Windbreaks as a pesticide drift mitigation strategy: a review

The use of natural and artificial barriers to mitigate pesticide drift from agricultural and forest applications is discussed. This technique has been considered as an alternative to current methods at a time when environmental concerns are under great public scrutiny. There has been a variety of research experiments on this subject from New Zealand to The Netherlands which have documented reductions in spray drift of up to 80-90%. However, there are still enormous data gaps to utilize this method accurately. The aerodynamic factors of wind barriers and shelter effects on crop growth and yield have been well investigated. In contrast, some of the important aspects of drift mitigation, e.g. porosity and turbulence, have been difficult to obtain and no standard methodologies are currently available to evaluate and classify windbreaks and shelterbelts or to determine their efficiency in reducing drift. Thus there is a significant opportunity to incorporate windbreaks into the tool set of drift mitigation tactics. Government policies, initiatives, legislation, etc, which currently address water quality, BMP, stewardship, buffers, etc, are issues which so far have not included windbreaks as a valuable drift mitigation strategy.     

Genetic engineering of plant volatile terpenoids: effects on a herbivore,a predator and a parasitoid

BACKGROUND: Most insect‐resistant transgenic crops employ toxins to control pests. A novel approach is to enhance the effectiveness of natural enemies by genetic engineering of the biosynthesis of volatile organic compounds (VOCs). Before the commercialisation of such transgenic plants can be pursued, detailed fundamental studies of their effects on herbivores and their natural enemies are necessary. The linalool/nerolidol synthase gene FaNES1 was constitutively expressed from strawberry in three Arabidopsis thaliana accessions, and the behaviour of the aphid Brevicoryne brassicae L., the parasitoid Diaeretiella rapae McIntosh and the predator Episyrphus balteatus de Geer was studied. RESULTS: Transgenic FaNES1‐expressing plants emitted (E)‐nerolidol and larger amounts of (E)‐DMNT and linalool. Brevicoryne brassicae was repelled by the transgenic lines of two of the accessions, whereas its performance was not affected. Diaeretiella rapae preferred aphid‐infested transgenic plants over aphid‐infested wild‐type plants for two of the accessions. In contrast, female E. balteatus predators did not differentiate between aphid‐infested transgenic or wild‐type plants. CONCLUSION: The results indicate that the genetic engineering of plants to modify their emission of VOCs holds considerable promise for facilitating biological control of herbivores. Validation for crop plants is a necessary next step to assess the usefulness of modified volatile emission in integrated pest management. Copyright © 2012 Society of Chemical Industry     

Implementation of a herbicide simulation model in a geographical information system with an example of a site-specific application

A Geographical Information System (GIS) was combined with a model for simulating leaching and degradation of herbicides. The model uses first–order kinetics to simulate degradation, and a cascade model to simulate transport. This system was tested with data from a 16 km² research catchment in northern Germany. Geometrical, topological, and soil data of this area were stored in a GIS. For the whole area, divided into small homogeneous sites (ecotopes), model runs were carried out. The system is able to handle data for all ecotopes automatically and to present calculated results on the behaviour of herbicides as distributed over time and depth for the area. An application of ethofumesate made in sugar–beet in spring and recropping of winter wheat after beet harvest was modelled. Degradation/sorption parameters were estimated from similar soils. Simulation results showed slower degradation in the sandy sites of the catchment, compared to the more loamy regions. Residues of herbicide remaining after beet harvest were greater than 20% of the applied dose in the sandy soils after 150 days. Hence, high risk of damage to the following crop of winter wheat was predicted. At the other sites residues remaining were between 2% and 20% of the applied dose. Einbindung eines Simulationsmodells zum Herbizidverhalten in ein Geographisches Informationssystem–Beispiel zur schlagspezifischen Anwendung Ein Geographisches Informationssystem (GIS) wurde mit einem Simulationsmodell für Herbizidabbau und –einwaschung kombiniert. Grundlage der Abbausimulation ist eine Kinetik 1. Ordnung, der Transport im Boden wird mit Hilfe eines Kaskadenmodells berechnet. Das System wurde in einem Intensiv–Untersuchungsgebiet (16 km²) in Norddeutschland getestet. Geometrische und topologische Daten der Fläche sowie Bodendaten sind im GIS gespeichert. Für die gesamte Fläche, die in kleine homogene Teilflächen (Ökotope) aufgeteilt wurde, wurden Simulationsberechnungen durchgeführt. Das System ist in der Lage, Daten für alle Ökotope automatisch bereitzustellen und die Ergebnisse zum Einwaschungs– und Abbauverhalten für die gesamte Fläche in ihrer Verteilung über Zeit und Tiefe darzustellen. Als Szenario wurde die Applikation von Ethofumesat in Zuckerrüben im Frühjahr mit einem Nachbau von Winterweizen nach der Rübenemte gewählt. Abbauund Sorptionsparameter waren in ähnlichen Böden ermittelt worden. Die Simulationsergebnisse zeigten einen langsameren Abbau in den sandigen Böden verglichen mit den lehmigen. In den sandigen Böden lagen die Rückstandsgehalte nach 150 Tagen übe 20 % der Ausgangskonzentration, wodurch ein hohes Nachbaurisiko für Winterweizen prognostiziert wurde. Für den Rest der Fläche lagen die Rückstände zwischen 2% und 20% der Ausgangskonzentration.     

