The role of synthetic pesticides in the intensification of highland agriculture in Thailand

The objective of this study is to quantify the relationship between synthetic pesticide use and agricultural intensification in the northern highlands of Thailand. We surveyed the crop management decisions of 295 farmers across 12 villages, and assessed the level of pesticide use in terms of monetary value, the active ingredients used, and using the Environmental Impact Quotient method. The results show that 77% of the farmers relied solely on synthetic pesticides for their pest management activities. The average farmer used 13.3 kg of active ingredients per hectare of agricultural land, but the variation was large. The highest levels of pesticide use were observed with the cultivation of cut flowers and greenhouse vegetables, while greater land use intensity was associated with increased usage of synthetic pesticides and a greater potential environmental impact. We found that those farmers following public certification of Good Agricultural Practices (Q-GAP), were neither able to reduce pesticide use nor its environmental impact. The findings suggest that to limit the environmental impact caused by the use of synthetic pesticides, greater priority must be given to developing and promoting non-synthetic methods of pest control together with gradually restricting the supply of highly hazardous pesticides.     

Prediction of the environmental concentration of pesticide in paddy field and surrounding surface water bodies

Pesticides are very important in European rice production. For appropriate environmental protection, it is useful to predict the potential impact of pesticides after application, in paddy fields, in paddy runoff, and in the surrounding water, by calculating predicted environmental concentrations (PECs). In this paper, a joint simulation is described, coupling a field-scale pesticide fate model (RICEWQ) and a transportation model (RIVWQ) to evaluate the potential for predicting environmental concentrations of pesticides in the paddy field and adjacent surface water bodies and comparing the predicted values with the monitoring data. The results demonstrate that the application of the calibrated field-scale RICEWQ model is a conservative method to predict the PEC at the watershed level, overestimating the observed data; the coupled RICEWQ and RIVWQ models could be adequately used to predict PECs in the surrounding water at watershed level and in the higher tier risk assessment procedure.     

Risk analysis of pesticides applied to rice paddies using RICEWQ 1.6.2v and RIVWQ 2.02

Rice is commonly cultivated in Southern Europe in large river basins where the extensive use of herbicides may impact water quality at basin scale level. Consequently, pesticide risk assessment would be more relevant when considering a rice cultivation area as a whole. Accordingly, two watershed-scale scenarios were developed to represent the specific agronomic, water and pesticide management practices of rice cultivation in Greece. These scenarios were utilized for the parameterization of the rice water quality model (RICEWQ) 1.6.2v and the surface water model river water quality (RIVWQ) 2.02. in order to predict the environmental concentrations of pesticides in groundwater (GW) and surface water (SW) systems within a rice area. The annual average pesticide concentrations at 1 m depth, predicted by RICEWQ were used to assess the risk for GW contamination. The predicted exposure concentrations derived through modelling and eco-toxicological endpoints obtained from the literature, were used to calculate acute and long-term toxicity exposure ratios (TERs) for aquatic organisms. Application of these scenarios with RICEWQ and RIVWQ models enabled us to perform a risk assessment exercise for several herbicides registered in Greece for use in rice. Such a risk assessment approach could be further scaled up to represent a whole rice cultivated basin in order to be used for regulatory purposes.     

Adoption of leaf color chart for nitrogen use efficiency in rice: Impact assessment of a farmer-participatory experiment in West Bengal,India

Unbalanced and excessive use of N-fertilizers causes environmental pollution, lodging of plants and increased pest pressure, in addition to increased cost to farmers from excessively applied fertilizers and pesticides. N application at the right time and in right amount is critical for healthy plant and environment. Rice leaf color intensity is directly related to leaf chlorophyll content and leaf nitrogen status. The concept for the use of leaf color as an indicator to apply N in rice was crystallized during 1990s. The International Rice Research Institute and the Philippine Rice Research Institute developed a leaf color chart (LCC) that helps guide farmers for real-time nitrogen management in rice farming. The technology is inexpensive, and easily affordable by most resource poor rice farmers. In 2003 we initiated a farmer-participatory research to validate real-time N management in rice by the use of LCC in West Bengal state of India. After 3 years of validation research, a survey was conducted to assess the adoption and impact of LCC. The survey was conducted in both intervention and adjacent control villages and data were collected from 20% farm households selected randomly. In this paper, we report findings of the study on the determinants of adoption of LCC, and its effect on fertilizer and pesticides use.     

