Effects Of Several Fungicides Research Articles

Effects of Several Fungicides on the Spore Growth Period of Alternaria dauci, a Carrot Black Leaf Blight Fungus, Using a Rezasulin-based Spore Survival Assay

The effects of five fungicides on the spore growth phase of Alternaria dauci, which causes carrot leaf blight, were tested using the spore viability assay (SVA) and agar dilution method (ADM). The average EC50 values for chlorothalonil against seven isolates of A. dauci examined by SVA and ADM were 14.21 μg/ml and more than 100 μg/ml. Dithianon and folpet also had lower EC50 values in SVA than in ADM, while iminoctadine tris-albesilate had lower EC50 value in ADM. For fluazinam, the EC50 values of SVA and ADM were 1.63 and 2.40 μg/ml, respectively. As EC50 values of five fungicides according to the spore growth phase of A. dauci KACC 42997, the efficacy of each fungicide as chlorothalonil, dithianon, and folpet decreased when treated after spore germination rather than when treated with spores before germination. However, iminoctadine tris-albesilate was more effective when treated after spores germinated than when treated before treatment. The excellent effect of fluazinam on the pathogen was maintained until A. dauci KACC 42997 was cultured in potato dextrose broth for 6 hr and the germ tube grew beyond the size of the spore. However, when treated with iminoctadine tris-albesilate and fluazinam after culturing for 12 hr, as the EC50 values of the two fungicides increased to 8.87 and 20.65 μg/ml, their efficacies decreased. The results of this study show that the treatment time of the fungicide should be determined by considering the effect of the fungicide on the spore growth phase of pathogens.

Study on the effect of wheat yellow rust disease on grain yield

Wheat provides food for 40 percent of the world’s population. As of July 2022, 770.3 million tons of wheat grains were grown in the countries of the world. In recent years, as a result of climate change, rainfall in some countries is low or in some countries it is high, as a result of which various diseases appear, affecting wheat harvest as well as all agricultural crops. Wheat is affected by several fungal diseases and causes damage to the crop, among these diseases yellow rust kills a large part of the wheat crop. The article presents information on the effect of yellow rust disease on the crop and the effect of several fungicides against it.

Evaluation of Fungicides and Management Strategies against Cercospora Leaf Spot of Olive Caused by Pseudocercospora cladosporioides

Cercospora leaf spot of olive (CLSO), caused by Pseudocercospora cladosporioides, is one of the most important foliar diseases of olives worldwide. This study aimed to evaluate the effect of a wide range of fungicides on mycelial growth and conidial germination of P. cladosporioides in vitro, and to evaluate the effect of several fungicides, application timings and management strategies (conservative and risky) to control CLSO under field conditions. Of the studied fungicides, strobilurin compounds and benomyl were the most effective active ingredients, followed by folpet, captan and maneb, in inhibiting mycelial growth and conidial germination. The pyraclostrobin + boscalid treatment was effective under field conditions, even without the application of supplementary copper. Treatments conducted in October or March were more effective than those conducted in May. Management strategies based on the author’s experience reduced copper applications up to 32.0% and 50.0% (conservative and risky strategy, respectively) in comparison to the reduction with the traditional strategy, without increasing CLSO incidence. This work provides useful information about effective formulations against CLSO and a reduction in unnecessary fungicide applications in an effort to implement IPM in olive orchards under Mediterranean conditions.

Control Effects of Several Fungicides on Jujube Anthracnose and Fungicide Resistance Monitoring

Among 6 fungicides, fluazinam, which had an excellent inhibitory effect on mycelial growth and spore germination, was also effective in controlling jujube anthracnose in the field. While EC50 values of metconazole and tebuconazole ranged from 0.2 to 0.9 μg/ml and from 0.4 to 1.1 μg/ml against the mycelial growth, respectively, each inhibitory effect on spore germination was low by 7.4% and 11.1% at 50.0 μg/ml. In the field test, they showed the control value of 80.5% and 77.0%, respectively. The protective fungicides, as mancozeb and folpet, which had a low inhibitory effect on the mycelial growth, but had a high inhibitory effect of spore germination, showed excellent disease control activities by 87.6% and 92.0% in the field. Showing a result of resistance monitoring conducted with the isolates of Colletotricum gloeosporioides, the resistance against carbendazim was already generated in the field, but it was thought that there was no resistance to pyraclostrobin, fluazinam and tebuconazole. However, if the resistance factor value of the population of C. gloeosporioides isolates to pyraclostrobin was high by 160.4, the diversity of the response to the fungicide in the population was high, so it should be taken more attention to the resistance management.

