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Oral Sesssion 12—Vegetable Crops Culture & Management 1 Moderator: Albert Sutherland 19 July 2005, 10:00 a.m.–12:00 p.m. Room 106
A distance learning homepage at: http://www.bsi.vt.edu/welbaum/hort4764/ was created to teach an introductory college-level course on vegetable crops to students at Virginia Tech. The course was created to serve students in the horticulture program at Virginia Beach, Va., students in the Commonwealth who cannot take classes on the Blacksburg campus, and students on the Blacksburg campus who could not schedule the classroom-based course. The course is not selfpaced, but directs students through 44 lessons on various topics including detailed descriptions of 28 different vegetables. The site is primarily in HTML format with archived student projects and old exams in PDF format. Audio clips are used to emphasis key information and to add a personal touch. There are >550 pictures and descriptions of vegetables and vegetable crop production linked to the website. Students can be examined using a computer testing system call Whizquiz that grades and corrects each exam. “Web Forum” software enables online discussion among students and the instructor. Discussion sessions have been successfully conducted between students and guests at distant locations. Links are provided to over 25 other websites with information on vegetable crops. The project was funded by a USDA/CSREES Higher Education Challenge Grant.
Growth-chamber studies were conducted to examine the ability of seven vegetable crops-`Blue Lake' bean (Phaseolus vulgaris L.), `Detroit Dark Red' beet (Beta vulgaris L.), `Burgundy' okra (Abelmoschus esculentus (Moench), `Little Marvel' pea (Pisum sativum L.), `California Wonder' bell pepper (Capsicum annuum L.), `New Zealand' spinach (Spinacia oleracea L.), and `Beefsteak' tomato (Lycopersicon esculentum Mill.)–to adjust osmotically in response to water-deficit stress. Water stress was imposed by withholding water for 3 days, and the adjustment of leaf and root osmotic potentials upon relief of the stress and rehydration were monitored with thermocouple psychrometers. Despite similar reductions in leaf water potential and stomata1 conductance among the species studied, crop-specific differences were observed in leaf and root osmotic adjustment. Leaf osmotic adjustment was observed for bean, pepper, and tomato following water-deficit stress. Root osmotic adjustment was significant in bean, okra, pea, and tomato. Furthermore, differences in leaf and root osmotic adjustment were also observed among five tomato cultivars. Leaf osmotic adjustment was not associated with the maintenance of leaf growth following water-deficit stress, since leaf expansion of water-stressed bean and pepper, two species capable of osmotic adjustment, was similar to that of spinach, which exhibited no leaf osmotic adjustment.
Abstract
Although there are several ways to discuss mechanization of crop production, I have chosen the evolutionary approach. Mechanization goes through evolutionary stages. As new crops are mechanized, the intermediate steps could be by-passed if the evolutionary pattern is understood. Let us examine some of the steps taken in mechanization with various vegetable crops.
Abstract
I welcome this opportunity to discuss this topic but would preface the discussion by giving some information as to how far along we are in vegetable mechanization. We shall be talking primarily about mechanization at harvest because with all vegetables there is mechanized planting and subsequent culture, but with various degrees of precision, depending upon the crop and its environment
We thank the Organic Farming Research Foundation for funding this evaluation of summer cover crop species. We also thank Jane Frampton, Joe Difeo, and Tim Mathews for their technical support, and the staff at the Tidewater Research Station
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.
Funding for this project was provided in part by USDA NCR-SARE grant No. 25-6205-0042-027, PPRC MSU (Pickle and Pepper Research Committee for Michigan State University), PPI (Pickle Packers International Inc.), and the Michigan Vegetable Council
139 ORAL SESSION 38 (Abstr. 645–650) Sustainable Agriculture–Vegetables
The necessity of achieving appropriate nitrogen fertilization of vegetable crops relates to both economical and environmental sustainability. Split nitrogen applications have been shown to improve N-use efficiency, in line with the aforementioned objective and should therefore be encouraged. Given the variation in the amount of N naturally provided to, or uptaken by, the crop, strategies are required to tailor supplementary fertilization to actual crop needs, keeping in mind the absolute requirement for optimal yield in quality and quantity. It is suggested that the fertilization rates applied at sowing or later in the season can be figured in two manners. The first relies on modelling; the second on measurements. The modelling (N budget) approach, mostly linked to initiatives on the European continent, would be most applicable to the determination of the first fertilizer dressing. When a plant stand is established, however, canopy-based measurements made either directly or remotely could be developed to make use of the capability of the plants to integrate the properties of the soil environment and to decide upon further top-dressed applications. For this purpose, a fully fertilized “reference plot” has to be introduced in the field in order to overcome the variability induced by season, site and cultivar. With the emergence of “precision farming” and “remote sensing technologies” it is now possible to adjust fertilizer inputs not only at the field level but also within fields based on actual, localized requirements.