Fusarium head blight(FHB) caused by Fusarium graminearum is a devastating fungal disease on small grain cereal crops,because it reduces yield and quality and causes the mycotoxin contamination to the grain.Dynamins an...Fusarium head blight(FHB) caused by Fusarium graminearum is a devastating fungal disease on small grain cereal crops,because it reduces yield and quality and causes the mycotoxin contamination to the grain.Dynamins and dynamin-related proteins(DRPs) are large GTPase superfamily members,which are typically involved in the budding and division of vesicles in eukaryotic cells,but their roles in Fusarium spp.remain unexplored.Here,we found that FgDnm1,a DRP and homolog to Dnm1 in Saccharomyces cerevisiae,contributes to the normal fungal growth,sexual reproduction and sensitivity to fungicides.In addition,we found FgDnm1 co-localizes with mitochondria and is involved in toxisome formation and deoxynivalenol(DON) production.Several quinone outside inhibitors(QoIs) and succinate dehydrogenase inhibitors(SDHIs) cause fragmentated morphology of mitochondria.Importantly,the deletion of FgDnm1displays filamentous mitochondria and blocks the mitochondrial fragmentation induced by QoIs and SDHIs.Taken together,our studies uncover the effect of mitochondrial dynamics in fungal normal growth and how such events link to fungicides sensitivity and toxisome formation.Thus,we concluded that altered mitochondrial morphology induced by QoIs and SDHIs depends on FgDnm1.展开更多
Leaf and fruit spot (Pseudocercospora angolensis) disease of citrus attacks leaves, fruits, and young twigs of the plant. The disease can cause a yield loss of (50% to 100%) in areas with high rainfall and humidity du...Leaf and fruit spot (Pseudocercospora angolensis) disease of citrus attacks leaves, fruits, and young twigs of the plant. The disease can cause a yield loss of (50% to 100%) in areas with high rainfall and humidity during the active growth stages of the crop. Currently, citrus plantations in the south, south-west and north-west of Ethiopia are seriously affected by this disease. As a result, this study was proposed to study the effect of fungicides in controlling. And candidate fungicides were: Carbonchlor 50% SC only, Benline 50% WP only, Bellis 38% WG only, Carbonchlor 50% SC combined with Bellis 38% WG, Benline 50% WP combined with Carbonchlor 50% SC and Benline 50% WP combined with Matco 72% WP for effective management of citrus leaf and fruit spot (Pseudocercospra angolensis) disease. The study was carried out in 2021 cropping season. A Randomized Complete Block Design (RCBD) with three replications was the design applied. The result showed that the highest level of efficacy (90.46%) was produced by Bellis 38% WG fungicide followed by Carbonchlor 50% SC (86.50%), Bellis 38% WG + Carbonchlor 50% SC (82.00%), Carbonchlor 50% SC + Benline 50% WP (67.89%), Benline 50% WP (65.62%) and Matco 72% WP + Benline 50% WP (49.48%). Therefore, based on the outcome of the study application of Bellis 38% WG only followed by Carbonchlor 50% SC only, Carbonchlor 50% SC combined with Benline 50% WP, Bellis 38% WG combined with Carbonchlor 50% SC, Bellis 38% WG only, Benline 50% WP only and Matco 72% WP combined with Benline 50% WP were effective fungicides to be used for the control of leaf and fruit spot disease.展开更多
[Objectives]The paper was to identify the characteristics and the potency of new fungicides to rice blast disease,and study their preventive and therapeutic effects on the disease.[Methods]Six new and conventional fun...[Objectives]The paper was to identify the characteristics and the potency of new fungicides to rice blast disease,and study their preventive and therapeutic effects on the disease.[Methods]Six new and conventional fungicides with different mechanisms of action were selected to compare their preventive and therapeutic effects on rice seedling blast in greenhouse.[Results]The agents which showed to be highly efficacious in blast prevention(greater than 90%)were 25%pyraclostrobin EC,20%fenoxanil SC,75%tricyclazole WP and 50%prochloraz-manganese WP sprayed at the dosages of 112.5-150,180-360,270-450 and 450-600 g/ha,respectively.The therapeutic effect of new fungicides 25%pyraclostrobin EC and 50%prochloraz-manganese WP on rice blast were above 90%when the dosages were 90-150 and 360-600 g/ha,respectively.The therapeutic effect of the conventional fungicide 40%isoprothiolane EC on rice blast was 69.04%when the dosage was 480 g/ha,while those of other fungicides were worse.[Conclusions]Both 25%pyraclostrobin EC and 50%prochloraz-manganese WP have good preventive and therapeutic effects on rice blast,which will provide a reference for the use of these fungicides in the field.展开更多
In this research,the inhibitory effect of 16 fungicides on Colletotrichum horri causing persimmon anthracnose was investigated using mycelial growth method and spore germination method. The results showed that among t...In this research,the inhibitory effect of 16 fungicides on Colletotrichum horri causing persimmon anthracnose was investigated using mycelial growth method and spore germination method. The results showed that among the 16 tested fungicides,10% of Difenoconazole WG,33. 5% of Copper quinolate SC,25%of Bromothalonil EC,70% of Mancozeb WP,430 g/L of Tebuconazole SC,50% of Prochloraz-manganese chloride and 400 g/L of Flusilazole EC achieved the best inhibitory effect on mycelial growth of C. horri,with the inhibition rate of 100%; 70% of Polyram WG,33. 5% of Copper quinolate SC,25% of Bromothalonil EC,70% of Mancozeb WP,50% of Chlorobromoisocyanuric acid AF,50% of Triram WP and 400 g/L of Flusilazole achieved the best inhibitory effect on spore germination of C. horri,with the germination rate of 0. In conclusion,33. 5% of Copper quinolate SC,25% of Bromothalonil EC,70% of Mancozeb WP and 400 g/L of Flusilazole EC achieved the best inhibitory effect both in mycelial growth and spore germination,which could be used as the preference fungicides for the control of persimmon anthracnose,and 70% of Polyram WG and 50% of Triram WP achieved the secondly best inhibitory effect,which could be used as alternative fungicides. The results of this research could provide scientific evidence for the effective control of persimmon anthracnose,and more optional pesticides for utilization in the production practice of persimmon industry.展开更多
The effects of biofungicide formula containing the biocontrol agent Trichoderma harzianum (Jn14) as wettable powder in combination with the fungicides pyrimethanil and a mixture of cyprodinil and flydioxonil on Botryt...The effects of biofungicide formula containing the biocontrol agent Trichoderma harzianum (Jn14) as wettable powder in combination with the fungicides pyrimethanil and a mixture of cyprodinil and flydioxonil on Botrytis cinerea of strawberry in vitro, in vivo and in greenhouse were studied. The pathogen B. cinerea was more affected in vitro by low concentrations of the fungicides tested above 0.4 μg·ml-1 than the bioagent T. harzianum (Jn14). The later was almost insensitive to pyrimethanil. In the same direction, gray mould disease severity on strawberry detached leaves and whole plants was reduced up to 89% by the tested fungicides, compared to the control, while the application of T. harzianum (Jn14) alone reduced disease severity up to 45% on strawberry detached leaves, compared to the control. In the integrated control approach, the combination of T. harzianum (Jn14) with higher concentrations of the tested fungicides (ED50) completely inhibited strawberry gray mould disease severity in pots and the greenhouse.展开更多
