Effects Of Agrochemicals Research Articles

Cyclic Synthetic Peroxides Inhibit Growth of Entomopathogenic Fungus Ascosphaera apis without Toxic Effect on Bumblebees.

In recent years, the number of pollinators in the world has significantly decreased. A possible reason for this is the toxic effects of agrochemicals reducing the immunity of insects that leads to their increased susceptibility to pathogens. Ascosphaera apis is a dangerous entomopathogenic fungus, afflicting both honeybees and bumblebees. We investigated fungicide activity of cyclic synthetic peroxides against A. apis isolated from Bombus terrestris L. The peroxides exhibited high mycelium growth inhibition of A. apis up to 94–100% at concentration 30 mg/L. EC50 values were determined for the most active peroxides. Two peroxides showed higher antifungal activity against A. apis than the commercial fungicide Triadimefon. The studied peroxides did not reduce the ability of bumblebees to fly and did not lead to the death of bumblebees. A new field of application for peroxides was disclosed.

New findings on the effect of glyphosate on autotrophic and heterotrophic picoplankton structure: A microcosm approach

Massive use of glyphosate-based herbicides in agricultural activities has led to the appearance of this herbicide in freshwater systems, which represents a potential threat to these systems and their communities. These herbicides can affect autotrophic and heterotrophic picoplankton abundance. However, little is known about glyphosate impact on the whole structure of these assemblages. Herein, we used an 8-day long microcosm approach under indoor controlled conditions to analyze changes in the structure of picoplankton exposed to a single pulse of glyphosate. The analyzed picoplankton correspond to two outdoor ponds with contrasting states: “clear” (chlorophyll-a = 3.48 μg L−1± 1.15; nephelometric turbidity, NTU = 1) and “turbid” (chlorophyll-a = 105.96 μg L−1 ± 15.3; NTU = 48). We evaluated herbicide impact on different picoplankton cytometric populations and further explored changes in bacterial dominant operational taxonomic units (OTUs) fingerprinting. We observed that glyphosate induced a drastic decrease in the abundance of phycocyanin-rich picocyanobacteria. Particularly, in the turbid system this effect resulted in an 85 % decrease in the abundance of the whole autotrophic picoplankton. Glyphosate also changed the structure of the heterotrophic fraction by means of changing bacterial dominant OTUs fingerprinting patterns in both systems and by shifting the relative abundances of cytometric groups in the clear scenario. These results demonstrate that upon glyphosate exposure picoplanktonic fractions face not only the already reported changes in abundance, but also alterations in the composition of cytometric groups and of bacterial dominant operational taxonomic units. This research provides suitable and still little explored tools to analyze agrochemical effects on picoplanktonic communities.

Effect of FYM, mulching and agro-chemicals on growth parameters of wheat (Triticum aestivum L.) crop under different sowing dates

A field experiment was conducted at was conducted at Instructional Farm, Rajasthan College of Agriculture, Udaipur during rabi 2016-17 to study the effect of FYM, mulching and agro-chemicals on growth of wheat (Triticum aestivum L.) crop under different sowing dates. The experiment consisted of 12 treatment combinations comprising of two sowing dates (Timely, Late) and six management practices, viz., control, FYM, Mulching, FYM + Mulching, FYM + Mulching + ZnSO4 and FYM + Mulching + KCl (P0, P1, P2, P3, P4, P5). The experiment was conducted in factorial randomized block design and replicated thrice. Results showed that timely sowing of crop had significant effect on various growth parameters i.e., plant height, dry matter accumulation, CGR, RGR and total number of tillers. Timely sown crop recorded significantly higher growth parameters which was found statistically superior over late sown crop treatment. Result further showed that 10 t ha-1 FYM + 4.0 t ha-1 Mulch + 0.2% KCl (P5) recorded highest growth parameters followed by 10 t ha-1 FYM + 4.0 t ha-1 Mulch + 0.5% ZnSO4 (P4) and 10 t ha-1 FYM + 4.0 t ha-1 Mulch (P3).

