for Environmental Risk Assessment It is clear from the previously cited examples that introduction of genes for modified ethylene signaling can cause a broad range of effects, including both intended phenotypes and unintended secondary effects. From a
Holly A. Little, Rebecca Grumet and James F. Hancock
John D. Lea-Cox
In 1998, the state of Maryland adopted some of the toughest nutrient management planning regulations in the Nation, requiring virtually all agricultural operations plan and implement nitrogen and phosphorus-based management plans by Dec. 2002. The nursery and greenhouse industry is faced with a far more complicated nutrient management planning process than traditional agronomic planning scenarios. Factors include a large number (>500) of plant species, various fertilization and irrigation strategies, with crop cycles ranging from 6 weeks (bedding plants) to upwards of 15 years for some tree species in field production, often with a lack of knowledge of specific nutrient uptake rates and utilization. In addition, unique infrastructural and site characteristics that contribute to water and nutrient runoff from each nursery contribute to a multitude of variables that should be considered in the planning process. The challenge was to identify a simple, effective process for nutrient management planning that would a) provide an accurate assessment of nutrient loss potential from this wide variety of production scenarios, b) identify those specific factors that contribute most to nutrient leaching and runoff, and c) provide a mechanism to economically assess the various risk management (mitigation) scenarios. This risk assessment process provides information on a number of fixed (site) and dynamic (management) variables for soils/substrates, irrigation and fertilization practices, together with any surface water management systems (e.g. containment ponds, riparian buffers). When all the risk factors for a nursery are evaluated and scored, the complete picture of risk assessment then emerges. By identifying higher risk factors and evaluating different risk management options, the grower and/or nutrient management planner can then choose economic alternatives to reduce the potential for nutrient runoff.
Mathews L. Paret, Asoka S. de Silva, Richard A. Criley and Anne M. Alvarez
Fourteen species of ginger belonging to Zingiberaceae and Costaceae were evaluated for susceptibility to the bacterial wilt pathogen Ralstonia solanacearum (Rs) race 4 (ginger strains) by several methods of inoculation, including tests to simulate natural infection. Twelve of 14 species tested were highly susceptible to all strains of Rs race 4 upon stem inoculation, and susceptible plants wilted within 21 days. In contrast to previous reports that Rs strains from an invasive alien species, kahili ginger (Hedychium gardenarium), are nonpathogenic on ornamental gingers, the kahili ginger strain wilted both ornamental and edible ginger (Zingiber officinale) species within 21 days. Pour inoculation to the base of 11 plant species to simulate natural infection confirmed the ability of Rs to invade all the tested species without root wounds. Shampoo ginger (Zingiber zerumbet) was the most susceptible (wilted in 26 days) whereas pink ginger (Alpinia purpurata) and red ginger (A. purpurata) were the least susceptible and wilted in 71 and 76 days respectively. Pathogen survival in potting medium was evaluated by enumerating viable cells in effluent water from drenched pots with and without infected edible ginger after stem or rhizome inoculation. Ralstonia solanacearum survived in plant-free potting medium for 120 days and for 150 to 180 days in potting medium with infected edible ginger. The ability of Rs race 4 to infect many ginger species without wounding and to survive for long periods indicates that high risks will be incurred if the kahili ginger strain is inadvertently introduced from the forest reserves into ginger production areas.
Byron L. Frenz and Jack E. Staub
Development projects in developing countries are generally considered to be speculative investments. Potentially significant returns on investment opportunities are often overlooked by assuming that investment risks in developing countries are greater or less manageable than the risks of investment in developed countries. An import purchasing-risk evaluation identified the costs associated with the production and export of processing cucumbers (Cucumis sativus L.) from Hispaniola (Haiti and the Dominican Republic) to the United States. Although production and export analyses suggested that Hispaniola might not replace Mexico as the primary source of cucumbers for processing in the United States between November and April, Hispaniola affords the U.S. processing industry with an alternative investment option for reducing single-sourcing raw product risk. Therefore, an import diversification evaluation was conducted using Monte Carlo simulation to define a investment-risk model. Monte Carlo simulations of the means and variances of the components of cost andprice were used to assess investment risk under various investment strategies. This model identified sources of cost variation which were then used to characterize export risks derived from growing processing cucumbers on Hispaniola. It was determined that U.S. processors can reduce overall purchasing-risk by diversifying Mexican production to Hispaniola. Through the creation of a strategic transportation alliance between the U.S. and Hispaniola project participants, the export-import costs were such that the investment-risk model identified the allocation of 80% of the production in Mexico and 20% in Haiti as the most favorable diversification strategy. This strategy offered less risk and greater potential long-term returns than purchasing cucumbers solely in Mexico.
