Transport of the systemic fungicide cela W 524 in barley plants (part I)

Doses of 11–20 mg of the title compound in aqueous formulation were added to barley plants in pots. Radioactivity and biological activity against Puccinia coronata on eight different sections of the shoots as well as the inhibition of Cladosporium spore development on thin-layer chromatograms from methanolic extracts were followed during the first 24 h. Transport velocities, distribution and useful doses are discussed.     

Transport of the systemic fungicide cela W 524 (triforine) in barley plants. II. Uptake and metabolism

After soil drench application of triforine (5 mg) to 35 barley plants in pots, a maximum of 7.5 μg a.i./g shoots (fresh weight) was found on the second day. The biological (effective) half-life was 9 to 10 days. Doses of 50 mg resulted in impaired absorption rather than increased foliar concentration. On day 8 piperazine comprised 20% of the radioactivity of the four metabolites found in the shoots. An additional metabolite appears solely in the soil.     

Preparation,properties and activity of PP969, a triazole fungicide with high systemic activity

PP969 is a novel 1,4-ketol compound containing the 1,2,4-triazole ring which has high systemic activity against a variety of fungal pathogens. It is a single diastereoisomer whose absolute configuration has been determined by X-ray analysis. The fungicidal activities of the structurally related 1,4-dione and 1,4-diols were found to be much less than that of PP969. Its biological potential as a systemic compound for controlling foliar fungal diseases either by soil or stem application is being explored.     

Aims and activities of industry's fungicide resistance action committee (FRAC)1

FRAC is a GIFAP-sponsored inter-company committee dedicated to prolonging the effectiveness of fungicides liable to encounter resistance problems and to limit crop damage during the emergence of resistance. Through FRAC and the Working Groups it co-ordinates, companies are striving to establish more effective communications to alert all people involved in the research, production, marketing, registration and use of fungicides to the problems of resistance. With an enlightened attitude, effective strategies can be conceived and adopted. Co-operative action is deemed essential if the invaluable option of chemical disease control for crops is to be preserved. Working Groups for acylalanines, benzimidazoles, dicarboximides and sterol inhibitors are well organized and functioning in various monitoring studies and cooperative actions. FRAC meets regularly to review the activities of the Working Groups and to deal with the wider aspects of fungicide resistance. FRAC initiates, stimulates and monitors Working Groups, provides guidelines and co-ordinates the efforts of the Working Groups, helps Working Groups communicate their conclusions, publicises guidelines on procedures/definitions of practical resistance research, provides technical counsel for fungicide-resistance courses and research studies, and liaises with universities, advisers, farmers, distributors, governments.     

The hydroxyanilide fenhexamid,a new sterol biosynthesis inhibitor fungicide efficient against the plant pathogenic fungus Botryotinia fuckeliana (Botrytis cinerea)

Fenhexamid, a recently developed botryticide, is shown here to inhibit sterol biosynthesis. When the fungus Botryotinia fuckeliana was grown in the presence of fenhexamid, the ergosterol content was reduced, and three 3‐keto compounds, 4α‐methylfecosterone, fecosterone and episterone, accumulated, suggesting an inhibition of the 3‐keto reductase involved in C‐4 demethylation. Thus, fenhexamid belongs to a new, promising class of sterol biosynthesis inhibitors not previously used in agriculture or in medicine. © 2001 Society of Chemical Industry     

Effects of adjuvants on the performance of a novel powdery mildew fungicide, 1-(4-chlorobenzyl)-4-phenylpiperidine

The effects of adjuvants on the performance of a dispersible concentrate formulation (DCI) of a novel powdery mildew fungicide, 1-(4-chlorobenzyl)-4-phenylpiperidine (I) were investigated. The method involved assessment, under glasshouse conditions, of the therapeutic (curative) control of infections of powdery mildew (Erysiphe graminis DC f.sp. hordei Marchal) on barley (Hordeum vulgare, L.) eight to nine days after spray application to plants that had been inoculated one day prior to spraying. The results from the first trial showed that marked improvements (∽five-fold) in the performance of DCI could be obtained by the spray tank addition of some types of surfactant adjuvants and a series of further trials investigating a wide range of adjuvants was conducted. Nonylphenol, alkylamine and alcohol ethoxylates varying in mean ethylene oxide content between 5 and 20 moles were highly effective. There were indications that optimum performance enhancements were obtained with these surfactants containing between 5 and 10 moles ethylene oxide. Lower enhancements, sometimes only marginal, were obtained from trisiloxane, phosphate ester, propylene oxide, alkylamine-propylene oxide and castor oil ethoxylates and also alkyl polyglucoside biosurfactants. Negligible adjuvant enhancements were observed with emulsifiable paraffinic/naphthenic and rape seed oils, though slightly better enhancements were seen with an emulsifiable transmethylated rape seed oil and, interestingly, larger enhancements with an emulsifiable lipophilic alcohol. A final trial identified the alcohol ethoxylate, ‘Dobanol’ 91-6, as the most effective adjuvant and that its optimum application rate under glasshouse conditions was 250 g ha^-1. This information will be used to guide the design of field trials. © 1997 SCI     

