Too much to handle? Pesticide dependence of smallholder vegetable farmers in Southeast Asia

Assessment of residues from common pesticides and associated risks in Pakistan

Pesticide residues have become an escalating concern in Pakistan, raising significant risks to both public health and the environment. This review overviews the current status of pesticide contamination in the country, with a specific focus on residue levels in relation to Maximum Residue Limits (MRLs) and a comparative analysis with regional and global counterparts. Several studies reveal that 30% to 70% of tested food products, including fruits, vegetables, and animal-derived products, especially in Punjab and Sindh, exceed established MRLs. This level of contamination is considerably higher than in neighboring countries such as India, where MRL exceedance ranges from 20 to 30%, and Bangladesh, which reports lower levels due to stricter regulatory efforts. In comparison, developed countries, including those in the European Union and the United States, report less than 5% of food samples exceeding MRLs, often falling below 1% due to stringent safety standards. The high prevalence of pesticide residues in Pakistan poses severe health risks, including neurological disorders, reproductive problems, and cancer, particularly in vulnerable groups like children and pregnant women. Key factors contributing to these elevated pesticide levels include insufficient knowledge of safe pesticide use, the unregulated application of banned or expired products, improper safety protocols, and malfunctioning equipment. A prevailing reliance on pesticides as the sole pest control method further hinders the adoption of Integrated Pest Management (IPM) strategies. In conclusion, pesticide residue levels in Pakistan are above permissible MRLs compared to regional and global standards, underscoring the need for urgent improvements in pesticide regulation, enforcement, and the promotion of sustainable pest control methods like IPM to better protect human health and the environment.

Loss-of-function in testis-specific serine/threonine protein kinase triggers male infertility in an invasive moth

Genetic biocontrol technologies present promising and eco-friendly strategies for the management of pest and insect-transmitted diseases. Although considerable advancements achieve in gene drive applications targeting mosquitoes, endeavors to combat agricultural pests have been somewhat restricted. Here, we identify that the testis-specific serine/threonine kinases (TSSKs) family is uniquely expressed in the testes of Cydia pomonella, a prominent global invasive species. We further generated male moths with disrupted the expression of TSSKs and those with TSSKs disrupted using RNA interference and CRISPR/Cas9 genetic editing techniques, resulting in significant disruptions in spermiogenesis, decreased sperm motility, and hindered development of eggs. Further explorations into the underlying post-transcriptional regulatory mechanisms reveales the involvement of lnc117962 as a competing endogenous RNA (ceRNA) for miR-3960, thereby regulating TSSKs. Notably, orchard trials demonstrates that the release of male strains can effectively suppress population growth. Our findings indicate that targeting TSSKs could serve as a feasible avenue for managing C. pomonella populations, offering significant insights and potential strategies for controlling invasive pests through genetic sterile insect technique (gSIT) technology.

A chromosome-level genome assembly of the legume pod borer, Maruca vitrata Fabricius (Lepidoptera: Crambidae)

Maruca vitrata, a significant pest of legumes, impacts food security in Asia and Africa. This study presents a high-quality genome assembly of M. vitrata, utilizing advanced sequencing technologies including Nanopore long-read, MGI short-read, and Hi-C. The genome, totaling 482.3 Mb with a contig N50 of 2.91 Mb, features 41.58% repetitive sequences and encompasses 13,320 protein-coding genes. We performed comparative genomic analyses to affirm the accuracy and completeness of the protein sequences assembled, ensuring the assembly's integrity. Additionally, the annotation of 83 Cytochrome P450 (CYP) genes further confirms the comprehensive nature of the genome assembly and its annotations. This genome assembly not only deepens our understanding of M. vitrata biology but also supports the development of sustainable pest management strategies. This research highlights the importance of genomics in advancing sustainable agricultural solutions through innovative pest management approaches.

The role of market in motivating farmers to reduce pesticide use: Evidence from vegetable farms in Shiraz

The overuse of pesticides has harmful impacts on both the environment and human health. Implementing efficient techniques is crucial to manage pesticides and reduce negative impacts effectively. In order to achieve this objective, we evaluated the harm of pesticide application in vegetable fields in Shiraz and identified the factors that impact farmers' behavior in using pesticides. The Environmental Impact Quotient (EIQ) indicator was initially utilized to evaluate the effects of pesticide residues on both human health and the environment. Afterwards, the Logit model was employed to investigate the likelihood of excessive pesticide usage among farmers. Our findings suggest that farmers may not give high importance to environmental and human health considerations when deciding on pesticide usage. Market incentives, such as the quantity and price of vegetables produced without pesticide use, play a significant role in reducing pesticide use in Shiraz vegetable farms. The results of the study can help policy makers in implementing pesticide-free agricultural practices.

Individual self-regulation, external monitoring, and farmers' safe production behavior: Evidence from the Kuan-chung Plain, China

Sustainable agricultural development requires comprehending the fundamental factors influencing farmers' adoption of safe production behavior. This study investigates intrinsic and extrinsic determinants, encompassing the influence of individual self-regulation and external monitoring, regarding the endorsement of safe labor practices among farmers in Kuan-Chung Plain, China. The findings underscore the pivotal role of personal self-regulation in stimulating farmers' implementation of safe production behavior. Additionally, governmental and public monitoring can act as catalysts, motivating farmers to shift from conventional agricultural production methods to safer alternatives. Moreover, the results revealed that a synergistic effect arises from the collaboration between public and governmental monitoring, combined with individual self-regulation. This collaborative approach significantly enhances farmers' propensity to embrace safe production behavior. Hence, policymakers should prioritize educating farmers on ethical restraint, optimizing policy strategies, and strengthening supervision practices to establish an effective platform for public monitoring. These measures will augment farmers' comprehension of the significance of safe production behavior and empower them to proactively implement these behaviors.

Strategies for mitigation of pesticides from the environment through alternative approaches: A review of recent developments and future prospects

Chemical-based peticides are having negative impacts on both the healths of human beings and plants as well. The World Health Organisation (WHO), reported that each year, >25 million individuals in poor nations are having acute pesticide poisoning cases along with 20,000 fatal injuries at global level. Normally, only ∼0.1% of the pesticide reaches to the intended targets, and rest amount is expected to come into the food chain/environment for a longer period of time. Therefore, it is crucial to reduce the amounts of pesticides present in the soil. Physical or chemical treatments are either expensive or incapable to do so. Hence, pesticide detoxification can be achieved through bioremediation/biotechnologies, including nano-based methodologies, integrated approaches etc. These are relatively affordable, efficient and environmentally sound methods. Therefore, alternate strategies like as advanced biotechnological tools like as CRISPR Cas system, RNAi and genetic engineering for development of insects and pest resistant plants which are directly involved in the development of disease- and pest-resistant plants and indirectly reduce the use of pesticides. Omics tools and multi omics approaches like metagenomics, genomics, transcriptomics, proteomics, and metabolomics for the efficient functional gene mining and their validation for bioremediation of pesticides also discussed from the literatures. Overall, the review focuses on the most recent advancements in bioremediation methods to lessen the effects of pesticides along with the role of microorganisms in pesticides elimination. Further, pesticide detection is also a big challenge which can be done by using HPLC, GC, SERS, and LSPR ELISA etc. which have also been described in this review.

Southeast Asia's environmental challenges: emergence of new contaminants and advancements in testing methods

Emerging contaminants, including pharmaceuticals, personal care products, microplastics, and per- and poly-fluoroalkyl substances, pose a major threat to both ecosystems and human health in Southeast Asia. As this region undergoes rapid industrialization and urbanization, the increasing presence of unconventional pollutants in water bodies, soil, and various organisms has become an alarming concern. This review comprehensively examines the environmental challenges posed by emerging contaminants in Southeast Asia and recent progress in toxicity testing methods. We discuss the diverse range of emerging contaminants found in Southeast Asia, shedding light on their causes and effects on ecosystems, and emphasize the need for robust toxicological testing methods. This review is a valuable resource for researchers, policymakers, and environmental practitioners working to mitigate the impacts of emerging contaminants and secure a sustainable future for Southeast Asia.

