. In some cases stems froze and the plants toppled. In 3-year-old and older plants, damage was variable with some leaf collapse and stems broken, or damaged with corking-over taking place. Damage to inflorescences ranged from death and abscission, to distorted flowers and shriveled and split peduncles. Plant health was a concern following the freeze episode, and throughout the subsequent growing season. The fungicide fenhexamid received emergency registration to combat recurring problems in Botrytis control. The seed crop for 2002 was light. Damaged seedling gardens were replanted. Older gardens will undergo a period of adjustment. Root yield in 2002 was reduced by 30%, a 500 t (551.1 tons) loss. The full extent of the damage and associated financial implications are unknown and could impact the industry until 2005.
Red-skinned, Fresh-market Potato Varieties for Northeastern Florida Production
Authors: Hutchinson C.M. , White J.M. , Haynes K.G. , Gergela D.M. , Solano P.A. , Lippi C.S.
Published: December 2018

Potato (Solanum tuberosum) is an important agricultural crop for Florida. From 1996 to 2000, the winter and spring potato crop was grown on an average of 15,782.7 ha (39,000 acres) and valued at $117 million. Variety evaluation and selection is an important tool to improve production efficiency and increase the competitiveness of Florida growers. A red-skinned potato variety evaluation was conducted in northeastern Florida in 2002. The experimental design was a 4 (site) × 5 (variety) factorial with four replications at each site. The four sites were the University of Florida's Plant Science Research and Extension Unit and three local commercial farms. Potato varieties in the trial were `Red LaSoda', `LaRouge', B0984-1, B1145-2, and B1758-3. Marketable tuber yields were 36.3, 35.6, 30.2, 20.3, and 21.4 t·ha-1 (324, 318, 269, 181, and 191 cwt/acre) respectively, with tuber yields of the two named varieties significantly higher than the numbered entries. Specific gravity ranged from 1.060 (`Red LaSoda') to 1.070 (B0984-1). There were no significant differences among entries for total cull weight or the incidence of hollow heart, brown rot, or corky ringspot. However, a higher percentage of B0984-1 tubers showed symptoms of internal heat necrosis than all other varieties. Potato varieties ranked from lowest to highest in overall appearance were `LaRouge', `Red LaSoda', B1758-3, B0984-1, and B1145-2. Higher appearance ratings in the numbered entries were attributed to darkerred skin color, rounder tuber shape, and shallower eyes compared to `Red LaSoda' and `LaRouge'. `Red LaSoda' and `LaRouge' will continue to be recommended as the standard redskinned potato varieties for Florida. However, B0984-1 and B1145-2 had desirable characteristics and should be planted in larger plantings to further evaluate quality and production characteristics.
Performance of Chip Processing Potato Varieties in Northeastern Florida
Authors: Hutchinson C.M. , White J.M. , Gergela D.M. , Solano P.A. , Haynes K.G. , Wenrich R. , Lippi C.S.
Published: December 2018

Potato (Solanum tuberosum) is a high value crop in Florida. It consistently ranks in the top five valued vegetable crops produced in the state. The identification of new potato varieties that improve production efficiency is an imperative because of constantly evolving market and production demands. A chip potato variety evaluation experiment was conducted in northeast Florida in 2002 to compare the production characteristics of industry standards to advanced selections. The potato varieties evaluated in this experiment were bred specifically for processing by the potato chip industry. The experimental design was a four (site) by five (variety) factorial with four replications at each site. The sites were the University of Florida's research farm in Hastings, FL and three commercial farms in the surrounding area. Potato varieties were two seed sources of `Atlantic', as well as, `Snowden', B0564-8, and B0766-3. Marketable yield for each variety was 39.4, 33.4, 38.4, 33.6, and 33.6 t·ha-1 (351, 298, 343, 300, and 300 cwt/acre), respectively. Total yield of B0564-8 was statistically equivalent to an `Atlantic' standard at all four locations and similar to `Snowden' at three of four locations. Specific gravity of B0564-8 and B0766-3 was significantly lower than that of `Atlantic' from both sources but within acceptable range for chip potatoes. B0564-8 tubers had the highest overall appearance ratings and the most consistent size and shape. B0564-8 and B0766-3 tubers had a significantly lower percentage of hollow heart and internal heat necrosis than `Atlantic' tubers. This resulted in overall better chip ratings for the numbered entries compared to `Atlantic' tubers. A potential fit for B0564-8 and B0766-3 in northeastern Florida production may be as a late season chip variety when the potential for the development of internal heat necrosis increases.
Field Application of Chelated Calcium: Postharvest Effects on Cantaloupe and Honeydew Fruit Quality
Authors: Lester Gene E. , Grusak Michael A.
Published: December 2018

