Low Pesticide Use Research Articles

Risks and opportunities of increasing yields in organic farming. A review

Current organic agriculture performs well in several sustainability domains, like animal welfare, farm profitability and low pesticide use, but yields are commonly lower than in conventional farming. There is now a re-vitalized interest in increasing yields in organic agriculture to provide more organic food for a growing, more affluent population and reduce negative impacts per unit produced. However, past yield increases have been accompanied by several negative side-effects. Here, we review risks and opportunities related to a broad range of sustainability domains associated with increasing yields in organic agriculture in the Northern European context. We identify increased N input, weed, disease and pest control, improved livestock feeding, breeding for higher yields and reduced losses as the main measures for yield increases. We review the implications of their implementation for biodiversity, greenhouse gas emissions, nutrient losses, soil fertility, animal health and welfare, human nutrition and health and farm profitability. Our findings from this first-of-its-kind integrated analysis reveal which strategies for increasing yields are unlikely to produce negative side-effects and therefore should be a high priority, and which strategies need to be implemented with great attention to trade-offs. For example, increased N inputs in cropping carry many risks and few opportunities, whereas there are many risk-free opportunities for improved pest control through the management of ecosystem services. For most yield increasing strategies, both risks and opportunities arise, and the actual effect depends on management including active mitigation of side-effects. Our review shows that, to be a driving force for increased food system sustainability, organic agriculture may need to reconsider certain fundamental principles. Novel plant nutrient sources, including increased nutrient recycling in society, and in some cases mineral nitrogen fertilisers from renewable sources, and truly alternative animal production systems may need to be developed and accepted.

Indirect effects of agricultural pesticide use on parasite prevalence in wild pollinators

Insect pollinators appear to be experiencing worldwide declines, a phenomenon that has been correlated both with exposure to chemical pesticides and disease prevalence. These factors have been found to have strong and often interacting negative effects on multiple pollinator species in laboratory based studies, however their interactions in the field are less clear. To try and understand the link between pesticide use on pollinator communities, and how this might impact on disease transmission, we took two complementary approaches. First, we undertook a series of pollinator surveys to assess the abundance and diversity of pollinator groups across British agricultural field sites subject to varying levels of pesticide use. We then screened the offspring of two taxa of tube nesting solitary bees (Osmia bicornis and Megachile spp.) for three parasite groups commonly associated with pollinators. We found lower pollinator abundance, group richness and diversity across agricultural sites associated with higher pesticide use. Specifically, there were fewer honey bees, hoverflies, solitary bees and wasps. Surprisingly, we found a lower prevalence of all three parasite groups in O. bicornis offspring reared in sites associated with higher pesticide use compared to lower pesticide use. We also found a lower prevalence of Ascosphaera but a higher prevalence of Microsporidia in Megachile offspring reared in sites associated with higher pesticide use compared to lower pesticide use. Together, our results suggest that agricultural sites associated with higher pesticide use may be affecting pollinators indirectly by disrupting community structure and influencing disease epidemiology and vectoring opportunities. This highlights the importance of understanding the interactions between pesticide use and disease in both managed and wild bee populations for the future mitigation of pollinator declines.

Positive correlation between pesticide sales and central nervous system and cardiovascular congenital abnormalities in Brazil

Background: This study investigated the association between pesticide exposure in Brazil (2005–2013) with rates of central nervous system (CNS) and cardiovascular system (CVS) congenital abnormalities in 2014. Method: An exposure variable was established from data on production and sales of pesticides (kg) per crop area (ha) for 2012 and 2013 years. The Brazilian states were divided into three categories: high, medium, and low pesticide use and rate ratios were estimated for each group of states (CI: 95 %). Results: In 2013 and 2014, the high use group presented a 100 and a 75 % increase, and the medium group a 65 and 23 % increase, respectively, in the risk of CNS and CVS congenital abnormalities at birth, compared to the low use group. Conclusion: These findings suggest that pesticide exposure could be associated with increased risk of congenital malformations at birth in Brazil.