Fungal-based bioherbicides for weed control: a myth or a reality?

The use of bioherbicides containing fungal active ingredients or natural fungal molecules is one of the possible solutions to reduce the use of chemical products. This paper focuses on studies of bioherbicides, including both living fungi and natural fungal molecules, published in the last 45 years, and their associated weed targets; current problems in the development of bioherbicides are also discussed. Bibliometric methods based on the Web of Science database were used to analyse relevant articles published between 1973 and 2018. Overall analysis suggested that interest in bioherbicides extends over the preceding thirty years, when many potential microorganisms and natural fungal molecules were proposed. Furthermore, analysis of about 229 articles indicated an encouraging exploitable potential, although there is a real gap between the number of experimental studies and the small number of products currently on the market. A dozen fungal-based bioherbicides are on the market in the United States and Canada, while countries, such as China and South Africa, have one, and none is available in Europe. The active ingredients in these bioherbicides are living fungi, but no fungal molecule-based product is thus far on the market. Reasons for this gap include production hurdles, formulation process, ecological fitness, duration of herbicidal effects, and costly and time-consuming registration procedures. However, it is clear that analysis of fungus–plant interactions provides a promising source of bioherbicides that may be applied to appropriate cropping systems for environment-friendly, sustainable weed control.     

Biodiesel as a carrier for pesticide formulations: a green chemistry approach

Abstract

This article discusses the present status and future scope of biodiesel as a carrier/diluents and alternative source to hazardous volatile organic compounds for liquid pesticide formulations. Development of user and environment-friendly liquid pesticide formulations for sustainable agriculture is the key focus of today’s agrochemical industries. Organic solvents play an important role in ensuring the efficient distribution and delivery of active ingredients (a.i.) during application of liquid pesticide formulations. Presently used petroleum-based solvents have many disadvantages such as low flash points, high volatility, flammability, phytotoxicity, and inhalation problems to users, etc. However, at present it seems that the use of renewable resources, especially plant oils, oils ester (fatty acids alkyl ester) like biodiesel has the capacity to replace the traditional petroleum-based solvents in liquid pesticide formulations with having sustainable characteristics like high flash point, safer storage, transportation and application. Biodiesel which is easily reproducible from waste cooking oil, waste edible oil, animal fat, etc. may be a suitable alternative green solvent for liquid pesticide formulations in the near future.     

