Crop Disease Control Research Articles

Potential risk of drift from inclined fan nozzles

ABSTRACT Pest, disease and weed control in large-scale crops depend on the application of agrochemicals. These applications are subject to several factors that can lead to drift. The objective of this study was to evaluate the effect of spray nozzles with inclined flat jet, on the drift. The drift was collected in a 10 m wind tunnel, with a spray system inside. The samples were collected in 5 horizontal points, from 2.0 to 6.0 m away from the spray nozzle and 5 points in the vertical, from 0.1 to 0.5 m away from the lower base of the wind tunnel, totaling 25 sample points. The mixture applied was glyphosate (isopropylamine salt, 1080 g a.e. ha-1) with 2,4-D (dimethylamine salt, 1.005 g a.e. ha-1). The nozzles J3D 100 025, JGC 120 02, JAP 110 015 and ADI 110 015 (control), inclined by 37.5º, 20º, 15º and 0º, respectively, were used in two directions of spray: upwind and downwind of the air flow direction. The nozzles J3D, JGC and JAP, when inclined downwind reduced the drift by 16.1, 2.6 and 39.0%, respectively, relative to the control, and when inclined upwind, reduced drift by 53.4, 3.9 and 18.6%, respectively, relative to the control. Spray nozzles with second-generation air-induction inclined flat jet (JAP) and standard inclined flat jet (J3D) reduce the collected drift compared to the nozzle without inclination, regardless of wind flow direction.

Pesticides in agriculture

Pesticides in agriculture

Sustainable food systems for Africa

Two conceptual models of the progression of small scale farmers in sustainable agriculture and of the characteristics of production, equity, natural resource management and sustainability are presented and their implications are discussed. The models inform an analysis of two development programmes, and they are linked to long term comparative organic farming systems research trials, which have been running for four years in South Africa’s Southern Cape, comparing organic and conventional farming systems, crop rotation and mono-cropping, biological and chemical pest and disease control and water use efficiency in cabbage, sweet potato and cowpea crops. In Africa the high cost and limited availability of agricultural inputs make agro-ecological approaches attractive, as they are practically possible (with low levels of external inputs) and improve carbon sequestration, dietary diversity and food quality. The challenges for viable organic farming systems are thus seen to include: improving soil fertility (especially acidity and available soil P), controlling pests and diseases and convincing consumers of the quality of organic products. Benefits include: reduced dependency on externally-purchased agricultural inputs, lower soil acidity, higher soil water retention, sequestration of soil carbon, improved soil microbiology, better agro-biodiversity and elimination of poisons from the food chain. Support for small scale farmers will require technical and training support, market linkages and quality management.

Exploration on Strengthening Treatment Method of Integral Stressed Bridge under Special Load

Based on the characteristics and current situation of crop diseases and insect pests, this paper analyzes the problems of farmers’ lack of awareness of prevention and control, blind introduction of quarantine pests that lead to the spread of quarantine pests, and lack of advanced pest control technology in the prevention and control of crop diseases and pests. , For reference and reference.

Functional Analysis of the Melanin-Associated Gene CmMR1 in Coniothyrium minitans.

Coniothyrium minitans is a sclerotial parasite, which has been investigated for commercial control of crop diseases caused by Sclerotinia sclerotiorum. Previously, we obtained a T-DNA insertional mutant, ZS-1TN24363, which did not produce melanin during conidiation. To understand the function of melanin in C. minitans, we cloned the gene that was disrupted by the T-DNA insertion, and found that this gene, called CmMR1, encoded a putative protein of 1,011 amino acids, which is a homolog of the transcription factor MR. Full-length CmMR1 contains 3,167 bp, with three exons and two introns. To confirm that the disrupted gene is responsible for the melanin-deficiency of the mutant, CmMR1 was disrupted and three targeted knockout mutants were obtained. Biological assays showed that the phenotype of the targeted knockout mutants was similar to that of the T-DNA insertional mutant. Furthermore, gene complementation confirmed that CmMR1 is responsible for the mutant phenotype. CmMR1 disruption did not affect hyphal growth, conidiation, and parasitization of C. minitans, however, the ROS accumulation increased and tolerance to UV light decreased significantly in the mutants. Our result may enhance the understanding of melanin in the ecology of C. minitans on molecular level.

Signatures of Insecticide Selection in the Genome of Drosophila melanogaster.