Reducing pesticide use while preserving crop productivity and profitability on arable farms.

Achieving sustainable crop production while feeding an increasing world population is one of the most ambitious challenges of this century1. Meeting this challenge will necessarily imply a drastic reduction of adverse environmental effects arising from agricultural activities2. The reduction of pesticide use is one of the critical drivers to preserve the environment and human health. Pesticide use could be reduced through the adoption of new production strategies3-5; however, whether substantial reductions of pesticide use are possible without impacting crop productivity and profitability is debatable6-17. Here, we demonstrated that low pesticide use rarely decreases productivity and profitability in arable farms. We analysed the potential conflicts between pesticide use and productivity or profitability with data from 946 non-organic arable commercial farms showing contrasting levels of pesticide use and covering a wide range of production situations in France. We failed to detect any conflict between low pesticide use and both high productivity and high profitability in 77% of the farms. We estimated that total pesticide use could be reduced by 42% without any negative effects on both productivity and profitability in 59% of farms from our national network. This corresponded to an average reduction of 37, 47 and 60% of herbicide, fungicide and insecticide use, respectively. The potential for reducing pesticide use appeared higher in farms with currently high pesticide use than in farms with low pesticide use. Our results demonstrate that pesticide reduction is already accessible to farmers in most production situations. This would imply profound changes in market organization and trade balance.

Economic sustainability: Less pesticide rarely causes loss.

A large-scale study covering a wide range of arable farming systems reveals that, besides the obvious environmental benefits, low pesticide use rarely decreases productivity and profitability.

Detecting pyrethroid resistance in predatory mites inhabiting soil and litter: an in vitro test.

While resistance against insecticides is widely known in pest arthropods, it remains poorly known in non-target arthropods of the same agrosystems. This may be of crucial importance in the context of organic pest management or integrated pest management. First, stopping of pesticide pressure during farm conversion may lead to important rearrangements of non-target communities due to fitness cost of resistance in populations of some species. Second, resistant biological agents may be useful to farms with low synthetic pesticide use. Communities of mesostigmatid mites, encompassing numerous predatory species, are supposed to be involved in important ecological processes in both crop soils and animal litter/manure. Here we provide a tarsal contact method for assessing resistance in different populations from various species of mesostigmatid mites. Analyses of data from repeated tests on three populations from different mesostigmatid families proved the method to be robust and able to generate consistent and reliable mortality percentages according to insecticide concentration. Our bioassay system allows for both one-shot estimate of pyrethroid sensitivity in mite populations and estimation of how it changes over time, making possible survival analyses and assessment of recovery from knockdown. The rating system retained makes it possible to score response to insecticides in a consistent and standard way in species from different mesostigmatid families. © 2016 Society of Chemical Industry.

Sustainability of European winter wheat- and maize-based cropping systems: Economic, environmental and social ex-post assessment of conventional and IPM-based systems

