Farmers’ Knowledge and Awareness towards the Use of Agrochemicals in Vegetable Cultivation, Fako Cameroon

Agrochemicals are contemporary, omnipresent tool used in vegetable cultivation. Farmers’ knowledge and awareness of the proper usage of agrochemicals are critical for mitigating the negative effects on human health. This cross-sectional study was aimed at assessing the usage knowledge, risk awareness of toxicological and chemical classes, proper handling and use practices for agrochemicals homologated for use in vegetable farming, and the occurrence of health-related symptoms as a result of exposure among these farmers. The study included 93 vegetable growers from agricultural hotspot towns in Fako, southwest Cameroon. The field study, ran from November 2021 to December 2023, using a questionnaire to collect information on farmers demographic, and their knowledge of pesticide classes, and the related risk of associated with the handling of agrochemicals. Results show that all vegetable farmers, particularly those engaged in agribusiness, employ pesticide inputs to maximize production. Six pesticides, two fertilizer types, and one unknown substance were identified. While 23 active compounds were found, the most utilized were abamectin, emamectin (10.46%), dimethoate (9.30%,) and ethoprophos (8.13%). Two active chemicals, dimethoate and methalaxyl, are illegal yet remain in circulation. Toxicological classes I and II, with the greatest harmful effect on human health, were the most commonly utilized (64.27%). Thirty-nine percent of farmers never use personal protection equipment when working with agrochemicals, demonstrating a significant gap in knowledge and awareness of agrochemicals and their various applications and handling procedures in the field. The government should implement an intensive specialized educational program for on-field farmers with incentives in order to promote sustainable agriculture methods that ensure environmental and human safety.

英文版中国农药工业会刊--《China Agrochemicals》

《China Agrochemicals》—中国农药工业的第一份纯英文版刊物,于2006年10月创刊。本刊定位于国外的、关注于中国农药工业生产和发展的农药从业人员。通过对中国农药工业发展概况的描述与展望。

Agrochemicals and the Ghanaian Environment, a Review

Agrochemicals are generally recognized as a significant factor in enhancing the ability to meet Ghana’s need for sufficient, safe and affordable food and fiber, however, increased usage have led to environmental deterioration. In Ghana agriculture and public health sectors remain the major contributors of pollutants into the environment. This is a systematic review of studies done in Ghana to give an integrated picture of agrochemicals especially pesticides exposure to humans, animals, plants, water, soil/sediment and atmosphere in Ghana. Although the widespread usage of agrochemicals in Ghana has contributed immensely to increased food supply and improvement in public health, it has caused tremendous harm to the environment. Water bodies, fish, vegetables, food, soil and sediment have been found to be pesticide contaminated. There is considerable evidence that farmers have overused agrochemicals especially pesticides. It is evident from biological monitoring studies that farmers are at higher risk for acute and chronic health effects associated with pesticides due to occupational exposure. Furthermore the intensive use of pesticides involves a special risk of for field workers, consumers and unacceptable residue levels in exportable products may serve as barrier to international trade. This review will set the future course of action of different studies on agrochemical usage and pesticide exposure in Ghana.

Toxic Effects of Four Commonly-used Agrochemicals on Arma chinensis and Picromerus lewisi

This study was conducted to investigate the toxic effects of four different agrochemicals on Arma chinensis and Picromerus lewisi . Cypermethrin·phoxim, imidacloprid and fenvalerate had higher toxic effects on A. chinensis and P. lewisi . After the application of the agrochemicals, the released stink bugs could not well survive and propagate. Though the herbicide （glyphosate ammonium） had no direct toxic effects on A. chinensis and P. lewisi , their survival and propagation were affected after the application of the herbicide into natural environment. Therefore, to ensure better survival and propagation of the two kinds of stink bugs in natural environment, local agrochemical management should be strengthened, and the concept of green environmental protection should be constructed and popularized.