Degradation of a sulfonamide herbicide as a function of soil sorption

The degradation of DE-498 (proposed common name flumetsulam) was studied in 21 US soils as a first step in developing a management plan for this new herbicide. Degradation half-lives were shorter in soils that adsorbed the compound less. Adsorption was lower in soils with higher pH and lower organic carbon content. Degradation half-lives were thus influenced by both pH and organic carbon: they were in the range 2–4 weeks in higher pH soils (pH 5 7.0) unless the organic carbon content was above 2.5%, at which half-lives were in the range 1–3 months. In medium pH soils (6.4 pH 6.9) half-lives were 1–2 months, while in lower pH soils (5.9 pH 6.3) they were 1–4 months. The laboratory data were supported by the response of sunflowers (Helianthus annuus L.) planted 1 year after application of flumetsulam to different soils. A quantitative model relating half-life to sorption K_d (r²= 0.85) was coupled with an additional equation relating sorption K_d to the proportion of neutral and anionic forms of the compound at different pH values. The study allows estimates of this herbicide's degradation in soil to be made if its pH and organic carbon content are known. Degradation d'un herbicide sulfonamide en fonction de la capacité d'absorption du sol La dégradation du flumetsulam a étéétudiée dans les sols aux Etats Unis comme premier stade dans le développement d'un plan d'utilisation de ce nouvel herbicide. Les demi-vies de dégradation étaient plus courtes dans les sols qui absorbaient moins le produit. L'absorption était plus faible dans les sols à pH élevé et à faible teneur en carbone organique. Les demi-vies étaient ainsi sous l'influence du pH et du carbone organique: elles étaient de 2 à 4 semaines pour les pH de sols élevés (pH 7) sauf si le carbone organique était au dessus de 2,5%, dans ce cas, les demi-vies etaient de 1 à 3 mois. Dans les sols à pH moyen (6,4 pH 6,9) les demi-vies étaient de 1 à 2 mois, tandis que dans les sols à pH faible (5,9 pH 6,3) elles étaient de 1 à 4 mois. Les résultats de laboratoire ont été confirmés par le comportement de tournesols plantés un an aprfès l'application de flumetsulam dans différents sols. Un modèle reliant la demi-vie au coefficient d'absorption Kd (r²= 0.85) a été couplé avec une équation additionelle reliant le coefficient d'absorption Kd à la proportion de particules neutres et anioniques de la molécule aux différents pH. L'étude permet de faire des estimations de la dégradation de cet herbicide dans le sol dès que le pH et la teneur en carbone organique sont connus. Abbau eines Sulfonamid-Herbizids als Funktion der Bodensorption Der Abbau von Flumetsulam (DE-498) wurde in 21 Böden untersucht, um eine Grundlage zur Produktentwicklung dieses neuen Herbizids zu gewinnen. Die 50%ige Verlustrate (DT₅₀) war in schwächer sorptiven Böden kürzer. Bei hohem pH-Wert und geringem Gehalt an organischer Substanz war die Adsorption schwächer. Die DT₅₀ wurde durch den pH-Wert und den Gehalt organischer Substanz wie folgt beeinflußt: Sie betrug 2 bis 4 Wochen in Böden mit pH >7,0 (wenn der C_org-Gehalt nicht über 2,5% lag; dort dann 1 bis 3 Monate), 1 bis 2 Monate bei 6,4 < pH < 6,9 und 1 bis 4 Monate bei 5,9 < pH < 6,3). Die Ergebnisse der Laboruntersuchungen wurden durch Untersuchungen an Sonnenblumen gestützt. die 1 Jahr nach Applikation von Flumetsulam auf verschiedenen Böden angebaut wurden. Ein quantitatives Modell über das Verhältnis der Verlustrate zum Sorptionskoeffizienten K_d (r²= 0,85) wurde mit einer zusätzhchen Gleichung der Beziehung des Sorptionskoeffizienten K_d zum Verhältnis der neutralen und der anionischen Verbindungen des Wirkstoffs bei verschiedenen pH-Werten verknüpft. Aufgrund der Untersuchungen kann der Abbau dieses Herbizids in Böden bekannten pH-Werts und C_org-Gehalts abgeschätzt werden.     