Long-term monitoring reveals among-year consistency in the ecological impacts of insecticides on animal communities in paddies

Abstract Semi-natural mesocosm experiments have been proposed as a powerful approach for evaluating the realised rather than potential ecotoxicological effects of agrochemicals on biological communities. However, there is uncertainty in the results from such experiments due to spatio-temporal variability in various ecological factors, such as community composition. Therefore, long-term studies evaluating such variability are critical for assessing the utility of mesocosm experiments, although few studies have been conducted over multiple years. We conducted a multiple-year (i.e., three-year) mesocosm experiment to examine the effects of three systemic insecticides (clothianidin, fipronil, and chlorantraniliprole) on aquatic animal communities in experimental paddies, and we evaluated the among-year variability in these ecotoxicological effects. We found substantial variation in community composition among years. However, when we controlled for this variability by performing partial redundancy analysis (partial RDA), we found that paddy community composition was significantly different between the three insecticide treatments irrespective of year. Moreover, we identified some taxa that consistently decreased in abundance following exposure to each insecticide and may thus be regarded as indicator taxa of the environmental stress caused by the insecticides (e.g., clothianidin: Gerris lacustris (water striders), fipronil: Orthetrum albistylum speciosum (dragonflies), and chlorantraniliprole: Hydroglyphus japonicus (beetles)). Our study suggests the utility of multiple-year, semi-natural mesocosm experiments not only for evaluating the temporal variability in ecotoxicological effects but also for identifying potential robust indicator organisms that consistently decrease in abundance in response to specific agrochemicals irrespective of the variability in ecological factors under realistic conditions.

Understanding the Perceptions of Sustainable Coffee Production: A Case Study of the K’Ho Ethnic Minority in a Small Village in Lâm Đồng Province of Vietnam

This case study used anthropological and culture concept methodologies to evaluate the perceptions of sustainable coffee production of the K’Ho ethnic minority in Di Linh district, Lâm Đồng province in the Central Highlands of Vietnam. Sustainable production is a means of mitigating the increasing impacts of climate change upon the region. The Central Highlands is a major coffee production hub and Di Linh is the largest coffee growing region of Lâm Đồng province. The case study included in-depth interviews with farmers based on open-ended questions and a questionnaire about sustainable coffee indicators. The survey invited farmers to quantify the current status of their social, economic, and environmental sustainability. Our study revealed that the unique, government sponsored development of coffee farms led to fast production rates and quick economic prosperity. But, it also resulted in a prolonged monoculture system of coffee production and high chemical use; causing farm productivity to decline and social, economic, and environmental vulnerability to increase. The K’Ho farmers in a small village are noticing the devastating long-term effects of agrochemicals, but have had some initial success exploring the potential benefits of reverting to traditional farming methods.

Evaluating the toxic potential of agrochemicals on the hypothalamic‐pituitary‐thyroid axis in tilapia(Oreochromis mossambicus)

Agrochemicals are a major cause of concern for the aquatic environment because of their toxicity, persistence, and tendency to accumulate in the organisms. The impact of these chemicals on aquatic organisms is due to their movement from various diffuse or point sources, which poses a great threat to aquatic fauna especially fishes, which constitute one of the major sources of protein-rich food for mankind. The present study is a first of its kind, where the toxic potential of two sublethal concentration (LC1/10th and LC1/25th) of four different classes of agrochemicals have been tested (Insecticide- Imidacloprid-0.074 ppm, 0.02 ppm, Fungicide-Curzate- 4.9 ppm, 1.96 ppm, Herbicide- Pyrazosulphuron ethyl-50 ppm, 20 ppm and Fertilizer-Micronutrient mixture 500 ppm, 200 ppm) on candidate markers of hypothalamus pituitary-thyroid axis (TSH, T3, T4, TSHβr) in Oreochromis mossambicus (tilapia) by validating hormonal level and mRNA expression. The results reveal that exposure to agrochemicals resulted in a broad range of alterations with maximum damage being caused by insecticide followed by herbicide and fungicide in that order on the thyroid axis. The results of the present study highlight the need for more detailed studies on the effects of agrochemicals that accumulate in organisms and propose that there should be a check on the rampant use of agrochemicals.

Side Effects of Agro-chemicals on Beekeeping in East and West Gojjam Zones of Amhara Region, Ethiopia