Resistance to insecticides has evolved in multiple insect species, leading to increased application rates and even control failures. Understanding the genetic basis of insecticide resistance is fundamental for mitigating its impact on crop production and disease control. We performed a GWAS approach with the Drosophila Genetic Reference Panel (DGRP) to identify the mutations involved in resistance to two widely used classes of insecticides: organophosphates (OPs, parathion) and pyrethroids (deltamethrin). Most variation in parathion resistance was associated with mutations in the target gene Ace, while most variation in deltamethrin resistance was associated with mutations in Cyp6a23, a gene encoding a detoxification enzyme never previously associated with resistance. A “nested GWAS” further revealed the contribution of other loci: Dscam1 and trpl were implicated in resistance to parathion, but only in lines lacking Wolbachia. Cyp6a17, the paralogous gene of Cyp6a23, and CG7627, an ATP-binding cassette transporter, were implicated in deltamethrin resistance. We observed signatures of recent selective sweeps at all of these resistance loci and confirmed that the soft sweep at Ace is indeed driven by the identified resistance mutations. Analysis of allele frequencies in additional population samples revealed that most resistance mutations are segregating across the globe, but that frequencies can vary substantially among populations. Altogether, our data reveal that the widely used OP and pyrethroid insecticides imposed a strong selection pressure on natural insect populations. However, it remains unclear why, in Drosophila, resistance evolved due to changes in the target site for OPs, but due to a detoxification enzyme for pyrethroids.

Phosphites attenuate Sclerotinia sclerotiorum-induced physiological impairments in common bean

Phosphites, marketed as foliar fertilizers and resistance activators, have been shown to be useful for the control of diseases in many profitable crops. Despite the importance of white mold, caused by Sclerotinia sclerotiorum, to reduce common bean yield, knowledge of the phosphites´ effect on disease control at the physiological level is still missing. In this study, the leaf gas exchange and chlorophyll a fluorescence parameters variable-to-maximum chlorophyll a fluorescence ratio (Fv/Fm), photochemical yield [Y(II)], yield for dissipation by down-regulation [Y(NPQ)], yield for non-regulated dissipation [Y(NO)], and electron transport rate (ETR) as well as the concentrations of photosynthetic pigments in common bean plants that were sprayed with zinc (Zn) or copper (Cu) phosphites and challenged or not with S. sclerotiorum were determined. Based on the in vitro assays, Zn and Cu phosphites inhibited fungal mycelial growth in a dose-dependent manner, but the Cu phosphite showed to be more fungitoxic. Lesion area and white mold severity were reduced by Zn and Cu phosphites, but the Zn phosphite was more effective. Fungal infection dramatically decreased the values of net carbon assimilation rate, stomatal conductance to water vapor and transpiration rate on non-sprayed plants. Increases in internal CO2 concentration indicated that fungal-induced photosynthetic impairments were chiefly governed by biochemical limitations, but these impairments were greatly abrogated in the Zn and Cu phosphite-sprayed plants. Similarly, the photochemical dysfunctions stemmed from S. sclerotiorum infection were limited in the Zn and Cu phosphite-sprayed plants. Concentrations of chlorophyll a + b and carotenoids decreased on inoculated plants, but lower reductions were recorded on Zn and Cu phosphites-sprayed plants. In conclusion, the potential of Zn and Cu phosphites in attenuate the S. sclerotiorum-induced physiological impairments in common bean leaflets was demonstrated and may be an effective mean for managing this disease under field conditions.

Influence of triazole pesticides on tillage soil microbial populations and metabolic changes

Pesticides are generally applied to agricultural soil to control crop diseases, with the critical goal of preventing yield loss and optimizing economic returns. However, the excessive utilization of pesticides in agriculture is a severe environmental and human health problem. In the present study, effect of triazole based fungicide, propiconazole on soil physicochemical properties, stimulatory impact of propiconazole residue on soil microbial communities and soil enzyme activities (phosphatise and urease) in contaminated red sandy loam and deep black soils of paddy (Oryza sativa L.) fields at different concentrations were evaluated. The liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) analysis showed high levels of propiconazole residues of 434 and 426 ng g−1 in red sandy loam and deep black soils, respectively. A total of 27 bacterial and 18 fungal strains were isolated from propiconazole-contaminated soils, identified by molecular markers and had their sequences deposited in the GenBank. We observed a pronounced increase in soil microbial growth, and urease and phosphatase activities at lower propiconazole concentrations up to 2 weeks post-treatment. On the contrary, the microbial growth and urease and phosphatase activities were relentlessly reduced at higher propiconazole concentrations and a long incubation period after 2 to 4 weeks of post-treatment. Overall, it was concluded that the concentration-dependency and incubation period of propiconazole would enhance the growth and activity of soil microbes and enzymes respectively and the higher application will be detrimental to the soil health.