In order to ensure higher sustainability of winter wheat and maize production in Europe, cropping systems featuring different levels of Integrated Pest Management (IPM) need to be tested in the field and validated for their sustainability before being adopted by farmers. However, the sustainability evaluation of cropping systems is difficult to perform effectively due to the complex economic, social and environmental dimensions of sustainability. Within the EU research project PURE, nine long-term experiments were conducted in various European regions from 2011 to 2014, comparing two IPM levels against the conventional system (CS) in winter wheat- and maize-based cropping systems. IPM1 encompassed some pesticide use in semi-diverse crop rotations while IPM2 favoured reduced- and non-chemical methods in diverse rotations. The modified DEXiPM (DEXi Pest Management) model for arable cropping systems was used for ex-post assessments to compare the economic, environmental and social sustainability of these systems. The assessments showed that in six out of nine trials the CS was overall unsustainable because of low evaluation of the environmental sustainability that was mainly due to high pesticide use and simplified crop rotations where the choice of crops is primarily market-driven. In contrast, six IPM1 and five IPM2 systems could be classified as sustainable, achieving ‘medium’ or ‘high’ scores for all three sustainability dimensions. Differences in the socio-economic conditions across countries and/or climatic and soil conditions across experimental trials highlighted that IPM is based on general principles that must be adapted to address specific local conditions. Overall, IPM systems included more diverse crop rotations and practices compared to the CS, promoting IPM-based strategies with less pesticide use but also a reduced reliance on pesticides that could partially compensate for any yield reductions by the savings on pesticide and application costs. It is recommended that the results of the study should be disseminated to policy-makers, advisors and farmers and that their implementation should be considered on a regional level. Regional policies to encourage the adoption of more sustainable systems based on IPM principles, as well as better support by more closely involving the regional advisory services for the general implementation of IPM is further recommended. Ex-post analysis with DEXiPM also identified the constraints of the IPM1 and IPM2 systems evaluated as not sustainable. These were related to i) environmental issues for those IPM1 systems that still relied mainly on pesticide use and had less diverse crop rotations, and ii) economic issues for IPM2 systems, mainly due to the choice of less profitable crops in the rotation, as well as to yield penalties caused by the very low pesticide use or replacing pesticides with less effective non-chemical methods. The identification of these constraints is a valuable input to the local and regional discussion on how to adopt IPM and develop more sustainable cropping systems.

Profiling farming management strategies with contrasting pesticide use in France

Reducing pesticide use in agriculture is a major challenge to improve sustainability of cropping systems. It is critical to identify effective integrated farming strategies able to decrease substantially pesticide use. This study is based on a unique French national network of 1012 arable commercial farms involved in a pesticide reduction program. These farms displayed contrasting levels of pesticide use, and covered a large diversity of environmental characteristics and farming practices. Our objective was to identify profiles of management strategies showing contrasting pesticide use levels in France. Two categories of factors potentially related to pesticide use were considered successively, namely factors describing production situations and factors describing management strategies. Regression tree methods were applied to the dataset to identify combinations of factors associated with low vs. high pesticide use levels. Results showed that, among the factors describing production situations, the presence of livestock, climate conditions, and to a lesser extent soil characteristics were able to discriminate groups of farms with contrasting pesticide use levels. Among the factors describing management strategies, the crop sequence, the crop diversity, the pesticide spraying techniques, and soil tillage were frequently selected for discriminating farms characterised by low vs. high pesticide use levels, whereas specific factors such as mechanical weeding, crop cultivars and sowing dates were related with pesticide use in some production situations only. Across production situations, several contrasting strategies led to low levels of pesticide use. Besides, within each considered production situation, different strategies appeared associated with low levels of pesticide use. Our results reveal that a large diversity of strategies exists for controlling pests, weeds and diseases without high levels of pesticide use.

Examining impacts of current-use pesticides in Southern Ontario using in situ exposures of the amphipod Hyalella azteca.

In situ exposures with Hyalella azteca were used to assess impacts of current-use pesticides in Southern Ontario, Canada. Exposures were conducted over 2 growing seasons within areas of high pesticide use: 1 site on Prudhomme Creek and 3 sites on Twenty Mile Creek. Three sites on Spencer Creek, an area of low pesticide use, were added in the second season. Surface water samples were collected every 2 wk to 3 wk and analyzed for a suite of pesticides. Hyalella were exposed in situ for 1 wk every 4 wk to 6 wk, and survival and acetylcholinesterase (AChE) activity were measured. Pesticides in surface waters reflected seasonal use patterns: lower concentrations in spring and fall and higher concentrations during summer months. Organophosphate insecticides (chlorpyrifos, azinphos methyl, diazinon) and acid herbicides (2,4-dichlorophenoxyacetic acid [2,4-D], mecoprop) were routinely detected in Prudhomme Creek, whereas neutral herbicides (atrazine, metolachlor) dominated the pesticide signature of Twenty Mile Creek. Spencer Creek contained fewer pesticides, which were measured at lower concentrations. In situ effects also followed seasonal patterns: higher survival and AChE activity in spring and fall, and lower survival and AChE activity during summer months. The highest toxicity was observed at Prudhomme Creek and was primarily associated with organophosphates. The present study demonstrated that current-use pesticides in Southern Ontario were linked to in situ effects and identified sites of concern requiring further investigation.