Acute and joint toxicity of three agrochemicals to Chinese tiger frog （Hoplobatrachus chinensis） tadpoles

We studied acute and joint toxicity of three different agrochemicals （chlorantraniliprole, flubendiamide-abamectin and penoxsulam） to Chinese tiger frog （Hoplobatrachus chinensis） tadpoles with the method of stability water tests. Results showed that the three agrochemicals increased tadpole mortality. For acute toxicity, the LC50 values after 24, 48 and 72 h of chlorantraniliprole, flubendiamide-abamectin and penoxsulam exposure were 5.37, 4.90 and 4.68 mg/L; 0.035, 0.025 and 0.021 rag/L; 1.74, 1.45 and 1.29 mg/L, respectively. The safety concentrations （SC） of chlorantraniliprole, fiubendiamide-abamectin and penoxsulam to the tadpoles were 1.23, 0.30 and 0.003 mg/L, respectively. Based on these findings, chlorantraniliprole and penoxsulam were moderately toxic, while flubendiamide-abamectin was highly toxic. All pairwise joint toxicity tests showed moderate toxicity. The LCs0 values after 24, 48 and 72 h of exposure were 7.08, 6.61 and 6.03 mg/L for chlorantra- niliprole＋penoxsulam, with corresponding values of 2.455, 2.328 and 2.183 mg/L for chlorantraniliprole＋flubendiamide-abamectin, and 1.132, 1.084 and 1.050 mg/L for penoxsulam＋flubendiamide-abamectin, with safe concentrations of 1.73, 0.63 and 0.30 mg/L, respectively. For toxic evaluations of pairwise combinations of the three agrochemicals, only the joint toxicity of chlorantraniliprole and flubendiamide-abamectin after 24 h was found to be synergistic, whereas all other tests were antagonistic. Our findings provide valuable information on the toxic effects of agrochemicals on amphibians and how various types of agrochemicals can be reasonably used in agricultural areas.

Indole derivatives as agrochemicals:An overview

Indole is a biologically active compound formed by the fusion of benzene and pyrrole,and it is widely found in natural products and drugs.Due to the unique structure and properties of indole,its derivatives often exhibit distinctive physiological activities,which has led to widespread attention in the field of pesticide development.Analyzing the design strategies and structure-activity relationships(SARs)of compounds is a crucial step in developing novel pesticides.This review mainly summarizes indole compounds with plant growth regulating,antiviral,fungicidal,herbicidal,and insecticidal activities,with the aim of providing new insights into the discovery and mechanism of action of novel indole-based pesticides.

Engineering microbes to overproduce natural products as agrochemicals

Current agricultural practices heavily rely on the excessive application of synthetic pesticides and fertilizers to meet the food demands of the increasing global population.This practice has several drawbacks including its negative impact on the environment and human health.Recently,the use of natural products has gained interest as alternatives to these synthetic agrochemicals due to their selective working mechanisms and biodegradability.In order to efficiently produce these natural agrochemicals,engineering microorganisms is emerging as an increasingly viable approach,and it is anticipated that it will have a significant market share in the near future.This approach manipulates the metabolism of microbes to manufacture the desired natural compounds from low-cost starting materials.This review discusses recent examples of this approach.The produced natural products can serve as biopesticides or plant growth regulators for the sustainable improvement of plant growth and disease control.The challenges in further developing these strategies are also discussed.

Making the Complicated Simple:A Minimizing Carrier Strategy on Innovative Nanopesticides

The flourishing progress in nanotechnology offers boundless opportunities for agriculture,particularly in the realm of nanopesticides research and development.However,concerns have been raised regarding the human and environmental safety issues stemming from the unrestrained use of non-therapeutic nanomaterials in nanopesticides.It is also important to consider whether the current development strategy of nanopesticides based on nanocarriers can strike a balance between investment and return,and if the complex material composition genuinely improves the efficiency,safety,and circularity of nanopesticides.Herein,we introduced the concept of nanopesticides with minimizing carriers(NMC)prepared through prodrug design and molecular self-assembly emerging as practical tools to address the current limitations,and compared it with nanopesticides employing non-therapeutic nanomaterials as carriers(NNC).We further summarized the current development strategy of NMC and examined potential challenges in its preparation,performance,and production.Overall,we asserted that the development of NMC systems can serve as the innovative driving force catalyzing a green and efficient revolution in nanopesticides,offering a way out of the current predicament.