Pesticide screening of surface water and soil along the Mekong River in Cambodia

Widespread use of pesticides globally has led to serious concerns about environmental contamination, particularly with regard to aquatic and soil ecosystems. This work involved investigating concentrations of 64 pesticides in surface-water and soil samples collected in four provinces along the Mekong River in Cambodia during the dry and rainy seasons (276 samples in total), and conducting semi-structured interviews with local farmers about pesticide use. Furthermore, an ecological risk assessment of the detected pesticides was performed. In total, 56 pesticides were detected in surface water and 43 in soil, with individual pesticides reaching maximum concentrations of 1300 ng/L in the surface-water samples (tebufenozide) and 1100 ng/g dry weight in the soil samples (bromophos-ethyl). The semi-structured interviews made it quite evident that the instructions that farmers are provided regarding the use of pesticides are rudimentary, and that overuse is common. The perceived effect of pesticides was seen as an end-point, and there was a limited process of optimally matching pesticides to pests and crops. Several pesticides were used regularly on the same crop, and the period between application and harvest varied. Risk analysis showed that bromophos-ethyl, dichlorvos, and iprobenfos presented a very high risk to aquatic organisms in both the dry and rainy seasons, with risk quotient values of 850 for both seasons, and of 67 in the dry season and 78 in the rainy season for bromophos-ethyl, and 49 in the dry season and 16 in the rainy season for dichlorvos. Overall, this work highlights the occurrence of pesticide residues in surface water and soil along the Mekong River in Cambodia, and emphasizes the urgent need for monitoring and improving pesticide practices and regulations in the region.

Policy options for promoting wider use of biopesticides in Thai agriculture

Biopesticides are rapidly growing in importance for crop protection globally, but nearly all growth is happening in high income countries. No previous work systematically analyzed how lower-income countries can better benefit from the increased availability of biopesticides, which is important because these countries are particularly affected by the adverse effects of chemical pesticide use. Here we review the legislation of biopesticides in Thailand and combine this with stakeholder interviews and interview data from 300 smallholder farmers producing rice, fruit, vegetables, and flowers. We find that Thailand has adopted a biopesticide registration system that facilitates a fast-track registration, but it is still relatively costly considering the small market size. While 65 % of the sampled farmers used biopesticides, most farmers still heavily relied on conventional pesticides as their main method to control pests. Education, farming experience, positive attitudes of biopesticides, adoption of other integrated pest management methods and contacts with government extension agents were positively associated with biopesticide use. Coordinated action is needed to stimulate the supply of a wider range of biopesticide products while promoting adoption among farmers.

Synthesis and Biological Activity of Silicon-Containing Ethylsulfonylpyridine Insecticides

Ethylsulfonylpyridines are a novel chemical class of insecticides with excellent broad-spectrum activity and an unprecedented mode of action. With the objective of discovering novel ethylsulfonylpyridines with a broader spectrum, wider range of uses, and/or improved properties, we have started a research program aimed at introducing silicon motifs and studying their biological effects. We designed a series of Oxazosulfyl analogues where the hydrogen atom at the 5-position of the pyridyl moiety is replaced by a trialkylsilyl group and prepared these compounds applying denovo synthetic methodology. Our novel ethylsulfonylpyridines exhibit excellent insecticidal activities. The best compound, A18, resulting from our research exhibited an LC50 value of 0.30 mg/L against Plutella xylostella and reached the activity level of the commercial standard Oxazosulfyl. Our findings confirmed our working hypothesis that at the 5-position of the pyridyl moiety larger groups with different hydrophobic, electronic, and steric properties are tolerated.

Study on Rapid Detection of Pesticide Residues in Shanghaiqing Based on Analyzing Near-Infrared Microscopic Images

Aiming at guiding agricultural producers to harvest crops at an appropriate time and ensuring the pesticide residue does not exceed the maximum limit, the present work proposed a method of detecting pesticide residue rapidly by analyzing near-infrared microscopic images of the leaves of Shanghaiqing (Brassica rapa), a type of Chinese cabbage with computer vision technology. After image pre-processing and feature extraction, the pattern recognition methods of K nearest neighbors (KNN), naïve Bayes, support vector machine (SVM), and back propagation artificial neural network (BP-ANN) were applied to assess whether Shanghaiqing is sprayed with pesticides. The SVM method with linear or RBF kernel provides the highest recognition accuracy of 96.96% for the samples sprayed with trichlorfon at a concentration of 1 g/L. The SVM method with RBF kernel has the highest recognition accuracy of 79.16~84.37% for the samples sprayed with cypermethrin at a concentration of 0.1 g/L. The investigation on the SVM classification models built on the samples sprayed with cypermethrin at different concentrations shows that the accuracy of the models increases with the pesticide concentrations. In addition, the relationship between the concentration of the cypermethrin sprayed and the image features was established by multiple regression to estimate the initial pesticide concentration on the Shanghaiqing leaves. A pesticide degradation equation was established on the basis of the first-order kinetic equation. The time for pesticides concentration to decrease to an acceptable level can be calculated on the basis of the degradation equation and the initial pesticide concentration. The present work provides a feasible way to rapidly detect pesticide residue on Shanghaiqing by means of NIR microscopic image technique. The methodology laid out in this research can be used as a reference for the pesticide detection of other types of vegetables.

Vulnerable groups and protective habits associated with the number of symptoms caused by pesticide application in Kratie, Cambodia: a cross-sectional questionnaire study

Objective: The present study aimed to identify pesticide poisoning symptoms and related protective habits to effectively prevent pesticide poisoning among farmworkers in Kratie, Cambodia, where pesticide poisoning is an urgent public health problem. Materials and Methods: This cross-sectional study based on a questionnaire survey analyzing social demographics, number of symptoms, and protective behavior regarding pesticide application was conducted in Kratie Province from January 25 to 31, 2021. In total, 210 farmworkers completed the survey. The effects of social demographics and pesticide-protective behavioral scores on the number of symptoms were investigated using multivariable regression analysis. Results: The observed number of symptoms was 1.16 times higher among women (P=0.004), increased with the duration of work, and decreased with age. In addition, we identified five significant pesticide-protective behaviors: 1) preparing using gloves, 2) using protective equipment, 3) avoiding wiping sweat, 4) avoiding leaking, and 5) resting when feeling ill. Pesticide-protective behaviors tended to decrease with the duration of working years in the low-education group (B=-0.04, SE=0.01), whereas no association was observed in the high-education group (B=0.01, SE=0.01). Conclusion: Pesticide-protective behaviors significantly correlated with fewer symptoms. The female and aging groups required continuous special education or instructions for implementing pesticide-protective actions, especially the aforementioned five protective actions.

Assessment of pesticide safety knowledge and practices in Vietnam: A cross-sectional study of smallholder farmers in the Mekong Delta

Over the past three decades, the Vietnamese Mekong Delta has experienced a significant increase in agricultural productivity, partly achieved through increased agrochemical use. To abate negative effects on human and environmental health, several national programs were launched to enhance safer pesticide use. This study aimed to assess the patterns and relationships of official sustainable agriculture educational programs, pesticide safety knowledge, and practices of smallholder farmers in the Mekong Delta. A cross-sectional survey was conducted with 400 smallholder farmers from three communes in Thoi Lai district (Can Tho province) from March to May 2020. Twenty-four questions on pesticide safety knowledge and practices were used to identify traits using latent class analysis. Adjusted generalized linear regression was used to assess determinants of pesticide safety knowledge and estimate associations of pesticide safety knowledge with pesticide practices. 96.2% of participants have used at least one WHO class II pesticide during the past year while the use of specific personal protective equipment was limited mainly due to unavailability (37.0%) or discomfort (83.0%). High education (Odds Ratio (OR), 95% Confidence Interval; 3.84, 1.70-9.45), exposure to official educational programs (1.87, 1.13-3.12), peer-to-peer knowledge exchange (3.58, 2.18-6.00), and learning from governmental extension services (2.31, 1.14-4.98) were positively associated with increased pesticide safety knowledge. Compared to poor practices, pesticide safety knowledge was increasingly positively associated with intermediate (1.65, 1.02-2.66) and good pesticide practices (8.96, 2.58-31.12). These findings highlight the importance of school education and educational programs, access to PPE, and addressing discomforts of PPE to improve the protection of farmers from pesticide exposures. Simultaneously, pesticide market authorization processes should be reconsidered to promote the authorization of less toxic products. Further in-depth studies on the nature of pesticides used, nonuse of personal protective equipment, and effectiveness of educational programs will further define leverage points for safer pesticide use.