Tracking on-farm innovations to unearth alternatives to the dominant soybean-based system in the Argentinean Pampa

Farming activities in the Argentinean Pampa have focused on soybean production since the 1990s. The resulting cropping systems may not be sustainable in the long run due to development of glyphosate-tolerant weeds, homogenization of landscape mosaics, and pollutions. Here, we used the tracking on-farm innovation method to produce resources for the design of alternatives. The five steps of tracking on-farm innovation were (1) characterization of the soybean-based dominant cropping system, (2) identification of producers developing alternative systems, (3) description of these cropping systems and their agronomic logic, which is the link between the producer practices and their motives when choosing these practices, (4) multicriteria assessment of the performances of the systems, and (5) analysis of the development conditions of the most efficient systems. We identified 22 alternative cropping systems developed by farmers. These systems all include original practices: diversification of crop rotations (22 cases), occasional return to tillage (15 cases), and low pesticide use (16 cases). Some alternative systems were more sustainable than the soybean-based system, as shown by lower economic risk level, better ability to maintain soil organic carbon content, and less glyphosate-tolerant weeds. Our results show overall that tracking on-farm innovations is an efficient method to get references on alternative cropping systems developed by farmers.

Exploring cost dominance in crop farming systems between high and low pesticide use

The purpose of this paper is to assess cost dominance in direct inputs between arable crop-based systems using low or high pesticide levels per hectare. Our investigation departs from a traditional efficiency analysis and aims at comparing two minimal direct cost functions excluding pesticide expenses. This means that we evaluate the gap between two efficient frontiers instead of focusing on individual farm inefficiency scores. Our only objective is to compare two optimal cost benchmarks for systems respectively defined with high or low pesticide levels per hectare by varying their scale and output mix. A robust approach frontier is introduced to control the influence of potential outliers and unobserved heterogeneity. Based on 707 French crop farms observed in 2008, our simulations show that agricultural practices using less pesticide per hectare are unambiguously more cost-competitive in terms of direct inputs while inducing no other substitution costs. This cost dominance is a robust phenomenon regardless of the size and scope of crop activities, which supports more ecofriendly practices.

Integrated Pest Management for Sustainable Intensification of Agriculture in Asia and Africa.

Integrated Pest Management (IPM) is a leading complement and alternative to synthetic pesticides and a form of sustainable intensification with particular importance for tropical smallholders. Global pesticide use has grown over the past 20 years to 3.5 billion kg/year, amounting to a global market worth $45 billion. The external costs of pesticides are $4–$19 (€3–15) per kg of active ingredient applied, suggesting that IPM approaches that result in lower pesticide use will benefit, not only farmers, but also wider environments and human health. Evidence for IPM’s impacts on pesticide use and yields remains patchy. We contribute an evaluation using data from 85 IPM projects from 24 countries of Asia and Africa implemented over the past twenty years. Analysing outcomes on productivity and reliance on pesticides, we find a mean yield increase across projects and crops of 40.9% (SD 72.3), combined with a decline in pesticide use to 30.7% (SD 34.9) compared with baseline. A total of 35 of 115 (30%) crop combinations resulted in a transition to zero pesticide use. We assess successes in four types of IPM projects, and find that at least 50% of pesticide use is not needed in most agroecosystems. Nonetheless, policy support for IPM is relatively rare, counter-interventions from pesticide industry common, and the IPM challenge never done as pests, diseases and weeds evolve and move.

