Cost-effective Management Programs Research Articles

Spatial and Temporal Variation in Stored-Product Insect Pest Distributions and Implications for Pest Management in Processing and Storage Facilities

Abstract Insect infestations can result in a damaged or destroyed product, costing producers and retailers millions of dollars annually. Postharvest insects move through space searching for mates, food, and shelter. Movement of product, sanitation activities, and insecticide applications also drive their spatial distribution patterns. Determining spatial distributions and population density of insects provides important information to develop targeted and cost-effective management programs. Monitoring data collected using traps to capture insect pests have provided information under a range of conditions: in bins of grain, grain elevator silos and their immediate environment, milling and processing facilities, commercial warehouses, and retail stores. In evaluating available data, we identified key influences that may be leveraged to increase the impacts of future monitoring schemes. Species-specific locations of infestation were common among stored product insect pests and seasonal variation was highly influential in population growth patterns. Competition among different species also drives spatial and temporal distributions and overlap among species is rare. Vertical distribution of insects was common in bins, elevators, and silos. More insects were often found in the receiving and storage areas of mills and processing facilities and insects often migrated into facilities from surrounding natural reservoirs. Previously stored grain and spillage can also harbor insect populations, which also reinforces the need for sanitation in and around stored grain products. Continued monitoring research will provide information to develop predictive tools which will use behavioral patterns to further our understanding of these insect pests within these unique facilities and circumstances.

Efficiency of different spatial and temporal strategies for reducing vertebrate pest populations

Understanding effectiveness of control strategies of pest species is fundamental for planning efficient and cost-effective management programs. In addition to culling rates, there are many potential factors that can determine efficiency of different management strategies, including demographic processes such as immigration rates, birth dynamics, and spatial ecology. We developed a stochastic, data-based simulation model of feral swine population dynamics which accounted for social dynamics in space. We tested the impacts of different spatio-temporal management strategies (i.e., culling rates, timing of culling during the year, spatial pattern of culling and strength of a barrier to immigration) on population response and efficiency. The spatial culling strategy dramatically impacted efficiency of control – using zonation required removal of fewer pigs (up to 46% less) to achieve similar reductions compared with other spatial strategies. Also, our spatially-explicit model predicted that lower culling intensities could be used to achieve population reductions when zonation was applied relative to predictions from harvesting theory based on simple logistic models. As culling intensity increased (≥50% of target population annually) and the target population reached low density (<5% of original density), effects of spatial strategy became less pronounced relative to immigration barrier effects. Lastly, for the same level of moderate culling effort, prioritization of culling during the low-birthing period generally resulted in faster population reduction to near zero abundance relative to prioritization during the high-birthing period, or spreading the work over a year period, but the significance of this effect depended on the spatial culling strategy and culling intensity. Our results imply that continually updating knowledge of current abundance during management may not only be important for determining culling quotas, but also for updating and optimizing management strategies. When the management goal is maximum population control, consideration of birth and spatial dynamics can increase return on management effort and bring to light management inefficiencies.

Challenges and Strength of Current Industrial Energy Efficiency Management Practices in Steam Industries

The aim of this study is to achieve greater output by examining the existing way of coordinating the determined attempts of Steam Industries in South Africa to successfully reach a sustainable industrial development by using energy source adequately in a more competent way. Furthermore into the study we look at obstacles that prevent and those that leads to maximum utilization of energy management measures and also highlights the effects of implementing cheap available energy source in South Africa. The investigation and analysis have shown that energy is not well managed in Steam Industries and that the use of energy is minimized and not fully utilized due to poor management and lack of knowledge. Another detection was that lack of government structured and strategic measures of implementing and motivating the use of energy effectively. The effective and rational use of available power by Steam Industries in South Africa is a key player in developing a sustainable industrial development. The use of energy efficiency management strategies has contributed an increase in economic and improve environmentally friendly in the industrial sector. The slow pace adoption of energy saving and cost effective management programmes are negatively impacting on the benefits to Steam Industries in South Africa. In conclusion the study finds that the economy can be boosted by implementing energy efficiency management programmes and environmentally friendly. These will also stabilize the negative impact of energy raising prices.

Life cycle assessment of nutrient remediation and bioenergy production potential from the harvest of hydrilla ( Hydrilla verticillata)

Hydrilla ( Hydrilla verticillata) is one of the world’s most problematic invasive aquatic plants. Although management of hydrilla overgrowth has often been based on use of chemical herbicides, issues such as the emergence of herbicide-resistant hydrilla biotypes and the need for in situ nutrient remediation strategies have together raised interest in the use of harvester machines as an alternative management approach. Using a life cycle assessment (LCA) approach, we calculated a range of net energy and economic benefits associated with hydrilla harvests and the utilization of biomass for biogas and compost production. Base case scenarios that used moderate data assumptions showed net energy benefit ratios (NEBRs) of 1.54 for biogas production and 1.32 for compost production pathways. NEBRs for these respective pathways rose to 2.11 and 2.68 when labor was excluded as a fossil fuel input. Base case biogas and compost production scenarios respectively showed a monetary benefit cost ratio (BCR) of 1.79 and 1.83. Moreover, very high NEBRs (3.94 for biogas; 6.37 for compost) and BCRs (>11 for both biogas and compost) were found for optimistic scenarios in which waterways were assumed to have high hydrilla biomass density, high nutrient content in biomass, and high priority for nutrient remediation. Energy and economic returns were largely decoupled, with biogas and fertilizer providing the bulk of output energy, while nutrient remediation and herbicide avoidance dominated the economic output calculations. Based on these results, we conclude that hydrilla harvest is likely a suitable and cost-effective management program for many nutrient-impaired waters. Additional research is needed to determine how hydrilla harvesting programs may be most effectively implemented in conjunction with fish and wildlife enhancement objectives.

Broadcast Applications of Glyphosate Control Nutsedge at a South Georgia Forest Tree Nursery

Abstract Nutsedge is a major weed problem in some southern forest tree nurseries. Although herbicides can control most weeds in nurseries, control of nutsedge is usually dependent on fumigation. The purpose of this study was to examine the effectiveness of broadcast applications of glyphosate for control of nutsedge. Single and multiple applications of glyphosate at 2.2 kg ai/ha greatly reduced the density of nutsedge shoots and viable tubers at a south Georgia forest tree nursery. The first application in June 1999 reduced nutsedge shoots by approximately 98%. Subsequent applications during September and October 1999 had no additional detectable effect. Although applications in August and September 2000 greatly reduced the amount of nutsedge in previously untreated areas, their effect did not appear to be as great as glyphosate applications during the first year. Rainfall before and after glyphosate applications, and plant age at the time of application may have influenced the level of nutsedge control in year two. Nutsedge shoots and viable tubers were reduced to near zero levels in plots treated over a 2 yr period. The use of broadcast applications of glyphosate may be of value in developing a more cost-effective management program for nutsedge control in southern forest tree nurseries. South. J. Appl. For. 27(3):176–179.