Fractions of the Lippia origanoides extract induce the polyphenol oxidase and phenylalanine ammonia lyase enzymes in Solanum lycopersicum

The resistance of the pathogenic fungi to fungicides and the perspective of induced resistance to plants guides the search for molecules to promote the sustainable control of agricultural crop diseases. The exhaustion of conventional sources gives a direction for the search of exotic plants from arid environments or with medicinal properties. This study aims to evaluate the antifungal activity of the Anadenanthera colubrina, Lippia origanoides, Mimosa tenuiflora and Myracrodruon urundeuva species and subsequently the specie with the best antifungal activity was used to evaluate the potential in inducing the enzyme activity. The antifungal effect was determined with 10 fungi using the crude ethanol extract at 100 and 1000 μg mL- 1 concentrations. The L. origanoides extract was the most effective and inhibited 100% of the pathogens. The L. origanoides extract was fractioned with hexane, chloroform, ethyl acetate and methanol. The hexane fraction inhibited 100% of the growth of pathogens at 400 μg mL−1. The in vitro evaluation of the ability to induce enzymes in Solanum lycopersicum (Micro-Tom cultivar) was determined with the increase of oxidative enzymes, polyphenol oxidase and phenylalanine ammonia lyase activity. The ability to induce enzymes was determined with 400 μg mL−1 of the crude extract and L. origanoides fractions. The crude extract did not induce the enzyme activity and the fractions induced the polyphenol oxidase and phenylalanine ammonia lyase enzymes. The results confirmed the broad spectrum antifungal activity of the L. origanoides crude extracts. The partition revealed fractions with different capacities to induce enzymes associated to the resistance that was not revealed by the crude extract.

Real time portable genome sequencing for global food security

Crop losses due to viral diseases and pests are major constraints on food security and income for millions of households in sub-Saharan Africa (SSA). Such losses can be reduced if plant diseases and pests are correctly diagnosed and identified early. Currently, accurate diagnosis for definitive identification of plant viruses and their vectors in SSA mostly relies on standard PCR and next generation sequencing technologies (NGS). However, it can take up to 6 months before results generated using these approaches are available. The long time taken to detect or identify viruses impedes quick, within-season decision-making necessary for early action, crop protection advice and disease control measures by farmers. This ultimately compounds the magnitude of crop losses and food shortages suffered by farmers. The MinION portable pocket DNA sequencer was used, to our knowledge globally for the first time, to sequence whole plant virus genomes. We used this technology to identify the begomoviruses causing the devastating cassava mosaic virus, which is ravaging smallholder farmers’ crops in sub-Saharan Africa.

Model-Based Forecasting of Agricultural Crop Disease Risk at the Regional Scale, Integrating Airborne Inoculum, Environmental, and Satellite-Based Monitoring Data

Crop diseases have the potential to cause devastating epidemics that threaten the world’s food supply and vary widely in their dispersal pattern, prevalence and severity. It remains unclear what the impact disease will have on sustainable crop yields in the future. Agricultural stakeholders are increasingly under pressure to adapt their decision-making to make more informed and efficient use of irrigation water, fertilizers and pesticides. They also face increasing uncertainty in how best to respond to competing health, environment and (sustainable) development impacts and risks. Disease dynamics involves a complex interaction between a host, a pathogen, and their environment, representing one of the largest risks facing the long-term sustainability of agriculture. New airborne inoculum, weather, and satellite-based technology provide new opportunities for combining disease monitoring data and predictive models – but this requires a robust analytical framework. Integrated model-based forecasting frameworks have the potential to improve the timeliness, effectiveness and foresight for controlling crop diseases, while minimizing economic costs and environmental impacts, and yield losses. The feasibility of this approach is investigated involving model and data selection. It is tested against available disease data collected for wheat stripe (yellow) rust (Puccinia striiformis f.sp. tritici) (Pst) fungal disease within southern Alberta, Canada. Two candidate, stochastic models are evaluated; a simpler, site-specific model, and a more complex, spatially-explicit transmission model. The ability of these models to reproduce an observed infection pattern is tested using two climate datasets with different spatial resolution - a reanalysis dataset (~55 km) and weather station network township-aggregated data (~10 km). The complex spatially-explicit model using weather station network data had the highest forecast accuracy. A multi-scale airborne surveillance design that provides data would further improve disease risk forecast accuracy under heterogeneous modeling assumptions. In the future, a model-based forecasting approach, if supported with an airborne surveillance monitoring plan, could be made operational to provide agricultural stakeholders with reliable, cost-effective, and near-real-time information for protecting and sustaining crop production against multiple disease threats.

