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1.
Cyclization of 3‐aryl‐1‐(2‐hydroxyphenyl)prop‐2‐en‐1‐ones with hydrazine hydrate in refluxing formic acid afforded the title ligands, 5‐aryl‐1‐formyl‐4,5‐dihydro‐3‐(2‐hydroxyphenyl)‐1H‐pyrazoles (HL1–HL4, Ar = Ph, 4‐CH3O‐C6H4‐, 2‐furyl, 2‐thienyl). Reaction of HL1–HL4 with the divalent metal ions, Mn2+, Co2+, Ni2+, Cu2+, and Zn2+, afforded novel complexes of the type [ML2] (M = metal ion; L = deprotonated ligand) which were characterized by elemental analyses, molecular weight determinations, molar conductances, magnetic moments and electronic and infrared spectral data. The ligands behaved as tridentate, coordinating through the phenolic oxygen after deprotonation, N‐2 of the pyrazole ring and oxygen of the 1‐formyl group. The ligands and their complexes were evaluated for growth‐inhibiting activity against four phytopathogenic fungi. Macrophomina phaseoli was generally most sensitive followed by Alternaria alternata and Colletotrichum falcatum while Fusarium oxysporum was least sensitive to the tested compounds. The ligand HL1 and its complexes showed the best activity against the fungi tested. © 2000 Society of Chemical Industry 相似文献
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Phototransformation of metoxuron [3‐(3‐chloro‐4‐methoxyphenyl)‐1,1‐dimethylurea] in aqueous solution
Abdelaziz Boulkamh Dominique Harakat Tahar Sehili Pierre Boule 《Pest management science》2001,57(12):1119-1126
UV irradiation of metoxuron in aerated aqueous solution at 254 nm or between 300 and 450 nm led initially to an almost specific photohydrolysis of the C–Cl bond, resulting in the formation of 3‐(3‐hydroxy‐4‐methoxyphenyl)‐1,1‐dimethylurea (MX3) and hydrogen chloride. The quantum yield was determined to be 0.020 (±0.005) in solutions irradiated at 254 nm. Five minor photoproducts were also identified, in particular the dihydroxydimethoxybiphenyl derivatives resulting from the phototransformation of MX3. Irradiation increased the toxicity of an aqueous solution of metoxuron to the marine bacterium Vibrio fischeri. © 2001 Society of Chemical Industry 相似文献
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Janusz Pop&#x;awski Boena &#x;ozowicka Alina T Dubis Barbara Lachowska Zbigiew Winiecki Jan Nawrot 《Pest management science》2000,56(6):560-564
All isomers of α‐asarone [(E)‐4‐prop‐1‐enyl‐1,2,5‐trimethoxybenzene] were tested for their feeding deterrent activity against adults of Sitophilus granarius and Tribolium confusum and larvae of Trogoderma granarium and Tribolium confusum. (E)‐2‐prop‐1‐enyl‐1,3,5‐trimethoxybenzene exhibited the strongest deterrent activity against all the species tested. The total coefficients of deterrency for this compound were 140.6 and 169.7 for Tribolium confusum adults and larvae, respectively, and 144.9 and 104.6 for larvae of Trogoderma granarium and adults of Sitophilus granarius, respectively. © 2000 Society of Chemical Industry 相似文献
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Insecticidal δ‐endotoxin proteins, degraded from parasporal crystals by protease, were recovered by a simple procedure using heat treatment, solubilization, and ultrafiltration of a fermentation broth of Bacillus thuringiensis subsp kurstaki HD‐1. A 68 kDa insecticidal protein was obtained and characterized by SDS‐PAGE. The procedure described gave a nearly quantitative recovery of toxicity. Furthermore, bioassay results on larvae of the diamondback moth (Plutella xylostella) showed that the 68 kDa δ‐endotoxin fraction (P1) was the principal insecticidal component to this target insect. A similar molecular mass polypeptide P2 (65 kDa) which was solubilized together with P1 from the parasporal crystals, gave relatively low mortality. © 2000 Society of Chemical Industry 相似文献
5.
