Efficacy Of Pesticides Research Articles

Using a Generalized Linear Mixed Model Framework to Account for Spatial Variability in a Comparison of Orchard Sprayer Efficacy

Uniform application of pesticides in vineyard and orchard systems can be difficult to achieve due to variability in the density and structure of the crop canopy. Depending on the equipment used and environmental conditions, applications can result in poor spray coverage, spray drift, and wasted spray which, in turn, are manifested as a combination of poor pesticide efficacy, economic losses and potential environmental problems for the grower. A study was therefore designed and carried out to test new sprayer equipment aimed at addressing these issues. Statistically, the study presented a unique replicated three dimensional spatial design which captured response variability (coverage) both within and across trees in an orchard setting. Application of a generalized linear mixed model framework allowed comparison of sprayer designs in terms of their application efficiencies while accounting for the intra- and inter-tree correlation of the coverage response. Examples demonstrating various models and their associated correlation structures are given and the resulting interpretations discussed.

Advances in Research of Botanical Insecticide

Botanical insecticides have advantages of wide range of sources, easily made with local materials, low-cost, cost savings, useful and safe to people, animals and crops, etc. The compound of botanical insecticide is an effective way to improve the efficacy of such pesticides. With the development of green agriculture, it will gain more and more attention.

Field Efficacy of Chemical Pesticides against Maruca vitrata Fabricius (Lepidoptera: Crambidae) Infesting Soybean in Brazil

The soybean pod borer, Maruca vitrata, can cause great damage by attacking pods from soybean plants. The aim of this study was to evaluate the field efficacy of chemical pesticides, when applied in spray, against soybean pod borer. The experiment was conducted in the experimental area of Funda&ccedil&atildeo, MS, in Maracaju, MS, Brazil, in the growing season 2012/2013. The randomized block design was used with six treatments (teflubenzuron, flubendiamide, methomyl, chlorantraniliprole + lambda-cyhalothrin, chlorpyrifos, and a control treatment without insecticide) and five replications, on cultivar BMX Turbo RR. Evaluations were performed at one, four, seven, 10, and 14 days after pesticides application (DAA), and were based on the percentage of attacked plants with M. vitrata presence, and the number of alive larvae per plant. On each evaluation, 10 plants per plot were analyzed. The data were subjected to ANOVA and the treatment means were compared by Tukey test at 5% probability. Pesticides teflubenzuron, flubendiamide, chlorantraniliprole + lambda-cyhalothrin, and chlorpyrifos significantly reduced the percentage of attacked plants by M. vitrata. Chlorpyrifos, teflubenzuron, and chlorantraniliprole + lambda-cyhalothrin showed higher field efficacy to control M. vitrata from the first day after application. However, flubendiamide showed good efficacy from 10 days after application, and joined the group with higher efficacy (chlorpyrifos, teflubenzuron, and chlorantraniliprole + lambda-cyhalothrin). Methomyl showed no field efficacy against legume pod borer.

Field evaluation of different chemical pesticides against aphid toxoptera aurantii on different tea (Camellia sinensis L.) cuttings under high shade nursery

Experiment was conducted at National Tea & High Value Crops Research Institute, Shinkiari, Mansehra-Pakistan during 2011-12 with the objectives to evaluate the efficacy of different chemical pesticides i.e. Tarzan (Cypermethrin 10EC), Piceal (Alphacypermethrin 10SC) and Buzer (Alphacypermethrin 10% W/V) were used to compare their effectiveness in relation to control the aphid infestation on growing shoots and their control at nursery stage. The mortality of aphid on tea cutting significantly affected under chemical pesticide Tarzan caused highest mortality 64%, 63%, 52%, 55%, 59%, 59%, 41% and 54% respectively, pesticide Piceal ranked second in relation to efficacy against aphid with insect mortality 36%, 40%, 40%, 28%, 37%, 36%, and 43% respectively. Whereas insecticide Buzer showed less efficacy among the other two insecticides on all tea cuttings application after 24 hours. Similar trend was observed in other treatments.