Inhibition of acetyl-coenzyme a carboxylase by coenzyme a conjugates of grass-selective herbicides

A total of 146 samples of different kinds of cheeses produced in Spain were analysed in order to ascertain the specific contamination pattern. The organochlorine compounds studied were those most commonly investigated in previous surveys: α-HCH, β-HCH, γ-HCH (lindane), γ-HCH, chlordane, aldrin, dieldrin, endrin, heptachlor, heptachlor epoxide, and the isomers and metabolites of DDT. α-HCH, β-HCH, γ-HCH, chlordane, p,p′, DDT, and p,p′-DDE were found in more than 76% of samples; p,p′-DDE and γ-HCH were the most frequently detected, with frequencies of 100 and 97.9% respectively. γ-HCH, aldrin, dieldrin, heptachlor, heptachlor epoxide, o,p′-DDT, p,p′-DDD and o,p′-DDD were observed at lower frequencies. No residues of endrin were detected in any sample. Insecticides exceeding the maximum residue limits (MRLs) were chlordane, β-HCH, α-HCH and γ-HCH, with 42, 20, eight and six samples respectively. Mean residues of organochlorines found were as follows (μ kg^?1 butterfat): α-HCH = 46.3; β-HCH = 46.5; γ-HCH = 54.2; δ-HCH = 16.9; aldrin = 16.7; dieldrin = 9.7; heptachlor = 15.9; heptachlor epoxide = 14.8; chlordane = 50.2; o,p′-DDT = 5.1; p,p′-DDT = 12.4; o,p′-DDT = 19.6; p,p′-DDD = 46.7; o,p′-DDE = 6.9; p,p′-DDE = 40.7 (.DDT = 55.0). Estimated dietary intakes (EDIs) from cheese consumption were compared to acceptable daily intakes (ADIs) for the pesticides where residues exceeded the MRL. EDIs calculated were in all cases below ADIs, and, therefore, based on the ADIs, there is no health risk involved in the consumption of cheese from Spain arising from organochlorine residues.     

Improved control of clubroot (Plasmodiophora brassicae) by a mixture of a fungicide and a plant defense inducer

Journal of Plant Diseases and Protection - The mixtures of 10&nbsp;% cyazofamid SC and 25&nbsp;% methiadinil SC were selected at different concentrations in root irrigation treatment of...     

Flonicamid, a novel insecticide with a rapid inhibitory effect on aphid feeding

Flonicamid (IKI220; N-cyanomethyl-4-trifluoromethylnicotinamide), a pyridinecarboxamide compound, is a novel systemic insecticide with selective activity against hemipterous pests, such as aphids and whiteflies, and thysanopterous pests. The purpose of this study is to clarify the biological properties of flonicamid against aphids. Flonicamid is very active against aphids, regardless of differences in species, stages and morphs. This compound inhibited the feeding behaviour of aphids within 0.5 h of treatment without noticeable poisoning symptoms such as convulsion, and this antifeeding activity was not recoverable until death. The nymphs born from adults exposed to flonicamid for 3 h showed high mortality. The effect of flonicamid on the feeding activity of an individual aphid was studied using electronic monitoring of insect feeding behaviour (EMIF). Although the treated aphid attached the head of its proboscis to the leaf surface, salivation and sap feeding were strongly inhibited. These results suggest that the main insecticidal mechanism of flonicamid is starvation based on the inhibition of stylet penetration to plant tissues.     

Application of a mathematical function for a temperature optimum curve to establish differences in growth between isolates of a fungus

A function that approximates the curve of the growth rate of the mycelium of the imperfect fungusSphaeropsis sapinea in relation to temperature is proposed. This function contains three free parameters, representing maximum growth rate, optimum temperature and shape of the curve. It was applied to data from an experiment with 27 isolates, in which the growth rate was measured in two replications at ten temperatures ranging from ?2 °C to 45 °C. Fitting the function to data from each isolate in each replication resulted in estimates of three parameters in which the information about the curve contained in the ten original observations is compressed. The estimates of the optimum temperature and of the shape were used in a further statistical analysis aimed at comparing the isolates and at ascertaining whether they could be divided into a few distinct groups, possibly related to different strains. The latter proved not to be the case.     