Several heat‐based methods, such as soil solarization, are being developed as alternative practices for managing soil‐borne pests and pathogens. The effectiveness of these practices is often inconsistent or marginal, thus commanding the need for their integration with other methods. The main objective of this study was to determine synergistic interaction between soil fumigants and temperature. Soil infested with citrus nematode Tylenchulus semipenetrans was exposed to methyl bromide or 1,3‐dichloropropene at various temperatures. Fumigant degradation was concurrently measured and concentration‐time index (ct) was calculated and correlated to the recovered nematode population. In untreated soil, nematode survival was not affected by temperatures of 20–30 °C, but was strongly reduced at ≥ 40 °C. In fumigated soil, nematode suppression was much greater at 30 °C than at 20 °C, and the ct required for nematode elimination at 30 °C was < 50% of that needed at 20 °C for both fumigants. These results suggest that these fumigants became more active with increasing temperature in the sub‐lethal temperature range. It also implies that, when integrated with a heat‐based practice, reduced rates of fumigants may provide adequate pest control, thus minimizing the environmental input of chemical fumigants. © 2000 Society of Chemical Industry 相似文献
6.
BACKGROUND: Biocontrol achieved by a single biocontrol agent is generally inconsistent under field conditions. The aim of the present study was to increase the competitiveness and efficacy of biocontrol agents by using them together with cattle manure. RESULTS: The effects of antagonistic fungi [Aspergillus niger v. Teigh., Paecilomyces lilacinus (Thom) Samson and Penicillium chrysogenum Thom] and plant‐growth‐promoting rhizobacteria (PGPR) [Azotobacter chroococcum Beijer., Bacillus subtilis (Ehrenberg) Cohn and Pseudomonas putida (Trev.) Mig.] were assessed with cattle manure on the growth of tomato and on the reproduction of Meloidogyne incognita (Kof. & White) Chitwood. Application of antagonistic fungi and PGPR alone and in combination with cattle manure resulted in a significant increase in the growth of nematode‐inoculated plants. The highest increase (79%) in the growth of nematode‐inoculated plants was observed when P. putida was used with cattle manure, followed by use of P. lilacinus plus cattle manure. Paecilomyces lilacinus resulted in a high reduction in galling and nematode multiplication, followed by P. putida, B. subtilis, A. niger, A. chroococcum and P. chrysogenum. The combined use of P. lilacinus with cattle manure resulted in a maximum reduction in galling and nematode multiplication. CONCLUSION: Application of P. lilacinus or P. putida with cattle manure was useful to achieve greater biocontrol of M. incognita on tomato. Copyright © 2009 Society of Chemical Industry 相似文献
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Biorational and regular insecticide applications were evaluated for management of the diamondback moth (DBM) Plutella xylostella in cabbage (Brassica oleracea var capitata) in Karnataka State, India, in 1996 and 1997. The IPM programme, based on the pheromone trap catch threshold of eight moths per trap per night, included utilization of the parasitoid Cotesia plutellae. (250 000 adults ha−1), the predator Chrysoperla carnea (2500 eggs ha−1), the neem‐based chemical nimbecidine (625 ml ha−1), the bacterium Bacillus thuringiensis (500 ml ha−1), and the synthetic insecticide phosalone (2.8 litre ha−1). The IPM programme induced a reduction of trap catches, egg and larval populations and, therefore, a low level of damage to the crop. The economic analysis showed that the cost of the IPM treatments was also considerably lower than that of ordinary insecticide practice (average of $62 relative to $123 ha−1, respectively). Gross profit was also clearly higher in IPM plots than in farmer's fields, ranging from $777 to $810 ha−1 in the IPM plots compared with $456 to $462 ha−1 in the insecticide‐treated fields. As a consequence of lower input costs and higher gross profit, net profit in IPM treatments was even more favourable, and the economic savings associated with the utilization of the IPM programme amounted to $380 ha−1 in 1996 and $410 ha−1 in 1997. © 2000 Society of Chemical Industry 相似文献
9.
