PEST CONTROL DECISION MAKING: SUGAR BEET IN ENGLAND

This paper discusses approaches to the problem of pest control decision making. A farmer's pest control decisions are shown to depend on his subjective perception of the pest hazard, the controls he recognises as available to him, his subjective estimate of their net effect, and his individual decision rule or goal. A case study is discussed in which a decision model is used to compare objective pest observation with subjective perceptions of sugar beet growers. Applications of such a model for improving pest control decisions are suggested.     

Regional economic impacts of a plant disease incursion using a general equilibrium approach*

The present study uses a dynamic multiregional computable general equilibrium (CGE) model to estimate the micro‐ and macroeconomic effects of a hypothetical disease or pest outbreak. Our example is a Karnal bunt incursion in wheat in Western Australia. The extent of the incursion, the impact of the disease or pest on plant yields, the response of buyers, the costs of eradication and the time path of the scenario contribute to outcomes at the industry, regional, state and national levels. We decompose the contribution of these individual direct effects to the overall impact of the incursion. This might provide some guidance regarding areas for priority in attempting to eradicate or minimise the impacts of a disease or pest. The study also introduces a theory of dynamic regional labour adjustment in which economic events may lead to both real wage differentials and worker migration between regions.     

Endogenous risk in weed control management

Weed control decisions are modeled in an endogenous risk framework where a producer invests in self-insurance and self-protection to reduce the severity of a realized pest infestation, or reduce the likelihood the infestation occurs. Self-insurance and self-protection are risk-reducing technologies that capture both the type and quantity of herbicides used. We supply conditions to unambiguously sign the effects of an increase in the probability of application or effectiveness failure and increased application or effectiveness uncertainty on optimal herbicide choices. If self-protection and self-insurance are stochastic substitutes, non-point source pollution policies targeted to reduce herbicide loadings can increase the use of more persistent herbicides. Policies that decrease loadings by reducing total mass may induce a substitution to herbicides more damaging or more likely to be transported to sensitive areas.     

Cooperative membership and adoption of green pest control practices: Insights from rice farmers

Reducing the use of chemical pesticide while preserving crop yield is a practical strategy that makes agricultural production economically, socially and environmentally sustainable. Although the adoption of green pest control practices can help achieve such a goal, its adoption rate remains quite low. This study explores whether membership in agricultural cooperatives improves smallholder farmers' adoption of green pest control practices, utilising farm-level data surveyed from rice farmers in China. To enrich our understanding, we also investigate how the adoption of green pest control practices mediates the effects of cooperative membership on chemical pesticide expenditures. An endogenous switching probit model and a bootstrap-based mediation method are employed to achieve these goals. The empirical results show that cooperative membership significantly increases the probability of adopting physical pest control practices (e.g. pest-killing lamps or sticky plate traps) and biological pest control practices (e.g. biopesticides) by 6% and 19%, respectively. Cooperative membership significantly reduces chemical pesticide expenditures through its mediation effect on improving the probability of adopting biological pest control practices. There is also a complementary relationship between physical and biological pest control practices in pest management of rice production. The adoption of physical pest control practices significantly increases rice yield, while the adoption of biological pest control practices does not.     

农业社会化服务能促进农户采用亲环境农业技术吗

使用亲环境农业技术是治理农业面源污染、改善耕地质量和提升农业绿色发展程度的重要举措。本文基于农业社会化服务视角,采用农户微观调查数据,利用倾向得分匹配法和mvprobit方法,定量测度了农户购买不同环节的农业社会化服务对其亲环境农业技术采用的影响效应。研究结果表明,农户购买农业社会化服务对其采用亲环境农业技术具有显著促进作用。然而,不同环节的农业社会化服务对其采用的影响差异较大,购买施肥和施药等社会化服务能显著促进农户采用施肥技术和病虫害专业化统防统治,而整地、插秧和收割等机械化服务的影响并不显著。随耕地经营规模扩大,农户购买插秧、整地、收割、施药和施肥等社会化服务和其采用亲环境农业技术的可能性均不断提高。未来中国应进一步推动规模经营和农业社会化服务组织发展,强化农业社会化服务组织在施肥施药环节的作用,并对不同环节的社会化服务区别对待,规范其行为,降低农业社会化服务组织的不确定性,防范服务风险,更好发挥农业社会化服务对提高农业绿色发展程度的带动作用。     