Wheat blast, caused by a fungal pathogen, <i><span style="font-family:Verdana;">Magnaporthe oryzae Tritichum </span></i><span style="font-family:Verdana;">(</span&g...Wheat blast, caused by a fungal pathogen, <i><span style="font-family:Verdana;">Magnaporthe oryzae Tritichum </span></i><span style="font-family:Verdana;">(</span><i><span style="font-family:Verdana;">MoT</span></i><span style="font-family:Verdana;">) pathotype (wheat isolates), was first reported in Bangladesh among Asian countries in 2016. It is a serious disease of wheat causing yield failures and significant economic losses during epidemic years. Extensive use of persistent synthetic pesticides to control notorious wheat blast imposes enormous threat to human health and environment. In addition, the increasing demand for organic food has stimulated people to look for alternative methods. Nowadays, the need for synthetic chemical-free agricultural practices is gaining importance due to effective in managing crop pests, inexpensive, biodegradable, easily available and have low toxicity to non-target organisms. In order to identify active plants, 12 kinds of methanol extracts obtained from 12 medicinal plants were conducted </span><i><span style="font-family:Verdana;">in vitro</span></i><span style="font-family:Verdana;"> to test the effect against </span><i><span style="font-family:Verdana;">Magnaporthe oryzae Triticum </span></i><span style="font-family:Verdana;">(</span><i><span style="font-family:Verdana;">MoT</span></i><span style="font-family:Verdana;">) pathotype. The remarkable inhibitory activity {(29.6 ± 01.5) mm, (25.1 ± 01.0) mm and (20.0 ± 02.0) mm zone of inhibition)} exhibited by the extracts (5 mg/disk) obtained from </span><i><span style="font-family:Verdana;">Artemisia indica</span></i><span style="font-family:Verdana;"> (Nagdona), </span><i><span style="font-family:Verdana;">Persicaria orientalis</span></i><span style="font-family:Verdana;"> (Bishkatali) and </span><i><span style="font-family:Verdana;">Clerodendrum indicum</span></i><span style="font-family:Verdana;"> (Bamonhati), respectively. Other medicinal plant extracts did not show any significant or no activity at all. Therefore, the three plant extracts might be a promising source for developing natural fungicides against wheat blast.</span>展开更多
The morphophysiological and molecular-genetic parameters of T. caries isolates collected from various fields of Southern Urals agrocenoses have been analysed. Isolate 1 of wheat callus had a high growth rate in vitro ...The morphophysiological and molecular-genetic parameters of T. caries isolates collected from various fields of Southern Urals agrocenoses have been analysed. Isolate 1 of wheat callus had a high growth rate in vitro even in the presence of 0.1 mg/l fungicide Baitan. Isolate 2 of wheat callus had a low growth rate whereas 0.1 mg/l Baitan significantly inhibited its growth. Comparison of nucleotide sequences of 18S RNA gene of the two isolates showed high level of homology between them, but a large number of nucleotide substitutions have been found. The most characteristic excision was five nucleotides at position 461 of the isolate 2, compared with the isolate 1. Our results allow to assume that the environmental stress including high pesticide concentration may cause the resistance of T. caries pathogen to fungicides.展开更多
A method for the simultaneous determination of a series of chlorinated insecticides and fungicides as residues in ginseng is presented in this article. Pulverized samples are subjected to Soxhlet extraction with aceto...A method for the simultaneous determination of a series of chlorinated insecticides and fungicides as residues in ginseng is presented in this article. Pulverized samples are subjected to Soxhlet extraction with acetone-petroleum ether and the extract is partitioned between petroleum ether and aqueous sodium sulfate solution (2:98). The combined petroleum ether phase is cleaned up by sulfuric acid and analyzed by capillary gas chromatography using 63Ni electron capture detector. Recoveries from the different concentrations for 11 kinds of chlorinated insecticides and fungicides are between 92.40 and 103.7% with coefficients of variations ranged 1.22 and 9.53% without samples, and between 89.00% and 104.10% with coefficients of variations between 1.16% and 9.16% with samples. The detection limits are 0.2- 7.0 ng/kg.展开更多
A series of diheterocyclic compounds containing 1,2,4-triazolo [1,5-a]pyrimidine and 1, 3,4-oxadiazole were designed and synthesized starting from 2-mercapto-5,7-dimethyl-1,2,4- triazolo [1,5-a] pyrimidine. The struct...A series of diheterocyclic compounds containing 1,2,4-triazolo [1,5-a]pyrimidine and 1, 3,4-oxadiazole were designed and synthesized starting from 2-mercapto-5,7-dimethyl-1,2,4- triazolo [1,5-a] pyrimidine. The structure of all compounds prepared were confirmed by 1H NMR spectroscopy and elemental analysis. The preliminary bioassay indicated that the title compounds displayed good fungicidal activity against Rhizoctonia solani.展开更多
The increasing demand for safe food without preservatives or pesticides residues has encouraged several studies on natural products with antifungal activity and low toxicity.In this study,ethanolic extracts from leave...The increasing demand for safe food without preservatives or pesticides residues has encouraged several studies on natural products with antifungal activity and low toxicity.In this study,ethanolic extracts from leaves and fruit residues(peel and seeds)of three Brazilian savanna species(Acrocomia aculeata,Campomanesia adamantium and Caryocar brasiliense)were evaluated against phytopathogenic fungi.Additionally,the most active extract was chemically characterized by ESI-MS and its oral acute toxicity was evaluated.Extracts from C.brasiliense(pequi)peel and leaves were active against Alternaria alternata,Alternaria solani and Venturia pirina with minimal inhibitory concentrations between 350 and 1000 lg/mL.When incorporated in solid media,these extracts extended the lag phase of A.alternata and A.solani and reduced the growth rate of A.solani.Pequi peel extract showed better antifungal activity and their ESI-MS analysis revealed the presence of substances widely reported as antifungal such as gallic acid,quinic acid,ellagic acid,glucogalin and corilagin.The oral acute toxicity was relatively low,being considered safe for use as a potential natural fungicide.展开更多
Anthracnose is the one of the most devastating diseases of mango produced in the southern part of Senegal. The field trials against post harvest rot due to anthracnose took place in three orchards over two production ...Anthracnose is the one of the most devastating diseases of mango produced in the southern part of Senegal. The field trials against post harvest rot due to anthracnose took place in three orchards over two production seasons, in 2009 and 2010. Three systemic fungicides (thiophanate methyl, azoxystrobin and myclobutanyl) and one contact fungicide (mancozeb) were tested for their efficacy. The first treatments in 2009 took place in the rainy season, while 20% of mangoes on trees exhibited anthracnose lesions. At ripening stage, 100% of fruits from non treated control mango trees were affected by anthracnose and got rotten, while between 73.2% and 80% of mangoes ripened free of disease when treated with thiophanate methyl. With the treatment with azoxystrobin, between 46.6% and 60% of fruits were not infected. Treatment with myclobutanyl was less effective. This level of effectiveness was clearly improved in 2010 by preventive spraying, days ahead of onset of the rainy season, before the appearance of anthracnose symptoms on fruits. The level of effectiveness was higher respectively for thiophanate methyl (between 96% and 100% of fruits not infected) and azoxystrobin (between 84% and 96% of fruits not infected).展开更多