Neurobehavioral effects of exposure to organophosphates and pyrethroid pesticides among Thai children

The use of pesticides for crop production has grown rapidly in Thailand during the last decade, resulting in significantly greater potential for exposure among children living on farms. Although some previous studies assessed exposures to pesticides in this population, no studies have been conducted to evaluate corresponding health effects. Twenty-four children from a rice farming community (exposed) and 29 from an aquaculture (shrimp) community (control) completed the study. Participants completed a neurobehavioral test battery three times at 6 month intervals: Session I: preliminary orientation; Session II: high pesticide use season; Session III: low pesticide-use season. Only sessions II and III were used in the analyses. High and low pesticide use seasons were determined by pesticide use on rice farms. Urinary metabolites of organophosphates (OPs) and pyrethroids (PYR) were analyzed from first morning void samples collected the day of neurobehavioral testing. Rice farm participants had significantly higher concentrations of dialkylphosphates (DAPs) (common metabolites of OPs) and TCPy (a specific metabolite of chlorpyrifos) than aquaculture farm children during both seasons. But, TCPy was significantly higher during the low rather than the high pesticide use season for both participant groups. Rice farm children had significantly higher DCCA, a metabolite of PYR, than aquaculture participants only during the high exposure season. Otherwise, no significant differences in PYR metabolites were noted between the participant groups or seasons. No significant adverse neurobehavioral effects were observed between participant groups during either the high or low pesticide use season. After controlling for differences in age and the Home Observation for Measurement of the Environment (HOME) scores, DAPs, TCPy, and PYR were not significant predictors of adverse neurobehavioral performance during either season. Increasing DAP and PYR metabolites predicted some relatively small improvement in latency of response. However, due to the small sample size and inability to characterize chronic exposure, any significant differences observed should be regarded with caution. Moreover although not statistically significant, confidence intervals suggest that small to moderate adverse effects of pesticide exposure cannot be ruled out for some indicators of neurobehavioral performance.

Environmental pesticides increase the risk of developing hypertrophic pyloric stenosis

BackgroundHypertrophic pyloric stenosis (HPS) is a condition noted within the first several weeks of life that results in hypertrophy of the pyloric muscle between the stomach and duodenum. The etiology has not been elucidated but genetic and environmental influences are suspected. We hypothesized that agricultural pesticides would be associated with an increased incidence of pyloric stenosis. Study DesignData from infants with HPS were obtained from the Indiana Birth Defects Registry (IBDR) for all counties in Indiana from 2005 to 2009. Data from all live births were obtained from the Indiana State Health Department (ISHD). Maternal demographics and clinical characteristics of infants were abstracted. The US Geological Survey (USGS) provided estimated use of agricultural pesticides (EPEST), and these values were correlated with HPS incidence. Univariate and multivariate logistical regression models were used to assess the association between HPS risk and pesticide use. ResultsA total of 442,329 newborns were studied with 1313 HPS cases recorded. The incidence of HPS was 30/10,000 live births. HPS incidence was correlated with total county pesticide use, as well as subcategories of pesticides (fungicides, fumigants, insecticides, herbicides). Indiana counties were then divided into low, moderate and high pesticide use (mean±standard deviation: 127,722±73,374, 308,401±36,915, and 482,008±97,260pounds of pesticides). Incidence of HPS was 26, 29, and 36 cases per 10,000 in low, moderate and high pesticide-use counties respectively. Subset analysis showed that the positive association between HPS and county pesticide use was more likely for male infants from mothers who were white, aged 20–35years, had education at high school or lower, and smoked (p<0.05). ConclusionPesticide use correlated significantly with incidence of HPS. Positive correlations between HPS risk and pesticide use were found for most risk factors. Further studies will be needed to verify our findings and further delineate the nature of this correlation.

Reconciling pesticide reduction with economic and environmental sustainability in arable farming.