Commercially grown honeydew fruit (Cucumis melo Inodorus group) and netted cantaloupe fruit (C. melo Reticulatus group) in low-humidity regions of the U.S. are typically field packed, eliminating the possibility for postharvest chelated-calcium dip treatments to extend fruit shelf life. In this study, calcium treatments were applied to orange-flesh honeydew fruit commercially grown in 2001 and 2002 in Sacramento Valley, Calif. and orange-fleshed netted cantaloupe fruit commercially grown in 2002 in Imperial Valley, Calif., and Rio Grande Valley, Texas. Aminoacid-chelated calcium and mannitol-complexed calcium compounds were applied to field-grown plants at the rate of 2.3 L·ha-1 (1 qt/acre) at 0, 1, 2, or 4 total applications during growth of honeydew and cantaloupe fruit. Applications were A) at female flowering, B) within 15 days (cantaloupe) or 20 days (honeydew) after flowering, C) within 30 days (cantaloupe) or 40 days (honeydew) after female flowering, and/or D) within 3 to 5 days before abscission. One application equaled (A) or (D), two applications equaled (A + B) or (C + D) and four applications equaled (A + B + C + D). Evaluations of fully abscised fruit were exterior and interior firmness, marketability, calcium concentrations, interior soluble solids concentration (sugars), and consumer preference (taste) following harvest and up to 3 weeks commercial/retail storage. Cantaloupe fruit at both locations did not appear to benefit from preharvest plant applications of calcium when compared to fruit from plants treated with water. Honeydew fruit, however, did and the benefit was observed both years. Honeydew fruit that received four preharvest plant applications of calcium, regardless of source, were generally superior in firmness, marketability, and had a higher calcium concentration than fruit from plants receiving water or one or two applications of calcium. Fruit sugars and taste were not affected by preharvest plant applications of calcium.
Assessing the Efficacy of Preharvest Fungicide Applications to Control Postharvest Diseases of Florida Citrus
Authors: Ritenour Mark A. , Pelosi Robert R. , Burton Michael S. , Stover Eddie W. , Dou Huating , McCollum T. Gregory
Published: December 2018

Studies were conducted between November 1999 and April 2003 to evaluate the effectiveness of compounds applied preharvest for reducing postharvest decay on many types of fresh citrus (Citrus spp.) fruit. Commercially mature fruit were harvested two different times after the compounds were applied, degreened when necessary, washed, waxed (without fungicide), and then stored at 50 °F (10.0 °C) with 90% relative humidity. Compared to control (unsprayed) fruit, preharvest application of benomyl or thiophanate-methyl resulted in significantly (P < 0.05) less decay of citrus fruit after storage in nine out of ten experiments, often reducing decay by about half. In one experiment, pyraclostrobin and phosphorous acid also significantly decreased total decay by 29% and 36%, respectively, after storage compared to the control. Only benomyl and thiophanate-methyl significantly reduced stem-end rot (SER; primarily Diplodia natalensis or Phomopsis citri) after storage, with an average of 65% less decay compared to the control. Though benomyl significantly reduced anthracnose (Colletotrichum gloeosporioides) in two of four tests with substantial (>20%) infection and phosphorous acid significantly reduced it once, thiophanate-methyl did not significantly reduce the incidence of anthracnose postharvest. The data suggests that preharvest application of thiophanate-methyl may reduce postharvest SER and total decay similar to preharvest benomyl treatments.
Hedge Pruning Pecan
Authors: Wood Bruce W. , Stahmann Deane
Published: December 2018

An ever increasing cost:price squeeze on the profitability of pecan (Carya illinoinensis) farming is driving a search for alternate husbandry approaches. `Wichita' and `Western' trees maintained at relatively high tree population density, by mechanized hedge pruning and topping, produced greater nut yield than an orchard treatment in which tree population density was reduced by tree thinning (144% for `Wichita' and 113% for `Western Schley'). Evaluation of three different hedge pruning strategies, over a 20-year period, identified a discrete canopy hedge pruning and topping strategy using a 2-year cycle, as being superior to that of a discrete canopy hedge pruning and topping strategy using an 8-year cycle, but not as good as a continuous canopy hedge pruning and topping strategy using a 1-year cycle. An evaluation of 21 commercial cultivars indicated that nut yields of essentially all cultivars can be relatively high if properly hedge pruned [annual in-shell nut yields of 2200 to 3626 lb/acre (2465.8 to 4064.1 kg·ha-1), depending on cultivar]. Comparative alternate bearing intensity and nut quality characteristics are reported for 21 cultivars. These evaluations indicate that pecan orchards can be highly productive, with substantially reduced alternate bearing, when managed via a hedge-row-like pruning strategy giving narrow canopies [3403 lb/acre (3814.2 kg·ha-1) for `Wichita' and 3472 lb/acre (3891.5 kg·ha-1) for `Western Schley']. North-south-oriented (N-S) hedgerows produced higher yields that did east-west (E-W) hedgerows (yield for N-S `Wichita' was 158% that of E-W trees and N-S `Western Schley' was 174% that of E-W trees).