Developing a pesticide risk assessment tool to monitor progress in reducing reliance on high-risk pesticides

A methodology is presented for the development of a pesticide risk assessment tool that was used to monitor progress in reducing use of high-risk pesticides in Wisconsin potato production. Multi-attribute toxicity factors are calculated that reflect each pesticide’s acute and chronic toxicity to mammals, birds, fish and small aquatic organisms, and compatibility with biointensive Integrated Pest Management. These factors are then multiplied by the pounds of active ingredient of a given pesticide applied to estimate pesticide-specific toxicity units. Wisconsin potato industry baseline toxicity units by type of pesticide and for 11 targeted higher-risk pesticides are presented for 1995. Reductions in toxicity units from this baseline are reported for 1997 and 1999, as are reductions achieved in a commercial-scale field experiment in 2000.     

Factors determining adoption of integrated pest management by vegetable growers in Nakhon Ratchasima Province,Thailand

Widespread use of highly toxic pesticides primarily for agricultural purpose has generated increasing concerns about the negative impact of pesticides on human health and the environment. Integrated pest management (IPM) usually seeks to minimize the use of pesticides and can be utilized to solve pest problems while minimizing risks to people and the environment. A total of 220 vegetable farmers in Nakhon Ratchasima Province of Thailand was interviewed with the objective of investigating the factors determining their adoption or non-adoption of IPM practices. The findings demonstrated that farmers had different uncompromising reasons for determining the use of IPM for their insect pest management. Higher costs of insecticides (91%), adverse effects of insecticides on human health and the environment (80%), and a greater risk of insect pests developing resistance to insecticides (28%) were the primary reasons for the adoption of IPM by vegetable growers in the study area. The reasons for the rejection of IPM practice were unsuitability of IPM for a large farm (52%), implementation difficulties (80%) and a greater belief in synthetic insecticides and their efficacy for target pest control (39%). A comparison between the IPM and the non-IPM farmers showed a significant difference (P < 0.01) in farmers' knowledge of pest management, which influenced IPM adoption or non-adoption. The IPM farmers had greater knowledge about identifying natural enemies and their beneficial role in controlling insect pests, about plant extracts and their efficacy in controlling insect pests and about sticky traps and their efficacy in monitoring natural enemies and controlling insect pests. For example, 24% of IPM farmers had knowledge of natural enemies whereas it was only 4% for the non-IPM farmers. A logistic regression model was fitted which showed that lower cost of pest management, better knowledge on IPM after training and availability of extension services were the factors which influenced farmers' adoption of IPM practice. The non-IPM farmers rejected adoption of IPM due to the common belief that natural enemies would not be effective in controlling insect pests and yields of vegetables would not be increased by practicing IPM.     

Pesticide use in rice and rice–fish farms in the Mekong Delta, Vietnam

Pest management practices among rice and rice–fish farmers and their perception of problems related to pests and pesticides were surveyed in the Mekong Delta. A total number of 64 different pesticides were identified during the survey. Approximately 50% were insecticides, 25% were fungicides and 25% were herbicides. The main insecticides used were pyrethroids (42%) carbamates (23%) and cartap (19%). Non-IPM farmers used twice as many pesticides as IPM farmers. Their application frequency and the amount of active ingredient used were 2–3 times higher per crop, as compared to IPM farmers. During the last three years IPM farmers estimated that they had decreased the amount of pesticides used by approximately 65%, while non-IPM farmers said that they had increased the amount of pesticide used by 40%. Also, farmers growing fish in their rice fields used less pesticide than farmers growing only rice, as pesticides adversely affect cultures of fish. Taking a long-term perspective integrated rice–fish farming with IPM practices provides a sustainable alternative to intensive rice mono-cropping, both from an economic as well as an ecological point of view.     