The study was conducted in West and East Gojjam Zones of Amhara Region Ethiopia to determine commonly used agro-chemicals and timing of applications, their effects on honeybee by itself and beekeeper farmers used cultural practices to minimize agro-chemical side effects on honeybee; Questionnaire survey methods, key informants interview and focus group discussion were used for the study. In the questionnaire survey, 384 respondent beekeepers from 4 Woredas, 20 Kebeles (376 male and 8 female) were interviewed. Descriptive, frequency with SPSS version 20 were used. The majority of farmers spray herbicides before blooming in August and insecticides at diseases and pests observed in October, November and December. Surprisingly, almost all respondents interviewed (98.7%) have confirmed that they know the negative effects of agro-chemicals on the health status and life of the honeybee. Apparently pesticides have been causing considerable damage by killing honeybees and causing yield decline due to miss use of agrochemicals. 90.9% of the non-beekeepers who use agro-chemical had no willingness to use non-chemical or alternative mechanisms to control pests and weeds. The main reported reason for the non-beekeepers not informing others about their plan to apply agro-chemicals is their laziness and jealousy; only 8.1% of respondents have willingness to use non-chemical or cultural weed and pest control mechanisms to save honeybee colonies as well as to keep their farmlands as organic. Overall the level of cooperation between beekeepers and non-beekeepers with regard to responsible use of agro-chemicals is very weak and certainly not considerate of mutual benefits and environmental protection. Essential to capacitate beekeepers in terms of technical knowledge and skills to better manage and need concerted action to develop appropriate agro-chemical application modalities that minimize side effects on honeybees and economic losses would be recommended.

Health Must Be Recognized as the Human Right It Is: Héctor Javier Sánchez MD MSSenior Researcher, Department of Society, Culture and HealthEl Colegio de la Frontera Sur (ECOSUR), Chiapas, Mexico.

Dr Héctor Javier Sánchez specializes in public health and research methodology and holds a master's degree in epidemiology. He is a senior researcher in the Society, Culture and Health Department at El Colegio de la Frontera Sur, Mexico. The Colegio is a public research institu-tion concentrating on environmental, economic and social issues related to a sustainable future for Mexico's southern border area, and belongs to the National Council of Science and Technol-ogy (CONACYT). In Chiapas State, the country's poorest region and home to many indigenous peoples, Dr Sánchez has carried out studies on TB, poverty and health, domestic violence, hu-man rights, maternal-child health and the effect of agrochemicals on human health.

Toxicological assessments of agrochemical effects on stingless bees (Apidae, Meliponini)

Bee pollination is crucial for ecosystem maintenance and crop production. The ubiquity of bee pollinators in agricultural landscapes frequently results in their exposure to agrochemicals, which has been associated with their decline. Stingless bees are wild pollinators restricted to the Pantropical region, and like honey bees, are suffering colony losses. However, stingless bees and honey bees do not show the same behaviors, therefore, methods used for risk assessment of honey bees cannot be utilized on stingless bees. Herein, we describe protocols to standardize methods that allow for the exploration of lethal and sublethal effects of agrochemicals via acute and chronic exposure of stingless bees. The in vitro rearing used for chronic exposure from the egg to the adult stage proved to be effective in obtaining relevant screenings. In addition, we performed a meta‐analysis and summarized the results of toxicological studies conducted with the protocols described. The meta-analyses indicated a reduction in survival under acute and chronic exposures to agrochemicals, and revealed that our protocols for toxicological assessments did not have publication bias for either acute or chronic exposure. These findings proved that these standardized protocols are reliable for toxicological research on stingless bee.

Agrochemicals and human well-being: A review in context of Indian agriculture

Modern chemicals, in form of fertilizers and pesticides, have undoubtedly increased the food production worldwide. Over use of chemical application and its effect on environment and human health could not be neglected any further. Residual effect of agrochemicals could be seen in both the terrestrial life and marine life. Future food demand must be achieved with better quality food, along with use of less toxic chemicals. Alternate practices like introduction of GMOs, precision agriculture and IPM must be put into practice, to lessen the load of chemical use. This review evinces the health hazards caused due to misuse and over use of agrochemicals and also talks about the contributing factors, of which poor education and extension system plays pivotal role. Improving the literacy among the farmers, strengthening the extension, training and involvement of media could provide scope for reducing vulnerability of farmers to health related issues caused by prolong exposure to the toxic chemicals.

Alternativas de control orgánico in vitro para Dactylonectria torresensis en la mora de castilla (Rubus glaucus) en Ecuador