Ecological risk assessment and environment carrying capacity of soil pesticide residues in vegetable ecosystem in the Three Gorges Reservoir Area

Soil contamination by pesticide residues has become an increasing concern of ecological protection. However, the soil environmental carrying capacity (SECC) of pesticide residues in agricultural ecosystems was limited studied. Based on the concept of ecological risk assessment, a modified system on the environment carrying capacity was proposed for estimate SECC of pesticide residues in agricultural soils. Subsequently, the assessment on ecological risk and SECC of soil pesticide residues in vegetable ecosystem were performed in the Three Gorges Reservoir Area (TGRA). In 201 topsoil samples, 62.1% of the pesticide compounds were detected over limit of quantitation, and exhibit a high proportion of multiple pesticide contamination. Pyrethroid insecticides and herbicide glyphosate showed most frequent occurrence and high levels. The SECC of the TGRA varies with the limit standard, annual cumulative amount and risk quotient of each pesticide contaminant in soils. Except that fenpropathrin has exceeded SECC, chlorfenapyr, β-cyfluthrin and glyphosate posed the greatest threat to SECC in the next 50 years. Additionally, ecological risks by pesticide residues in vegetable ecosystem can be affected by various planting activities. These results will contribute to guide the rational application of pesticides and control soil environmental risks, thereby achieving the agricultural green development in the TGRA.

Effects of Market Incentives and Livelihood Dependence on Farmers' Multi-Stage Pesticide Application Behavior-A Case Study of Four Provinces in China

Improvement in pesticide application and efficiency structure has long been recognized as having great significance in reducing pollution, ensuring food safety, and promoting green agricultural development. Based on theoretical analysis, using the survey data of 766 farmers in key tea areas in Shaanxi, Sichuan, Zhejiang, and Anhui provinces in China, the study empirically analyzes the influence of market incentives and livelihood dependence on farmers' multi-stage pesticide application behavior. More specifically, the study employed ordered probit analysis to craft its findings. The dependent variable of this study is the multi-stage pesticide application problem of farmers, and the core independent variables are market incentives and livelihood dependence, and the judgment is based on the core variable coefficients of the econometric model of farmers at each stage. The study found the following: (i) Market incentives significantly prompted some farmers to give up synthetic pesticide application and farmers tend to choose green pesticides in the type of pesticide application. (ii) Livelihood dependence meant that the proportion of tea income significantly prompts farmers to apply pesticides, and also creates a tendency for farmers to choose green and low-toxic pesticides in the type of pesticide application. The planting period tends to have a moderate impact on applying green and low-toxic pesticides. (iii) The interaction term of market incentives and the proportion of tea income has no significant impact on farmers' multi-stage pesticide application behavior. The interaction term of market incentives and planting years has impacted negatively on whether farmers apply pesticides, and has no significant impact on farmers' choice of pesticide application types, but makes farmers increase the amount of green and low-toxic pesticides. (iv) The education level of the household head significantly promotes farmers to choose green and low-toxic pesticides. Seemingly, the brand effect of pesticides significantly encourages farmers to choose green and low-toxic pesticides. In external support, technical training significantly encourages farmers to choose green and low-toxic pesticides. Furthermore, better infrastructure and local market conditions significantly encourage farmers to reduce the use of conventional pesticides.

Environmental monitoring and potential health risk assessment from Pymetrozine exposure among communities in typical rice-growing areas of China

Pymetrozine is one of the most commonly used insecticides in China. This study was conducted to analyse Pymetrozine's potential exposures through various environmental routes beyond the treatment areas. The aim was to estimate the potential health risk for communities due to non-dietary exposures to Pymetrozine in soil and paddy water. Data on registration of pesticides in China, government reports, questionnaires, interviews and literature reviews as well as toxicological health investigations were evaluated to determine the hazard and dose-response characteristics of Pymetrozine. These were based on the US EPA exposure and human health risk assessment methods and exposure data from soil and paddy water samples collected between 10 and 20 m around the resident's location. The exposure doses from dermal contact through soil and paddy water were estimated. The potential cancer risk from the following exposure routes was evaluated: ingestion through soil; dermal contact exposure through soil; dermal contact exposure through paddy water. The potential total cancer risk for residents was estimated to be less than 1 × 10^-6. These were relatively low and within the acceptable risk levels. The potential hazard quotient (HQ) from acute and lifetime exposure by dermal contact through paddy water and soil and acute and lifetime exposure by soil ingestion for residents was less than 1, indicating an acceptable risk level. This study suggested that there were negligible cancer risk and non-cancer risks based on ingestion and dermal contact routes of exposure to residents.

Sustainable Organic Farming, Food Safety and Pest Management: An Evolutionary Game Analysis

There is an increasing realization that industrial, large-scale agriculture can negatively impact both food quality and the environment, and that alternatives should be thoroughly considered. Consisting of various participants with distinct and often competing interests, organic food chains have a dynamic structure. We consider an evolutionary game theory model for the dynamics of an organic supply chain with farmers, their customers and the government as the main stakeholders. After describing stakeholder strategies and constructing appropriate payoff matrices for the interactions between farmers and customers and between farmers and the government, respectively, sufficient conditions for the stability of the equilibria for the associated replicator equations were found. Those conditions were then interpreted in practical terms, the corresponding possible outcomes being determined and numerically illustrated. It was seen that a sustainable shift from a conventional strategy to an organic one requires the efforts of all involved stakeholders. As far as the evolutionary interaction between farmers and customers is concerned, it was seen that the purchasing power and the organic awareness of customers are of the utmost importance for the establishment and diffusion of organic strategies in the supply chain. Furthermore, a situation in which the preferences of farmers and consumers for an organic (or conventional) strategy change periodically may occur. Regarding the evolutionary interaction between farmers and the government, strong support for organic farmers is needed at first, and then the consumption habits and environmental awareness of the consumers can be cultivated. This promotes the establishment, development and enrichment of an organic supply chain which, at a certain point, can persist even without governmental subsidies.

Sustainable management of transboundary pests requires holistic and inclusive solutions

Globalization and changing climates are aggravating the occurrence and impacts of transboundary pests, and driving the emergence of new threats. Most of the low- and middle-income countries in Africa, Asia and Latin America are not fully prepared in terms of surveillance, diagnostics, and deployment of plant health solutions due to several factors: adequate investment is lacking; knowledge is inadequate; and connections from the local to global, and global to local are insufficient. Effectively countering the current and emerging threats to plant health requires a holistic approach that includes: 1) globally coordinated diagnostic and surveillance systems; 2) epidemiological modelling, risk assessment, forecasting and preparedness for proactive management and containment; and 3) implementation of context-sensitive, eco-friendly, gender-responsive and socially inclusive integrated disease and pest management approaches to reduce the impacts of devastating transboundary pests and diseases. Despite several success stories where major pests and diseases have been brought to control through integrated approaches, further multi-institutional and multi-disciplinary efforts are necessary. Plant health management requires stronger interface between the biophysical and social sciences, and empowerment of local communities. These reflections derive from the proceedings of a webinar on “Transboundary Disease and Pest Management,” organized by CGIAR (Consultative Group on International Agricultural Research) on March 3, 2021, in recognition of the United Nations designated International Year of Plant Health.

Contrasting National Plant Protection Needs, Perceptions and Techno-Scientific Capabilities in the Asia-Pacific Region

Pests and pathogens inflict considerable losses in global agri-food production and regularly trigger the (indiscriminate) use of synthetic pesticides. In the Asia-Pacific, endemic and invasive organisms compromise crop yields, degrade farm profitability and cause undesirable social-environmental impacts. In this study, we systematically assess the thematic foci, coherence and inclusiveness of plant protection programs of 11 Asia-Pacific countries. Among 23 economically important diseases and 55 pests, survey respondents identified rice blast, rice brown planthopper, citrus greening disease, Tephritid fruit flies and fall armyworm as threats of regional allure. These organisms are thought to lower crop yields by 20–35% and cause management expenditures up to US$2,250 per hectare and year. Though decision-makers are familiar with integrated pest management (IPM), national programs are invariably skewed toward curative pesticide-intensive control. Pesticide reductions up to 50–100% are felt to be feasible and potentially can be attained through full-fledged IPM campaigns and amended policies. To rationalize farmers' pesticide use, decision criteria (e.g., economic thresholds) wait to be defined for multiple crop x pest systems and (participatory) training needs to be conducted e.g., on (pest, disease) symptom recognition or field-level scouting. Efforts are equally needed to amend stakeholder perceptions on ecologically based measures e.g., biological control. Given that several Asia–Pacific countries possess robust techno-scientific capacities in various IPM domains (e.g., taxonomy, molecular diagnostics, socioeconomics), they can take on an active role in regionally coordinated campaigns. As such, one can reinvigorate IPM and ensure that preventative, non-chemical pest management ultimately becomes the norm instead of the exception throughout the Asia–Pacific.