Controle químico da mela-das-sementes e do carvão em cultivares de Brachiaria brizantha

RESUMO O Brasil é o maior produtor, consumidor e exportador mundial de sementes de espécies forrageiras tropicais. Contudo, a produção tem sido ameaçada pela presença de fungos e fitonematoides, os quais podem reduzir a produtividade e/ou a qualidade das sementes produzidas, além de constituírem barreiras sanitárias para vários países importadores dessas sementes. Em Brachiaria spp., as principais doenças são a mela-das-sementes e o carvão, causadas, respectivamente, pelos fungos Claviceps maximensis e Ustilago operta. Apesar da grande demanda pelo setor produtivo, poucos são os estudos relacionados a estratégias de controle das doenças. Assim, realizou-se este trabalho objetivando-se avaliar a eficiência de fungicidas no controle das referidas doenças. Implantaram-se quatro experimentos, sendo dois na Embrapa Gado de Corte, em Campo Grande-MS, e dois em Paraíso das Águas-MS. Foram utilizadas as cultivares BRS Piatã e Xaraés, ambas pertencentes à Brachiaria brizantha. Foram avaliados os efeitos de vários fungicidas (g ia/ha), os quais foram aplicados em três épocas para Campo Grande: plantas com 10% de antese, 20 e 40 dias após a primeira aplicação. Em Paraíso das Águas, os fungicidas foram aplicados uma única vez, nas plantas com 10% de antese. Na cultivar BRS Piatã, para Campo Grande, os melhores resultados obtidos para o controle da mela-das-sementes foram com os tratamentos T7 (trifloxistrobina + ciproconazole (150,0 + 64,0)) e T11 (primeira aplicação: piraclostrobina (97,5) + epoxiconazole (60,0), segunda aplicação: tebuconazole (120,0), terceira aplicação: piraclostrobina (97,5) + epoxiconazole (60,0)). Na cultivar Xaraés, a doença foi menos expressiva nos tratamentos T4 (piraclostrobina (175,0)), T6 (azoxistrobina + ciproconazole (80,0 + 32,0)), T9 (primeira aplicação: piraclostrobina (175,0); segunda e terceira aplicações: piraclostrobina + epoxiconazole (99,75 + 37,5)) e T11 (primeira aplicação: piraclostrobina (97,5) + epoxiconazole (60,0), segunda aplicação: tebuconazole (120,0), terceira aplicação: piraclostrobina + epoxiconazole (97,5 + 60,0)). Não houve ocorrência de carvão para ambas as cultivares em Campo Grande. Para BRS Piatã, no experimento de Paraíso das Águas-MS, apesar da intensidade de mela-das-sementes e de carvão não terem sido expressivas, no tratamento T4 (piraclostrobina (175,0) a produtividade de sementes puras foi 69,6% maior que a testemunha, produzindo 456,78 kg/ha, demonstrando alta relação benefício/custo com o referido tratamento. Tal resultado em T4 pode ter sido expressão de efeitos fisiológicos proporcionados pela piraclostrobina. A aplicação de fungicidas na parte aérea das plantas de BRS Xaraés de Brachiaria brizantha em Campo Grande, onde houve alta incidência dos fungos Alternaria spp., Bipolaris spp., Curvularia spp., Fusarium spp. e Phoma spp. nas sementes, revelou o efeito benéfico do tratamento, sobretudo do T7 (trifloxistrobina + ciproconazole (150,0 + 64,0)), o qual reduziu significativamente a ocorrência de Bipolaris spp., Fusarium spp. e Phoma spp. Em Paraíso das Águas, onde a incidência dos referidos patógenos foi menor, os resultados não foram conclusivos.