Risk assessment of pesticide spray drift from citrus applications with air-blast sprayers in Spain

There have been no previous risk assessment studies on citrus pesticides in Spain. The aim of this work was to estimate the risks caused by worst-case drift scenarios of the principal pesticides used on the crop, assessing possible damage to the environment and human health. A field survey was carried out, characterizing the specific conditions of plant protection product applications to citrus crops in Spain. Six targets were identified as being the most affected by droplet spray drift in Spain, and more broadly in most Mediterranean conditions: aquatic organisms, earthworms, bees, adult bystanders, child bystanders and residents. Three drift estimation models were used to assess the amount of drift at specific distances downwind of a field in order to calculate Risk Indicators. These showed safe conditions for earthworms and residents, but also indicated that some pesticides may pose a risk to aquatic organisms, even with a 20 m buffer zone, and also to bees, and adult and child bystanders. In general, results generated similar consequences of hazard risk independent of the drift prediction model used, indicating that toxicological data are more relevant for predicting risks.     

Risk assessment of pesticides in paddy fields and the Safīdrūd River in Gīlān,Iran

Safīdrūd River is the longest river in northern Iran and serves 2.5 million people as a water resource for drinking, irrigation, pisciculture, and recreation. To evaluate the fate of pesticides in paddy fields on the Safīdrūd river bank and the Safīdrūd basin, a comprehensive model is developed in this paper to predict pesticide concentration. The model includes degradation and sorption to soil in paddy field and two-dimensional turbulent with degradation in river. To investigate the effects of pesticides on health, an inclusive risk assessment is defined by parameters such as the maximum annual prediction environmental concentration and mean prediction environmental concentration of pesticides in the intake zone of the Safīdrūd river for the Rasht water treatment plant. The risk quotient of all pesticides were higher than 1 (i.e., for Diazinon it was calculated to be 670) which indicate high risk in the Rasht potable water and can potentially cause various digestive cancers and other refractory and mutagenic diseases. As a result, it is necessary to codify the global planning of pesticide application in the paddy fields by the local government.     

Impact of integrated pest management of vegetables on pesticide use in subtropical Jammu,India

In a study at the subtropical vegetable-growing areas of the state of Jammu and Kashmir (J&K), a quasi-experimental research design with a non-equivalent control group was employed to examine the impact of an integrated pest management (IPM) program implemented from 2008 to 2010 on the adoption of non-chemical pest management practices, pesticide use by weight (active ingredient [a.i.]), pesticide use frequency, field use environment impact (FEIQ) and safe handling and application of pesticides by IPM-trained farmers. There was no significant change in adoption of non-chemical practices, other than pheromone traps used by okra (Abelmoschus esculentus (L.) Moench) growers. Growers reduced FEIQ by 17.9 per hectare from 2008 to 2010. Pesticide use (a.i.) did not decrease significantly, and frequency decreased significantly by 72.4% only in cauliflower (Brassica oleracea L. var. botrytis). The vegetable growers did not use protective equipment while handling and applying pesticides thus putting themselves at risk. Implementation of IPM thus needs to be reexamined to significantly reduce pesticide use by weight, treatment frequency and FEIQ.     

Worldwide Sustainability Hotspots in Potato Cultivation. 2. Areas with Improvement Opportunities

Agriculture has a large impact on the environment and retailers increasingly stimulate their suppliers to reduce the environmental impact of agricultural production. The environmental impact resulting from producing a commodity can be measured with a life cycle analysis (LCA) but performing an LCA is costly and time-consuming. In the first paper of this series a practical and general method to identify hotspot areas in crop production on a global scale was developed. The method was implemented for potatoes. The objective of the work reported here was to evaluate the tool and to identify improvement opportunities for each of seven indicators: yield, erosion risk, nitrogen surplus, depletion of water reserves, biocide use, carbon footprint, and impact on biodiversity. The tool produces realistic outputs that can be used to target improvement efforts and thus improves the use efficiency of limited resources. The tool can be expanded to produce similar results for other crops; methods to improve the resolution of the tool are discussed.     