Understanding how food safety risk perception influences dietary decision making among women in Phenom Phnom Penh, Cambodia: a qualitative study

OBJECTIVES

To determine women's perception of the risk of food safety and how it relates to diet, health and decision making as part of formative research for a market-based intervention that aims to improve the safety of animal-source foods sold in informal markets.

DESIGN

Qualitative study including in-depth personal interviews with 24 caregivers were conducted and complemented with a second follow-up PhotoVoice interview, which allowed the women to photograph their meals and perceptions of food safety and nutrition. Interview data were analysed using thematic analysis in MAXQDA. Participants were purposively sampled from a larger Safe Food, Fair Food for Cambodia study, conducted from May to August 2018.

SETTING

Urban and periurban neighborhoods of Phnom Penh, Cambodia.

PARTICIPANTS

24 female caregivers (mothers and grandmothers) of children under age 5, each interviewed twice.

FINDINGS

A primary food safety concern expressed was that chemicals (pesticides and other agricultural additives) in animal-source foods, fruits and vegetables may impact the health of their families by causing diarrhoea and problems during pregnancy. This fear created a lack of trust in markets, which influenced their food purchasing behaviours and strategies for making the food safer for their families. These mitigation strategies, including food selection and cleaning, vary among the women but are perceived as important to be able to provide their families with what they define as safe meals.

CONCLUSIONS

Interventions that wish to decrease rates of foodborne illness and increase animal source food consumption should also address the belief that the food system has been compromised by the addition of pesticides and agricultural additives.

The role of crop insurance in reducing pesticide use: Evidence from rice farmers in China

Pesticides play a significant role in increasing agricultural yields. However, the overuse of chemical pesticides on crops is a major challenge faced by China, which damages human health, threatens food security, and increases production costs. This paper provides empirical evidence on the relationship between crop insurance and pesticide use. Based on micro-survey data collected from 3410 households, we estimate a control function (CF) approach and find that farmers who purchase crop insurance use 33.30% lower pesticides than those who do not. A series of robustness tests confirm these findings. The results of the moderating effect analysis suggest that rice cultivation training, experience, schooling years, and agricultural laborers can negatively moderate the effect of crop insurance on pesticide use. Furthermore, we also find that the treatment effect of crop insurance is stronger for farmers who are most inclined to purchase crop insurance.

Ample room for reducing agrochemical inputs without productivity loss: The case of vegetable production in Uruguay

Vegetables are commonly produced with high inputs of pesticides and fertilisers to boost production and meet cosmetic market standards. Yet, reports on the relationships between agrochemical inputs and crop productivity are scattered and an overview is missing. We assessed the relationship between pesticide and nutrient inputs and crop productivity for five vegetable crops in the south of Uruguay at field and farm level and explored the relation with farm resource endowment. We analysed crop yield and input use for tomato, onion, sweet potato, and strawberry with a dataset of 82 farms and 428 fields constructed between 2012 and 2017. Clear crop-specific patterns in pesticide and nutrient input levels were found, despite considerable variation across fields within the same crop. Strawberry and long cycle tomato had the greatest pesticide input regarding of the number of applications (20 and 18, respectively) and pesticide load (21 kg AI ha^-1). Cumulative nutrient inputs were greatest for long cycle tomato (1127 kg ha^-1). The relationships between inputs and yield were weak or non-significant, indicating inefficiencies and overuse of inputs, and there was no agronomical rationale for input use. We found substantial variation in management practices between fields and farms. In several cases, 21% of the fields and 17% of the farms producing onion, strawberry and tomato, attained relatively high yield levels with limited input levels. Yield and input use levels were not related to farm resource endowment. Our findings question the efficiency of the current high levels of pesticide and nutrient inputs in Uruguayan vegetable systems. The inputs may pose environmental and human health risks and in most cases did not increase yields. Learning from positive deviant farmers in combination with guided farm redesign, high-quality extension services, and use of context-specific knowledge and technologies may equip farmers to use more sustainable management practices.

Chitosan Nanoparticles-Based Ionic Gelation Method: A Promising Candidate for Plant Disease Management

By 2050, population growth and climate change will lead to increased demand for food and water. Nanoparticles (NPs), an advanced technology, can be applied to many areas of agriculture, including crop protection and growth enhancement, to build sustainable agricultural production. Ionic gelation method is a synthesis of microparticles or NPs, based on an electrostatic interaction between opposite charge types that contains at least one polymer under mechanical stirring conditions. NPs, which are commonly based on chitosan (CS), have been applied to many agricultural fields, including nanopesticides, nanofertilizers, and nanoherbicides. The CS-NP or CS-NPs-loaded active ingredients (Cu, saponin, harpin, Zn, hexaconazole, salicylic acid (SA), NPK, thiamine, silicon, and silver (Ag)) are effective in controlling plant diseases and enhancing plant growth, depending on the concentration and application method by direct and indirect mechanisms, and have attracted much attention in the last five years. Many crops have been evaluated in in vivo or in greenhouse conditions but only maize (CS-NP-loaded Cu, Zn, SA, and silicon) and soybean (CS-NP-loaded Cu) were tested for manage post flowering stalk rot, Curvularia leaf spot, and bacterial pustule disease in field condition. Since 2019, five of eight studies have been performed in field conditions that have shown interest in CS-NPs synthesized by the ionic gelation method. In this review, we summarized the current state of research and provided a forward-looking view of the use of CS-NPs in plant disease management.

Farmers' knowledge and practice regarding good agricultural practices (GAP) on safe pesticide usage in Indonesia

Synthetic pesticides are widely applied for pest and disease control in Indonesia. However, a lack of knowledge and use of Good Agricultural Practices (GAP) for safe pesticide usage among Indonesian farmers remains a problem. This study aims to investigate the gap between farmers' knowledge of GAP for safe pesticide usage and their application of it. This research was conducted in 2020 in five Indonesian provinces. Primary data collection was by means of a survey, in which 298 respondents answered structured questionnaires. The survey also identified the sources of the information recorded and the respondents’ experience of pesticide exposure. The analysis tools used were the Wilcoxon Signed Ranked Test and Importance-Performance Analysis (IPA). There were significant differences in the results of the first analysis. These results appear to confirm the results of further analysis using IPA, which show that a high level of knowledge does not mean that farmers will apply this knowledge in practice: this is particularly relevant to wearing gloves and masks, using tools to remove blockages, never clearing blocked nozzles by blowing into them, and disposing of empty containers properly. Nevertheless, in some cases high levels of knowledge do result in high levels of application. Cases of pesticide exposure affecting human health by causing symptoms such as dizziness, nausea, and vomiting confirm that GAP for pesticide usage are not being implemented properly by some farmers. It is therefore recommended that their knowledge should be enhanced through the series of technical training programs using participatory approaches, so that farmers accumulate knowledge which will drive them to adopt GAP for safe pesticide usage.

Urinary Organophosphate Metabolites and Metabolic Biomarkers of Conventional and Organic Farmers in Thailand

Organophosphate (OP) pesticides are used by most farmers to remove insects and to increase productivity; however, questions remain on the long-term health impacts of their use. This study assessed the relationship between OP biomarker levels and metabolic biomarker parameters. Conventional farmers (n = 213) and organic farmers (n = 225) were recruited, interviewed, and had physical health examinations. Serum glucose and lipid profiles, triglycerides, total cholesterol, high-density lipoproteins (HDL), and low-density lipoproteins (LDL) were measured. The average age, gender, education, and self-reported agricultural work time, work in second jobs, smoking status, alcohol consumption, insecticide use at home, home location near farmlands and years of pesticide use were significantly different between the conventional and organic farmers. The urinary OP metabolite levels were also significantly different between the two groups. With an increase in urinary diethyl phosphate, dimethyl phosphate and dialkyl phosphate metabolites, the total cholesterol, LDL and HDL, were significantly increased for all farmers after controlling for age, gender, alcohol consumption, years of pesticide use, and home location near farmlands. The results are consistent with our previous studies which suggests that pesticide usage, especially organophosphates, may increase the risk of cardiovascular disease and stroke among Thai farmers.