Reducing pesticide use is one of the high-priority targets in the quest for a sustainable agriculture. Until now, most studies dealing with pesticide use reduction have compared a limited number of experimental prototypes. Here we assessed the sustainability of 48 arable cropping systems from two major agricultural regions of France, including conventional, integrated and organic systems, with a wide range of pesticide use intensities and management (crop rotation, soil tillage, cultivars, fertilization, etc.). We assessed cropping system sustainability using a set of economic, environmental and social indicators. We failed to detect any positive correlation between pesticide use intensity and both productivity (when organic farms were excluded) and profitability. In addition, there was no relationship between pesticide use and workload. We found that crop rotation diversity was higher in cropping systems with low pesticide use, which would support the important role of crop rotation diversity in integrated and organic strategies. In comparison to conventional systems, integrated strategies showed a decrease in the use of both pesticides and nitrogen fertilizers, they consumed less energy and were frequently more energy efficient. Integrated systems therefore appeared as the best compromise in sustainability trade-offs. Our results could be used to re-design current cropping systems, by promoting diversified crop rotations and the combination of a wide range of available techniques contributing to pest management.

Environmental exposure to pesticides and cancer risk in multiple human organ systems

There is growing evidence on the association between long-term exposure to pesticides in occupational settings and an elevated rate of chronic diseases, including different types of cancer. However, data on non-occupational exposures are scarce to draw any conclusion. The objective of this study was to investigate the putative associations of environmental pesticide exposures in the general population with several cancer sites and to discuss potential carcinogenic mechanisms by which pesticides develop cancer. A population-based case–control study was conducted among people residing in 10 Health districts from Andalusia (South Spain) to estimate the risk of cancer at different sites. Health districts were categorized into areas of high and low environmental pesticide exposure based on two quantitative criteria: number of hectares devoted to intensive agriculture and pesticide sales per capita. The study population consisted of 34,205 cancer cases and 1,832,969 age and health district matched controls. Data were collected by computerized hospital records (minimum dataset) between 1998 and 2005. Prevalence rates and the risk of cancer at most organ sites were significantly higher in districts with greater pesticide use related to those with lower pesticide use. Conditional logistic regression analyses showed that the population living in areas with high pesticide use had an increased risk of cancer at all sites studied (odds ratios between 1.15 and 3.45) with the exception of Hodgkin's disease and non-Hodgkin lymphoma. The results of this study support and extend previous evidence from occupational studies indicating that environmental exposure to pesticides may be a risk factor for different types of cancer at the level of the general population.

Bt cotton, damage control and optimal levels of pesticide use in Pakistan

AbstractWe use farm survey data and a damage control framework to analyze impacts of Bt cotton on yields and pesticide use in Pakistan. We also derive optimal levels of pesticide use with and without Bt, taking into account health and environmental externalities. This has not been done previously in the literature. Conventional cotton growers suffer from significant insect crop damage; they underuse pesticides from a profit-maximizing perspective. Yet, the picture is reversed when externalities are also considered. The social optimum of pesticide use is much lower than the private optimum, and both optima are lower with Bt than without this technology. Bt controls pest damage more effectively. Hence, yields on Bt farms are about 20 per cent higher in spite of lower pesticide use. Large pest damage is a typical phenomenon in developing countries. In such situations, Bt can contribute to productivity growth, while reducing pesticide applications and associated negative externalities.

Pesticides, depression and suicide: A systematic review of the epidemiological evidence

It has been suggested that high exposure to pesticides, including poisoning, experienced by agriculture workers and rural residents may result in an elevated risk of psychiatric disorders and suicidal behavior. Epidemiological data supporting this hypothesis are very limited. An updated systematic review was conducted in epidemiologic literature on the relationship of pesticide exposure with depression and suicide published over the last 15 years by using MEDLINE database. A total of 11 studies on depression and 14 studies on suicide met inclusion criteria. Depression or other psychiatric disorders have shown increased risks associated with previous pesticide poisoning in 5 studies, with statistically significant odds ratios (OR) ranging from 2.08 to 5.95. Lower risk estimates have been found for chronic pesticide exposure. Among studies on suicide, 4 reports found increased suicide rates in areas with intensive pesticide use (OR between 1.60 and 2.61) compared to areas with lower pesticide use. Occupation in agriculture has shown a significant association with higher suicide risk than other occupational groups in 4 studies (OR between 1.30 and 4.13), but not in one recent report. Regarding specific pesticides, lifetime use of chlorpyrifos was related with increased suicide mortality (OR=2.37) in one study. Scientific evidence of association between pesticide exposure and either depression or suicide has been shown in some populations, in studies using varying epidemiological approaches, but is still very limited and inconclusive. Review of the literature warrants further research to explore such relationships, in particular prospective studies among large samples of high- and low-dose-exposed workers, using detailed exposure assessments, and evaluating other potential sources of psychological stress.