Variation in pesticide hazard from arable crop production in Great Britain from 1992 to 2008: An extended time-series analysis

Efforts to assess reductions in the hazard posed by pesticides in arable systems present complex problems to policy makers both nationally and at a European level. Attempts to monitor changes in hazard rely to a large extent on the quality of the surveillance and the indices used to collate multi-faceted data. This study is an update on previous work using the Environmental Impact Quotient (EIQ) to evaluate changes in pesticide hazard following the introduction of the European Directive 91/414/EEC. Findings from the study suggest that pesticide hazard has decreased during the study period 1992–2008 although reduction was not even across all crop types or time periods, with limited change in the past six years. This study is proposed as baseline for further monitoring of the effectiveness of the new European regulations 1107/2009 ‘the placing of plant protection products on the market’ to further reduce the impact of pesticides on non-target organisms.     

Motivations for adopting biological control among Iranian rice farmers

While research on biological control of crop pests is quite popular, it seldom targets motivations of farmers for adopting this practice. A survey of 283 rice farmers was conducted in Mazandaran province of northern Iran to study farmers' motivations for biological control adoption as an alternative control method of Asiatic rice borer [Chilo suppressalis (Walker)] and explain potential differences in motivations among different groups of farmers. Face to face interviews were used to address farmers' motivations based on a list of motivation statements found in previous studies and modified by extension officers and farmers who had adopted biological control in the study area. Factor analysis of a motivation list with 15 items revealed four main groups of factors explaining the adoption of biological control by rice farmers; these were ‘health maintenance’, ‘economic benefit’, ‘social acceptance’, and ‘environmental protection’. Men gave high scores to motivations related to ‘economic benefit’ and ‘social acceptance’, whereas women preferred mostly motivations related to ‘health maintenance’. Well-educated farmers (e.g., some college education) preferred motivations for ‘health maintenance’ more than farmers with lower education or no education at all. Participation in extension programs was associated with preference of non-economic motivations of biological control adoption, while membership in local associations (such as rural cooperatives or producers' groups) encouraged motivations related to ‘social acceptance’. Farmers who used family labor force in their fields or farmers who perceived pesticides as harmful substances showed strong motivations primarily for ‘health maintenance’ along with ‘environmental protection’. Small area of land under cultivation and low annual farm income were strongly linked with motivations for ‘economic benefit’. Besides economic motivations, policies for the promotion of biological control adoption should embrace a wide set of farmers' motivations when developing new and properly tailored extension programs.     

Integrated Plant Protection in Potatoes: Review of the French Situation

Among arable crops, potato needs more interventions against bio-aggressors than other crops. In France, in 2014, the mean treatment frequency index was about 18 per year including 14 solely for late blight (Phytophthora infestans) protection. Many French and European regulations make this dependency on pesticides extremely precarious. Media pressure is already very strong and is encouraging reform of crop protection. For 7 years, Arvalis has been conducting research programmes to find alternative or complementary methods to pesticides for potato protection. These studies have been focussing on weeds, soil pests, late blight, skin blemish diseases, haulm destruction and sprout control. For example, the means for an integrated protection system against late blight are in place; they include prophylactic measures, less sensitive cultivars, risk assessment by a decision support tool, strain monitoring, choice of suitable fungicides, precision spraying and defence stimulants. Other research programmes on biocontrol and service plants (e.g. for biofumigation) also receive attention. Our results are significant but remain insufficient yet, as protection methods need to be further adapted. Time is running out to provide farmers with innovative methods to protect their crops without loss of profitability in the coming years.     

高尔夫球场农药环境行为的研究进展

高尔夫球场农药对人类和环境的潜在危害是目前国内外普遍关注的问题。本文对国内外相关文献进行综述，并指出目前该研究存在的问题：高尔夫球场农药主要通过挥发、淋溶和径流等途径影响人类健康和周边环境。然而，目前高尔夫球场农药的生物代谢、降解和土壤吸附等行为及其受农药、草坪、土壤特性及气候条件等因素的影响研究尚未深入、系统地开展，因此较难正确评估高尔夫球场农药的环境风险，相关研究需进一步开展。     

Development of an innovative conceptual model and a tiered testing strategy for the ecological risk assessment of rice pesticides