Evaluating the Potential of Protected Cultivation for Off-Season Leafy Vegetable Production: Prospects for Crop Productivity and Nutritional Improvement

The effects of different protective structures on horticultural and nutritional yield of amaranth and water spinach were studied in three seasons of 2020–2021 in Taiwan. The number of people that can receive recommended dietary intake of iron and β-Carotene from vegetables grown under different production conditions was also estimated. The yield of white and red amaranths was consistently better (7.68–19.70 t/ha) under pink poly-net house in all the seasons, but the yield of water spinach was consistently better under white poly-net house (16.25–20.88 t/ha). Spider mite (fall & spring) and aphid (winter) infestation was mostly observed on all crops under poly-net houses. Neoxanthin, lutein and β-carotene were almost two-fold higher in red amaranth harvested from poly-net houses than open field. Based on the RDI values, β-Carotene supply to both men and women (14+) was consistently higher in all crops produced under pink ploy-net houses in all seasons, except for white amaranth produced under white poly-net house during winter. Its supply to 64,788 more men and 83,298 more women was estimated for red amaranth harvested from pink poly-net house than other production conditions. α-carotene was 2–3 fold higher in amaranths and water spinach harvested from poly-net houses than open field. The iron content of the amaranths was lower in poly-net houses (234.50–574.04 g/ha) than open field (645.42–881.67 g/ha) in the fall, but its supply from pink poly-net house was comparable with open field in the winter. However, pink poly-net house was the highest iron supplier from water spinach (323.90 g/ha) in the winter, which was estimated to provide iron to 19,450–22,939 more men and women than other production conditions. Both poly-net houses were the sole supplier of iron through amaranths in the spring, with pink poly-net house supplying iron to 2,000–5,000 more men and women. Thus, protected cultivation not only leads to more marketable yields but also results in higher quantities of health promoting nutrients. Hence, pink poly-net house may be considered to produce more nutritious vegetables, especially during the off-season to bridge the gaps in the seasonal variations in vegetable consumption, besides providing better income opportunities to the smallholder farmers.

Pesticides use and health impacts on farmers in Thailand, Vietnam, and Lao PDR: Protocol for a survey of knowledge, behaviours and blood acetyl cholinesterase concentrations

Pesticides use in Southeast Asia has increased steadily, driven by the growth of large-scale commercial farming, as well as a desire to maximise food production in rural subsistence economies. Given that use of chemical pesticides, such as organophosphates and carbamates, has known potential health impacts, there are concerns about the safety of agricultural workers, and a need for a better evidence base to underpin regulation and worker education. This study, undertaken in 9 districts in Lao PDR, Thailand and Vietnam, will interview agricultural workers to investigate how they use pesticides, their knowledge of risks and self-protective practices, and their self-reported illness symptoms. In each district researchers will recruit and interview 120 participants engaged in vegetable farming, who have recently used pesticides, making a total of 1080 subjects divided equally between the three study countries. Workers’ degree of pesticides exposure will be determined from acetyl cholinesterase concentrations in capillary blood samples collected using field test kits, and these data will be analysed together with the interview findings. Country findings will be compared and contrasted, and general patterns noted. Knowledge gained about risky behaviours, self-protective practices and degree of association with serious pesticides exposure will assist policy makers and inform health improvement programmes.

What agro-input dealers know, sell and say to smallholder farmers about pesticides: a mystery shopping and KAP analysis in Uganda

BACKGROUND

Pesticides can have negative effects on human and environmental health, especially when not handled as intended. In many countries, agro-input dealers sell pesticides to smallholder farmers and are supposed to provide recommendations on application and handling. This study investigates the role of agro-input dealers in transmitting safety information from chemical manufacturers to smallholder farmers, assesses the safety of their shops, what products they sell, and how agro-input dealers abide by laws and recommendations on best practices for preventing pesticide risk situations.

METHODS

Applying a mixed-methods approach, we studied agro-input dealers in Central and Western Uganda. Structured questionnaires were applied to understand agro-input dealers' knowledge, attitude and practices on pesticides (n = 402). Shop layout (n = 392) and sales interaction (n = 236) were assessed through observations. Actual behavior of agro-input dealers when selling pesticides was revealed through mystery shopping with local farmers buying pesticides (n = 94).

RESULTS

While 97.0% of agro-input dealers considered advising customers their responsibility, only 26.6% of mystery shoppers received any advice from agro-input dealers when buying pesticides. 53.2% of products purchased were officially recommended. Sales interactions focused mainly on product choice and price. Agro-input dealers showed limited understanding of labels and active ingredients. Moreover, 25.0% of shops were selling repackaged products, while 10.5% sold unmarked or unlabeled products. 90.1% of shops were lacking safety equipment. Pesticides of World Health Organization toxicity class I and II were sold most frequently. Awareness of health effects seemed to be high, although agro-input dealers showed incomplete hygiene practices and were lacking infrastructure. One reason for these findings might be that only 55.7% of agro-input dealers held a certificate of competency on safe handling of pesticides and even fewer (5.7%) were able to provide a government-approved up-to-date license.

CONCLUSION

The combination of interviews, mystery shopping and observations proved to be useful, allowing the comparison of stated and actual behavior. While agro-input dealers want to sell pesticides and provide the corresponding risk advice, their customers might receive neither the appropriate product nor sufficient advice on proper handling. In light of the expected increase in pesticide use, affordable, accessible and repeated pesticide training and shop inspections are indispensable.

Farmer perceptions and willingness to pay for novel livestock pest control technologies: A case of tsetse repellent collar in Kwale County in Kenya

Tsetse-transmitted Animal African Trypanosomosis (AAT) is one of the most important constraints to livestock development in Africa. Use of trypanocides has been the most widespread approach for the management of AAT, despite the associated drug resistance and health concerns associated with drug metabolites in animal products. Alternative control measures that target tsetse fly vectors of AAT, though effective, have been hard to sustain in part because these are public goods applied area-wide. The International Centre of Insect Physiology and Ecology (icipe) and partners have developed and implemented a novel tsetse repellent collar (TRC) applied on animals to limit contact of tsetse flies and livestock, thereby reducing AAT transmission. The TRC has now advanced to commercialization. A household-level survey involving 632 cattle keeping households, was conducted in Shimba Hills region of Kwale County, where field trials of the TRC have been previously conducted to assess farmers’ knowledge, perception, and practices towards the management of tsetse flies, their willingness to pay (WTP) for the TRC, and factors affecting the WTP. Almost all the respondents (90%) reported that tsetse flies were the leading cattle infesting pests in the area. About 22% of these correctly identified at least four AAT clinical signs, and even though many (68%) used trypanocidal drugs to manage the disease, 50% did not perceive the drug as being effective in AAT management (50%). Few respondents (8%) were aware of the harmful effects of trypanocidal drugs. About 89% of the respondents were aware of icipe TRC, and 30% of them were using the field trial collars during the survey. Sixty-three (63%) of them were willing to pay for the TRC at the same cost they spend treating an animal for AAT. On average farmers were willing to pay KES 3,352 per animal per year. Male educated household heads are likely to pay more for the TRC. Moreover, perceived high AAT prevalence and severity further increases the WTP. Wider dissemination and commercialization of the herd-level tsetse control approach (TRC) should be encouraged to impede AAT transmission and thus enhance food security and farm incomes among the affected rural communities. Besides the uptake of TRC can be enhanced through training, especially among women farmers.

Animal African Trypanosomosis is a tropical disease that is of economic importance in Sub-Saharan Africa. The livestock sub-sector supports approximately 600 million smallholders in developing countries through employment, income from livestock products, and improving crop productivity through draft power and manure. Efforts to reduce rural poverty and improve food security and nutrition, therefore, require utilizing livestock to their full potential. Trypanosomosis results in anemia, emaciation, productivity loss, and mortality, and remains a leading constraint to livestock development in Africa. To reduce the risks associated with the use of trypanocides, alternative control measures that target the vector- tsetse fly need to be developed and widely disseminated. The International Centre of Insect Physiology and Ecology (icipe) and partners have—developed and implemented a novel tsetse repellent collar that shields animals from getting into contact with the vector, thereby preventing trypanosomosis transmission. The collar has now advanced to a commercialization stage. We conducted community and household-level surveys to assess farmer’s knowledge, perception, and practices regarding tsetse pest and trypanosomosis, and their willingness to pay for the novel tsetse repellent collar. We found that the pest is the main cattle production constraint and the cause of the associated disease, although there exists a gap in the identification of the clinical signs of the disease. Besides, most farmers rely on trypanocidal drugs for the treatment of their animals despite their human health and environmental risks. However, the majority were willing to buy the newly developed canvas collar. A male head of a household with a higher level of education is likely to pay more for the novel tsetse repellent collar. Besides, perception of high prevalence and severity of AAT is likely to increase the willingness to pay for the herd-level technology. The findings emphasize the need for wider dissemination and commercialization of the tsetse repellent collar technology to reduce trypanosomosis transmission and hence enhance food security and farm incomes in the affected regions in Africa.