소면적 재배작물의 약효 및 안전성 그룹화 적용 연구

Abstract This study was carried out to investigate the pesticide efficacy and crop safety among differentleafy vegetables applied with foliar spraying under greenhouse and to check extrapolating from some trialdata to other minor crops. Leafy vegetables used in this study were: lettuce (Lactuca sativar), leaf broccoli(Brassica oleracea.), chicory (Cichorium intybus.), chinese cabbage (Brassica campestris subsp. napus var.pekinensis), radish (Raphanus sativus), rape (Brassica napus), crown daisy (Chrysanthemum coronarium),edible burdock (Arctium lappa), endive (Cichorium endivia) and mustard greens (Brassica jumcea). Based onthe result of control efficacy, all crops were classified into the groups. The results showed the probabilities ofextrapolating the control value data of minor crop within the same group. It would be possible to use thepesticides which are already been registered for similar crops to those crops have no registered pesticides.Key words Pesticide, Crop protection product, Minor use, Minor crop, Major crop

Aerial treatments in forest protection – research methodology

Abstract Treatment effectiveness in forest protection against harmful insects depends not only on pesticide efficacy of the product applied, but also on a number of other factors including assurance that a given insecticide reaches the pest living in the canopy. In the treatments with the use of aerial equipment (silva-aerial) it is advisable to consider species and age diversity of protected tree stands. The paper presents research methodology on the assessment of spray structure and density, penetration of spray droplets into the canopy as well as a degree of coverage and incorporation in tree crowns. The methodology proposed takes into account characteristics of the forest area studied and its surroundings, as well as the parameters and equipment of the measurement line. There were determined: operation requirements for the aircraft and its test and registration equipment as well as demands on pilot qualifications, flight performance on the measurement line and weather conditions allowing for conducting test trials. In the paper, there are presented a set of values and mathematical formulas needed for the analyses. Taking into account ecological threats, there were included the methods on evaluation of spray drift of the liquid distributed over the forest.

Efficacy of an Essential Oil-Based Pesticide for Controlling Bed Bug (Cimex lectularius) Infestations in Apartment Buildings.

Bed bugs (Cimex lectularius L. and Cimex hemipterus F.) are among the most difficult urban pests to manage. Many essential oil-based bed bug control products that are considered reduced risk to mammals compared to synthetic insect neurotoxins have become commercially available, but their effectiveness as a stand-alone control method is unknown. This study assessed the field efficacy of an essential oil-based bed bug control product (EcoRaider; a.i. 1% geraniol + 1% cedar oil + 2% sodium lauryl sulfate) compared to a pyrethroid and neonicotinoid mixture spray (0.075% Temprid SC; a.i. beta-cyfluthrin + imidacloprid). After 12 weeks, the three treatments—EcoRaider, Temprid SC, and EcoRaider + Temprid SC caused 92.5 ± 2.7, 92.9 ± 3.0, and 91.7% ± 2.7% bed bug count reduction, respectively. No significant differences existed in the bed bug reduction among the treatments. Bed bugs were eliminated from only 22% of the treated apartments. Among those still with bed bugs, 76% of the residents did not know bed bugs were present. We documented the residents’ self-control practices and discussed the potential of using essential oil-based insecticides in bed bug management programs to minimize the health risks to building occupants and pets and to slow down the development of insecticide resistance.