Transcriptomic evidence for involvement of reactive oxygen species in Rhizoctonia solani AG1 IA sclerotia maturation.

Rhizoctonia solani AG1 IA is a soil-borne fungal phytopathogen that can significantly harm crops resulting in economic loss. This species overwinters in grass roots and diseased plants, and produces sclerotia that infect future crops. R. solani AG1 IA does not produce spores; therefore, understanding the molecular mechanism of sclerotia formation is important for crop disease control. To identify the genes involved in this process for the development of disease control targets, the transcriptomes of this species were determined at three important developmental stages (mycelium, sclerotial initiation, and sclerotial maturation) using an RNA-sequencing approach. A total of 5,016, 6,433, and 5,004 differentially expressed genes (DEGs) were identified in the sclerotial initiation vs. mycelial, sclerotial maturation vs. mycelial, and sclerotial maturation vs. sclerotial initiation stages, respectively. Moreover, gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) analyses showed that these DEGs were enriched in diverse categories, including oxidoreductase activity, carbohydrate metabolic process, and oxidation-reduction processes. A total of 12 DEGs were further verified using reverse transcription quantitative PCR. Among the genes examined, NADPH oxidase 1 (NOX1) and superoxide dismutase (SOD) were highly induced in the stages of sclerotial initiation and maturation. In addition, the highest reactive oxygen species (ROS) production levels were detected during sclerotial initiation, and enzyme activities of NOX1, SOD, and catalase (CAT) matched with the gene expression profiles. To further evaluate the role of ROS in sclerotial formation, R. solani AG1 IA was treated with the CAT inhibitor aminotriazole and H2O2, resulting in the early differentiation of sclerotia. Taken together, this study provides useful information toward understanding the molecular basis of R. solani AG1 IA sclerotial formation and maturation, and identified the important role of ROS in these processes.

Combining R gene and quantitative resistance increases effectiveness of cultivar resistance against Leptosphaeria maculans in Brassica napus in different environments.

Using cultivar resistance against pathogens is one of the most economical and environmentally friendly methods for control of crop diseases. However, cultivar resistance can be easily rendered ineffective due to changes in pathogen populations or environments. To test the hypothesis that combining R gene-mediated resistance and quantitative resistance (QR) in one cultivar can provide more effective resistance than use of either type of resistance on its own, effectiveness of resistance in eight oilseed rape (Brassica napus) cultivars with different R genes and/or QR against Leptosphaeria maculans (phoma stem canker) was investigated in 13 different environments/sites over three growing seasons (2010/2011, 2011/2012 and 2012/2013). Cultivar Drakkar with no R genes and no QR was used as susceptible control and for sampling L. maculans populations. Isolates of L. maculans were obtained from the 13 sites in 2010/2011 to assess frequencies of avirulent alleles of different effector genes (AvrLm1, AvrLm4 or AvrLm7) corresponding to the resistance genes (Rlm1, Rlm4 or Rlm7) used in the field experiments. Results of field experiments showed that cultivars DK Cabernet (Rlm1 + QR) and Adriana (Rlm4 + QR) had significantly less severe phoma stem canker than cultivars Capitol (Rlm1) and Bilbao (Rlm4), respectively. Results of controlled environment experiments confirmed the presence of Rlm genes and/or QR in these four cultivars. Analysis of L. maculans populations from different sites showed that the mean frequencies of AvrLm1 (10%) and AvrLm4 (41%) were less than that of AvrLm7 (100%), suggesting that Rlm1 and Rlm4 gene-mediated resistances were partially rendered ineffective while Rlm7 resistance was still effective. Cultivar Excel (Rlm7 + QR) had less severe canker than cultivar Roxet (Rlm7), but the difference between them was not significant due to influence of the effective resistance gene Rlm7. For the two cultivars with only QR, Es-Astrid (QR) had less severe stem canker than NK Grandia (QR). Analysis of the relationship between severity of stem canker and weather data among the 13 sites in the three growing seasons showed that increased severity of stem canker was associated with increased rainfall during the phoma leaf spot development stage and increased temperature during the stem canker development stage. Further analysis of cultivar response to environmental factors showed that cultivars with both an Rlm gene and QR (e.g. DK Cabernet, Adriana and Excel) were less sensitive to a change in environment than cultivars with only Rlm genes (e.g. Capitol, Bilbao) or only QR (e.g. DK Grandia). These results suggest that combining R gene and QR can provide effective, stable control of phoma stem canker in different environments.