Socioecological Factors and Farmer Perceptions Impacting Pesticide Use and Pollinator Conservation on Cucurbit Farms

While research suggests that pollinator decline is linked with agricultural practices, it is unclear whether farmers share this view and adapt management to promote pollinators based on their understanding of these threats. To address these issues, we surveyed farmers of pollinator-dependent cucurbit crops across four states in the Midwest, USA. We grouped farmers by their perceptions of pollinator declines and routes of pesticide exposure and used statistical models to evaluate if farmers manage pests and pollinators based on these perceptions. Out of 93 completed surveys, 39% of farmers believed pollinators were in decline. When grouped, 17% of farmers were classified as proponents, ranking (on a 1–5 Likert scale) the factors mediating pesticide exposure and pollinator declines as important or highly important. For comparison, 44 and 39% of farmers were classified as neutral or skeptical, respectively, of these same factors. Compared to the neutral and skeptic groups, proponents were on average younger, had fewer years farming but more years in family farming, and were more dependent on income from outside the farming system. Proponents also on average reported smaller farms, higher pest richness, more land in cucurbit production, and greater richness of crops that are not pollinator dependent, when compared to the neutrals and skeptics. We did not find pest and pollinator management to be related to farmer perceptions of pollinator decline or routes of pesticide exposure, but farmers classified as pollinator “proponents” were more likely to indicate participation in future pollinator habitat restoration programs. Rather, management strategies were better explained by on-farm environmental conditions (e.g., pest richness, farm size, number of pollinator dependent crops) and economic factors (e.g., sources of income). Generally, our research shows that farmers who perceive pollinator threats may not be using pollinator supportive practices. Thus, while some farmers believe in pollinator declines, there remains a need to connect this knowledge with on-farm practices.

Exposure to multiple pesticides and neurobehavioral outcomes among smallholder farmers in Uganda

BACKGROUND

Multiple epidemiological studies have shown that exposure to single pesticide active ingredients or chemical groups is associated with adverse neurobehavioral outcomes in farmers. In agriculture, exposure to multiple pesticide active ingredients is the rule, rather than exception. Therefore, occupational studies on neurobehavioral effects of pesticides should account for potential co-exposure confounding.

METHODS

We conducted a cross-sectional study of 288 Ugandan smallholder farmers between September and December 2017. We collected data on self-reported use of pesticide products during the 12 months prior to survey and estimated yearly exposure-intensity scores for 14 pesticide active ingredients using a semi-quantitative exposure algorithm. We administered 11 neurobehavioral tests to assess five neurobehavioral domains. We implemented a Bayesian Model-Averaging (BMA) approach to examine the association between exposure to multiple pesticides and neurobehavioral outcomes, while accounting for multiple testing. We applied two levels of inference to determine (1) which neurobehavioral outcomes were associated with overall pesticide exposure (marginal inclusion probability (MIP) for covariate-only models <0.5) and (2) which specific pesticide active ingredients were associated with these outcomes (MIP for models where active ingredient was included >0.5).

RESULTS

Seventy-two percent of farmers reported use of pesticide products that contained at least one of 14 active ingredients, while the applicators used in median three different active ingredients (interquartile range (IQR) 4) in the 12 months prior to the study. The most widely used active ingredients were glyphosate (79%), cypermethrin (60%), and mancozeb (55%). We found that overall pesticide exposure was associated with impaired visual memory (Benton Visual Retention Test (BVRT)), language (semantic verbal fluency test), perceptual-motor function (Finger tapping test), and complex attention problems (Trail making A test and digit symbol test). However, when we looked at the associations for individual active ingredients, we only observed a positive association between glyphosate exposure and impaired visual memory (-0.103 [95% Bayesian Credible Interval (BCI)] [-0.24, 0] units in BVRT scores per interquartile range (IQR) increase in annual exposure to glyphosate, relative to a median [IQR] of 6 [3] units in BVRT across the entire study population).

CONCLUSIONS

We found that overall pesticide exposure was associated with several neurobehavioral outcome variables. However, when we examined individual pesticide active ingredients, we observed predominantly null associations, except for a positive association between glyphosate exposure and impaired visual memory. Additional epidemiologic studies are needed to evaluate glyphosate's neurotoxicity, while accounting for co-pollutant confounding.

Pesticides: formulants, distribution pathways and effects on human health - a review

Pesticides are commonly used in agriculture to enhance crop production and control pests. Therefore, pesticide residues can persist in the environment and agricultural crops. Although modern formulations are relatively safe to non-target species, numerous theoretical and experimental data demonstrate that pesticide residues can produce long-term negative effects on the health of humans and animals and stability of ecosystems. Of particular interest are molecular mechanisms that mediate the start of a cascade of adverse effects. This is a review of the latest literature data on the effects and consequences of contamination of agricultural crops by pesticide residues. In addition, we address the issue of implicit risks associated with pesticide formulations. The effects of pesticides are considered in the context of the Adverse Outcome Pathway concept.

Farmers' knowledge, attitudes and practices towards management of cassava pests and diseases in forest transition and Guinea savannah agro-ecological zones of Ghana

Background: Cassava is a major staple root crop in Ghana, which serves as a food security and an income generating crop for farming families. In spite of its importance, the crop is plagued with biotic factors such as pests and diseases, resulting in yield and income reductions. Methods: Farmers' knowledge, attitudes and practices towards cassava pest and disease management were investigated. A mixed research questionnaire was used to collect both qualitative and quantitative data from 94 cassava farm households across two major cassava growing agro-ecologies. Results: Using descriptive statistics, parametric and non-parametric analysis, our study revealed that farmers' knowledge on cassava pests was high but low for diseases. Whiteflies ( Bemisia tabaci Gennadius), grasshoppers ( Zonocerus variegatus), aphids ( Aphis gossypii Glover), mealybugs ( Phenacoccus manihoti), termites ( Isoptera), and grasscutters ( Thryonomys swinderianus) were perceived as the most common damaging pests. Farmers' descriptions showed that disease pathogens attacked foliar tissues, stem and root tissues and caused leaf dropping and die back. Cassava mosaic disease and root rot were the most common diseases; however, disease descriptions suggested the incidence of viral, bacterial and fungal diseases. Some of the farmers observed mixed symptoms on their farms. The results also showed that only 25.5% cultivated improved varieties. Management actions applied included field sanitation practices and pesticide application. The effectiveness level of the control actions was rated moderately effective. Conclusions: The analysis showed heterogeneity in personal and farm level characteristics of respondents across the two agro-ecologies, but agro-ecologies were independent of the management practices employed. There is a need to improve farmers' access to improved disease-free planting materials through efficient dissemination pathways and increase farmers' knowledge on cassava pests, diseases and integrated management through publfic awareness creation and capacity building by extension agents and research institutions. Continued government investment is needed to achieve sustainable outcomes.

A Comparison of Pesticide Risk Beliefs between Farmers and Farmworkers: Implications for Risk Communication and Education

Understanding the multi-dimensional risk beliefs of agricultural audiences allows risk communicators and educators to target those beliefs to improve practices. This study was designed to assess pesticide risk beliefs among English-speaking farmers and Spanish-speaking farmworkers and to compare their beliefs. The Pesticide Risk Beliefs Inventory (PRiBI) is a 19-item quantitative instrument used to assess the alignment of risk beliefs with those beliefs of experts in the field. A higher score on the PRiBI relates to an agreement with expert beliefs regarding pesticide risk. Farmers' and farmworkers' scores were signficiantly different on items corresponding to the use of physical properties to determine risk and specific adverse health outcomes associated with pesticide exposure. With an understanding that farmworkers rely on the physical properties of pesticides to assess risk, educators and farmers can encourage more reliable ways to assess pesticide hazards.

Impact of farm size on intensity of pesticide use: Evidence from China

The average amount of pesticides used per hectare in China is roughly five times of the world average. Understanding the drivers of pesticide use will help reduce excessive pesticide use in China. Using farm-level cross-sectional data, county-level and province-level panel data, this study investigates the impact of farm size on the intensity of pesticide use. The results indicate that farm size has a significant negative impact on the intensity of pesticide use. On average, a 1% increase in farm size is associated with a 0.2% decrease in pesticide use per hectare. The study suggests that promoting the development of relatively large-scale farms can reduce the intensity of pesticide use in China.