John A. Muir and Richard S. Hunt
Introductions of white pine blister rust (WPBR, causal fungus: Cronartium ribicola J.C. Fischer) to eastern and western North America before 1915 caused such extensive damage that western white pine (Pinus monticola D. Don) was essentially abandoned as a manageable forest tree species for over 60 years. Recent results from WPBR resistance selection and breeding programs, and from field trials of tree spacing, pruning and bark excision treatments have supported efforts to increase establishment and to intensively manage western white pine. Western white pine is a desirable component in many forested areas because of its faster growth and much higher value compared to many other associated tree species. It also has a low susceptibility to armillaria root disease caused by Armillaria ostoyae (Romagnesi) Herink and laminated root rot, caused by Phellinus weirii (Murr.) Gilb. Some regulations, e.g., Forest Practices Code of British Columbia (BC) Act, require anyone who harvests timber on provincial forestland and uses western white pine for reforestation to either plant genetically resistant western white pine stock or prune susceptible young trees for protection. Risks of increased WPBR associated with increased commercial cultivation of gooseberries and currants (Ribes L.) have yet to be determined. However, major threats appear to include 1) increase in local amounts of spores for nearby infection of pines; and 2) possible introductions or development of new, virulent races of C. ribicola, particularly from eastern to Pacific northwestern North America. In view of these possible threats, we recommend that existing regulations and legislation should be amended, or possibly new measures enacted, to permit propagation and commercial cultivation only of varieties of Ribes that are immune or highly resistant to WPBR.
Manuela Baietto and A. Dan Wilson
crucial risk factor that increases the probability that urban trees will fail, but environmental stresses, competition, anthropogenic disturbance, and the activities of other organisms are contributing factors considered in risk assessments ( Ossenbruggen
Hector German Rodriguez, Jennie Popp, Curt Rom, Heather Friedrich and Jason McAfee
. Note that year 0 is included to represent cash flows occurred in the soil preparation year that need not be discounted. The PV of net returns or NPV is used in the risk assessment component of the AIEDST. The larger the NPV, the better is the investment
J.T. Reed, M.R. Williams and D. Fleming
Results from research funded by RAMP (Risk Assessment and Mitigation Program) funds conducted with sweetpotato growers in Mississippi during 2004 and 2005 are discussed. Insects were sampled on a weekly (2004) or biweekly (2005) schedule on land planted to potatoes with and without insecticidal input. Potatoes were harvested from each cooperator's field and evaluated for insect damage one or more times at the end of the season. Insect pest populations in Mississippi sweetpotatoes were relatively low during 2004 and 2005. Under these conditions, the percentage of sweetpotatoes damaged by insects was only slightly reduced by insecticides. Chrysomelid leaf beetles including flea beetles, cucumber beetles and tortoise beetles were the most obvious group of pest insects. The most prominent insect species in sweep net samples during the season was the sweetpotato flea beetle, however damage by this pest was negligible. The most damaging insect based on our evaluation of root damage was the twelve-spotted cucumber beetle. Root feeding by whitefringed beetles, white grubs, and sugarcane beetles was sporadic within the fields in the study, and damage by these insects was generally minimal in 2004 and 2005. Preliminary assessments of the effect of crops planted the year previous to the planting of sweetpotatoes indicate the following order of greater to lesser insect damage: pasture, soybeans, corn, sweetpotato, and cotton. Delay of harvest beyond the optimum harvest date tended to increase insect damage in marketable roots. Pesticide evaluations associated with the study indicate that some reduction in damaged roots may be derived from application of a soil-incorporated insecticide at lay by.
production and marketing risk assessment. Findings are expected to generate valuable information for research and extension program priorities and topic areas. Use of Eye-tracking Technology in Retail Horticulture Eye-tracking hardware and software allow
W.G. Harris, M. Chrysostome, T.A. Obreza and V.D. Nair
et al., 1998 ). This concern has stimulated much interest in risk assessment and mitigation approaches involving land-applied P. A number of states, including Florida, have drafted a “P index” tailored to the perceived risk factors for soils of the