[Objective]The study was to evaluate the indoor toxicity and field efficacy of five Strobilurins fungicides including pyraclostrobin 250 g/L EC,azoxystrobin 250 g/L SC,kresoxim-methyl 50%WG,picoxystrobin 22.5%SC and t...[Objective]The study was to evaluate the indoor toxicity and field efficacy of five Strobilurins fungicides including pyraclostrobin 250 g/L EC,azoxystrobin 250 g/L SC,kresoxim-methyl 50%WG,picoxystrobin 22.5%SC and trifloxystrobin 50%WG against Phomopsis asparagi(Sacc.)Bubak,and to screen out effective fungicides.[Method]The toxicity was tested by mycelial growth rate method.The field trials were carried out by routine spraying method.[Result]The indoor toxicities successively were pyraclostrobin>kresoxim-methyl>picoxystrobin>trifloxystrobin>azoxystrobin.The EC50 values were 6.1029,52.5591,83.8257,129.8616 and 252.1214 mg/L,respectively,all significantly higher than that of benzimidazole fungicide carbendazim(753.3650 mg/L).The field efficacies successively were pyraclostrobin>kresoxim-methyl≥picoxystrobin≥azoxystrobin≥trifloxystrobin.The control effects were 81.20%,77.95%,74.80%,71.69%and 68.54%,respectively,all significantly higher than that of benzimidazole fungicide carbendazim(48.27%).[Conclusion]The five Strobilurins fungicides all have good toxicity and field efficacy against P.asparagi.展开更多
An experiment was carried out to study the outcome of environmental factors (Temperature, Relative Humidity, Rainfall) and<span style="font-family:;" "=""> </span><span style=&q...An experiment was carried out to study the outcome of environmental factors (Temperature, Relative Humidity, Rainfall) and<span style="font-family:;" "=""> </span><span style="font-family:Verdana;">management of the purple blotch disease of onion using five treatments (Rovral + Ridoil gold with 3,4,5,6 sprays and control). The Taherpuri variety was used during the 2015-2016 cropping seasons at BARI, Gazipur, Bangladesh.</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">In the experiment, the purple blotch disease surfaced at the end of January</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">2016 and was severe in late February to March (PDI 76.12%) due to temperature and RH above 24</span><span style="font-family:Verdana;">°C and 95%, respectively.</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">As for the chemical control, the PDI for the treatments ranged from 50.66% to 83.33%.</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">Significantly higher stem height was recorded by T</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> (68.06 cm), where six sprays of Rovral + Ridomil were applied. The minimum stem height was recorded in T</span><sub><span style="font-family:Verdana;">5</span></sub><span style="font-family:Verdana;"> (59.23 cm). The maximum stem number per hill was recorded in T</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> (2.30) numerically but differed significantly with T</span><sub><span style="font-family:Verdana;">5</span></sub></span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">(2.00), where fungicides were not applied. The maximum lesion area was measured in T</span><sub><span style="font-family:Verdana;">5</span></sub><span style="font-family:Verdana;"> (25.26 mm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">). Regarding PDI (Percent disease index), there was a significant difference among the treatments. The PDI value on purple blotch of onion ranged from 34.00 to 83.33. The lowest PDI was assessed in T</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> (34.00). Statistical analysis revealed that a significant decrease of PDI on purple blotch was recorded under treatments of T</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;">, T</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">, T</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;">, and T</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> (39.20</span></span><span style="font-family:Verdana;">%</span><span style="font-family:Verdana;">, 45.60</span><span style="font-family:Verdana;">%</span><span style="font-family:Verdana;">, 49.59</span><span style="font-family:Verdana;">%</span><span style="font-family:;" "=""><span style="font-family:Verdana;">, and 59.19%) on controlling the disease and giving the optimum yield but all of them significantly differed with T</span><sub><span style="font-family:Verdana;">5</span></sub><span style="font-family:Verdana;"> (83.33%) where no fungicides were sprayed.</span></span>展开更多
[Objective]The paper was to compare the indoor toxicities of sixteen fungicides on mycelial growth and spore germination of Monilinia fructicola,to screen out effective fungicides and to discuss use characteristics of...[Objective]The paper was to compare the indoor toxicities of sixteen fungicides on mycelial growth and spore germination of Monilinia fructicola,to screen out effective fungicides and to discuss use characteristics of various types of fungicides.[Method]The inhibitory activities of 16 fungicides on mycelial growth and spore germination were determined by mycelial growth rate method and spore germination method.[Result]The EC50 values of 16 fungicides against mycelial growth ranged from 0.0184 to 61.5305 mg/L.Prochloraz,tetramycin,fenbuconazole and fludioxonil had strong inhibitory activities on mycelial growth,and their EC50 values were 0.0184,0.0456,0.0531 and 0.0814 mg/L,respectively,significantly lower than those of other 12 fungicides.The EC50 values of 16 fungicides against spore germination ranged from 0.0084 to 189.3938 mg/L.Tetramycin and chlorothalonil had strong inhibitory activities on mycelial growth,and their EC50 values were 0.0084 and 0.0378 mg/L,respectively,significantly lower than those of other 14 fungicides.[Conclusion]The 16 fungicides had great value in preventing and controlling peach brown rot.Benzimidazoles,diformimides and ergosterol inhibitors had good inhibitory activities on mycelial growth.Strobilurins,succinate dehydrogenase inhibitors and multiple-site protective fungicides had good inhibitory activities on spore germination.The agricultural antibiotics tetramycin,phenazine-1-carboxylic acid and pyrrole fungicide fludioxonil had good inhibitory activities on mycelial growth and spore germination.展开更多
Onion is an important vegetable in Senegal horticulture, where it occupies the first place. However in the greatest areas production like the Gandiolais, in the North of Senegal, Pink root disease caused by a soil bor...Onion is an important vegetable in Senegal horticulture, where it occupies the first place. However in the greatest areas production like the Gandiolais, in the North of Senegal, Pink root disease caused by a soil born fungus Pyrenochaeta terrestris (Hansen) Gorentz, Walker and Larson affects its productivity especially in nursery. On soil sterilized and inoculated by the fungus, we tested 5 natural fungicides and 2 synthetic fungicides, to measure their effectiveness on the Pink root disease on onion, in nursery. The device used is a split plot with 4 repetitions and 8 treatments. The measured variables are the emergence rates, the survival rates and the infestation rates. Our experimentations have shown that, for the emergence rates, there is no significant difference between thiophanate-methyl (Pelt 44), Carbendazim (Bavistine), Azadirachta indica A. Juss and Carica papaya L. It is the same between C. papaya and Moringa oleifera Lam, between M. oleifera and Cassia alata L. It is also the same between C. alata and Crotolaria retusa L. Regarding the survival rates, there is no significant difference between thiophanate-methyl, Azadirachta indica, Carbendazim, C. papaya and M. oleifera. The same is true between M. oleifera and Cassia alata, and between C. alata and C. retusa. Concerning the infestation rates, apart from the control check, all other treatments show no difference.展开更多