Variation in Deposition of an Air-Assisted Sprayer in Open Field Due to Wind Conditions

<abstract><title><italic>Abstract</italic></title> . Wind conditions can change the uniformity of spray deposition in orchards by deflecting the spray droplet trajectory or reducing its speed. Inadequate pesticide deposition on tree foliage may reduce the pesticide efficacy, whereas overdosing is uneconomical and harmful to the environment. A field study was conducted to determine wind effects on spray deposition at different distances from an air-assisted sprayer. The sprayer was driven at two speeds in two travel directions with two different nozzle sizes in an open field (no trees). Using Pyranine-10G as tracer, spray droplet movement was sampled on artificial targets. The targets were located on both sides at 3, 6, and 9 m from the sprayer centerline and at 1, 2, and 3 m height within each distance. The samples were analyzed fluorometrically. Wind components perpendicular to the sprayer path increased the deposition downwind while reducing it upwind. Higher wind speeds increased the differences between the depositions on the two sides of the sprayer. The changes in deposition were clearer at farther distances from the sprayer. Overall, the downwind-to-upwind deposition ratios at 3, 6, and 9 m distances were 1.2, 2.1, and 11.9, respectively. Driving against the wind (headwind) gave less deposition than driving in the wind direction (tailwind). In all cases, reducing the sprayer ground speed increased the deposition.

Using next-generation sequencing to detect mutations endowing resistance to pesticides: application to acetolactate-synthase (ALS)-based resistance in barnyard grass, a polyploid grass weed.

Next-generation sequencing (NGS) technologies offer tremendous possibilities for accurate detection of mutations endowing pesticide resistance, yet their use for this purpose has not emerged in crop protection. This study aims at promoting NGS use for pesticide resistance diagnosis. It describes a simple procedure accessible to virtually any scientist and implementing freely accessible programs for the analysis of NGS data. Three PCR amplicons encompassing seven codons of the acetolactate-synthase gene crucial for herbicide resistance were sequenced using non-quantified pools of crude DNA extracts from 40 plants in each of 28 field populations of barnyard grass, a polyploid weed. A total of 63,959 quality NGS sequence runs were obtained using the 454 technology. Three herbicide-resistance-endowing mutations (Pro-197-Ser, Pro-197-Leu and/or Trp-574-Leu) were identified in seven populations. The NGS results were confirmed by individual plant Sanger sequencing. This work demonstrated the feasibility of NGS-based detection of pesticide resistance, and the advantages of NGS compared with other molecular biology techniques for analysing large numbers of individuals. NGS-based resistance diagnosis has the potential to play a substantial role in monitoring resistance, maintaining pesticide efficacy and optimising pesticide applications.

English

We consider a delayed Pest-predator model under insecticide use. First, the paper considers the stability and local Hopf bifurcation for a modified Pest-predator model with time delay. In succession, using the normal form theory and center manifold argument, we obtain some explicit results which determine the stability, direction and other properties of bifurcation periodic solutions. I. INTRODUCTION With the rapid development of chemistry, many pesticides are applied in the world. However, insecticide pollution is also recognized as a major health hazard to human beings and to natural enemies. Thus it is required that we should combine pesticide efficacy tests with biological control research, so that the effects on the pest and the natural enemies are considered as a unified whole. Many researchers have been devoting to study the Pest-predator model. In this paper, our research is based on the Pest-predator models under insecticide use. However, here we consider the model with time delay. Let x(t), y(t) denote the density of the pest and predator (natural enemies) at the time t, respectively. We could have the Pest-predator model as followings

Defining terms for proactive management of resistance to Bt crops and pesticides.

Evolution of pest resistance to pesticides is an urgent global problem with resistance recorded in at least 954 species of pests, including 546 arthropods, 218 weeds, and 190 plant pathogens. To facilitate understanding and management of resistance, we provide definitions of 50 key terms related to resistance. We confirm the broad, long-standing definition of resistance, which is a genetically based decrease in susceptibility to a pesticide, and the definition of "field-evolved resistance," which is a genetically based decrease in susceptibility to a pesticide in a population caused by exposure to the pesticide in the field. The impact of field-evolved resistance on pest control can vary from none to severe. We define "practical resistance" as field-evolved resistance that reduces pesticide efficacy and has practical consequences for pest control. Recognizing that resistance is not "all or none" and that intermediate levels of resistance can have a continuum of effects on pest control, we describe five categories of field-evolved resistance and use them to classify 13 cases of field-evolved resistance to five Bacillus thuringiensis (Bt) toxins in transgenic corn and cotton based on monitoring data from five continents for nine major pest species. We urge researchers to publish and analyze their resistance monitoring data in conjunction with data on management practices to accelerate progress in determining which actions will be most useful in response to specific data on the magnitude, distribution, and impact of resistance.