Fluorine-containing agrochemicals in the last decade and approaches for fluorine incorporation

In this review, the methodologies for fluorine incorporation of 40 fluorine-containing agrochemicals that received an international standardization organization(ISO) name during the last decade are described.The predominant approach for fluorine introduction of these agrochemicals is to use a fluorine-containing building block. Here we present how the fluorine-containing building blocks are introduced into these agrochemicals. The synthetic methods of fluorine-containing building blocks that are not easily available are also specifically discussed. Fluoroarenes, difluomethylarenes and trifluomethylarenes are the main building blocks that have been used in this review. Fluorine-containing small molecules, such as alcohol,amine, ketoester, olefin are also widely used. The only example of late-stage fluorination is the synthesis of fungicide quinofumelin. We believe the fluorine introduction methods described here can provide ideas for the development of new and economical pesticide synthetic routes, and stimulate researchers to develop new fluorine incorporation methods and create new pesticides.

Effects of Imazethapyr-Based Herbicide Formulation in the Zebrafish (Danio rerio) Hepatocyte Cell Line (ZF-L): Cytotoxicity and Oxidative Stress

Seizures of agrochemical formulations have increased in Brazil and Rio Grande do Sul is among the Brazilian states with the highest number of seizures of these products obtained illicitly. The use of illicit formulations can cause significant harm to agricultural production, the environment, and non-target species. This study evaluated the cytotoxicity and oxidative stress of a seized formulation containing the herbicide imazethapyr (IMZT). Characterization of the herbicide included gas chromatography-mass spectrometry (GC-MS) and thermal analyses (thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC)). Hemolytic and cytotoxicity assays in ZF-L hepatic cells showed IC50 values of 12.75 µg/mL, 3.01 µg/mL, 2.67 µg/mL, and 1.61 µg/mL for erythrocytes, [3(4,5-dimethyl)-2 bromide-5 diphenyl tetrazolium] (MTT), neutral red (NR), and lactate dehydrogenase (LDH) assays, respectively. The median IC50 of 2.84 µg/mL was used in oxidative stress assays, revealing increased reactive oxygen species (ROS) production, reduced total sulfhydryl content, and decreased superoxide dismutase (SOD) and catalase (CAT) activity. This study is the first to report in vitro oxidative stress induced by IMZT in the ZF-L cell line, emphasizing the importance of in vitro assays for assessing the toxic effects of seized agrochemicals on human health and the environment.

Assessing the impact of agrochemicals on schistosomiasis transmission: A mathematical study

Schistosomiasis is a snail-borne parasitic disease,which is affecting almost 240 million people worldwide.The number of humans affected by schistosomiasis is continuously increasing with the rise in the use of agrochemicals.In this paper,a mathematical model is formulated and analyzed to assess the effect of agrochemicals on the transmission of schistosomiasis.The proposed model incorporates the effects of fertilizers,herbicides and insecticides on susceptible snails and snail predators along with schistosomiasis disease transmission.The existence and stability of the equilibria in the model are discussed.Sensitivity analysis is performed to identify the key parameters of the proposed model,which contributes most in the transmission of this disease.Numerical simulations are also performed to assess the impact of fertilizers,herbicides and insecticides on schistosomiasis outbreaks.Our study reveals that the agricultural pollution can enhance the transmission intensity of schistosomiasis,and in order to prevent the outbreak of schistosomiasis,the use of pesticides should be controlled.

Is there an inverted U-shaped curve？ Empirical analysis of the Environmental Kuznets Curve in agrochemicals

As the largest contributor to water impairment, agriculture-related pollution has attracted the attention of scientists as well as policy makers, and quantitative information is being sought to focus and advance the policy debate. This study applies the panel unit root, heterogeneous panel cointegration, and panel-based dynamic ordinary least squares to investigate the Environ- mental Kuznets Curve on environmental issues resulting from use of agricultural synthetic fertilizer, pesticide, and film for 31 provincial economies in China's Mainland from 1989 to 2009. The empirical results indicate a positive long-ran co-integrated relationship between the environ- mental index and real GDP per capita. This relationship takes on the inverted U-shaped Environmental Kuznets Curve, and the value of the turning point is approximately 10,000-13,000, 85,000-89,000 and over 160,000 CNY, for synthetic fertilizer nitrogen indicator, fertilizer phos- phorus indicator and pesticide indicator, respectively. At present, China is subject to tremendous environmental pressure and should assign more importance to special agriculture-related environmental issues.