Fungicides which are not easily degradable have the greatest adverse effects on soil microbes. These pesticides negatively affect the growth and multiplication of fungi and bacteria and consequently cause the disturba...Fungicides which are not easily degradable have the greatest adverse effects on soil microbes. These pesticides negatively affect the growth and multiplication of fungi and bacteria and consequently cause the disturbance of the natural soil microbial balance. In this study two fungicide tolerant isolates of rhizobia;clover isolate (TA1) and peanut isolate (8) were assessed in their capacity to degrade Vitavax and Rizolex. The performance of these isolates in fungicides degradation was tested using the colorimetric assay for Rizolex and the HPLC analysis for Vitavax to detect the degradation products. Using HPLC analyses, the control sample showed specific peak indicating the Vitavax presence in the medium. The specific peak did not change in the control samples throughout the experiment.With the strainTA1 the specific peak of the Vitavax fungicides started to reduce as the incubation time goes on. The Vitavax fungicide did not degrade completely after 240 hours of incubation with rhizobial isolate. The Rizolex used in this study contained blend of Thiram (active ingredient of Rizolex) and Tolcofs methyl fungicides in 1:1 ratio. The biodegradation of Rizolex in the liquid media showed the formation of two new intermediates which were released into the medium indicating the degradation of the tested fungicide by peanut rhizobial isolate No. 8 in 48 hrs of incubation 45% of this compound was degraded. This work shows that the selection of fungicides tolerant rhizobial strains is important to protect the rhizobial inoculants from the toxic effect of the pesticides.展开更多
Biological methodologies (</span><i><span style="font-family:Verdana;">in vitro</span></i><span style="font-family:Verdana;"> and </span><i><span ...Biological methodologies (</span><i><span style="font-family:Verdana;">in vitro</span></i><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">in vivo</span></i><span style="font-family:Verdana;">) were tested on </span><i><span style="font-family:Verdana;">Venturia inaequalis</span></i><span style="font-family:Verdana;"> to assay sensitivity of populations treated with the SDHI penthiopyrad, fluxapyroxad and fluopyram that showed a field poor control in an experimental Centre. In comparison, sensible populations were tested. </span><i><span style="font-family:Verdana;">I</span></i><i><span style="font-family:Verdana;">n vitro</span></i><span style="font-family:Verdana;"> trials, the poorly controlled populations presented moderate increases of EC</span><sub><span style="font-family:Verdana;">50</span></sub><span style="font-family:Verdana;"> and RF values in all three years in which tests were carried out. The </span><i><span style="font-family:Verdana;">in vivo</span></i><span style="font-family:Verdana;"> trials in glasshouse showed that the activity of SDHI fungicides on field poorly controlled populations was highly reduced. These populations can be defined as “resistant” as the high loss of sensitivity and activity were repeatedly assessed in field and glasshouse. Trials showed that these reductions were manifested by curative applications and not by preventive ones, as already ascertained for </span><i><span style="font-family:Verdana;">V. inaequalis </span></i><span style="font-family:Verdana;">populations resistant to AP and DMI fungicides. </span><span><span style="font-family:Verdana;">The cross-resistance of resistant populations to the three SDHIs was highly positive among them. In bibliography, there are only researches of cross-resistance among SDHIs starting from isolates resistant to boscalid, with results of different sensitivities and cross-resistance. These results with populations of </span><i><span style="font-family:Verdana;">V. inaequalis</span></i><span style="font-family:Verdana;"> resistant to the three SDHI offer practical evaluations in cross-resistance.展开更多
Tobacco black shank caused by Phytophthora parasitica var.nicotianae(Breda de Hean)is one of the most serious diseases in tobacco growing,and few effective fungicides are available currently.The purpose of this study ...Tobacco black shank caused by Phytophthora parasitica var.nicotianae(Breda de Hean)is one of the most serious diseases in tobacco growing,and few effective fungicides are available currently.The purpose of this study was to assess the feasibility of using fluazinam to treat tobacco black shank disease.In vitro toxicities of fluazinam to 62 isolates of P.nicotianae were determined by mycelial growth rate method.The EC50 values ranged from 0.294 6 to 2.389 9 μg/mL with a mean of 1.084 0 μg/mL.The sensitivity distribution was unimodal,and there was no resistant isolate in P.nicotianae population.The carboxylic acid amide(CAA)fungicides were single-site in action and activity to oomycetes.The synergistic interactions were tested by Wadley method between fluazinam and dimethomorph,flumorph,mandipropamid,respectively.The mixture containing dimethomoph:Huazinam at 1:2 ratio showed additive actions,with the synergy ratio of 1.2.The mixture containing flumorph and fluazinam at 1:5 ratio had the highest synergy ratio(SR 2.07).Mandipropamid and fluazinam had an additive interaction and the proportion of 2:1 had the lowest EC50 value(0.020 7 μg/mL).This study demonstrated the sensitivity of P.nicotianae to fluazinam,and provided the experimental foundation to use fluazinam for tobacco black shank management.展开更多
[Objective] The paper was to select different fungicides for field efficacy test against pear scab in summer.[Method] Five treatments were designed in the test,including 10% difenoconazole WDG 6 000 times dilution,50%...[Objective] The paper was to select different fungicides for field efficacy test against pear scab in summer.[Method] Five treatments were designed in the test,including 10% difenoconazole WDG 6 000 times dilution,50% captan WP 600 times dilution,30% pyraclostrobin SC 2 000 times dilution,430 g/L tebuconazole 4 000 times dilution,and water(control).[Result] 10% Difenoconazole WDG 6 000 times dilution,50% captan WP 600 times dilution,30% pyraclostrobin SC 2 000 times dilution,430 g/L tebuconazole SC 4 000 times dilution had good control effects against pear scab,and the efficacies were 89.13%-93.51%.[Conclusion] The results will provide the theoretical basis for field control of pear scab in summer.展开更多
基金supported by the National Natural Science Foundation of China (31772190)the Jiangsu Agriculture Science and Technology Innovation Fund, China (JASTIF) (CX(21)2037)the Postgraduate Research & Practice Innovation Program of Jiangsu Province, China (KYCX21_0631)。
文摘Fusarium head blight(FHB) caused by Fusarium graminearum is a devastating fungal disease on small grain cereal crops,because it reduces yield and quality and causes the mycotoxin contamination to the grain.Dynamins and dynamin-related proteins(DRPs) are large GTPase superfamily members,which are typically involved in the budding and division of vesicles in eukaryotic cells,but their roles in Fusarium spp.remain unexplored.Here,we found that FgDnm1,a DRP and homolog to Dnm1 in Saccharomyces cerevisiae,contributes to the normal fungal growth,sexual reproduction and sensitivity to fungicides.In addition,we found FgDnm1 co-localizes with mitochondria and is involved in toxisome formation and deoxynivalenol(DON) production.Several quinone outside inhibitors(QoIs) and succinate dehydrogenase inhibitors(SDHIs) cause fragmentated morphology of mitochondria.Importantly,the deletion of FgDnm1displays filamentous mitochondria and blocks the mitochondrial fragmentation induced by QoIs and SDHIs.Taken together,our studies uncover the effect of mitochondrial dynamics in fungal normal growth and how such events link to fungicides sensitivity and toxisome formation.Thus,we concluded that altered mitochondrial morphology induced by QoIs and SDHIs depends on FgDnm1.