Computer Aided Pesticide Design: A Rational Tool for Supplementing DDT Lacunae

The reliance of mankind on synthetic pesticide, particularly dichloro diphenyl-trichloro ethane (DDT) reached its zenith during 1950s-60s, since the first application during second world War. But very soon it faced a serious scientific opposition due to its bio-magnifying nature and was banned in 1970s in most part of world with certain exceptional usage in health control programmes. Although, the pesticidal activity range and economic viability of DDT has never been questioned and still there are several voices to bring back DDT. To answer this controversy is the search for new DDT like pesticide with similar pesticidal efficacy and lower ecological accumulative effects. Recent advances in computer aided molecular design has provided us very robust, economic and time and labour saving tool to design and develop new chemical entities with pesticidal activity similar to DDT and has good commercial prospects as well. The present paper reviews the brief history of DDT and the developments in computational and molecular design methods to rejuvenate the era of new pesticide research.

Efficacy of Botanical Pesticides in Controlling Insect Pests of Three Pigeon Pea Varieties

Pigeon Pea (Cajanus cajan) is a high-value crop with its nutritional and medicinal properties that could augment food security. Pigeon pea is prone to pests attack that could affect its yield, thus, this study is conceived. This study aimed to evaluate the effect of botanical pesticides in controlling insect pests of three pigeon pea varieties. Specifically, it sought to: 1) determine which of the botanical pesticides can effectively control insect pests of pigeon pea; 2) find out which among the pigeon pea varieties has the least damage by insect pests; and 3) identify and recommend the best-botanical pesticides to control insect pests of pigeon peas. The experiment was laid out in Factorial Randomized Complete Block Design. Data gathered were analyzed using the Analysis of Variance. Significant differences among treatment means were analyzed using the Duncan Multiple Range Test. The results implied that the botanical extract applied to the pigeon pea plants exhibited a significant effect in terms of controlling the pests. The results of the study conclude that the application of botanical extracts is comparably effective in controlling pests of pigeon pea. The study recommends that B1 (Neem Leaf Extract), B2 (Yellow Ginger Extract) and B3 (Hot Pepper Extract) can be used to control insect pests of pigeon peas; V2 (ICPL 87119) is recommended for production due to its resistance to pests.

INTEGRATION OF BOTANICAL PESTICIDE AND ENTOMOPATHOGENIC FUNGI TO CONTROL THE BROWN STINK BUG Riptortus linearis F. (HEMIPTERA: ALYDIDAE) IN SOYBEAN

ABSTRACTIntegration of botanical pesticide and entomopathogenic fungi to control the brown stink bug Riptortus linearis F. (Hemiptera: Alydidae) in soybean. The efficacy of botanical pesticides i.e. Annona squamosa seed powder (ASP) or Jatropha curcas seed powder (JSP) integrated with entomopathogenic fungi, Lecanicillium lecanii to control brown stink bug, Riptortus linearis F. was studied at Muneng Research Station, the Indonesian Legume and Tuber Crops Research Institute (ILETRI) in June up to September 2011. The purpose of the research was to determine the efficacy of integration the natural pesticides i.e, A. squamosa seed powder (ASP) and Jatropha curcas seed powder (JSP) and entomopathogenic fungi L. lecanii to control brown stink bug. The treatments were application of (1) ASP 50 g/l, (2) JSP 50 g/l, (3) ASP 50 g/l + L. lecanii 107/ml, (4) JSP 50 g/l + L. lecanii 107/ml, (5) L. lecanii 107/ml, (6) deltametrin and (7) control (untreated). Application of ASP and JSP combined with L. lecanii decreased the hatched eggs by 84% and 82%, respectively. However, reduction of hactched egg from a single application of ASP and JSP were 56-61% . ASP and JSP combined with L. lecanii reduced both nymphs and adult stink bug population built up and damage (empty pod). Application of ASP and JSP in combination with L. lecanii did not affects the survival of generalist predators such as Paederus sp., Oxyopes sp. and Coccinella sp. as opposed to chemical insecticide that did. The integration of ASP or JSP with entomopthogenic fungi L. lecanii was able to increase the efficacy of brown stink bug control.