Development of a new dispenser for microbiological control agents and evaluation of dissemination by bumblebees in greenhouse strawberries

BACKGROUND: To date, in modern agriculture, biological control strategies are increasingly becoming the preferred pest management approach. However, the success of microbiological control agents (MCAs) largely depends on efficient dissemination into the crop. The pollinator‐and‐vector technology employs pollinating insects like bees for a better dissemination. In this study, a new dispenser for bumblebee workers of Bombus terrestris L. was developed. Binab‐T‐vector and Prestop‐Mix were used as two typical MCA products for dissemination. RESULTS: In a first series of experiments in the laboratory for optimisation, the newly developed dispenser was a two‐way type dispenser, 20 cm long, with two rectangular compartments and different entrance and exit holes. In addition, the amounts of MCA loaded on the workers were 10 times higher with the new dispenser as compared with the side‐by‐side passageway (SSP) dispenser. Typically, the highest amounts were recovered from the thorax and legs of the workers. In a second series of experiments under greenhouse conditions with the use of queen‐right B. terrestris hives, successful dissemination in strawberry flowers was obtained at different distances from the hive (0–8 m, 8–18 m and 18–21 m), and the workers inoculated the first, second and third flowers that were consecutively visited. In addition, the new dispenser caused no adverse effects on worker foraging intensity, whereas a dramatic reduction was scored with an SSP dispenser. Finally, the data suggested that it is necessary to refill the newly developed dispenser at 3 day intervals. CONCLUSIONS: The results demonstrated that, with the use of the newly developed dispenser, bumblebee workers carried high amounts of MCA, and this resulted in a successful dissemination of MCA into strawberry flowers. Copyright © 2010 Society of Chemical Industry     

Laboratory trials of a new triazine herbicide (DPX 3674) on various aquatic species of macrophytes and algae

The new herbicide 3-cyclohexyl-6-(diméthylamino)-1-methyl-1,3,5-triazine-2,4 (1H,3H)-dione (DPX 3674), effective in controlling various terrestrial plants, was found in glasshouse trials to control Myriophyllum verticillatum, Potamogeton pectinatus and Vaucheria dichotoma at 1.0 ppm and Rhizoclonium hieroglyphicum and Cladophora glomerata at 0.5 ppm. A rapid reduction of the dissolved oxygen content of the water occurred during the first few days of treatment.     

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 % cyazofamid SC and 25 % methiadinil SC were selected at different concentrations in root irrigation treatment of...     

Systemic movement in cucumber plants and control of cucumber gray mould by a new fungicide,S-7131

Carbon-14-labelled S-7131 (N-(3′,5′-dichlorophenyl)-1,2-dimethylcyclopropane-1,2-dicarboximide) penetrated into the treated leaves of cucumber plants, moved to the stem and was then translocated both upwards and slightly downwards. Also through roots the fungicide was readily taken up and translocated to aerial parts. Autoradiographs showed that S-7131 had a tendency to accumulate at the leaf margin. In experiments with cucumber plants bearing flowers and fruits it was shown that S-7131 hardly moved from foliage to flowers and fruits. TLC analysis of radioactive extracts showed that S-7131 moved within plants in the unaltered form. Bioassay tests confirmed that systemic movement of S-7131 contributed to its high efficacy in disease control.     

A new disease of greenhouse tomatoes in Israel caused by a distinct strain ofTomato apical stunt viroid (TASVd)

Using the sequential PAGE method for detection of small circular RNA molecules we isolated a viroid from greenhouse-grown tomato plants exhibiting severe stunting in Israel. The viroid was transmitted to tomato and to several other solanaceous plants by graft and mechanical inoculation, but only tomato plants showed symptoms of disease. Cloning and sequencing revealed that the viroid RNA is composed of 363 nucleotides, has 92% identity with the type strain (Ivory Coast strain) ofTomato apical stunt viroid (TASVd) and 99% identity with the Indonesian strain of this viroid. The experimental host range of TASVd-Is differs significantly from that of the type strain of TASVd. The possible epidemiological consequences leading to TASVd spread in geographically distant areas are discussed. http://www.phytoparasitica.org posting Sept. 18, 2002. Corresponding author     

RH—2485对棉铃虫的室内药效试验

利用Rohm and Haas公司1996年推出的一种非甾醇类蜕皮激素竞争物RH-2485,用点滴法和喷雾法对棉铃虫防治效果进行了室内研究。结果表明,RH-2485可以引起棉铃虫非正常蜕皮。用25、50、100和150mg/L的RH-2485异丙醇溶液对2龄幼虫进行喷雾,阳性反应率为43.6％～94.9％。用RH-2485异丙醇溶液对6龄初蜕皮幼虫(进入6龄不超过1h)进行点滴,剂量为1、30、60、100和200ng/头,24h后阳性反应率为0～83.33％,而15d后的最终反应率为15.38％～96.67％。研究结果显示RH-2485对棉铃虫有显著引起非正常蜕皮的作用,可用于棉铃虫田间防治试验。     