浅谈进口大豆储粮害虫综合防治策略

针对进口大豆保管过程中遇到的储粮害虫防治难题,中央储备粮日照仓储有限公司积极响应国家关于保障食品安全的总体要求,在分析相关虫种生活习性的基础上,多措并举,积极探索储粮害虫综合防治策略,通过物理防治与化学防治相结合的方式,抑制虫害的发生发展,实现储粮熏蒸率逐年降低,有效夯实了绿色储粮管理基础。     

RISK-EFFICIENT THRESHOLDS FOR PEST CONTROL DECISIONS

Risk and uncertainty are incorporated in an economic model to develop risk-efficient pest control advice similar in character to advice currently being offered by researchers to farmers. An example to illustrate computation of risk-efficient advice is presented and implications of risk aversion for efficient pest control advice and average pesticide use are examined.     

Pests and pesticides,risk and risk aversion

Theoretical and applied literature on risk in decision making for agricultural pest control is reviewed. Risk can affect pesticide decision making either because of risk aversion or because of its influence on expected profit. It is concluded that risk does not necessarily lead to increased pesticide use by individual farmers. Uncertainty about some variables, such as pest density and pest mortality, does lead to higher optimal pesticide use under risk aversion. However, uncertainty about other important variables, such as output price and yield, leads to lower optimal levels of pesticide use. Neglect of these variables in most studies has led to the false assumption that pesticides are always risk-reducing inputs. Furthermore, there is evidence that, in general, the pesticide dosage which maximises expected profit is lower under risk than under certainty. Depending on the balance of forces to increase and decrease pesticide use under risk, in many circumstances the net effect of risk on optimal decision making for pest control may be minimal. The effect on risk of information about pest density and other variables (as in integrated pest management programmes) is discussed. Evidence on this issue is mixed. A range of analytical techniques for analysing risk in pest control is reviewed. Throughout the paper, gaps in the existing literature are identified.     

Pesticide Use and Fish Harvests in Vietnamese Rice Agroecosystems

Criticisms of the Green Revolution have focused on environmental and human health problems associated with pesticides. Pesticides may also have adverse effects on wild fish and other aquatic animals in rice paddies that supply an additional source of food and income for some farm households and provide natural pest control. We use survey data from the Mekong Delta region of Vietnam to estimate the impact of pesticides on fish harvests from rice fields. The results confirm findings of ecological studies that pesticide use harms fish populations. However, fish harvest losses are small enough that ignoring them is likely economically rational.     

山东省鼠类地理分布与鼠害防治研究

鼠类的调查研究对鼠害的防治有重要的意义。山东省鼠类的调查研究与鼠害防治已有多年历史,资料记载表明,大仓鼠、黑线仓鼠、黑线姬鼠、褐家鼠和小家鼠是全省范围内的优势种,是鼠害防治的重点。鼠害的防治技术主要有农业防治、化学防治、物理机械防治、生物防治以及免疫不育等高新技术防治。     

Impacts of price and exchange rate policies on pesticide use in the Philippines

Pesticide prices can influence producer decisions to apply pesticides as opposed to nonchemical means of pest control. Those prices are are turn influenced by price and exchange rate policies. The effective rate of protection for nine pesticides commonly applied to vegetables in the Philippines was calculated to determine whether government policies are creating incentives or disincentives to adopt more integrated pest management methods. Calculations found that direct price policies, primarily through an import tariff, tax pesticide use while an overvalued exchange rate subsidizes pesticide use. The net effect is a 6 to 8% pesticide subsidy. This subsidy results in economic surplus gains to vegetable producers and consumers when negative externalities associated with pesticide use are not accounted for. However, recent analysis of human health effects of pesticide use on rice in the Philippines demonstrates that these externalities can be substantial.     