Testing aldicarb as a bird repellent in a sprouting sugar beet field

Temik, the granular formulation of aldicarb [2-methyl-2(methylthio) propionaldehyde 0-(methylcarbamoyl) oxime], was placed together with sugar beet seeds during sowing along the rows, at a rate of 1.4 g/m, in a 1.5-ha experimental area within a 6-ha sugar beet field in an arid area with a long history of bird damage. Thirty-three chukar partridges, a major pest of sprouting crops, were observed foraging in the experimental area throughout the 4-week period between sowing and assessment of damage. Damage was restricted to the borders of the field, with a significant difference in level of damage between treated and control plots located along the borders; the size of damaged areas was about five times smaller in the treated plots than in the control plots. The results were interpreted as reflecting the repellent effect of aldicarb absorbed by the sprouts, and as establishment of a conditioned aversion by the chukars to sugar beet sprouts. The high toxicity of the treated sprouts was demonstrated when adult Japanese quail were fed sprouts collected from treated plots.     

RU-15525, a new pyrethroid with a very strong knockdown effect

(E)-5-Benzyl-3- furylmethyl (1-R),3-S)-2,2-dimethyl-3-(2,3,4,5-tetrahydro-2-oxothien-3-ylidenemethyl)cyclopropanecarboxylate or RU-15525 is a new pyrethroid. The action of this compound was tested on Musca domestica and Aedes aegypti and a very strong knockdown effect was observed in comparison with the knockdown effect of allethrin, bioallethrin and (S)-bioallethrin.     

Decline of a swarm of Schistocerca gregaria in a marginal invasion area

Observations were made on a caged batch of Schistocerca gregaria from a swarm which invaded Antalya (TR) on 1988-12-03. Females did not change their colour, and this might be a sign of lack of sexual maturity. Only 1.5% of the eggs deposited were viable. Mortality, apparently due to exhaustion during the crossing of the Mediterranean sea and unfavourable local winter conditions, and inviability of the eggs produced are proposed as detectable causes of the decline of S. gregaria in Antalya.     

Induced resistance against a bacterial disease by orysastrobin,a chemical fungicide

European Journal of Plant Pathology - Certain chemical pesticides control plant diseases through induction of systemic resistance mechanisms. In this study, orysastrobin, a “quinone outside...     

Foliar spray of validamycin a or validoxylamine a controls tomato fusarium wilt

ABSTRACT Tomato wilt, caused by the soilborne fungus Fusarium oxysporum f. sp. lycopersici, is effectively controlled by a foliar spray of validamycin A (VMA) or validoxylamine A (VAA) (>/=10 mug/ml); however, neither VMA nor VAA is antifungal in vitro. In pot tests, the effect of a foliar application of VMA or VAA at 100 mug/ml lasted for 64 days. Plants sprayed with VMA or VAA accumulated salicylic acid and had elevated expression of the systemic acquired resistance (SAR) marker genes P4 (PR-1), Tag (PR-2), and NP24 (PR-5). Foliar spray of VMA also controlled late blight and powdery mildew of tomato. The disease control by VMA and VAA lasted up to 64 days after treatment, was broad spectrum, and induced the expression of PR genes, all essential indicators of SAR, suggesting that VMA and VAA are plant activators. The foliar application of plant activators is a novel control method for soilborne diseases and may provide an economically feasible alternative to soil fumigants such as methyl bromide.     

Evaluation of a pelleted bait containing methyl anthranilate as a bird repellent

No-till agriculture involves the use of granular pesticide formulations, chemically treated seeds, and pelleted baits. Some of these may accidentally kill birds. We have tested whether methyl anthranilate (MA), a known bird repellent, would eliminate consumption of a pelleted bait. In two laboratory experiments and an outdoor aviary trial, cowbirds (Molothrus ater Bodd.) were presented with pellets containing pesticide and MA, pellets containing pesticide but no MA, and carrier pellets without pesticide or MA. Consumption of any formulation was low, but the addition of MA significantly decreased bait loss in the laboratory, and prevented the disappearance of bait in the outdoor trial.