The degradation of the insecticide WL 41706, (±)-α-cyano-3-phenoxybenzyl 2,2,3,3-tetramethylcyclopropanecarboxylate, (I), in two soils from Spain and one from the UK has been studied in the laboratory. Samples of (I) labelled separately with 14C in the benzyl ring (uniform labelling) and at C(1) of the cyclopropyl ring were used. The insecticide underwent degradation by hydrolysis at the cyano group to form the amide and carboxylic acid analogues. However, the major degradative route was hydrolysis at the ester linkage leading initially to the formation of 3-phenoxy-benzoic acid and 2,2,3,3-tetramethylcyclopropanecarboxylic acid. When a sandy clay soil was treated with [benzyl?14C]-WL 41706 under balance conditions, 14CO2 was evolved at a steady rate and 16 % of the applied radiolabel was detected as 14CO2 over a 26 week period. The rate of degradation of I was most rapid on a moist sandy clay (loss of 50 % initial quantity in 4 weeks) but it was considerably slower on dry sandy clay and moist clay soils (> 16 weeks). Under flooded, anaerobic conditions the rate of hydrolysis of the insecticide was slower than under aerobic conditions and the 3-phenoxybenzoic acid and 2,2,3,3-tetramethylcyclopropanecarboxylic acid were found to accumulate over the 24 weeks of the experiment. 相似文献
10.
Kazuo Yagi Kazuhiko Akimoto Norihiko Mimori Toshiro Miyake Masaki Kudo Kazutaka Arai Shigeru Ishii 《Pest management science》2000,56(1):65-73
A series of novel 3‐(2,4,6‐trisubstituted phenyl)uracil derivatives has been synthesised and assayed for insecticidal/acaricidal activity. The assay indicated certain requirements for optimal insecticidal activity, which can be summarised as follows: (a) the substituents on the phenyl ring should possess hydrophobicity and electron‐withdrawing properties, and the sum of their volumes determines the level of activity; (b) the substituent at the 6‐position on the uracil ring should also possess electron‐withdrawing properties and hydrophobicity, together with the correct volume; (c) the 1‐position on the uracil ring should be unsubstituted for activity against Nephotettix cincticeps and Epilachna vigintioctopunctata, but substituents with length C3 to C4 may be optimal for activity against Tetranychus urticae; (d) certain substituents at the 5‐position of the uracil ring give activity against E vigintioctopunctata and T urticae, but not against N cincticeps; (e) a thiocarbonyl group at the 2‐position of the uracil ring is less effective than a carbonyl group. Of the compounds assayed, 3‐(2,6‐dichloro‐4‐trifluoromethylphenyl)‐6‐trifluoromethyluracil showed high activity against all the species assayed. © 2000 Society of Chemical Industry 相似文献
11.
1,3‐Dichloropropene (1,3‐D), which consists of two isomers, (Z)‐ and (E)‐1,3‐D, is considered to be a viable alternative to methyl bromide, but atmospheric emission of 1,3‐D is often associated with deterioration of air quality. To minimize environmental impacts of 1,3‐D, emission control strategies are in need of investigation. One approach to reduce 1,3‐D emissions is to accelerate its degradation by incorporating organic amendments into the soil surface. In this study, we investigated the ability of four organic amendments to enhance the rate of degradation of (Z)‐ and (E)‐1,3‐D in a sandy loam soil. Degradation of (Z)‐ and (E)‐1,3‐D was well described by first‐order kinetics, and rates of degradation for the two isomers were similar. Composted steer manure (SM) was the most reactive of the organic amendments tested. The half‐life of both the (Z)‐ and (E)‐isomers in unamended soil at 20 °C was 6.3 days; those in 5% SM‐amended soil were 1.8 and 1.9 days, respectively. At 40 °C, the half‐life of both isomers in 5% SM‐amended soil was 0.5 day. Activation energy values for amended soil at 2, 5 and 10% SM were 56.5, 53.4 and 64.5 kJ mol?1, respectively. At 20 °C, the contribution of degradation from biological mechanisms was largest in soil amended with SM, but chemical mechanisms still accounted for more than 58% of the (Z)‐ and (E)‐1,3‐D degradation. The effect of temperature and amendment rate upon degradation should be considered when describing the fate and transport of 1,3‐D isomers in soil. Use of organic soil amendments appears to be a promising method to enhance fumigant degradation and reduce volatile emissions. Published in 2001 for SCI by John Wiley & Sons, Ltd 相似文献
12.