Sustainability Analysis of Cropland Use in Cropping-Pastoral Ecotone before and after the Grain-for-Green Policy:A Case Study from Yanchi County in Ningxia

[Objective] This study aimed to analyze the sustainability of cropland use in cropping-pastoral ecotone before and after the Grain-for-Green Policy. [Method] Using Yanchi County in Ningxia Hui Autonomous Region as a case study area, this investigation used the annual transfer rate of land use types, cropland suitability and emergy analysis to examine the major pressures affecting the sustainable use of cropland before and after the Grain-for-Green Policy. [Result] The expansion of con- struction land onto cropland was significant; the annual cropland area was still larger than the land area suitable for cropping after the policy; agrochemical inputs used for crop production gradually increased and unit crop outputs required more agro- chemical inputs. Cropland use sustainability showed a fluctuating downward trend. [Conclusion] The results imply that the protection of high quality cropland, further im- plementation of the policy and control of agrochemical inputs according to precipita- tion are the main measures needed for sustainable cropland use in cropping-pastoral ecotone.

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.

The Development of Modern Pesticides

The present paper deals with agrochemicals. The low toxicities to mammals and wild lives, greater selectivity against target organisms, and high levels of activity are particular features of many modern agrochemicals. It is suggested that integrated pest management(IPM), by means of a combination of biological and chemical controls has met with some success and the present approach is to optimize the use of chemicals rather than to eliminate them.

Rapid Screening of 26 Organophosphorus Pesticides in Fresh Milk by Ultra Liquid Chromatography Coupled With Quadrupole-Time of Flight Mass Spectrometry

[Objectives]A rapid screening and analysis method for 26 organophosphorus agrochemicals in fresh milk was established using ultra performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry.[Methods]Raw milk was extracted with acetonitrile solution containing 0.2%formic acid by volume,and purified with a Dikma ProElut QuECHERS solid phase extraction cartridge.Target compounds were separated on a Waters ACQUITY UPLC HSS T3 chromatographic column(2.1 mm×50 mm,1.8μm)with methanol-water solution as a mobile phase for gradient elution,and through scanning with an electrospray ion source in positive ion mode,26 kinds of organophosphorus agrochemicals could be accurately qualitatively determined within 10 min.[Results]When using formic acid acetonitrile with a volume fraction of 0.2%,there were more types of detected compounds and a greater recovery;and using B cartridge could effectively eliminate the interference of non-polar substances such as phospholipids,achieve higher number of detected compounds than those of A and C,and well separate the 26 kinds of agrochemical residues.[Conclusions]This study provides a reference method for the rapid screening of agrochemical residues in dairy cows in the future.

Agrochemical Concentration Level in Zaria Dam Reservoir and Ground Waters in the Environs

This study examines the effect of agrochemical used for faming in the Galma Dam area on the quality of water in the reservoir and well water around the reservoir. Nine sampling points upstream of the Galma Dam were randomly se- lected for the study. Also, six hand dug wells in use by adjacent communities were identified for ground water samples. The study covered the period July to September 2011. All measurements were in accordance with the Standard Methods for the Examination of Water and Wastewater. The parameters measured and their mean concentrations from the reser- voir are in the order of: Chlorides (0.600 - 0.900 mg/l);Nitrates (0.009 - 0.019 mg/l);Bicarbonates;0.444 - 1.900 mg/l);Total Phosphates (0.173 - 3.077 mg/l);Sulphates (0.617 - 3.587 mg/l);and pH (6.4 - 7.5). For the well water samples, the results ranged from 1.58 - 3.10 mg/l;0.14 - 0.03 mg/l;0.60 - 2.73 mg/l;0.08 - 1.89 mg/l;0.33 - 2.66 mg/l and 6.05 - 7.0 respectively in the order previously listed. The results were statistically analyzed using ANOVA at 95% confidence level. Chlorides showed no significant variation between sampling points but significant variation with dates of sam- pling for surface and well waters. Nitrates variations with both sampling points and dates of sampling were insignificant. Bicarbonates variations with sampling points and dates of sampling were highly significant. Total Phosphates and Sul- phates variations with sampling points and dates of sampling were insignificant and significant respectively. pH values variations with sampling points and dates of sampling were insignificant and highly significant respectively. Generally, the mean concentrations are within the WHO maximum limits of the parameters in drinking water and recommenda- tions were made regarding the use of agrochemicals for farming in the area.