Phyllonorycter apparella, a new record and a new pest of trembling aspen (Populus tremula) in Turkey

Phyllonorycter apparella (Herrich-Schäffer, 1855) (Lepidoptera: Gracillariidae) is a new record for the Turkish fauna and a new trembling aspen(Populus tremula L.) pest for Turkey. Its biology, damage and infestation ratio were studied in Sankami?. (Kars), Turkey, during 1996 and 1997.P. apparella has one generation a year. The developmental stages of the pest are described briefly. P.apparella hibernates in the adult stage. At the beginning of June, the adults appear. Females deposit their eggs on both leaf surfaces, generally one by one, 7–10 days after emerging. The early instars (sap-feeding larvae) start to mine mostly from the underside of leaves. Each mine has one larva, and each leaf may have up to 26 mines. The last instar (tissue-feeding larva) begins to pupate in the mine after mid August. The adults emerge from mid September to the beginning of October, and move to the trunks of old pine trees, where they hibernate in bark crevices. The infestation level may be as high as 90% of the leaves on some trees.     

Laboratory evaluation of trap color and vinegar,yeast and fruit juice lure combinations for monitoring of Zaprionus indianus (Diptera: Drosophilidae)

Abstract

Zaprionus indianus Gupta (Diptera: Drosophilidae) is a successful invasive drosophilid that is currently impacting fig production in Mexico and Brazil. Very few studies have examined the improvement of trapping strategies for this pest. Here, we compared visual responses of Z. indianus to different colors and olfactory cues. Orange and brown colored traps were among the most attractive in choice and no-choice tests, with violet and white being the least attractive colors. Orange traps with brown circles around the access holes were more attractive than uniformly orange traps. Apple cider vinegar was significantly more attractive to adults than sugar cane vinegar or grape juice but was not significantly more attractive than white wine and red wine vinegars. Captures of Z. indianus in apple cider vinegar-baited traps were not improved by the addition of grape, pineapple or apple juices, or when compared against a sucrose solution or grape juice fermented with Saccharomyces cerevisiae, or grape juice fermented with Candida tropicalis. Pairwise comparisons of Z. indianus attraction to S. cerevisiae and C. tropicalis indicated a high dependence on the growth media used. Orange traps with brown circles baited with apple cider vinegar may prove useful for monitoring this pest under field conditions.     

Isoflucypram,the first representative of a new succinate dehydrogenase inhibitor fungicide subclass: Its chemical discovery and unusual binding mode

Succinate dehydrogenase inhibitors (SDHIs) have played a crucial role in disease control to protect cereals as well as fruit and vegetables for more than a decade. Isoflucypram, the first representative of a newly installed subclass of SDHIs inside the Fungicide Resistance Action Committee (FRAC) family of complex II inhibitors, offers unparalleled long‐lasting efficacy against major foliar diseases in cereals. Herein we report the chemical optimization from early discovery towards isoflucypram and the first hypothesis of its altered binding mode in the ubiquinone binding site of succinate dehydrogenase. © 2020 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Laboratory evaluation of fipronil,a phenylpyrazole insecticide,against adult Anopheles (Diptera: Culicidae) and investigation of its possible cross‐resistance with dieldrin in Anopheles stephensi

Adult mosquitoes from two strains of Anopheles gambiae and from three strains of Anopheles stephensi were exposed to 0.25% fipronil‐treated papers in WHO test kits or to 500 mg fipronil m⁻² impregnated mosquito netting in bioassay spheres. For comparison, tests were also carried out with the pyrethroid permethrin, using the same methods and doses, and on papers treated with 0.4 and 4% of the cyclodiene insecticide dieldrin. Compared with the same doses of permethrin, fipronil showed less and delayed activity. Two of the An stephensi strains were resistant to fipronil and dieldrin. To investigate whether this was due to a resistance mechanism in the An stephensi strains acting against both insecticides, the most fipronil‐ and dieldrin‐tolerant strain was further selected in two separate lines with one of the insecticides, followed by tests with the insecticide that the line had not been selected with. This indicated a concomitant rise of resistance to dieldrin in the fipronil‐selected line and vice versa. Repeated back‐crossing of the two lines with a susceptible strain and re‐selection with either dieldrin or fipronil gave evidence for the involvement of a single resistance mechanism to both insecticides. Permethrin resistance in both lines declined with selection for dieldrin or fipronil and confirms the absence of cross‐resistance between fipronil and pyrethroids. © 2001 Society of Chemical Industry     

O-ethyl O-isopropyl O-(5-methoxy-1-methyl-6-oxo-1H-pyridazin-4-yl) phosphorothioate,a new experimental insecticide and acaricide

The insecticidal and acaricidal action, anti-cholinesterase activity and toxicity to rats of a new experimental pesticide, O-ethyl O-isopropyl O-(5-methoxy-1-methyl-6-oxo-1H-pyridazin-4-yl) phosphorothioate ( I ), and those of some by-products found in the technical material, are described. High insecticidal and acaricidal effectiveness of I was found in laboratory and field trials. The activity as a soil insecticide in field trials was equal to, or greater than, that of other chemicals used at present.