Esta investigación evaluó, en laboratorio, la eficiencia de los fungicidas de origen orgánico frente a los fungicidas químicos de uso convencional para controlar el crecimiento del Dactylonectria torresensis, considerada como una de las fitopatologías de importancia económica que afecta a la mora de castilla (Rubus glaucus) en Ecuador. El objetivo del estudio se basó en la necesidad imperante de buscar alternativas naturales y amigables con el ambiente, que permitan obtener alimentos limpios para la población. Para tal fin, se evaluó la eficiencia de los fungicidas convencionales de síntesis química: Azoxystrobin, Benomil, Carbendazim, Difeconazol, Fosetyl Aluminio, Tachigaren, Propiconazol, Penconazol, Metalaxil y Thiabendazole, cada uno en dosis de 100, 10 y 1 ppm, frente a la eficiencia de fungicidas de síntesis orgánica: aceite de neem, extracto de mirtáceas, extracto de ajo, sulfato cúplico pentahidratado y extracto de tomillo, aplicados en dosis de 300, 200, y 100 ppm. Se comprobó que el extracto de mirtáceas controló en 100 % del crecimiento micelial del Dactylonectria torresensis, y mostró resultados similares a los obtenidos con Carbendazim y Azoxystrobin. Se concluye, por lo tanto, que si existiera una alternativa para el control del hongo, esta podría ser utilizada comercialmente, y de esta manera disminuir el uso y los efectos nocivos de los agroquímicos convencionales.

Effect of Agrochemicals Used in the Cultivation of Soybean and Irrigated Rice on Beauveria bassiana (Bals.) Vuill. and Metarhizium anisopliae (Metsch.) Sorok

The objective of this work was to evaluate the fungitoxic effect of the agrochemicals used in the cultivation of soybean and irrigated rice on entomopathogenic fungi such as Beauveria bassiana and Metarhizium anisopliae by means of the mycelial growth, sporulation and spore germination. The isolates were inoculated in potato-dextrose-agar (PDA) medium containing the pesticides and exposed to spraying with the products. It was observed that chlorantraniliprole produced the best results regarding and was compatible with the two methods of contact of the product with the fungi. Flubendiamide it’s very toxic to fungi, producing 100% inhibition when incorporated into the medium, when by spraying, the fungus M. anisopliae got mycelial growth. Etofenprox and thiamethoxam changed their toxity classification according to the method of contact with product, was moderately compatible to B. bassiana and compatible to M. anisopliae and spinosad showed more compatibility with M. anisopliae than B. bassiana and was classified as compatible. Among fungicides the tricyclazole was the only compatible with the fungus by the spray method. The results showed that in vitro agrochemicals such as tricyclazole, thiamethoxam, flubendiamide and etofenprox are harmful to fungi. It was found that environmental interference could minimize the effects on organisms, especially when the chemicals are applied by spraying.

Effects of a herbicide on paddy predatory insects depend on their microhabitat use and an insecticide application.

Indirect effects of agrochemicals on organisms via biotic interactions are less studied than direct chemical toxicity despite their potential relevance in agricultural landscapes. In particular, the role of species traits in characterizing indirect effects of pesticides has been largely overlooked. Moreover, it is still unclear whether such indirect effects on organisms are prevalent even when the organisms are exposed to direct toxicity. We conducted a mesocosm experiment to examine indirect effects of a herbicide (pentoxazone) on aquatic predatory insects of rice paddies. Because the herbicide selectively controls photosynthetic organisms, we assumed that the effects of the herbicide on predatory insects would be indirect. We hypothesized that phytophilous predators such as some Odonata larvae, which cling to aquatic macrophytes, would be more subject to negative indirect effects of the herbicide through a decrease in abundance of aquatic macrophytes than benthic, nektonic, and neustonic predators. Also, we crossed-applied an insecticide (fipronil) with herbicide application to examine whether the indirect effects of the herbicide on the assembling predators act additively with direct adverse effects of the insecticide. The herbicide application did not decrease the abundance of phytoplankton constitutively, and there were no clear negative impacts of the herbicide on zooplankton and prey insects (detritivores and herbivores). However, the abundance of aquatic macrophytes was significantly decreased by the herbicide application. Although indirect effects of the herbicide were not so strong on most predators, their magnitude and sign differed markedly among predator species. In particular, the abundance of phytophilous predators was more likely to decrease than that of benthic, nektonic, and neustonic predators when the herbicide was applied. However, these indirect effects of the herbicide could not be detected when the insecticide was also applied, seemingly due to fipronil's high lethal toxicity. Our study highlights the importance of species traits such as microhabitat use, which characterize biotic interactions, for predicting indirect effects of agrochemicals. Given that indirect effects of the chemicals vary in response to species traits and direct toxicity of other chemicals, efforts to explain this variation are needed to predict the realistic risks of indirect effects of agrochemicals in nature.

