ASHS HortBase provides opportunities for change—change in how we author and deliver information to meet the needs of the inquirer for 24-hour access to specific, concise information for planning and decision support; change from individual autonomy to global collaboration to meet more economically the increasing needs for quality horticultural information with decreasing resources; change, by adding ASHS peer review, to meet the inquirer's need for validated information and to strengthen the educator's efforts in developing scholarly, shared information resources; change to strengthen the interaction between the educator and inquirer; change to broaden and enhance ASHS's role in providing validated, up-to-date horticultural information. HortBase is a service that ASHS is uniquely qualified to provide to its members and to worldwide horticultural inquirers. HortBase's unique characteristic is the dynamic pool of ASHS members who will serve as volunteer authors and reviewers, as well as users of HortBase. ASHS members will be the continuous infrastructure to sustain HortBase and to ensure its continuous evolution and renewal.
James L. Green
James L. Green
Since initiation of the research in 1990, diverse plants (92 genera from 47 families) have been grown in the closed, insulated pallet system (CIPS). Greater growth has occurred in various embodiments of the CIPS than in the open container system (OCS) controls. Branching of roots, and of shoots of some plants, is greater in CIPS. CIPS is a closed system; there is no circulation of irrigation solutions nor effluent discharge from CIPS. Water and fertilizer movement in CIPS is plant-driven, and use is 10% of that applied in overhead sprinkler fertigation of open containers. Tomato plants are more tolerant of saline irrigation water, and greenhouse tomato production is more profitable in CIPS than in the OCS. CIPS provides several pest management alternatives.
James L. Green
In intensive, open horticultural crop production systems, quantities of water and soluble fertilizers are convected by gravitational and evaporative flow through the plant root zone, with only a small fraction being captured by the plant root system. Principles and concepts developed in creating a protected diffusion zone (PDZ) within the closed, insulated pallet system (CIPS) have been extrapolated to create a protected zone for fertilizer diffusion in a surface-irrigated plant container or open field/landscape planting. Incorporating additional evaporative and gravitational water flow barriers has resulted in a semiclosed field system to minimize quantities of water and fertilizer applied and lost from the plant root zone. Use of saline water is more feasible in PDZ system than in open systems.
Edward F. Gilman and James L. Green
Electronic information systems provide efficient information management—development, updating, storage, retrieval, and delivery. No more stockpiling of printed, going-out-of-date information when specific, concise, up-to-date information can be obtained just in time from the Internet. Authoring for electronic media is different than authoring for the printed page. To use unique characteristics of electronic information systems, information is presented in chunks, small units of information that can combine text, video, or sound to present one concept or to answer one question. A chunk may be linked to other chunks to provide definitions and further elaboration of terms or ideas. A chunk may be linked to related chunks to provide comprehensive information inquiry-driven by and tailored to the inquirer's interests and understanding. A chunk may be linked to other chunks to provide definitions and further elaboration of terms or ideas. Collaboration is facilitated by the World Wide Web (Web). Shared development reduces redundant efforts and costs and results in better products than can be produced by autonomous efforts. Continual, shared development and updating keep the individual chunks and the linked chunks (URLs) up-to-date and dynamic. Educators can thread (link) selected web modules or chunks (URLs) together into dynamic study assignments or dynamic textbooks for courses of study. To obtain the best of both media, CD-ROM software can be designed to interact with a Web site. The ways that CD-ROM and online are interacting are varied and evolving. Graphics-rich databases such as color photographs of plants or pests and related text that do not require continual updating are well suited to CD-ROM. Web links from the CD-ROM to additional, dynamic information and updates at the Web site keep the CD-ROM live and current. ASHS members are uniquely qualified to generate continually updated, peer-reviewed horticultural information on the web for continuous access by the interested learner whose pathway on the web will be inquiry-driven.
Mohammed S. Albaho and James L. Green
To determine its effect on salinity of the growth medium and on tomato (Lycopersicon esculentum Mill.) growth and yield, the halophyte Suaeda salsa (L.) Pallas, or seepweed, was planted as a companion plant in the closed insulated pallet system (CIPS). In this production system, water moves from a bottom reservoir through capillary wicks to the medium in the root pouch in response to plant uptake. Fertilizers are placed at the top surface of the root matrix, so nutrient ions move downward to the roots by chemical ion diffusion to establish relatively stable chemical gradients within the matrix. Plants were subjected to capillary subirrigation water containing 0 or 4 g·L–1 NaCl. Sodium (Na+) concentration of the root medium at termination was 50% lower when S. salsa was grown in the same pouch with tomato. Sodium concentration was also significantly less in the tomato foliage, but S. salsa did not prevent suppression of growth of tomato plants by NaCl. Suaeda salsa plants reduced blossom end rot of tomato fruit but did not significantly affect fruit weight, number or yield.