文摘Leaf and fruit spot (Pseudocercospora angolensis) disease of citrus attacks leaves, fruits, and young twigs of the plant. The disease can cause a yield loss of (50% to 100%) in areas with high rainfall and humidity during the active growth stages of the crop. Currently, citrus plantations in the south, south-west and north-west of Ethiopia are seriously affected by this disease. As a result, this study was proposed to study the effect of fungicides in controlling. And candidate fungicides were: Carbonchlor 50% SC only, Benline 50% WP only, Bellis 38% WG only, Carbonchlor 50% SC combined with Bellis 38% WG, Benline 50% WP combined with Carbonchlor 50% SC and Benline 50% WP combined with Matco 72% WP for effective management of citrus leaf and fruit spot (Pseudocercospra angolensis) disease. The study was carried out in 2021 cropping season. A Randomized Complete Block Design (RCBD) with three replications was the design applied. The result showed that the highest level of efficacy (90.46%) was produced by Bellis 38% WG fungicide followed by Carbonchlor 50% SC (86.50%), Bellis 38% WG + Carbonchlor 50% SC (82.00%), Carbonchlor 50% SC + Benline 50% WP (67.89%), Benline 50% WP (65.62%) and Matco 72% WP + Benline 50% WP (49.48%). Therefore, based on the outcome of the study application of Bellis 38% WG only followed by Carbonchlor 50% SC only, Carbonchlor 50% SC combined with Benline 50% WP, Bellis 38% WG combined with Carbonchlor 50% SC, Bellis 38% WG only, Benline 50% WP only and Matco 72% WP combined with Benline 50% WP were effective fungicides to be used for the control of leaf and fruit spot disease.
基金Agricultural Science and Technology Development and Resource and Environmental Protection Management Fund of Guangdong Provincial Rural Revitalization Strategy Project(2022KJ153-06)Special Fund for China Agricultural Industry Research System(CARS-01-32,2022KJ105)+1 种基金"The 14 th Five-Year Plan"New Discipline Team Building Project of Guangdong Academy of Agricultural Sciences(202116TD)Science and Technology Plan Project of Shaoguan(210804164531395).
文摘[Objectives]The paper was to identify the characteristics and the potency of new fungicides to rice blast disease,and study their preventive and therapeutic effects on the disease.[Methods]Six new and conventional fungicides with different mechanisms of action were selected to compare their preventive and therapeutic effects on rice seedling blast in greenhouse.[Results]The agents which showed to be highly efficacious in blast prevention(greater than 90%)were 25%pyraclostrobin EC,20%fenoxanil SC,75%tricyclazole WP and 50%prochloraz-manganese WP sprayed at the dosages of 112.5-150,180-360,270-450 and 450-600 g/ha,respectively.The therapeutic effect of new fungicides 25%pyraclostrobin EC and 50%prochloraz-manganese WP on rice blast were above 90%when the dosages were 90-150 and 360-600 g/ha,respectively.The therapeutic effect of the conventional fungicide 40%isoprothiolane EC on rice blast was 69.04%when the dosage was 480 g/ha,while those of other fungicides were worse.[Conclusions]Both 25%pyraclostrobin EC and 50%prochloraz-manganese WP have good preventive and therapeutic effects on rice blast,which will provide a reference for the use of these fungicides in the field.
基金Supported by Key R&D Program of Shandong Province(2018GNC110013)the Innovative Project of Forestry Science and Technology of Shandong Provinc of China(LYCX04-2018-23)Agricultural Improved Seed Project of Shandong Province(2016LZG012)
文摘In this research,the inhibitory effect of 16 fungicides on Colletotrichum horri causing persimmon anthracnose was investigated using mycelial growth method and spore germination method. The results showed that among the 16 tested fungicides,10% of Difenoconazole WG,33. 5% of Copper quinolate SC,25%of Bromothalonil EC,70% of Mancozeb WP,430 g/L of Tebuconazole SC,50% of Prochloraz-manganese chloride and 400 g/L of Flusilazole EC achieved the best inhibitory effect on mycelial growth of C. horri,with the inhibition rate of 100%; 70% of Polyram WG,33. 5% of Copper quinolate SC,25% of Bromothalonil EC,70% of Mancozeb WP,50% of Chlorobromoisocyanuric acid AF,50% of Triram WP and 400 g/L of Flusilazole achieved the best inhibitory effect on spore germination of C. horri,with the germination rate of 0. In conclusion,33. 5% of Copper quinolate SC,25% of Bromothalonil EC,70% of Mancozeb WP and 400 g/L of Flusilazole EC achieved the best inhibitory effect both in mycelial growth and spore germination,which could be used as the preference fungicides for the control of persimmon anthracnose,and 70% of Polyram WG and 50% of Triram WP achieved the secondly best inhibitory effect,which could be used as alternative fungicides. The results of this research could provide scientific evidence for the effective control of persimmon anthracnose,and more optional pesticides for utilization in the production practice of persimmon industry.