Christian Mougin Claude Pericaud Christian Malosse Chantal Laugero Marcel Asther 《Pest management science》1996,47(1):51-59
Biotransformation of the insecticide lindane by the white rot basidiomycete Phanerochaete chrysosporium has been investigated in liquid cultures. Some polar metabolites and carbon dioxide were produced from the pesticide. Among the metabolites identified were tetrachlorocyclohexene, tetrachlorocyclohexene epoxide and tetrachlorocyclohexenol. When used as a substrate, tetrachlorocyclohexene was also converted by the fungus to tetrachlorocyclohexenol, polar metabolites and carbon dioxide. Three incubation conditions leading to low and high peroxidase production were assayed. Data from these experiments, as well as in-vitro incubations with purified enzymes, ruled out any involvement of the peroxidases in lindane biotransformation and mineralization. Moreover, 1-aminobenzotriazole (a P450 inactivator) drastically reduced pesticide metabolism. Conversely, phenobarbital (a P450 inducer) did not significantly increase lindane breakdown. 相似文献
13.
Michael E Scharf Blair D Siegfried Lance J Meinke Laurence D Chandler 《Pest management science》2000,56(9):757-766
Fipronil toxicity and metabolism were studied in two insecticide‐resistant, and one susceptible western corn rootworm (Diabrotica virgifera virgifera, LeConte) populations. Toxicity was evaluated by exposure to surface residues and by topical application. Surface residue bioassays indicated no differences in fipronil susceptibility among the three populations. Topical bioassays were used to study the relative toxicity of fipronil, fipronil + the mono‐oxygenase inhibitor piperonyl butoxide, and fipronil's oxidative sulfone metabolite in two populations (one resistant with elevated mono‐oxygenase activity). Fipronil and fipronil‐sulfone exhibited similar toxicity and application of piperonyl butoxide prior to fipronil resulted in marginal effects on toxicity. Metabolism of [14C]fipronil was evaluated in vivo and in vitro in the three rootworm populations. In vivo studies indicated the dominant pathway in all populations to be formation of the oxidative sulfone metabolite. Much lower quantities of polar metabolites were also identified. In vitro studies were performed using sub‐cellular protein fractions (microsomal and cytosolic), and glutathione‐agarose purified glutathione‐S‐transferase. Oxidative sulfone formation occurred almost exclusively in in vitro microsomal reactions and was increased in the resistant populations. Highly polar metabolites were formed exclusively in in vitro cytosolic reactions. In vitro reactions performed with purified, cytosolic glutathione‐S‐transferase (MW = 27 kDa) did not result in sulfone formation, although three additional polar metabolites not initially detectable in crude cytosolic reactions were detected. Metabolism results indicate both cytochromes P450 and glutathione‐S‐transferases are important to fipronil metabolism in the western corn rootworm and that toxic sulfone formation by P450 does not affect net toxicity. © 2000 Society of Chemical Industry 相似文献