Acute Changes in Thyroid Hormone Levels among Thai Pesticide Sprayers

The objective of this study was to investigate the relationship of acute pesticide exposures and acute changes in thyroid hormones among Thai farmers. We recruited 78 farmers, who were scheduled to spray insecticides (chlorpyrifos and/or cypermethrin) or herbicides (paraquat and/or glyphosate). On the day before spraying, farmers collected their first morning void urine and went for blood collection. On the spray day, urine samples were collected at end of the spraying event and they were interviewed with questionnaires. The next morning, the first morning void urine and blood samples were collected. Blood samples were analyzed for thyroid hormones. Urine samples were analyzed for the metabolites of the pesticide sprayed. The results showed that the thyroid hormones, free triiodothyronine (FT3) and total triiodothyronine (T3) were significantly reduced as urinary chlorpyrifos metabolite increased the day after spraying. Total thyroxine (T4) significantly increased as cypermethrin metabolites increased the day after spraying. T4 significantly increased as urinary glyphosate levels increased; however, FT3 and T3 decreased significantly as urinary paraquat levels increased the day after spraying. These findings suggest that acute exposures to the pesticides chlorpyrifos, cypermethrin, paraquat and glyphosate can produce acute effects on the hypothalamic-pituitary-thyroid (HPT) axis, acutely altering thyroid hormone levels.

Emergence of Maruca vitrata as a Major Pest of Food Legumes and Evolution of Management Practices in Asia and Africa

Legume pod borer, Maruca vitrata, has emerged as a major pest on food legumes in Asia and Africa. It is an oligophagous pest, feeding on over 70 species in Fabaceae. We examine the species complex in Asia, Africa, Oceania, and the Americas, with an emphasis on molecular taxonomy. Studies on pheromone production and perception suggest the existence of pheromone polymorphism, especially in Asia and Africa. No Maruca-resistant varieties are available in the major food legumes including cowpea, pigeonpea, mungbean, and yard-long bean. Legume growers use chemical pesticides indiscriminately, leading to the development of pesticide resistance. However recent developments in habitat management, classical biocontrol with more efficient parasitoids, biopesticides, and judicious use of insecticides pave the way for sustainable management of M. vitrata, which can reduce the pesticide misuse. Active engagement of the private sector and policy makers can increase the adoption of integrated pest management approaches in food legumes.

The global distribution of acute unintentional pesticide poisoning: estimations based on a systematic review

BACKGROUND

Human poisoning by pesticides has long been seen as a severe public health problem. As early as 1990, a task force of the World Health Organization (WHO) estimated that about one million unintentional pesticide poisonings occur annually, leading to approximately 20,000 deaths. Thirty years on there is no up-to-date picture of global pesticide poisoning despite an increase in global pesticide use. Our aim was to systematically review the prevalence of unintentional, acute pesticide poisoning (UAPP), and to estimate the annual global number of UAPP.

METHODS

We carried out a systematic review of the scientific literature published between 2006 and 2018, supplemented by mortality data from WHO. We extracted data from 157 publications and the WHO cause-of-death database, then performed country-wise synopses, and arrived at annual numbers of national UAPP. World-wide UAPP was estimated based on national figures and population data for regions defined by the Food and Agriculture Organization (FAO).

RESULTS

In total 141 countries were covered, including 58 by the 157 articles and an additional 83 by data from the WHO Mortality Database. Approximately 740,000 annual cases of UAPP were reported by the extracted publications resulting from 7446 fatalities and 733,921 non-fatal cases. On this basis, we estimate that about 385 million cases of UAPP occur annually world-wide including around 11,000 fatalities. Based on a worldwide farming population of approximately 860 million this means that about 44% of farmers are poisoned by pesticides every year. The greatest estimated number of UAPP cases is in southern Asia, followed by south-eastern Asia and east Africa with regards to non-fatal UAPP.

CONCLUSIONS

Our study updates outdated figures on world-wide UAPP. Along with other estimates, robust evidence is presented that acute pesticide poisoning is an ongoing major global public health challenge. There is a need to recognize the high burden of non-fatal UAPP, particularly on farmers and farmworkers, and that the current focus solely on fatalities hampers international efforts in risk assessment and prevention of poisoning. Implementation of the international recommendations to phase out highly hazardous pesticides by the FAO Council could significantly reduce the burden of UAPP.

Suggested policy and legislation reforms to reduce deleterious effect of pesticides in Lebanon

Countrywide pesticide management activities are resource draining, even for developed countries, which sometimes fall short in achieving the optimum protection against pesticides deleterious effects on humans and environment. Additionally, in Lebanon, basic flaws exist at different levels of pesticide management cycle. In this study, through an extensive review of relevant literature regarding the pesticides impact on humans and environment in Lebanon and adopted policies in existing legislation, several gaps have been identified. Accordingly, recommendations to reduce pesticide risk through a combination of reforms at the policy level and its tools, particularly legislation, are proposed. In our opinion, the starting point is to adopt a minimum list of lower risk pesticides supported by a combination of: "prescriptions" based on a comprehensive registration and an effective implementation systems, a suitable IPM/ICM government-supported credit system, traceability systems of agricultural commodities and pesticides containers, Pesticide stock management system to reduce the quantity of obsolete pesticides, and containers recycling system. For a global sustainability of pesticides risk reduction, a binding global intervention fostered by the UN, based on human rights for safe food, is called upon to ban hazardous pesticides-except those of WHO class IV- trafficking in developing countries scoring low in an international official assessment of their pesticides lifecycle management. At the same time, global funds should support pesticides alternatives and the enhancement of the developing countries capacities for pesticides lifecycle management, which is a part of a larger global matrix in risk reduction.

Effect of Pheromone-Mediated Mating Disruption on Pest Population Density of Maruca vitrata (Fabricius) (Crambidae: Lepidoptera)

Simple Summary

The legume pod borer is one of the most serious legume pests widely distributed in Asia, Africa, Australia, America, and Oceania. The use of synthetic pheromone lures has been developed as a more environmentally friendly alternative for its control. In this study, we evaluated the potential of the pheromone components as a mating disruption tool under laboratory and small-scale field conditions by identifying effective blends made out of single pheromone components or a different mix of them. The results from the laboratory experiment show that insects challenged with the blend ratio of 1:1:1 had lower fecundity and egg eclosion. A small-scale caged field experiment also showed a significantly disruption of normal mating with the above-mentioned ratio, leading to lower flower and pod damage, and higher mungbean yield. This study provides new evidence about the possibility to use pheromone components for mating disruption; however, more research is needed to determine appropriate ratios of pheromone blend to increase the effect of disruption. From an applied research perspective, more studies are needed to investigated the effectiveness of mating disruption strategy on different legume crops, dispenser types, release points in the field, and compatibility with conventional insecticides as part of an integrated pest management (IPM) combined approach.

Abstract

The legume pod borer (Maruca vitrata) is one of the most serious legume pests due to its wide host range and high damage potential. Pheromone components on M. vitrata have been previously identified, allowing research on more environmentally friendly IPM tools for its control. M. vitrata produces a three-component pheromone blend containing (E, E)-10,12-hexadecadienal (major), (E, E)-10,12-hexadecadienol (minor), (E)-10-hexadecenal (minor). This study focused on the efficacy of synthetic pheromone lures and their blend components for mating disruption in M. vitrata. Under laboratory conditions, the mating behavior of M. vitrata pairs was observed from 18:00 to 02:00 h in an interval of 20 min to assess the efficacy of different pheromone lures. The scotophase behavior results show that the complete pheromone blend (E, E)-10,12-hexadecadienal + (E, E)-10,12-hexadecadienol + (E)-10-hexadecenal with a blend ratio of 1:1:1 effectively disrupted mating. The impact on mating disruption was evident from the lower fecundity and egg hatch/eclosion. The same lures were evaluated in a small-scale caged field study. The results show that the pheromone blend of (E, E)-10,12-hexadecadienal + (E, E)-10,12-hexadecadienol + (E)-10-hexadecenal in a1:1:1 ratio significantly disrupted the normal mating, leading to lower flower and pod damage and higher mung bean yield.