Effect of Intercropping and Compost Application for the Management of Common Bean Anthracnose ( Colletotrichum lindemuthianum ) in North Shewa, Central Ethiopia

Common bean is grown for its high nutritive, medicinal and market value in Ethiopia. Anthracnose is among the major production constraint within central common bean producing regions of Ethiopia. Field experiments were conducted on two common bean varieties Awash Melka and Mexican 142 at Shewarobit and Ataye in 2016 and 2017 main cropping seasons with the objective of evaluating the effects of row intercropping, compost plus their integration on disease severity of common bean anthracnose. Field experiments revealed maximum disease severity on highly susceptible variety Mexican 142 than Awash Melka at both locations and during both cropping seasons. Significantly, the lowest (26.9%) mean final anthracnose severity was obtained from the integration of intercropping with compost application at Ataye during 2017 and (562% day) mean area under disease progress curve was obtained from the integration of intercropping with compost application at Shewarobit during 2017. Whereas significantly the highest (39%) mean final disease, severity and (849% day) mean AUDPC were recorded from the sole planting control plots in 2016 at Shewarobit. Integration of intercropping with compost application as ecofriendly disease management option was the appropriate management option of common bean anthracnose in the study area. Further studies of integrating management options need to be conducted to reduce the residual effects of agrochemicals.

Long-term dynamics of honey bee colonies following exposure to chemical stress

Pesticide residues have been linked to reduced bee health and increased honey bee colony failure. Most research to date has investigated the role of pesticides on individual honey bees, and it is still unclear how trace levels of pesticides change colony viability and productivity over seasonal time scales. To address this question we exposed standard bee colonies to chemical stressors known to have negative effects on individual bees, and measured the productivity of bee colonies across a whole year in two environments: near Tucson Arizona and Sydney Australia. We exposed hives to a trace amount of the neonicotinoid imidacloprid and to the acaricide thymol, and measured capped brood, bee and honey production, as well as the temperature and foraging force of the colonies. The effect of imidacloprid on colony dynamics differed between the two environments. In Tucson we recorded a positive effect of imidacloprid treatment on bee and brood numbers. Thymol was associated with short-term negative effects on bee numbers at both locations, and may have affected colony survival at one location. The overall benefits of thymol for the colonies were unclear. We conclude that long-term and colony-level measures of the effects of agrochemicals are needed to properly understand risks to bees.

Effects of Agrochemical Pollution on Schistosomiasis Transmission: A Systematic Review and Modeling Analysis

Background: Agrochemical pollution of surface waters is a growing global environmental challenge, especially in areas where agriculture is rapidly expanding and intensifying. Recent work suggests that agrochemicals may affect schistosomiasis transmission through direct and indirect effects on Schistosoma parasites, their intermediate snail hosts, snail predators, and snail algal resources. Methods: We conducted a systematic review of agrochemical effects on the lifecycle of Schistosoma spp. and fitted dose-response models to data relating components of the lifecycle and agrochemical concentrations. We incorporated these dose-response functions and environmentally-relevant concentrations of agrochemicals into a mathematical model to estimate agrochemical effects on schistosomiasis transmission. Findings: We derived 120 dose-response functions describing effects of agrochemicals on schistosome lifecycle components. Agrochemical effects on estimates of the basic reproduction number, R0, for S. haematobium ranged from an increase of 306% (IQR: 246% – 362%) to transmission elimination (R0 -> 0). Simulations of transmission dynamics subject to interacting annual mass drug administration and agrochemical pollution yield a median estimate of 64·82 (IQR: 62·52 – 67·68) DALYs lost per 100,000 people per year attributable to atrazine use. In areas where aquatic arthropod predators of intermediate host snails suppress transmission, the insecticides chlorpyrifos and profenofos may also increase disability (6·82 [4·13 – 8·69] and 103·06 [89·63 – 104·90] DALYs lost per 100,000 people per year, respectively) through their toxic effects to arthropods. Interpretation: Expected environmental concentrations of agrochemicals alter schistosomiasis transmission through direct and indirect effects on intermediate host and parasite densities. As industrial agricultural practices expand in areas where schistosomiasis is endemic, strategies to limit increases in transmission due to agrochemical pollution should be developed and pursued. Funding Statement: Funding from the National Institutes of Health [1R01TW010286 and R01AI125842], the National Science Foundation Water, Sustainability and Climate program [1360330 and 1646708] and DS421 training program [1450053], and by the University of California Multicampus Research Programs and Initiatives [award MRP-17-446315]. Declaration of Interests: The authors report no competing interests.

Effect of non-antifungal agrochemicals on the pathogenic fungus Cryptococcus gattii.