Field scale study on efficacy of miticide, against two spotted mites in Kenyanagro climatic zone

Two spotted spider mites (TSM)is an incident pest problem in Kenyan roses cultivators due to the climatic conditions. Paradigm shift from chemical to bio pesticide is at most important in order to reduce the threat to the environment and human health. This research is aimed to confirm the potency of contact botanical pesticide to be used as bio control againstspider mite at Kenyanagro climatic zone. Commercially available and proven chemical pesticides were used to access the efficacy of this botanical pesticide. M Impact, a botanical pesticide was analyzed for its effect on two spotted spider mites at field level on one acre one green houseand its effect was compared with the available chemical pesticides. M impact was found to be most effective in terms of its period of action and potency against two spotted mites, while other chemical miticides showed delayed effect due to their different mode of action. Keywords: Rose, Kenya, M impact, Two spotted mite

Coupling of Soil Solarization and Reduced Rate Fumigation: Effects on Methyl Iodide Emissions from Raised Beds under Field Conditions

Using field plots, we studied the effect on methyl iodide (MeI) emissions of coupling soil solarization (passive and active) and reduced rate fumigation (70% of a standard fumigation) in raised beds under virtually impermeable film (VIF). The results showed that for the standard fumigation and the passive solarization + fumigation treatments, emissions from the nontarped furrow were very high (∼50%). Emissions from the bed top and sidewall of these treatments were relatively low but were increased in the latter due to the longer environmental exposure of the VIF covering with the coupled approach (increased tarp permeability). Overall, this approach offered no advantage over fumigation-only in terms of emission reduction. With active solarization + fumigation, the large application of hot water during solarization apparently led to severely limited diffusion causing very low total emissions (<1%). Although this suggests a benefit in terms of air quality, a lack of diffusion could limit the pesticidal efficacy of the treatment.

Comparison of the effect of insecticides on three strains of Tyrophagus putrescentiae (Acari: Astigmata) using an impregnated filter paper test and a growth test

In this study, we compared the efficacy of insecticides against three strains of Tyrophagus putrescentiae using an impregnated filter paper test and a growth test. We tested the suppressive activity of commercial insecticides and their analytical standards (pirimiphos-methyl, cypermethrin, deltamethrin, chlorfenapyr, β-cyfluthrin). The strains of T. putrescentiae originated from a laboratory, a field and dog food. The mortality of the mites due to active ingredients and analytical standards was tested using an impregnated filter paper test after 24 h. Lethal doses, LD50 , LD95 and LD99 were determined. A growth test was used to observe the suppressive effect of the active ingredients on mites at 21 days after application of the active ingredients to wheat grain. The effective doses ED50 , ED95 and ED99 were determined, indicating the concentration at which the population was reduced by 50, 95 and 99% more than control. Cypermethrin, β-cyfluthrin and a formulation of deltamethrin with piperonylbutoxide in the pesticide K-Othrine showed low toxicity to mites. High toxicity was observed for chlorfenapyr (LD50 : 0.1-1 µg cm(-2) ; ED50 : 0.11-1.2 µg g(-1) ) and pirimiphos-methyl (LD50 : 0.01-0.06 µg cm(-2) ; ED50 : 0.2-12 µg g(-1) ). We did not find significant differences among the compared strains in terms of their sensitivity to highly toxic insecticides. The obtained results showed that a filter paper test is a more sensitive method of identifying differences in pesticide susceptibility among strains, but the efficacy of pesticides against one species should be tested using a growth test.