文摘The effects of biofungicide formula containing the biocontrol agent Trichoderma harzianum (Jn14) as wettable powder in combination with the fungicides pyrimethanil and a mixture of cyprodinil and flydioxonil on Botrytis cinerea of strawberry in vitro, in vivo and in greenhouse were studied. The pathogen B. cinerea was more affected in vitro by low concentrations of the fungicides tested above 0.4 μg·ml-1 than the bioagent T. harzianum (Jn14). The later was almost insensitive to pyrimethanil. In the same direction, gray mould disease severity on strawberry detached leaves and whole plants was reduced up to 89% by the tested fungicides, compared to the control, while the application of T. harzianum (Jn14) alone reduced disease severity up to 45% on strawberry detached leaves, compared to the control. In the integrated control approach, the combination of T. harzianum (Jn14) with higher concentrations of the tested fungicides (ED50) completely inhibited strawberry gray mould disease severity in pots and the greenhouse.
文摘Wheat blast, caused by a fungal pathogen, <i><span style="font-family:Verdana;">Magnaporthe oryzae Tritichum </span></i><span style="font-family:Verdana;">(</span><i><span style="font-family:Verdana;">MoT</span></i><span style="font-family:Verdana;">) pathotype (wheat isolates), was first reported in Bangladesh among Asian countries in 2016. It is a serious disease of wheat causing yield failures and significant economic losses during epidemic years. Extensive use of persistent synthetic pesticides to control notorious wheat blast imposes enormous threat to human health and environment. In addition, the increasing demand for organic food has stimulated people to look for alternative methods. Nowadays, the need for synthetic chemical-free agricultural practices is gaining importance due to effective in managing crop pests, inexpensive, biodegradable, easily available and have low toxicity to non-target organisms. In order to identify active plants, 12 kinds of methanol extracts obtained from 12 medicinal plants were conducted </span><i><span style="font-family:Verdana;">in vitro</span></i><span style="font-family:Verdana;"> to test the effect against </span><i><span style="font-family:Verdana;">Magnaporthe oryzae Triticum </span></i><span style="font-family:Verdana;">(</span><i><span style="font-family:Verdana;">MoT</span></i><span style="font-family:Verdana;">) pathotype. The remarkable inhibitory activity {(29.6 ± 01.5) mm, (25.1 ± 01.0) mm and (20.0 ± 02.0) mm zone of inhibition)} exhibited by the extracts (5 mg/disk) obtained from </span><i><span style="font-family:Verdana;">Artemisia indica</span></i><span style="font-family:Verdana;"> (Nagdona), </span><i><span style="font-family:Verdana;">Persicaria orientalis</span></i><span style="font-family:Verdana;"> (Bishkatali) and </span><i><span style="font-family:Verdana;">Clerodendrum indicum</span></i><span style="font-family:Verdana;"> (Bamonhati), respectively. Other medicinal plant extracts did not show any significant or no activity at all. Therefore, the three plant extracts might be a promising source for developing natural fungicides against wheat blast.</span>
文摘The morphophysiological and molecular-genetic parameters of T. caries isolates collected from various fields of Southern Urals agrocenoses have been analysed. Isolate 1 of wheat callus had a high growth rate in vitro even in the presence of 0.1 mg/l fungicide Baitan. Isolate 2 of wheat callus had a low growth rate whereas 0.1 mg/l Baitan significantly inhibited its growth. Comparison of nucleotide sequences of 18S RNA gene of the two isolates showed high level of homology between them, but a large number of nucleotide substitutions have been found. The most characteristic excision was five nucleotides at position 461 of the isolate 2, compared with the isolate 1. Our results allow to assume that the environmental stress including high pesticide concentration may cause the resistance of T. caries pathogen to fungicides.
文摘A method for the simultaneous determination of a series of chlorinated insecticides and fungicides as residues in ginseng is presented in this article. Pulverized samples are subjected to Soxhlet extraction with acetone-petroleum ether and the extract is partitioned between petroleum ether and aqueous sodium sulfate solution (2:98). The combined petroleum ether phase is cleaned up by sulfuric acid and analyzed by capillary gas chromatography using 63Ni electron capture detector. Recoveries from the different concentrations for 11 kinds of chlorinated insecticides and fungicides are between 92.40 and 103.7% with coefficients of variations ranged 1.22 and 9.53% without samples, and between 89.00% and 104.10% with coefficients of variations between 1.16% and 9.16% with samples. The detection limits are 0.2- 7.0 ng/kg.
基金The project was supported by the NNSF of China (Grant No. 29802002) the NSF of Hubei Province the Dawn Plan of Science and Technology for Young Scientists of Wuhan City and Foundation for University Key Teacher by the Ministry of Education of China.
文摘A series of diheterocyclic compounds containing 1,2,4-triazolo [1,5-a]pyrimidine and 1, 3,4-oxadiazole were designed and synthesized starting from 2-mercapto-5,7-dimethyl-1,2,4- triazolo [1,5-a] pyrimidine. The structure of all compounds prepared were confirmed by 1H NMR spectroscopy and elemental analysis. The preliminary bioassay indicated that the title compounds displayed good fungicidal activity against Rhizoctonia solani.
基金We are grateful to SaōPaulo Research Foundation for the financial support of this research and for the fellowships awarded to C.A.B.(FAPESP No.2011/19057-7)G.A.B.(FAPESP No.2012/21395-0)to Study Group of Cerrado Agroindustrial Processes(GEPPAC)of the Federal University of Grande Dourados to provide laboratories for plant material processing step.
文摘The increasing demand for safe food without preservatives or pesticides residues has encouraged several studies on natural products with antifungal activity and low toxicity.In this study,ethanolic extracts from leaves and fruit residues(peel and seeds)of three Brazilian savanna species(Acrocomia aculeata,Campomanesia adamantium and Caryocar brasiliense)were evaluated against phytopathogenic fungi.Additionally,the most active extract was chemically characterized by ESI-MS and its oral acute toxicity was evaluated.Extracts from C.brasiliense(pequi)peel and leaves were active against Alternaria alternata,Alternaria solani and Venturia pirina with minimal inhibitory concentrations between 350 and 1000 lg/mL.When incorporated in solid media,these extracts extended the lag phase of A.alternata and A.solani and reduced the growth rate of A.solani.Pequi peel extract showed better antifungal activity and their ESI-MS analysis revealed the presence of substances widely reported as antifungal such as gallic acid,quinic acid,ellagic acid,glucogalin and corilagin.The oral acute toxicity was relatively low,being considered safe for use as a potential natural fungicide.
文摘Anthracnose is the one of the most devastating diseases of mango produced in the southern part of Senegal. The field trials against post harvest rot due to anthracnose took place in three orchards over two production seasons, in 2009 and 2010. Three systemic fungicides (thiophanate methyl, azoxystrobin and myclobutanyl) and one contact fungicide (mancozeb) were tested for their efficacy. The first treatments in 2009 took place in the rainy season, while 20% of mangoes on trees exhibited anthracnose lesions. At ripening stage, 100% of fruits from non treated control mango trees were affected by anthracnose and got rotten, while between 73.2% and 80% of mangoes ripened free of disease when treated with thiophanate methyl. With the treatment with azoxystrobin, between 46.6% and 60% of fruits were not infected. Treatment with myclobutanyl was less effective. This level of effectiveness was clearly improved in 2010 by preventive spraying, days ahead of onset of the rainy season, before the appearance of anthracnose symptoms on fruits. The level of effectiveness was higher respectively for thiophanate methyl (between 96% and 100% of fruits not infected) and azoxystrobin (between 84% and 96% of fruits not infected).