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BACKGROUND: The susceptibility of adult house cricket, Acheta domesticus (L.), adult convergent lady beetle, Hippodamia convergens (Guérin‐Méneville), and larval fall armyworm, Spodoptera frugiperda (JE Smith), to resmethrin and δ‐phenothrin synergized with piperonyl butoxide (PBO) was evaluated in a laboratory bioassay procedure. RESULTS: The 1 day LC50 values for resmethrin + PBO were 23.2, 32.08 and 307.18 ng cm?2 for A. domesticus, H. convergens and S. frugiperda respectively. The 1 day LC50 values for δ‐phenothrin + PBO were 26.9, 74.91 and 228.57 ng cm?2 for A. domesticus, H. convergens and S. frugiperda respectively. The regression relationship between species mortality and concentration explained 51–81% of the variation for resmethrin + PBO and 72–97% of the variation for δ‐phenothrin + PBO. The LC50 values decreased with time for these insecticides for all surrogate species. In terms of sensitivities among the insects to resmethrin + PBO and δ‐phenothrin + PBO, A. domesticus was most sensitive, followed by H. convergens and then S. frugiperda. CONCLUSION: The results indicate that resmethrin + PBO was generally more toxic than δ‐phenothrin + PBO. Based on the results, A. domesticus seems to be a good surrogate species for estimating potential non‐target terrestrial insect impacts from exposure to pyrethroids used in public health applications. Copyright © 2008 Society of Chemical Industry 相似文献
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During the past 5 years, the Associated Unit between Institut Valencià d’Investigacions Agràries (IVIA) and Universitat Jaume I (UJI) has been working on the management of Rhynchophorus ferrugineus. The host status of Washingtonia filifera, Chamaerops humilis and Phoenix theophrasti was established, and complete resistance via antibiosis was described for W. filifera. A thermal constant (egg to adult) of 989.3 degree‐days has been established for R. ferrugineus when feeding in live P. canariensis. Based on this result, less than one annual generation is expected in areas with mean annual temperature below 15°C, and more than two if above 19°C. Assays on chemical control showed that a dose of 1.14 g aluminium phosphide m?3 for 3 days is enough to kill all stages of R. ferrugineus in infested palms. The efficacies of imidacloprid and a microencapsulated paint containing chlorpyrifos and pyriproxyfen were also studied. Imidacloprid had high efficacies when applied as a drench either as a preventive or a curative treatment, whereas the paint was effective as a preventive treatment only. Biological control by use of entomopathogenic nematodes and fungi has been explored. Steinernema carpocapsae resulted in high efficacies when applied in a chitosan formulation. Beauveria bassiana also gave very good results, and new assays are under way to improve its use. 相似文献
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Shaukath A Khanum Sheena Shashikanth Syagadadu Giriyanna Sathyanarayana Siddalingaiah Lokesh Saligrama A Deepak 《Pest management science》2009,65(7):776-780
BACKGROUND: Finger millet is a major food crop as well as feed and fodder for livestock, especially in regions of southern India. A sturdy crop to fluctuating environmental conditions, it can be cultivated in all seasons of the year. Leaf, neck and finger blast caused by Pyricularia grisea Sacc. and Bipolaris setariae (Saw.) Shoem, as well as leaf spot disease, Bipolaris nodulosa (Berk & M.A.Curtis) Shoem, are major production constraints in southern India. Apart from environmental conditions, the use of harvested seeds by farmers is a major reason for disease prevalence. Benzophenone analogues have been investigated for controlling phytopathogenic fungi. In addition, the most important applications of azetidin‐2‐ones are as antibiotics. Based on this information, the present study was conducted to explore the antifungal activity of integrated 2‐azetidinonyl and 1,3,4‐oxadiazoles moieties into a benzophenone framework. RESULTS: A simple high‐yielding method for the integration of heterocyclic rings, namely 