These data indicate that mechanized hedge pruning and topping offers an attractive alternative to the conventional husbandry paradigm.
Balancing Landscape Preferences and Water Conservation in a Desert Community
Authors: Spinti Jane E. , St. Hilaire Rolston , VanLeeuwen Dawn
Published: December 2018

We surveyed homeowners with residential landscapes in Las Cruces, N.M., to determine design features participants valued in their landscapes, their attitudes toward the landscape use of desert plants and opinions on factors that would encourage respondents to reduce landscape water use. We also determined whether the willingness to use desert plants in their landscapes related to the length of residency in the southwestern United States. At least 98% of respondents landscaped to enhance the appearance of their home and increase their property value. About half (50.6%) of the participants strongly agreed or agreed that the main reason to landscape was to display their landscape preferences. Many participants indicated they would use desert plants to landscape their front yard (80.3%) and back yard (56.3%), but relatively lower percentages of participants actually had desert landscapes in their front yard and back yard. Regardless of their property value, respondents were more likely to use desert plants in their backyard the shorter their stay in the desert. Data revealed that participants rank water shortages as the factor that would most likely cause them to reduce the amount of water they applied to their landscapes. We conclude that homeowners report willingness to use desert plants but desert-type landscapes are not a widespread feature of managed residential landscapes. Furthermore, water shortages and the length of time respondents spent in a desert environment would most likely influence water use in their landscapes.
Establishing Hard Fescue from Sod
Authors: Harivandi M. Ali , Hagan William L. , Mousli M. Zak , Wu Lin
Published: December 2018

Stand establishment of direct-seeded hard fescue (Festuca longifolia) is slow. Sodding could speed establishment in landscape plantings. This study looked at the effects of two sod thicknesses and different rates of nitrogen fertilization before and after sodding, on stand establishment and overall turf quality. Evaluations 2, 4 and 8 weeks after sodding assessed rooting and overall turf quality. Thicker sod showed better rooting 4 weeks after planting; after 8 weeks, rooting of both thicknesses was similar. Nitrogen fertilization before or after sodding did not affect rooting. More nitrogen led to better overall turf quality up to 4 weeks after planting; however, this quality difference disappeared 8 weeks after sodding.
The Virginia Commercial Greenhouse Industry—Current Practices and Future Needs Assessment
Authors: Scoggins Holly L. , Latimer Joyce G. , Barden Victoria T.
Published: December 2018

This report summarizes responses to a survey of Virginia's commercial greenhouse industry, conducted in 2000-01. The survey included questions about interests and needs of growers to assist Virginia Tech Horticulture faculty and staff in planning educational and research programming. Respondents were asked about current cultural practices, future plans for automation and technology, and impact of issues facing the greenhouse industry such as regulations and labor. The 273 responses were categorized based on the amount of heated greenhouse space: small, medium, large, or other (including part-time). Following analysis of the responses, focus groups were conducted across Virginia to further discuss issues raised in the survey.
Changing Content of the Nursery Grower's Sales Agreement
Authors: Hinson Roger A. , Navajas Roberto
Published: December 2018

Terms of sale can affect nursery growers' costs. Terms typically have included price, quantity, and quality, but others may be added when growers sell to large customers. Because the industry is very competitive, growers are hesitant to turn down a sale simply because they are asked to pay another cost or provide another service. For this study, a list of items that might be in the terms of sale was developed. Growers were surveyed to determine which of these items were included in the agreement in 1996 and 2001. McNemar's test was used to determine whether proportions of items being added to the agreement were significantly different from items being removed when considering the mass merchandiser and the garden center market channels. Five of the items had significantly more additions to the terms of sale for mass merchandisers, contrasted to four for the garden center channel. Two of these items, apply barcode stickers and continuous inventory replenishment, were significant for both channels. The other significant items for the mass merchandiser channel were provide custom containers, provide returnable shipping equipment, and take back unsold merchandise. These are items can that enhance competitive position and provide cost savings. For garden centers, the other two items with significantly different proportions were attach product information tags, which is a service demanded by consumers, and provide minimum volume, which can reduce the number of suppliers needed in this channel.