基金Supported by Agricultural Science and Technology Innovation Project of Shandong Academy of Agricultural Sciences"Key Technology for Green Prevention and Control of Diseases and Insect Pests of Major Crops"(CXGC2018E19).
文摘[Objective]The study was to evaluate the indoor toxicity and field efficacy of five Strobilurins fungicides including pyraclostrobin 250 g/L EC,azoxystrobin 250 g/L SC,kresoxim-methyl 50%WG,picoxystrobin 22.5%SC and trifloxystrobin 50%WG against Phomopsis asparagi(Sacc.)Bubak,and to screen out effective fungicides.[Method]The toxicity was tested by mycelial growth rate method.The field trials were carried out by routine spraying method.[Result]The indoor toxicities successively were pyraclostrobin>kresoxim-methyl>picoxystrobin>trifloxystrobin>azoxystrobin.The EC50 values were 6.1029,52.5591,83.8257,129.8616 and 252.1214 mg/L,respectively,all significantly higher than that of benzimidazole fungicide carbendazim(753.3650 mg/L).The field efficacies successively were pyraclostrobin>kresoxim-methyl≥picoxystrobin≥azoxystrobin≥trifloxystrobin.The control effects were 81.20%,77.95%,74.80%,71.69%and 68.54%,respectively,all significantly higher than that of benzimidazole fungicide carbendazim(48.27%).[Conclusion]The five Strobilurins fungicides all have good toxicity and field efficacy against P.asparagi.
文摘An experiment was carried out to study the outcome of environmental factors (Temperature, Relative Humidity, Rainfall) and<span style="font-family:;" "=""> </span><span style="font-family:Verdana;">management of the purple blotch disease of onion using five treatments (Rovral + Ridoil gold with 3,4,5,6 sprays and control). The Taherpuri variety was used during the 2015-2016 cropping seasons at BARI, Gazipur, Bangladesh.</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">In the experiment, the purple blotch disease surfaced at the end of January</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">2016 and was severe in late February to March (PDI 76.12%) due to temperature and RH above 24</span><span style="font-family:Verdana;">°C and 95%, respectively.</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">As for the chemical control, the PDI for the treatments ranged from 50.66% to 83.33%.</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">Significantly higher stem height was recorded by T</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> (68.06 cm), where six sprays of Rovral + Ridomil were applied. The minimum stem height was recorded in T</span><sub><span style="font-family:Verdana;">5</span></sub><span style="font-family:Verdana;"> (59.23 cm). The maximum stem number per hill was recorded in T</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> (2.30) numerically but differed significantly with T</span><sub><span style="font-family:Verdana;">5</span></sub></span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">(2.00), where fungicides were not applied. The maximum lesion area was measured in T</span><sub><span style="font-family:Verdana;">5</span></sub><span style="font-family:Verdana;"> (25.26 mm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">). Regarding PDI (Percent disease index), there was a significant difference among the treatments. The PDI value on purple blotch of onion ranged from 34.00 to 83.33. The lowest PDI was assessed in T</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> (34.00). Statistical analysis revealed that a significant decrease of PDI on purple blotch was recorded under treatments of T</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;">, T</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">, T</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;">, and T</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> (39.20</span></span><span style="font-family:Verdana;">%</span><span style="font-family:Verdana;">, 45.60</span><span style="font-family:Verdana;">%</span><span style="font-family:Verdana;">, 49.59</span><span style="font-family:Verdana;">%</span><span style="font-family:;" "=""><span style="font-family:Verdana;">, and 59.19%) on controlling the disease and giving the optimum yield but all of them significantly differed with T</span><sub><span style="font-family:Verdana;">5</span></sub><span style="font-family:Verdana;"> (83.33%) where no fungicides were sprayed.</span></span>
基金Major Science and Technology Innovation Project of Shandong Province(2018CXGC0213).
文摘[Objective]The paper was to compare the indoor toxicities of sixteen fungicides on mycelial growth and spore germination of Monilinia fructicola,to screen out effective fungicides and to discuss use characteristics of various types of fungicides.[Method]The inhibitory activities of 16 fungicides on mycelial growth and spore germination were determined by mycelial growth rate method and spore germination method.[Result]The EC50 values of 16 fungicides against mycelial growth ranged from 0.0184 to 61.5305 mg/L.Prochloraz,tetramycin,fenbuconazole and fludioxonil had strong inhibitory activities on mycelial growth,and their EC50 values were 0.0184,0.0456,0.0531 and 0.0814 mg/L,respectively,significantly lower than those of other 12 fungicides.The EC50 values of 16 fungicides against spore germination ranged from 0.0084 to 189.3938 mg/L.Tetramycin and chlorothalonil had strong inhibitory activities on mycelial growth,and their EC50 values were 0.0084 and 0.0378 mg/L,respectively,significantly lower than those of other 14 fungicides.[Conclusion]The 16 fungicides had great value in preventing and controlling peach brown rot.Benzimidazoles,diformimides and ergosterol inhibitors had good inhibitory activities on mycelial growth.Strobilurins,succinate dehydrogenase inhibitors and multiple-site protective fungicides had good inhibitory activities on spore germination.The agricultural antibiotics tetramycin,phenazine-1-carboxylic acid and pyrrole fungicide fludioxonil had good inhibitory activities on mycelial growth and spore germination.
文摘Onion is an important vegetable in Senegal horticulture, where it occupies the first place. However in the greatest areas production like the Gandiolais, in the North of Senegal, Pink root disease caused by a soil born fungus Pyrenochaeta terrestris (Hansen) Gorentz, Walker and Larson affects its productivity especially in nursery. On soil sterilized and inoculated by the fungus, we tested 5 natural fungicides and 2 synthetic fungicides, to measure their effectiveness on the Pink root disease on onion, in nursery. The device used is a split plot with 4 repetitions and 8 treatments. The measured variables are the emergence rates, the survival rates and the infestation rates. Our experimentations have shown that, for the emergence rates, there is no significant difference between thiophanate-methyl (Pelt 44), Carbendazim (Bavistine), Azadirachta indica A. Juss and Carica papaya L. It is the same between C. papaya and Moringa oleifera Lam, between M. oleifera and Cassia alata L. It is also the same between C. alata and Crotolaria retusa L. Regarding the survival rates, there is no significant difference between thiophanate-methyl, Azadirachta indica, Carbendazim, C. papaya and M. oleifera. The same is true between M. oleifera and Cassia alata, and between C. alata and C. retusa. Concerning the infestation rates, apart from the control check, all other treatments show no difference.