2‐azetidinonyl, at the benzophenone nucleus has been achieved, starting from substituted 2‐hydroxybenzophenones under mild conditions on a wet solid surface using microwave irradiation. In the present study, an array of newly synthesised compounds, 2‐azetidinonyl‐5‐(2‐benzoylphenoxy)methyl‐1,3,4‐oxadiazoles, were screened for their antifungal property against blast and leaf spot causing fungi associated with the seeds of finger millet, cv. Indof‐9. CONCLUSION: Two of the newly synthesised compounds showed promising effects in depleting the incidence of seed‐borne pathogenic fungi of finger millet. The suppression of Pyricularia grisea and Bipolaris setariae resulted in enhanced seed germination and seedling growth. Copyright © 2009 Society of Chemical Industry 相似文献
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Arbuscular mycorrhizal (AM) fungi known to cause plant growth depressions in tomato were examined for their biocontrol effects
against root rot caused by Pythium aphanidermatum. The main hypothesis was that plant growth suppressive AM fungi would elicit a defence response in the host plant reducing
Pythium root rot development. To test this hypothesis a fully factorial experiment was performed with AM fungi (Glomus intraradices, G. mosseae, G. claroideum or nonmycorrhizal), Pythium (± P. aphanidermatum) and harvest (7 and 14 days after pathogen inoculation (dapi)) as the main factors. Two weeks after AM fungi inoculation,
roots were challenged with P. aphanidermatum. Variables evaluated at each harvest were root colonization levels of the interacting fungi, plant growth responses, and expression
of a plant pathogenesis related protein gene (PR-1). All of the tested AM fungi caused marked growth suppressions, but did
not affect PR-1 gene expression or the phosphorous concentration in the host plant. Plants singly inoculated with P. aphanidermatum had an increased PR-1 expression and phosphorous concentration. Among the AM fungi included in the study only G. intraradices reduced the pathogen root infection level, measured both in terms of Pythium ELISA and by recovery on selective media and only at the first harvest. Likewise, P. aphanidermatum root infection reduced colonization levels of G. intraradices, but not that of the two other AM fungi. In conclusion, plant growth suppressive AM fungi may offer plant beneficial traits
in terms of biocontrol of root cortical pathogens. 相似文献
18.
杨树烂皮病生防链霉菌的筛选及鉴定 总被引：2，自引：0，他引：2
为明确能有效抑制杨树烂皮病菌的拮抗放线菌F58的生防效果及分类地位,采用平板对峙法、杯碟法和人工接种法分别测定了其活菌及发酵液的抑菌活性;并通过形态学、生理生化特征、16S rRNA及全细胞脂肪酸分析等方法研究了其分类地位。结果表明,拮抗放线菌F58对杨树烂皮病菌、杨树溃疡病菌、苹果斑点落叶病菌等13种供试植物病原菌均有抑制作用,抑菌谱广,其中对杨树烂皮病菌和杨树溃疡病菌抑制作用最强,抑菌带达30.2 mm以上,菌株F58发酵液对这2种病菌也有很强的抑制作用,抑菌圈直径分别为56.4 mm和42.7 mm;发酵液的无菌滤液对杨树烂皮病的保护效果和治疗效果分别达88.7%和73.4%。根据菌株形态、生理生化特性、16S rRNA序列比对及全细胞脂肪酸分析,鉴定拮抗放线菌F58为盐屋链霉菌Streptomyces sioyaensis。 相似文献
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1,5‐Diphenyl‐1‐pentanone (A) and 1,5‐diphenyl‐2‐penten‐1‐one (B) are natural products extracted for the first time from Stellera chamaejasme. Laboratory bioassay showed that the two products have strong contact activity and very good anti‐feedant activity against Aphis gossypii and Schizaphis graminum. Both products showed dose‐dependent relationships for both forms of activity against the two aphids, the contact activity of B being about twice that of A. Both products were inferior to methomyl in contact activity but superior in anti‐feedant activity against the two aphids. This is the first report of aphicidal activity in these two compounds, which may represent a new class of aphicide. © 2001 Society of Chemical Industry 相似文献