The chemical control of pests and weeds is employed to improve crop production and the quality of agricultural products. The intensive use of pesticides, however, may cause environmental contamination, thus altering microbial communities. Cryptococcus gattii is an environmental yeast and the causative agent of cryptococcosis in both humans and animals. Up to this day, the effects of agrochemicals on human pathogens living in nature are still widely unknown. In this work, we analyzed the susceptibility of C. gattii to nonfungicide agrochemicals (herbicides and insecticides). Microdilution and drug-combination susceptibility tests were performed for the herbicides flumioxazin (FLX), glyphosate (GLY), isoxaflutole (ISO), pendimethalin (PEND), and also for the insecticide fipronil (FIP). Moreover, these compounds were combined with the clinical antifungals amphotericin B and fluconazole. The MIC values found for the agrochemicals were the following: < 16μg/ml, for flumioxazin; 128 to 256μg/ml, for FIP, ISO, and PEND; and >256μg/ml, for GLY. Synergistic and antagonistic interactions, depending on the strain and concentration tested, were also observed. All strains had undergone adaptation to increasing levels of agrochemicals, in order to select the less susceptible subpopulations. During this process, one C. gattii strain (196L/03) tolerated high concentrations (50 to 900μg/ml) of all pesticides assessed. Subsequently, the strain adapted to flumioxazin, isoxaflutole and pendimethalin showed a reduction in the susceptibility to agrochemicals and clinical antifungals, suggesting the occurrence of cross-resistance. Our data point to the risk of exposing C. gattii to agrochemicals existing in the environment, once it might impact the susceptibility of clinical antifungals.

Mathematical Evaluation of the Effect of Agrochemicals on Human Health

The fast growing economical and political needs and demands for increase agricultural activities and produces in most parts of the world necessitate the need for a careful evaluation of the general crop cultivation processes and the increasing usage of diverse toxic chemicals in the form of pesticides, fertilizers, etc. in the agricultural sector to control pests and weeds to improve soil nutrients during cultivation and in some cases, for preservation of cultivated crops. Agrochemicals are used in a manner that suggests farmers do not take into cognisance the fact that residue of the chemicals which is harmful to man is always left on such foods. This paper applies a mathematical model to examine the impact of agrochemicals on human health by using the conventional principle of an SEIRS epidemic model. From the overall outcome, it was observed that the consumption of these hazardous plants before the elapse of the incubation (waiting) period affect the human health negatively. Consequently, the need for a wake up call to all farmers, agricultural workers, Government and Non-Governmental monitoring agencies to arise to the task of saving human lives from these toxic chemical residues in agricultural produces.

Desaparecimento de abelhas polinizadoras nos sistemas naturais e agrícolas: Existe uma explicação?

Desde a última década é notório o desaparecimento das populações de abelhas polinizadoras em diversos países. Esse grupo é responsável pela polinização e manutenção de centenas de espécies vegetais usadas na alimentação humana, além de contribuir de forma expressiva para o desenvolvimento socioeconômico de comunidades associadas à agricultura familiar. Neste trabalho, são discutidas as possíveis causas do desaparecimento, entre as quais se destacam: o desmatamento, reforçado pela carência de flora natural, o manejo inadequado de colmeias, as crescentes infestações de pragas nas colônias e o uso de agrotóxicos. Sugerem-se estratégias para a conservação de abelhas nativas e domesticadas, merecendo destaque: (a) a conservação da paisagem natural circundante às áreas agrícolas; (b) a profissionalização de apicultores no manejo nutricional e de conservação das colmeias; e (c) o contínuo desenvolvimento de estudos criteriosos sobre o efeito letal e subletal de agrotóxicos sobre os polinizadores.

Effect of Agrochemicals used Commonly in Rice Ecosystem on Meloidogyne graminicola

The effect of 14 insecticides, 6 fungicides and 6 herbicides used commonly in a rice ecosystem on mortality of infective stage juveniles (J2) of the rice root-knot nematode Meloidogyne graminicola, is reported in-vitro bioassays. Among the insecticides studied more than 50 per cent mortality was recorded with cartap hydrochloride, monocrotophos, chlorpyriphos and azadirachtin with a mean juvenile mortality of 100.00, 84.50, 70.50 and 80.00 per cent, respectively at 96 h post-exposure. Among the fungicides, more than 50 per cent mortality of J2 was observed with propiconazole (81.43%) and mancozeb (57.14%) at 96 h after exposure. Among herbicides, bispyribac sodium and pendimethalin resulted in 95.72 and 67.86 per cent mortality of J2 at 96 h of incubation. The insecticide cartap hydrochloride (50% SP) caused 100 per cent mortality of J2 within 24 h of exposure.