文摘Fungicides which are not easily degradable have the greatest adverse effects on soil microbes. These pesticides negatively affect the growth and multiplication of fungi and bacteria and consequently cause the disturbance of the natural soil microbial balance. In this study two fungicide tolerant isolates of rhizobia;clover isolate (TA1) and peanut isolate (8) were assessed in their capacity to degrade Vitavax and Rizolex. The performance of these isolates in fungicides degradation was tested using the colorimetric assay for Rizolex and the HPLC analysis for Vitavax to detect the degradation products. Using HPLC analyses, the control sample showed specific peak indicating the Vitavax presence in the medium. The specific peak did not change in the control samples throughout the experiment.With the strainTA1 the specific peak of the Vitavax fungicides started to reduce as the incubation time goes on. The Vitavax fungicide did not degrade completely after 240 hours of incubation with rhizobial isolate. The Rizolex used in this study contained blend of Thiram (active ingredient of Rizolex) and Tolcofs methyl fungicides in 1:1 ratio. The biodegradation of Rizolex in the liquid media showed the formation of two new intermediates which were released into the medium indicating the degradation of the tested fungicide by peanut rhizobial isolate No. 8 in 48 hrs of incubation 45% of this compound was degraded. This work shows that the selection of fungicides tolerant rhizobial strains is important to protect the rhizobial inoculants from the toxic effect of the pesticides.
文摘Biological methodologies (</span><i><span style="font-family:Verdana;">in vitro</span></i><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">in vivo</span></i><span style="font-family:Verdana;">) were tested on </span><i><span style="font-family:Verdana;">Venturia inaequalis</span></i><span style="font-family:Verdana;"> to assay sensitivity of populations treated with the SDHI penthiopyrad, fluxapyroxad and fluopyram that showed a field poor control in an experimental Centre. In comparison, sensible populations were tested. </span><i><span style="font-family:Verdana;">I</span></i><i><span style="font-family:Verdana;">n vitro</span></i><span style="font-family:Verdana;"> trials, the poorly controlled populations presented moderate increases of EC</span><sub><span style="font-family:Verdana;">50</span></sub><span style="font-family:Verdana;"> and RF values in all three years in which tests were carried out. The </span><i><span style="font-family:Verdana;">in vivo</span></i><span style="font-family:Verdana;"> trials in glasshouse showed that the activity of SDHI fungicides on field poorly controlled populations was highly reduced. These populations can be defined as “resistant” as the high loss of sensitivity and activity were repeatedly assessed in field and glasshouse. Trials showed that these reductions were manifested by curative applications and not by preventive ones, as already ascertained for </span><i><span style="font-family:Verdana;">V. inaequalis </span></i><span style="font-family:Verdana;">populations resistant to AP and DMI fungicides. </span><span><span style="font-family:Verdana;">The cross-resistance of resistant populations to the three SDHIs was highly positive among them. In bibliography, there are only researches of cross-resistance among SDHIs starting from isolates resistant to boscalid, with results of different sensitivities and cross-resistance. These results with populations of </span><i><span style="font-family:Verdana;">V. inaequalis</span></i><span style="font-family:Verdana;"> resistant to the three SDHI offer practical evaluations in cross-resistance.
文摘Ten different treatments viz. T<sub>0</sub> = Control, T<sub>1</sub> = Micronutrients (ZnSO<sub>4</sub> + Borax), T<sub>2</sub> = Rovral 50 WP + Micronutrients, T<sub>3</sub> = Dithane M-45 + Micronutrients, T<sub>4</sub> = Ridomil Gold + Micronutrients, T<sub>5</sub> = Cupravit + Micronutrients, T<sub>6</sub> = Rovral 50 WP, T<sub>7</sub> = Dithane M-45, T<sub>8</sub> = Ridomil Gold and T<sub>9</sub> = Cupravit were evaluated against the purple blotch complex disease of onion caused by Alternaria porri and Stemphylium vesicarium in field condition for bulb yield. In lab condition, all the tested chemical fungicides (Rovral 50 WP, Dithane M-45, Ridomil Gold MZ-72 and Cupravit 50 WP) significantly reduced mycelial growth of both pathogens. Among the fungicides, Rovral 50 WP @ 0.2% reduced the highest radial mycelial growth followed by Dithane M-45 @ 0.45% and Ridomil Gold MZ-72 @ 0.2% compared to control. In field experiment, application of Rovral 50 WP @ 0.2% along with micronutrients showed significant effect in reducing disease incidence and severity which significantly increased bulb yield and yield contributing characters.
文摘Tobacco black shank caused by Phytophthora parasitica var.nicotianae(Breda de Hean)is one of the most serious diseases in tobacco growing,and few effective fungicides are available currently.The purpose of this study was to assess the feasibility of using fluazinam to treat tobacco black shank disease.In vitro toxicities of fluazinam to 62 isolates of P.nicotianae were determined by mycelial growth rate method.The EC50 values ranged from 0.294 6 to 2.389 9 μg/mL with a mean of 1.084 0 μg/mL.The sensitivity distribution was unimodal,and there was no resistant isolate in P.nicotianae population.The carboxylic acid amide(CAA)fungicides were single-site in action and activity to oomycetes.The synergistic interactions were tested by Wadley method between fluazinam and dimethomorph,flumorph,mandipropamid,respectively.The mixture containing dimethomoph:Huazinam at 1:2 ratio showed additive actions,with the synergy ratio of 1.2.The mixture containing flumorph and fluazinam at 1:5 ratio had the highest synergy ratio(SR 2.07).Mandipropamid and fluazinam had an additive interaction and the proportion of 2:1 had the lowest EC50 value(0.020 7 μg/mL).This study demonstrated the sensitivity of P.nicotianae to fluazinam,and provided the experimental foundation to use fluazinam for tobacco black shank management.
基金Supported by Youth Fund Project of Hebei Academy of Agriculture and Forestry Sciences(2018020101)Science and Technology Plan of Hebei Province (16246327D)Special Financial Project of Hebei Province (F18R1908,2019-3-5-2)。
文摘[Objective] The paper was to select different fungicides for field efficacy test against pear scab in summer.[Method] Five treatments were designed in the test,including 10% difenoconazole WDG 6 000 times dilution,50% captan WP 600 times dilution,30% pyraclostrobin SC 2 000 times dilution,430 g/L tebuconazole 4 000 times dilution,and water(control).[Result] 10% Difenoconazole WDG 6 000 times dilution,50% captan WP 600 times dilution,30% pyraclostrobin SC 2 000 times dilution,430 g/L tebuconazole SC 4 000 times dilution had good control effects against pear scab,and the efficacies were 89.13%-93.51%.[Conclusion] The results will provide the theoretical basis for field control of pear scab in summer.