基于计划行为理论的粮农质量安全行为实施意愿及其影响因素分析

粮农作为粮食供应链的源头,其质量安全行为直接决定了粮食的质量安全情况。文章基于山东省17地市627户粮农的问卷调查数据,首先运用Logit模型分析了影响粮农质量安全行为实施意愿的影响因素,再通过ISM模型进一步分析了各影响因素之间的逻辑关系和层次结构。分析表明:粮农的文化程度、家庭年收入、种植规模、专业化程度、行为态度、优良品种选用认知、农药化肥安全使用认知、病虫害生物防治认知、产地检验9个因素对其质量安全行为的实施意愿有显著影响。其中,行为态度、家庭年收入、产地检验是表层直接因素,优良品种选用认知、农药化肥安全使用认知、病虫害生物防治认知是中层间接因素,文化程度、种植规模、专业化程度是深层根源因素。因此,加快培育新型粮农、提高农民收入、适当扩大生产规模、加大宣传力度、加强产地检验是优化粮农质量安全行为的有效途径。     

Farmers’ Preferences For Bluetongue Vaccination Scheme Attributes: An Integrated Choice and Latent Variable Approach

Re‐emergence of the bluetongue disease in Europe poses a continuous threat to European livestock production. Large‐scale vaccination is the most effective intervention to control virus spread. Compared to command‐and‐control approaches, voluntary vaccination approaches can be effective at lower costs, provided that farmers are willing to participate. We use a discrete choice experiment to estimate the preferences for vaccination scheme attributes, accounting for preference heterogeneity via an integrated choice and latent variable approach. In designing livestock disease control schemes, it is often argued that governments should use financial, incentive‐based policy instruments to compensate farmers for externalities, assuming they act in rational self‐interest. Our results suggest that in addition to economic motives, farmers can have intrinsic or social motives to invest in livestock disease control. Implications for the effectiveness of providing subsidy or information to motivate voluntary participation are discussed.     

Farmers,Biodiversity and Plant Protection: Developing a Learning Environment for Sustainable Tree Cropping Systems

More diverse, perennial cropping systems often have better natural mechanisms for keeping pests at bay. But while scientists emphasise the broad benefits of conservation in terms of effective ecosystem functioning, farmers are more interested in biodiversity for the provision of food or of services such as shade or windbreaks. Because of their limited knowledge of the role of biodiversity in plant protection, farmers sometimes unconsciously disturb natural regulatory mechanisms. Some citrus farmers in Vietnam introduced sapodilla as an intercrop to diversify their source of income, and because this fruit tree requires little care. However, this apparently worthwhile attempt to combine two valuable crops has misfired. The ecological conditions that traditionally sustained natural pest control in citrus have been disturbed, thus trapping farmers in the pesticide treadmill. The weaver ant Oecophylla smaragdina stopped protecting citrus from stinkbugs and leaf-feeding caterpillars after facing competition from the black ant Dolichoderus thoracicus, which favours sapodilla trees as a nesting habitat. To avoid similar scenarios in the future, methods for linking scientific research on ecosystem functions with farmers' own knowledge, experience and priorities are presented. Examples are given of ways in which farmers in perennial cropping systems learn, and how scientists can facilitate this learning process.     

Formal versus Informal System to Mitigate Non-point Source Pollution: An Experimental Investigation

Water pollution caused by aquaculture or agricultural activities negatively affects both the activity and downstream areas. A number of other upstream-downstream problems (e.g. water use, industrial/municipal water source pollution, salinity zoning problems) are examples of similar negative externalities. Non-point source pollution, which is either prohibitively costly or impossible to observe, is more feasible to identify, and hence mitigate at the aggregate level. We study experimentally the efficacy of two possible management systems: a centralised external, formal government-led monitoring and control system; a self-governing communication and informal system, both designed to manage shrimp farming, which generates a non-point source pollution with upstream-downstream externalities. Our results suggest that local communication and control outperforms the external monitoring and certification agency. These results, in conjunction with other relevant research, suggest that informal regulation and self-governance among shrimp farmers can be highly successful in tackling the pollution problem.     

Analysis of the Colorado potato beetle protection system in Finland

Invasive species, including plants, insects and other pests, are a serious threat to agricultural production and to the environment in general. Finland has traditionally had a favourable situation concerning invasives, partly due to its isolated geographical location. The situation may now be changing and one of the currently increasing threats is the Colorado potato beetle (CPB). Finland has designed a CPB protection policy incorporating a protected zone, which is commonly used to deal with invasive plant pests in other European countries. Within this zone, the randomly occurring CPB invasions are collectively fended off, to prevent the establishment of a permanent pest population and to minimise potential damage. This paper evaluates the economics of the current protection programme, comparing this to a hypothetical situation in which the current pre-emptive policy is abandoned and control relies on producers' individual reactive protection measures. The annual random pest invasions are modelled in a static stochastic framework. To date the pest has not been able to establish a permanent population in Finland. According to our analysis, the currently exercised pre-emptive policy is the cost-efficient choice at this point. The relatively low expected invasion magnitude is one of the key factors supporting the efficiency of the current system. Another reason is the fairly small damage incurred. However, when the invasions become larger and more frequent or the pest strains more cold-resistant, the future situation may change.     