Rice paddies constitute a very special agrobiosystem, which for some circumstances, could be considered as a human driven wetland. The complexity of such dynamic systems is a key element for conducting ecological risk assessments, in addition, the proximity of rice paddies to areas of high ecological value must be considered. This paper presents a new conceptual model for conducting ecological risk assessments of pesticides and other agrochemicals in rice, based on a combination of three main elements, the source of the stressor, the exposed environmental compartments and the relevance of the ecological receptors. A tiered testing strategy, starting with the standard requirements for pesticides and moving to specific higher tier studies with three levels of risk refinement is also presented.     

Farmers’ knowledge, perceptions and management of vegetable pests and diseases in Botswana

Vegetable farmers’ knowledge and perceptions of pests, diseases and pest management practices were investigated by interviewing 112 growers in Botswana between April and June 2004. Most of the farmers grew brassicae crops, Swiss chard and tomato, and considered arthropod pest problems as the major constraint to vegetable production. Bagrada hilaris Burm., Plutella xylostella L. and Brevicoryne barassicae L. were the most serious pests on brassicas, with red spidermites (Tetranychus spp.) being the most serious pests on tomato. Ninety-eight percent of farmers relied heavily on the use of synthetic pesticides to control these pests. Their decision to apply pesticides was mostly on noticing the presence of a pest or disease. An integrated pest management programme is needed to reduce over reliance on pesticides.     

Evaluating risk from insecticide use at the field and regional scales in Iran

Approximately 50% of all pesticides registered in Iran are insecticides with potential risk to human health and the environment. The environmental impact quotient (EIQ) is a pesticide risk indicator that was used to rank the inherent risk of 48 insecticides in use in 28 Iranian provinces and evaluate their environmental impact (EI) at the field and provincial scales over three growing seasons from 2001 to 2005. The results indicate that the introduction of new insecticides over the past decades has produced a negligible decrease in inherent risk. About 75% of provinces had low EI scores of 0.62–11.3. The highest EI and EI/ha scores were found in Kerman and Mazandaran provinces, mainly from increased usage (amount of active ingredient) rather than increased toxicity of insecticides. Inherent toxicity (EIQ) was not significant for increased EI in contrast to the increase in pesticide usage. On average, diazinon comprised 37% of total usage, carbaryl 12.2% and teflubenzuron 8% of total usage. The toxicity of these insecticides ranked lower for EIQ. In contrast, the total usage of environmentally high-risk insecticides (imidacloprid, fipronil, lindane) was relatively lower during the study period. Overall, the increased use of insecticides was not related to the increase in the area under cultivation, but to the type of crop grown (pistachios, vegetables) and to inappropriate spraying equipment and inadequate storage practices, both of which are common problems in developing countries.     

Pesticide diversity in rice growing areas of Northern Vietnam

Pesticide use in developing countries increases rapidly. In many regions, we miss knowledge of how frequently pesticides are applied and which active ingredients are used. We present a new cost-efficient and rapid assessment method of recording pesticides diversity in rice-dominated landscapes and present some evidence of the misuse of active ingredients in our study regions. We investigated 17 rice fields in two regions of Northern Vietnam in 2014 and 2015. At each region, we explore the abundance of pesticides used with three methods including (1) the novel approach of collecting pesticide packages close to our target rice fields, (2) observations of farmers spraying pesticides in the surrounding and (3) interviewing local farmers. By collecting pesticide packages, we found 811 packages containing 74 different active ingredients. On average, 19 active ingredients (ranging from four to 40 active ingredients) were applied with an average content of 275.3 g of active ingredients per site. Insecticide packages (39%) were most abundant followed by those of fungicides (31%), herbicides (16%) and other active ingredients (14%). On all sites, active ingredients banned in the European Union were applied by the farmers. Collecting pesticide packages proved to be an efficient and rapidly implemented method to obtain some baseline information about pesticide application (for Northern Vietnam). We suspect that improved agricultural extension services could contribute to good agricultural practices in pest management. Generally, better information and education for local farmers for appropriate use of pesticides seem a necessity.