Hymenopteran Parasitoids Associated With Frugivorous Larvae in a Brazilian Caatinga-Cerrado Ecotone

The purpose of this study was to investigate native species of parasitoids of frugivorous larvae and their associations with host plants in commercial guava orchards and in typical native dry forests of a caatinga-cerrado ecotone in the State of Minas Gerais, Brazil. Nine species of parasitoids were associated with larvae of Anastrepha (Tephritidae) and Neosilba (Lonchaeidae) in fruit of Psidium guajava L. (Myrtaceae), Ziziphus joazeiro Mart. (Rhamnaceae), Spondias tuberosa Arruda (Anacardiaceae), Spondias dulcis Forst. (Anacardiaceae), Syzygium cumini (L.) Skeels (Myrtaceae), and Randia armata (Sw.) DC. (Rubiaceae). Doryctobracon areolatus was the most abundant species, obtained from puparia of Anastrepha zenildae, An. sororcula, An. fraterculus, An. obliqua, and An. turpiniae. This is the first report of Asobara obliqua in Brazil and of As. anastrephae and Tropideucoila weldi in dry forests of Minas Gerais State. The number of species of parasitoids was higher in areas with greater diversity of cultivated species and lower pesticide use. The forest fragments adjacent to the orchards served as shelter for parasitoids of frugivorous larvae.

An agriculture and health inter-sectorial research process to reduce hazardous pesticide health impacts among smallholder farmers in the Andes

BackgroundThe use of highly hazardous pesticides by smallholder farmers constitutes a classic trans-sectoral ‘wicked problem’. We share our program of research in potato and vegetable farming communities in the Andean highlands, working with partners from multiple sectors to confront this problem over several projects.MethodsWe engaged in iterative cycles of mixed methods research around particular questions, actions relevant to stakeholders, new proposal formulation and implementation followed by evaluation of impacts. Capacity building occurred among farmers, technical personnel, and students from multiple disciplines. Involvement of research users occurred throughout: women and men farmers, non-governmental development organizations, Ministries of Health and Agriculture, and, in Ecuador, the National Council on Social Participation.ResultsPesticide poisonings were more widespread than existing passive surveillance systems would suggest. More diversified, moderately developed agricultural systems had lower pesticide use and better child nutrition. Greater understanding among women of crop management options and more equal household gender relations were associated with reduced farm pesticide use and household pesticide exposure. Involvement in more organic agriculture was associated with greater household food security and food sovereignty. Markets for safer produce supported efforts by smallholder farmers to reduce hazardous pesticide use.Participatory interventions included: promoting greater access to alternative methods and inputs in a store co-sponsored by the municipality; producing less harmful inputs such as compost by women farmers; strengthening farmer organizations around healthier and more sustainable agriculture; marketing safer produce among social sectors; empowering farmers to act as social monitors; and using social monitoring results to inform decision makers. Uptake by policy makers has included: the Ecuadorian Ministry of Health rolling out pesticide poisoning surveillance modeled on our system; the Ecuadorian Association of Municipalities holding a national virtual forum on healthier agriculture; and the Ecuadorian Ministry of Agriculture promulgating restrictions on highly hazardous pesticides in June 2010.ConclusionWork with multiple actors is needed to shift agriculture towards greater sustainability and human health, particularly for vulnerable smallholders.