Public Preferences and Willingness to Pay for Forest Disease Control in the UK

Invasive pests and diseases in trees impose a range of costs on society related to reductions in timber values, impacts on recreational opportunities and effects on forest biodiversity. These costs need to be considered when assessing control options and developing public policy. We investigate the preferences and willingness to pay of the UK general public for a range of forest disease control measures using a choice experiment with a sample of 605 people. Respondents were relatively well informed about general tree disease‐related issues, such as causes and general measures to minimise the risk of disease spread. They were less knowledgeable about specific tree diseases, with Dutch elm disease and chalara ash dieback being the most well known. We find that disease control programmes in publicly‐owned forests and forests owned by charitable trusts are more likely to be supported by the public than equivalent control programmes in privately‐owned and/or commercial forests. The nature of scientific uncertainty about diseases does not affect peoples’ preferences for disease control measures significantly. Higher respondent income, greater ex‐ante knowledge about tree diseases, and more frequent visits to forests are correlated with greater willingness to support publicly‐funded tree disease control programmes in forests. Better knowledge about tree diseases also improves the clarity of respondents’ choices. We find a negative sentiment against some disease control measures, such as clear felling of a forest, and chemical or biocide spraying. We conclude that there is significant public support for part‐financing forest disease control policies in the UK, but that this is conditional on forest ownership and the type of control measures used.     

Biosecurity in agriculture: an economic analysis of coexistence of professional and hobby production*

One component of biosecurity is protection against invasive alien species, which are one of the most important threats worldwide to native biodiversity and economic profitability in various sectors, including agriculture. However, agricultural producers are not homogeneous. They may have different objectives and priorities, use different technologies, and occupy heterogeneous parcels of land. If the producers differ in terms of their attitude towards invasive pests and the damages they cause, there are probably external effects in the form of pest spread impacts and subsequent damages caused. We study such impacts in the case of two producer types: profit‐seeking professional producers and utility‐seeking hobby producers. We show that the hobby producer, having first set a breeding ground for the pest, under‐invests in pest control. We also discuss potential policy instruments to correct this market failure and highlight the importance of considering different stakeholders and their heterogeneous incentives when designing policies to control invasive alien species.     

Estimating Bird Damage to Rice in Africa: Evidence from the Senegal River Valley

Granivorous birds, mainly the Red‐billed Quelea, have subsisted on cereal crops in Africa for centuries and have caused substantial damage. There is, however, limited recent evidence on their impact. We propose an indirect method to estimate bird‐inflicted crop losses by fitting a production function with a damage abatement component and pest intensity slope dummies on a panel database of rice farmers in the Senegal River Valley. This allows us to estimate both bird damage and marginal productivity of bird control at different levels of bird pressure. Annual bird damage is found to average around 13.2% of the potential rice production during the wet seasons of 2003–2007, which translates into an average annual economic loss of 4.7 billion FCFA (€7.1 million). Our results are consistent with farmers’ perceived bird‐inflicted crop losses, averaging 15.2%. More alarmingly, we observe declining marginal productivities of bird control under increasing bird pressure. Farmers indicate that at high bird pressure, the efficacy of traditional bird scaring methods is inadequate, which suggests that predictive (monitoring), preventive (population control) and protective (insurance) measures against massive invasions are more urgent than improving the average efficacy of curative measures (pest control). These findings are especially relevant to farmers and policy‐makers who are currently struggling to implement an ambitious food self‐sufficiency programme in Senegal.     

An Integrated Epidemiological-Economic Analysis of Foot and Mouth Disease: Applications to the Southern Cone of South America

Animal disease outbreaks impose significant economic costs that evolve over space and time, but few studies have explicitly modeled their temporal and spatial impacts. Using an integrated epidemiological-economic model, this article demonstrates a methodology that captures the dynamic and spatial effects of animal disease. The model is applied to foot-and-mouth disease in the Southern Cone of South America. The results demonstrate the benefits of spatially sensitive policies in which certain regions within the Southern Cone employ different, coordinated interventions. Further, they highlight policy relevant differences between the dominant short-run and long-run control options.