Mochiah M, N. Lamptey J, Manu-Aduening J, Pita J. Farmers’ knowledge, attitudes and practices towards management of cassava pests and diseases in forest transition and Guinea savannah agro-ecological zones of Ghana

Background: Cassava is a major staple root crop in Ghana, which serves as a food security and an income generating crop for farming families. In spite of its importance, the crop is plagued with biotic factors such as pests and diseases, resulting in yield and income reductions. Methods: Farmers’ knowledge, attitudes and practices towards cassava pest and disease management were investigated. A mixed method research questionnaire was used to collect both qualitative and quantitative data from 94 cassava farm households across two major cassava growing agro-ecologies. Results: Using descriptive statistics, parametric and non-parametric analysis, our study revealed that farmers’ knowledge on cassava pests was high but low for diseases. Whiteflies (Bemisia tabaci Gennadius), grasshoppers (Zonocerus variegatus), aphids (Aphis gossypii Glover), mealybugs (Phenacoccus manihoti), termites (Isoptera), and grasscutters (Thryonomys swinderianus) were perceived as the most common damaging pests. Farmers’ descriptions showed that disease pathogens attacked foliar tissues, stem and root tissues and caused leaf dropping and die back. Cassava mosaic disease and root rot were the most common diseases; however, disease descriptions suggested the incidence of viral, bacterial and fungal diseases. Some of the farmers observed mixed infections on their farms. The results also showed that only 25.5% cultivated improved varieties. Management actions applied included field sanitation practices and pesticide application. The effectiveness level of the control actions was rated moderately effective. Conclusions: The analysis showed heterogeneity in personal and farm level characteristics of respondents across the two agro-ecologies, but agro-ecologies were independent of the management practices employed. There is a need to improve farmers’ access to improved disease-free planting materials through efficient dissemination pathways and increase farmers’ knowledge on cassava pests, diseases and integrated management through publfic awareness creation and capacity building by extension agents and research institutions. Continued government investment is needed to achieve sustainable outcomes.

Biopesticide based sustainable pest management for safer production of vegetable legumes and brassicas in Asia and Africa

Vegetables are one of the important crops which could alleviate poverty and malnutrition among the smallholder farmers in tropical Asia and Africa. However, a plethora of pests limit the productivity of these crops, leading to economic losses. Vegetable producers overwhelmingly rely on chemical pesticides in order to reduce pest-caused economic losses. However, over-reliance on chemical pesticides poses serious threats to human and environmental health. Hence, biopesticides offer a viable alternative to chemical pesticides in sustainable pest management programs. Baculoviruses such as nucleopolyhedrovirus (NPV) and granulovirus (GV) have been exploited as successful biological pesticides in agriculture, horticulture and forestry. Maruca vitrata multiple nucleocapsid NPV (MaviMNPV) was found to be a unique baculovirus specifically infecting pod borer on food legumes, and it has been successfully developed as a biopesticide in Asia and Africa. Entomopathogenic fungi also offer sustainable pest management options. Several strains of Metarhizium anisopliae and Beauveria bassiana have been tested and developed as biopesticides in Asia and Africa. This review specifically focuses on the discovery and development of entomopathogenic virus and fungi-based biopesticides against major pests of vegetable legumes and brassicas in Asia and Africa. © 2019 Society of Chemical Industry.

Pheromone-binding proteins based phylogenetics and phylogeography of Maruca spp. from Asia, Africa, Oceania, and South America

Variations in the functional response of legume pod borer (Maruca vitrata) populations to sex pheromone blends were observed in Asia and Africa. Hence, this study was carried out to understand the differences in pheromone-binding proteins (PBPs) among Maruca populations in Asia, Africa, Oceania, and South America. A de novo transcriptome assembly was adopted to sequence the entire transcribed mRNAs in M. vitrata from Taiwan. The raw-sequence data were assembled using homologous genes from related organisms in GenBank to detect M. vitrata PBPs (MvitPBPs). Sections of the cDNA of MvitPBP of different length were used to design primers to amplify the full-length cDNA of PBPs. All three PBP sequences comprised three exons interspersed by two introns. In total, 92 MvitPBP1 haplotypes, 77 MvitPBP2 haplotypes, and 64 MvitPBP3 haplotypes were identified in 105, 98, and 68 Maruca individuals, respectively. High pairwise F ST values (0.41-0.73) and phylogenetic analyses distinguished the putative Maruca species in South America from those occurring in rest of the world, and possibly two putative subspecies in Asia and Africa. The haplotype networks and Automatic Barcode Gap Discovery analyses also confirmed these results. The negative Tajima's D and Fu's F S values showed the recent demographic expansion of Maruca populations. Thus, this study confirmed the presence of different Maruca species and/or subspecies in different continents based on the diversity within PBP genes. Additional sampling and studies are suggested for Oceania and South America. The genetic differences among Maruca populations should be carefully considered while using sex pheromone lures and bio-control agents.

Farmers’ Knowledge, Perceptions and Practices in Managing Weeds and Insect Pests of Common Bean in Northern Tanzania

Weeds and insect pests are among the serious constraints in common bean production in most rural communities. A survey of 169 smallholder farmers was conducted in two common bean-growing districts in northern Tanzania. The aim was to assess farmers’ knowledge, perceptions, current management practices and challenges in order to develop sustainable weed and insect pest management strategies. The results revealed that 83% of farmers perceived insect pests as the major constraint in common bean production, while 73% reported weeds as the main drawback. Insect pest management was mainly achieved through the use of synthetic pesticides, however, only 24% of farmers were able to apply, the rest could not afford due to high cost, limited access and lack of knowledge. Only 6.5% of farmers were aware of non-chemical methods and 2.1% did not practice any method in managing insect pests, both in the field and during storage. Moreover, farmers generally relied on experience in managing insect pests and weeds, and about 43% did not see the need to consult extension officers. These findings indicate that there is a need to sensitize and train farmers on the sustainable methods for pest and weed management in common bean farming systems in northern Tanzania.

What Do Romanian Farmers Think about the Effects of Pesticides? Perceptions and Willingness to Pay for Bio-Pesticides

Farmers’ knowledge and perception of risks associated with pesticides are core issues in adopting sustainable behavior related to pesticides. This study aimed to find out if Romanian farmers’ perceptions regarding the effects of conventional pesticides on pests, health, and the environment can predict farmers’ willingness to replace conventional pesticides with bio ones and to pay a higher price for the latter. This is the first investigation of Romanian farmers’ perceptions regarding pesticides, thus providing information useful both from the market and environmental protection perspectives. Binary logistic regression was performed to test the relationship between the perceived effect of pesticides, on the one side, and willingness to change conventional with bio-pesticides and willingness to pay for bio-pesticides, on the other side. It was found that the efficiency of conventional pesticides on combating pests and their effects on a farmer’s health can predict farmer willingness to replace conventional approaches with bio-pesticides. Conclusions disclose entry points for interventions aimed at improving communication and information strategies at the country level for raising awareness of the adverse effects of pesticide products, both at the food consumer and farmer levels.

Pesticide residues in Nepalese vegetables and potential health risks

We conducted this study in order to assess the pesticide residues in vegetables and examine the related human health risk. Therefore, residues of 23 pesticides (organophosphates, organochlorines, acaricides, fungicides, and insecticides of biological origin) were analysed in the three main vegetable crops grown in Southern Nepal: 27 eggplant, 27 chilli and 32 tomato samples representing (i) conventional (N = 67) and ii) integrated pest management (IPM) fields (N = 19). Pesticide residues were found in 93% of the eggplant samples and in all of the chilli and tomato samples. Multiple residues were observed in 56% of the eggplant samples, 96% of chilli samples and all of the tomato samples. The range (µg/kg) of total detected pesticide residues in eggplants, chillies and tomatoes was 1.71-231, 4.97-507, 13.1-3465, respectively. The most frequently detected pesticides in these vegetables were carbendazim and chloropyrifos. Pesticide residues in 4% of the eggplant, 44% of the tomato and 19% of the chilli samples exceeded the EU maximum residue limits (MRLs). The residues of triazophos, omethoate, chloropyrifos and carbendazim exceeded the EU MRLs. Compared to chilli and eggplant crops, more carbendazim was sprayed onto tomato crops (p < 0.05). We assessed adolescent and adult dietary exposure using hazard quotient (HQ) and hazard index (HI) equations for the identified pesticides. HQ> 1 was observed for chloropyrifos, triazophos and carbendazim in eggplants; profenofos, triazophos, dimethoate, omethoate, chloropyrifos and carbendazim in tomatoes; and dichlorvos and chloropyrifos in chillies. Of all of the HQs, the highest acute HQ (aHQ) was for triazophos (tomato) in adolescents (aHQ=657) and adults (aHQ=677), showing the highest risks of dietary exposure. The cumulative dietary exposure showed a higher HI for organophosphates (HI>83) and a lower HI for organochlorines, acaricides and biological insecticides (HI<1). The concentration of pesticide residues in the vegetable crops from the IPM field was considerably lower, suggesting a greater ability of IPM systems to reduce the dietary risks from exposure to pesticides.