Arbuscular Mycorrhizal Fungi Colonization in Upland Rice as Influenced by Agrochemical Application

Mycorrhizal status of rice under upland conditions was studied using potted seedlings, Percentage of arbuscular mycorrhizal fungi （AMF） root colonization varied between 17.35% and 37.18% over an age series of 7 to 70 days old rice plants, AMF root colonization was increased up to 35-42 days, beyond which the root colonization steadily declined, The vesicles appeared after two weeks and reached their maximum intensity on the 35th day. The arbuscules were formed late on the 42^rd day （2.93%） and slightly varied up to the 70^th day （3.03%）. Higher dosage of urea application suppressed plant growth whereas the superphosphate treatment had no marked impact on plant growth. Generally, application of these agrochemicals registered less influence on the hyphal colonization of AMF in rice plants, whereas arbuscular colonization was adversely affected by higher dosages of fertilizers. There were pronounced decreases in both the plant growth and their AMF colonization due to the application of systemic fungicides, carbendazim and thiophanate methyl. The application of single sprays of fungicides was less deleterious over multiple sprays.

Herbicidal Activity of Chlorimuron-ethyl （107 g/kg） Associated with Metribuzin （643 g/kg） on Sugar Cane Weeds and Its Effects on Soil Agrochemical Properties, in Burkina Faso

The efficiency and selectivity of chlorimuron-ethyl （107 g/kg） associated with metribuzin （643 g/kg）, against weeds which causes big damages to sugar cane, have been studied on the sugar cane field of Beregadougou. The experimental design was a Latin rectangle with eight treatments in four replications including an untreated control, manual weeding, a control product （Trifloxysulfuron-sdium 1.85% ＋ Ametryn 73.15%） and five rates of chlorimuron-ethyl associated with metribuzin. Weeds counting and weighing their dry biomass have been done using 0.25 m2 quadrants to determine their biological efficiencies. The soil nitrogen nitrate and assimilable phosphorus contents were evaluated on a spectrophotometer, those of available potassium on a flame photometer. The biological efficiency coefficients of this herbicide, varied from 12.41% to 100%, according to their dry biomass. High rates, phytotoxics, showed the best coefficients. At the sugar cane complete maturation, the higher rates of imposter led to an accumulation of nitrogen nitrate content and lower available phosphorus and potassium contents, compared to the untreated control. The rate of 1.20 kg/ha became the dose to apply against weeds and less toxic to the soil.

Effects of Organic and Chemical Agriculture Systems on Arbuscular Mycorrhizal Fungi and Green Tomato Production in Calakmul, Mexico

Organic agriculture is increasingly used as an alternative to conventional agriculture due to its positive impact on the health of ecosystems and agroecosystems. However, the outcome of organic agriculture in terms of the production of various crops remains uncertain due to the influence of many variables, rising questions about its advantages over conventional agriculture. This study assessed the impacts of organic agricultural system on arbuscular mycorrhizal (AM) fungi diversity in soil and green tomato (Physalis ixocarpa Brot. ex Horn) crop production. A field experiment was conducted using a random block design with five repetitions of the following treatments: a) Control (no fertilization, NF);b) Vermicompost use (OTV);c) OTV with vermicompost leaching (OTH);and d) Inorganic fertilization (CST). Throughout the crop cycle, soil samples were analyzed chemically, the relative growth rate (RGR) of the plants was measured, and the colonization and diversity of AM fungi were quantified in roots and soil;finally, above-ground, root biomass, and fruit production were measured. Organic fertilization (OTV, OTH) increased (p p > 0.05). It is concluded that organic agriculture management is essential to promote a greater AM fungi diversity and fungi root colonization. Plant-AM fungi interaction increases growth rates and it allows a similar tomato production compared with conventional agriculture.