James L. Green, James A. Robbins and Bruce A. Briggs
A closed, insulated, pallet production system (CIPPS) has been designed to meet current challenges: 1) Elimination of production related pollution. 2) Reduction and conservation of resources. 3) Improvement of working conditions. 4) Alternatives to pesticides. 5) Prevention of temperature extremes and rapid temperature fluctuations in the plant environment. Biological feasibility of CIPPS was established in research on pathogen epidemiology, water and fertilize efficiency, plant growth and development in CIPPS. Water and fertilizer ion movement-removal in the closed system was plant-driven in response to growth and transpiration; water and fertilizer use in CIPS was 10% of that applied to open containers. Growth of 28 plant species ranging from herbaceous annuals to woody perennials was greater in CIPPS than in control, individual containers. Phytophthora cinnamomi did not spread from inoculated to noninoculated plants within CIPPS. Inoculation with nonpathogenic bacteria increased plant growth (gfw) in CIPPS but not in open plant containers.
Robert L. Green, Ki S. Kim and James B. Beard
The objective of this study was to determine the effects of two plant growth regulators (PGR) and two soil moisture levels (SML) on the evapotranspiration (ET) rate, leaf extension rate (LER), and visual turfgrass quality of `Texas Common' St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] grown under glasshouse conditions in black plastic minilysimeters. Treatments included mefluidide at 0.42 kg·ha-1, flurprimidol at 0.84 kg·ha-1, and no PGR, each grown under optimal (– 0.01 MPa) or suboptimal (– 0.8 MPa) SML. Both flurprimidol and mefluidide significantly affected ET rate, LER, and turfgrass quality, whereas the durations of the responses to both PGR treatments were affected by SML. For both SML, the durations of significant reduction in ET rate, LER, and turfgrass quality were longer for flurprimidol than for mefluidide. Application of either PGR at either SML caused a significant reduction in ET rate averaging 18% and a significant reduction in LER averaging 83%. Flurprimidol was more effective than metluidide in terms of ET rate and LER reduction. However, the considerably longer duration of reduced turfgrass quality of flurprimidol-treated turf was a negative effect. Chemical names used: α-(1 -methylethyl)- α -[4-trifluoromethoxy)phenyl]-5-pyrimidinemethanol (flurprimidol) and N- [2,4-dimethyl-5-[[(trifluoromethyl) sulfonyl]amino]phenyI] acetamide (mefluidide).
Shaun F. Kelly, James L. Green and John S. Selker
The process of fertilizer diffusion was examined using KBr and NaBr salts placed at the top of columns filled with a container medium at an initial water content of 4.0, 2.5, or 1.0 g·g-1 (mass of water/mass of medium). Columns were sealed to create a protected diffusion zone (PDZ) shielding the system from water infiltration and evaporation. Bromide and water distributions were determined after 5, 10, 25, and 120 days. Using a Fickian diffusion model, effective diffusion coefficients calculated for Br- in the medium at 2.5 g·g-1 ranged from 2.7 to 4.6 × 10-6 cm2·s-1, which is 3 to 9 times less than the diffusion coefficient in water alone. Diffusion rates increased with increasing medium water content. Differences in the hygroscopicity and solubility of KBr and NaBr affected the distribution of water and diffusion rates in the columns. Redistribution of water was driven to a significant degree by vapor-phase transport, caused by large gradients in osmotic potential, and was most apparent at low water content. At high water content, water redistribution was affected by solution density gradients in the system. This significantly complicates the mathematical modeling of the system, which renders a simple Fickian diffusion model of limited predictive value in high and low water content media.
James L. Green, R.G. Linderman, B. Blackburn and K.A. Smith
Verticle gradients of moisture, salinity, specific fertilizer ions, and pH in the root zone in the closed, insulated pallet system (CIPS) are relatively stable compared with those in the open container system (OCS). Establishment of the VA mycorrhizal fungus Glomus intraradices and maintenance of the biocontrol fungus Trichoderma harzianum and the entomopathogenic nematode Steinernema carpocapsae were greater in CIPS than in control OCS. In CIPS, percent corn root length colonized by G. intraradices was greatest in roots in the top stratum of the root medium. Colonization was significantly greater in copper-coated root-containment pouches. Population maintenance in CIPS of T. harzianum, initially uniformly inoculated throughout the root medium, was highest in the top stratum of the root medium where K+ and
Milton E. McGiffen Jr., Robert L. Green, John A. Manthey, Ben A. Faber, A. James Downer, Nicholas J. Sakovich and Jose Aguiar
To test the usefulness of methanol treatments in enhancing yield and drought tolerance, we applied methanol with and without nutrients to a wide range of crops across California: lemon (Citrus limon L.), creeping bentgrass (Agrotis palustris Huds.), romaine lettuce (Lactuca sativa L.), carrot (Daucus carota L.), corn (Zea mays L.), wheat (Triticum aestivum L.), pea (Pisum sativum L.), and radish (Raphanus sativus L.). Environments included greenhouse and field tests in coastal, inland-valley, and desert locations. Methanol did not increase the yield or growth of any crop. In some cases, methanol caused significant injury and decreased yield.