Orchid cut flower industry has contributed substantially to the economy of Singapore, Thailand, Malaysia and other Asean countries. Singapore exports US$13 million dollar worth of orchid cut flower in 1990 and Thailand's export was at least 3 to 4 times higher. Germany and Japan are the major markets for tropical orchid cut flowers. Economically important orchid genera are Aranda, Dendrobium, Mokara, Oncidium and Vanda. This paper will review the agronomic practices in orchid cultivation, the current status and development of orchid industry and the research and development made towards the improvement of the orchid industry in Asean countries.
Lingxia Zhao, Chengxiang Qiu, Jingfu Li, Yourong Chai, Guoyin Kai, Zhugang Li, Xiaofen Sun and K.X. Tang
Solanum lycopersicoides is a valuable genetic resource for tomato (Lycopersicon esculentum) genetic improvement. However, there are few reports on its agronomic traits such as disease resistance and cold tolerance. In this paper, the resistance to cucumber mosaic virus (CMV) and leaf mold (Cladosporium fulvum Cooke) and cold tolerance of five lines of S. lycopersicoides were studied through investigation of disease inoculation and electrolyte leakage analysis. The results showed that S. lycopersicoides was highly resistant or immune to CMV and leaf mold and more tolerant to low temperature than L. esculentum. This study is helpful for the genetic improvement of tomato by using S. lycopersicoides as breeding materials.
Diego Barranco, Isabel Trujillo and Pilar Rallo
The cultivar Oblonga may have originated from a volunteer seedling at an orchard near Corning, Calif., about 1940. Its main virtue is its high degree of resistance to Verticillium dahliae. `Frantoio' is the main variety in Italy and has been planted worldwide because of its high content of top-quality oil. In the present study, we show that both cultivars have the same fifteen morphological and eight agronomical traits and both have amplified the same patterns for 22 RAPD primers and five SSRs. This indicates that `Oblonga' and `Frantoio' are probably the same cultivar.
J.G. Clapp Jr.
Urea-triazone-based nitrogen (N) solutions were evaluated for potential leaf injury on agronomic and horticultural crops at 61 commercial grower sites throughout the United States. Poliar spray solutions containing triazone N were used at concentrations ranging from 1.5% to 15.7%. Safe N concentrations for urea-triazone-based N products ranged from 1.5% for crops such as sweet corn, apple, cherry, and pear, and up to 15.7% for nursery root stocks. Urea-triazone-based N solutions were found to be much safer on crop foliage than ammonium-, nitrate-, and/or all urea-based foliar fertilizer products than reported in the literature.
Mohamed Benmoussa and Laurent Gauthier
To achieve high yield and better quality of soilless greenhouse tomato, it is necessary to keep the nutrient concentrations in the root environment at the target levels. Dynamic control of the nutrient solution composition can be used for this purpose. We developed a computer program that dynamically adjusts nutrient solution compositions based on various climatic and agronomic characteristics. The program integrates nutrient uptake and crop transpiration models and is part of a general-purpose greenhouse management and control software system developed at Laval University (GX). The architecture of the system and some simulation results comparing the effect of various control scenarios on the evolution of the composition of nutrient solutions are presented.
Mark e. Miller
Consumers of horticultural services deserve a standard to insure that practicing horticulturist have the necessary education, experience and continuing education to solve wide ranging problems from production horticulture to landscape management in an effective and environmentally conscious manner. A Certified Professional Sub-Board was established as a part of the American Registry of Certified Professionals in Agronomy, Crops, and Soils (ARCPACS) in November 1991. The ASHS support of certification of practicing horticulturist will primarily benefit those holding BS degrees. Forty percent of the American Society of Agronomy (ASA) 12,500 members highest earned degrees are BS and/or MS. By contrast only 5% of the 5,000 ASHS members are at the BS and/or MS levels. It is evident that ASA has been more perceptive of the needs of their undergraduate degree holders than ASHS. With the advent of CPH we can now begin to meet the needs of our BS and/or MS degree holders. Economic analysis reveals certification is beneficial to both the horticulturist and consumers.
Gary T. Roberson
Precision agriculture is a comprehensive system that relies on information, technology and management to optimize agricultural production. While used since the mid-1980s in agronomic crops, it is attracting increasing interest in horticultural crops. Relatively high per acre crop values for some horticultural crops and crop response to variability in soil and nutrients makes precision agriculture an attractive production system. Precision agriculture efforts in the Department of Biological and Agricultural Engineering at North Carolina State University are currently focused in two functional areas: site-specific management and postharvest process management. Much of the information base, technology, and management practices developed in agronomic crops have practical and potentially profitable applications in fruit and vegetable production. Mechanized soil sampling, pest scouting and variable rate control systems are readily adapted to horticultural crops. Yield monitors are under development for many crops that can be mechanically harvested. Investigations have begun to develop yield monitoring capability for hand harvested crops. Postharvest controls are widely used in horticultural crops to enhance or protect product quality.
Gary T. Roberson
Precision agriculture is a comprehensive system that relies on information, technology, and management to optimize agricultural production. While used for several years in agronomic crops, it is attracting increasing interest in horticultural crops. Relatively high per-acre crop values for some horticultural crops makes precision agriculture an attractive production system. Precision agriculture efforts in biological and agricultural engineering at North Carolina State Univ. are currently focused in two functional areas: site specific managment (SSM) and postharvest process managment (PPM). Much of the information base, technology, and management practices developed in agronomic crops have practical and potentially profitable applications in fruit and vegetable production. Mechanized soil sampling, and variable rate control systems are readily adapted to horticultural crops. Postharvest controls are widely used to enhance or protect product quality. These technologies and their applications will be discussed in this presentation. Yield monitors are under development for many crops that can be mechanically harvested. An overview of these developments will be discussed. In addition, low-cost technologies for entry into precision will be presented.
Juan Manuel González Gonzalez, Francisco Radillo Juarez, Marcelino Bazan Tene and Juan Carlos González Ramos
Soursop (Annonamuricata L.) is reproduced by seeds from `Criollo' cultivars in Mexico. The replication of desirable agronomic traits is difficult when selected plants are from sexual reproduction. The heterogeneity of plants is observed as taller trees, irregular fresh fruit yield, variable fruit quality, different insect pests, disease susceptibilities, and lower number of plants per hectare. There is an extended time period for recovering investments and commericialization problems due to fruit quality and price. Vegetative propagation is an alternative for reducing the heterogeneity of soursop trees. Three grafting methods were evaluated for propagating soursop in the dry tropic region of Colima, Mexico: 1) splice side graft; 2) wedge graft; and 3) bud graft. The experiment was carried out on the Tecoman Campus of the Universidad de Colima. Rootstocks were from 8-month-old healthy plants, 1-m tall and 1-cm diameter, obtained from `Criollo' seedlings, and the scions were obtained from a healthy 10-year-old `Sin Fibra' donor tree. This donor tree was selected for its excellent agronomic traits and fruit yield. Vigorous and terminal scions were used, disinfected with fungicide, and used the same day of excision. The experiment was distributed under a completely randomized design. Splice side grafting had 67% success after 60 days, while wedge grafting and bud grafting had 0% success.
Ellen T. Paparozzi, Walter W. Stroup and M. Elizabeth Conley
1 Dept. of Agronomy and Horticulture. For reprint requests, email address: email@example.com 2 Dept. of Statistics. Plant material was donated by Ecke's Poinsettias Inc. This article is submitted as Nebraska Agricultural Research Division journal series