Hyperspectral discrimination of foliar biotic damages in rice using principal component analysis and probabilistic neural network

Assessment of crop health status in real time could provide reliable and useful information for making effective and efficient management decisions regarding the appropriate time and method to control crop diseases and insect damage. In this study, hyperspectral reflectance of symptomatic and asymptomatic rice leaves infected by Pyricularia grisea Sacc, Bipolaris oryzae Shoem, Aphelenchoides besseyi Christie and Cnaphalocrocis medinalis Guen was measured in a laboratory within the 350–2 500 nm spectral region. Principal component analysis was performed to obtain the principal component spectra (PCs) of different transformations of the original spectra, including original (R), common logarithm of reciprocal (lg (1/R)), and the first derivative of original and common logarithm of reciprocal spectra (R′ and (lg (1/R))′). A probabilistic neural network classifier was applied to discriminate the symptomatic rice leaves from asymptomatic ones with the front PCs. For identifying symptomatic and asymptomatic rice leaves, the mean overall discrimination accuracies for R, lg (1/R), R′ and (lg (1/R))′ were 91.3, 93.1, 92.3 and 92%, and the mean Kappa coefficients were 0.771, 0.835, 0.829 and 0.82, respectively. To discriminate between disease and insect damage, the overall accuracies for R, lg (1/R), R′ and (lg (1/R))′ were 97.7, 98.1, 100 and 100%, and the Kappa coefficients were 0.962, 0.97, 1 and 1, respectively. These results demonstrated that hyperspectral remote sensing can discriminate between multiple diseases and the insect damage of rice leaves under laboratory conditions.

Utility of Arbuscular Mycorrhizal Fungi for Improved Production and Disease Mitigation in Organic and Hydroponic Greenhouse Crops

Arbuscular mycorrhizal (AM) fungi are considered to be enormously important in contemporary agriculture and horticulture for their ability to improve crop disease and fertility management in commercial field and greenhouse crop production. Recently, commercial greenhouse producers have begun using AM inoculum to increase yields and provide sustainable growing conditions in organic and hydroponic production systems. However, strong evidence in support of their effectiveness in hydroponic production is still lacking. Future research is expected to address benefits of the use of AM fungi in hydroponic greenhouse crops, such as defense against pathogen, herbivore attack and the effective management of photo-assimilates by plants, which are essential for fruit production. In order to increase our understanding of the usefulness of AM fungi in hydroponic greenhouses, large-scale trial and a cost-benefit evaluation of the process are needed. This article discusses the use of AM fungi for improving organic and hydroponic greenhouse crop production and disease control, considering that AM fungi inoculations in soil-based greenhouses and fields have proven to be very effective.

Effect of the addition of a fungicide to glyphosate applied postemergence on crop injury, disease control, and corn yield

The addition of pyraclostrobin, pyraclostrobin/fluxapyroxad, pyraclostrobin/metconazole, trifloxystrobin/propiconazole, azoxystrobin/propiconazole, and trifloxystrobin/prothioconazole fungicides to glyphosate reduced disease incidence up to 19% and disease severity up to 4% compared with glyphosate alone. Fungicides evaluated can be safely mixed with glyphosate for corn production, but fungicide use was not associated with increased corn yield.

Traditional knowledge on integrated pest and weed management in chayote (Sechium edule (Jacq.) Sw.) crops from localities of Chiapas, Mexico

This research was carried out in Villaflores and Villa Corzo, located in Chiapas State of Mexico. Specifically, throughout an ethno-agronomical approach, semi-structured interviews were designed and applied to the chayote producers who were selected by random routes. The results indicate the 57.89% of chayote producers in both municipalities, have allowed to control weeds in their crops, and being a higher proportion represented by Villaflores. Given these concerns, they prefer to control weeds throughout traditional methods, basically using mattocks with frequencies of 15 to 30 days after sowing or two to four times per cycle of crop production. Both pest and diseases are mainly controlled throughout chemical methods application. A preference to perform control among periods of higher rainfall or drought is not distinguished. A considerable percentage, which reaches 44% of the interviewed population among both municipalities, report they do not need to control pests and crop diseases.