Enzymatic activity and half-lives of capsaicin, dihydrocapsaicin, and pentadecanoic acid methyl ester in soil sprayed with hot pepper extract

Pest management is facing economic and ecological challenges in the United States and worldwide due to pest resistance, human and environmental hazards caused by use of synthetic pesticides. Natural product-based pesticides offer advantages that they are specific to the target species and typically have unique modes of action with little mammalian toxicity. Studies conducted at Kentucky State University revealed that the insecticidal and acaricidal performance of crude extracts from the fruits of Capsicum species justified the need for developing a natural pesticide formulation for agricultural use. Analysis of hot pepper extracts indicated the presence of three compounds having pesticidal efficacy: capsaicin, dihydrocapsaicin, and pentadecanoic acid methyl ester. The main objectives of this investigation were to: i) determine the half-live (T1/2 value) of capsaicin, dihydrocapsaicin, and pentadecanoic acid methyl ester in soil sprayed with hot pepper formulation and ii) assess the impact of hot pepper formulation on total soil enzyme activity. Analysis of soil sprayed with pepper extracts indicated that T1/2 values of capsaicin, dihydrocapsaicin, and pentadecanoic acid methyl ester were 7.3, 1.5, and 10.2 d, respectively. Hydrolysis of the fluorescein diacetate [3, 6-diacetylfluorescein (FDA)], used for measuring overall soil enzyme activities, indicated that total enzyme activities was slightly enhanced by 2% in soil sprayed with hot pepper extracts.

Advances in surfactants for agrochemicals

Pesticide efficacy is improved by surfactants. Increase in the foliar uptake is particularly useful for herbicides, growth regulators and defoliants, because less active compounds are needed, thus decreasing cost and pollution. Therefore, the choice of the adjuvant in an agrochemical formulation is crucial. The surfactants commonly used as adjuvants include anionic, non-ionic, amphoteric and cationic surfactants. This review analyses the role and properties of the new adjuvants for agriculture and the improvement of the ecotoxicity profile of the pesticide formulations in glyphosate formulation.

Evaluation of different botanical for the management of cowpea bruchid (Callosobruchus maculatus) in north-eastern Ethiopia

The pesticide efficacy of locally available seven botanicals “Gime” (Chenopodium ambrosioides), “Ayderke” (Jatropha curcas), Neem (Azadirachta indica), Melia (Melia azadirach), “Chobe” (Cisus rotonifolia), “Kelewa” (Maesa lanceolata) and “Antharfa” at a rate of 4% weight by weight was evaluated for the control of cowpea bruchid using 200 g cowpea seeds in 500 cm3 volume jar in 2010 and 2011 under laboratory condition at Sirinka Agricultural Research Centre. The combined analysis showed that “Gime” (both leaf and seed) had high speed of pesticide effect as it showed significantly higher per cent of parent adult mortality (84 and 71%, respectively) as to the standard check Malathion 5% dust (100%) in the first day of adult mortality count. “Antharfa” and “Ayderke” also have shown significantly higher per cent of parent adult mortality as to Malathion in the third and fifth day of adult mortality count, respectively. In the seventh day, all botanicals showed significantly higher per cent of adult mortality as compared to untreated check. “Gime” leaf and seed powder, “Ayderke” seed, Neem seed and “Antharfa” leaf powders significantly reduced the number of progeny emergence per day as compared to all other treatments. Moreover, these botanicals were effective in reducing per cent seed damage (0.00, 0.00, 0.57, 5.86 and 10.86%, respectively) and storage loss (0.00, 0.00, 0.073, 1.02 and 2.27%, respectively). Gime (both leaf and seed powder), “Ayderke” seed and Neem seed are locally available, simple for preparation and environmentally friendly. Therefore, these three botanicals can be recommended to satisfy the demand for organic food and save the seed damage and yield loss of cowpea caused by Callosobruchus maculates and bean bruchid (Zabrotes subfasciatus) which has similar biology with Callosobruchus maculatus.