The cyclic lipopeptide orfamide induces systemic resistance in rice to Cochliobolus miyabeanus but not to Magnaporthe oryzae.

The Pseudomonas- derived cyclic lipopeptide orfamide can induce resistance to Cochliobolus miyabeanus but not to Magnaporthe oryzae in rice. Abscisic acid signaling is involved in the induced systemic resistance response triggered by orfamide. Diverse natural products produced by beneficial Pseudomonas species have the potential to trigger induced systemic resistance (ISR) in plants, and thus may contribute to control of diseases in crops. Some beneficial Pseudomonas spp. can produce cyclic lipopeptides (CLPs), amphiphilic molecules composed of a fatty acid tail linked to an oligopeptide which is cyclized. CLPs can have versatile biological functions, but the capacity of Pseudomonas-derived CLPs in triggering ISR responses has barely been studied. Pseudomonas protegens and related species can produce orfamide-type CLPs. Here we show that in rice, orfamides can act as ISR elicitors against the necrotrophic fungus Cochliobolus miyabeanus, the causal agent of brown spot disease, but are not active against the blast fungus Magnaporthe oryzae. Orfamide A can trigger early defensive events and activate transcripts of defense-related genes in rice cell suspension cultures, but does not cause cell death. Further testing in rice cell suspension cultures and rice plants showed that abscisic acid signaling, the transcriptional activator OsWRKY4 and pathogenesis-related protein PR1b are triggered by orfamide A and may play a role in the ISR response against C. miyabeanus.

Does agricultural use of azole fungicides contribute to resistance in the human pathogen Aspergillus fumigatus?

Azole resistance in human fungal pathogens has increased over the past twenty years, especially in immunocompromised patients. Similarities between medical and agricultural azoles, and extensive azole (14α-demethylase inhibitor, DMI) use in crop protection, prompted speculation that resistance in patients with aspergillosis originated in the environment. Aspergillus species, and especially Aspergillus fumigatus, are the largest cause of patient deaths from fungi. Azole levels in soils following crop spraying, and differences in sensitivity between medical and agricultural azoles (DMIs), indicate weaker selection in cropping systems than in patients receiving azole therapy. Most fungi have just one CYP51 paralogue (isozyme CYP51B), but in Aspergillus sp. mutations conferring azole resistance are largely confined to a second paralogue, CYP51A. Binding within the active centre is similar for medical and agricultural azoles but differences elsewhere between the two paralogues may ensure selection depends on the DMI used on crops. Two imidazoles, imazalil and prochloraz, have been widely used since the early 1970s, yet unlike triazoles they have not been linked to resistance in patients. Evidence that DMIs are the origin, or increase the frequency, of azole resistance in human fungal pathogens is lacking. Limiting DMI use would have serious impacts on disease control in many crops, and remove key tools in anti-resistance strategies. © 2017 Society of Chemical Industry.

Exploratory Analysis on the Management of Agricultural Knowledge and Information by Smallholder Farmers in Batticaloa District

Extent of farmer knowledge and availability of reliable information at the level of farm are considered key driving forces in agricultural development as both support interchangeably to transform the livelihoods of rural poor into one with increased household income stability and food security. The farmers who do not have a free/subsidized and open/fair access to the vital agricultural information would, therefore, face severe difficulties in their attempt to achieve the goals of farming. The purpose of the study was to investigate the factors that trigger or hinder farmer access to agricultural knowledge and information. The smallholder agricultural farmers in the Batticaloa district in Sri Lanka was used as the case. A series of pre-tested structured questionnaire-based face-to-face interviews were carried out with a cross section of farmers (n=144) to gather data and both descriptive and quantitative techniques, including Factor and Logistics Regression analysis, were employed to analyse data. The results show that the level of acquisition of agricultural knowledge by farmers has a positive and negative relationship with the level of education and age of farmer, respectively. Amongst other factors, the farmers, in general, requested badly the valid and reliable agricultural information on a regular basis with regard to the market prices of inputs and outputs, credits/subsidies/loans etc. available and the measures of crop protection, i.e. pests and disease control. The inadequacy in information services and agricultural officers, limited infrastructure and insufficient funds/resources hinder farmer access to agricultural knowledge and information. The outcome of analysis, overall, implies the importance of developing appropriate packages to facilitate information sharing and knowledge mobilization and targeting so to specific farming communities in need with a right mix of market-based and regulatory incentives.