Effects of Several Fungicides on Apple Bitter Rot

Effects of Several Fungicides on Apple Bitter Rot

Effects of Several Fungicides on Stemphylium Leaf Spot of Asparagus

Effects of Several Fungicides on Stemphylium Leaf Spot of Asparagus

Phytotoxic effects of fungicides, insecticides and nonpesticidal components on pepper depending on water quality

Modern agriculture relies on simultaneous application of fungicides, insecticides, fertilizers and adjuvants. The selection of compounds for tank-mixes has been rarely studied and it presents a risk in the application of pesticides but the quality of water should also be considered. The aim of this study was to assess the phytotoxic effects of several fungicides, insecticides, a complex fertilizer, an adjuvant and their mixtures on pepper (Capsicum annuum L.) as a test plant, depending on water quality. The effects of the pesticides: azoxystrobin (Quadris, 0.75 l/ha), mancozeb (Dithane M-70, 2.5 kg/ha), thiamethoxam (Actara 25-WG, 0.07 kg/ha) and cypermethrin (Cipkord EC-20, 0.3 l/ha), a complex fertilizer (Mortonijc plus /hereinafter: M+/ 3kg/ha), an adjuvant (Sillwet 77-L, 0.1 l/ha) and their mixtures, were assessed depending on the quality of water (well water - slightly alkaline, very hard and with high nitrite content; tap water - neutral and slightly hard; surface water - alkaline, slightly hard and with high content of nitrite and ammonia) using a puncture method. The effects were assessed after seven days by measuring the diameter of chlorosis and/or necrosis around puncture sites, and were expressed in mm2. The significance of differences between treatments was analyzed using a one-way ANOVA (LSD 0.05 %). In the slightly alkaline and very hard well water, all spray liquids containing Dithane M-70 caused a significant increase in leaf chlorosis area (from 6.0 to 25.2 mm2), compared to the control and other treatments. In the neutral and slightly hard tap water, all spray liquids containing Dithane M-70 caused a significant increase in leaf chlorosis (5.3 to 7.9 mm2) compared to the control and the other spray liquids, although its phytotoxicity in that water was at a lower level than it was in well water. However, in the weakly alkaline and slightly hard surface water from the river Sava, Dithane M-70, Dithane M-70 + Actara WG-25, Dithane M-70 + Sillwet L-77, and Dithane M-70 + Actara 25-WG + M+ showed a significant increase in phytotoxicity, compared to the control.

Effect of Several Fungicides and Integrated Diseases Control of Stem Blight of Asparagus

Effect of Several Fungicides and Integrated Diseases Control of Stem Blight of Asparagus

Control químico de la roya asiática de la soya en el Planalto Medio, RS., Brasil.

The objective of this work was todetermine the effects of several fungicides on the controlof the soybean Asian rust. The experiment was conductedat the experimental fi elds of the Faculty of Agronomy andVeterinary Medicine, University of Passo Fundo, RS, Brazil,during the summer of 2009/2010. The incidence and numberof ureides/cm2, transformed to severity (%) were evaluated.The fungicides applied were tebuconazol and a mix ofepoxiconazol + piraclostrobina, at seven developmentalstages. Applications made before crop canopy closure weremore effective because the fungicides reached the lowerpart of the plants where the disease starts. The mix oftraizol + estrobirulina was more effective tan triazol alone incontrolling soybean Asian rust.

Preventive effect of several fungicides to tomato leaf mold caused by Passalora fulva

Preventive effect of several fungicides to tomato leaf mold caused by Passalora fulva

Control Effect of Several Fungicides to Thiophanate-Methyl, Boscalid, Strobilurin-Resistant Isolates of Cucumber Corynespora Leaf Spot Fungus

Control Effect of Several Fungicides to Thiophanate-Methyl, Boscalid, Strobilurin-Resistant Isolates of Cucumber Corynespora Leaf Spot Fungus

British Columbia Regional Meeting, 2008

British Columbia Regional Meeting, 2008

Impact of fungicides on Aspergillus carbonarius growth and ochratoxin A production on synthetic grape-like medium and on grapes

A study was undertaken to evaluate the impact of the application of several fungicide treatments used in Spanish vines on Aspergillus carbonarius growth and ochratoxin A production. Three trials were designed in order: (1) to screen 26 fungicides at the doses recommended by manufacturers on grape-like synthetic medium at 20 and 30°C; (2) to find out the minimum inhibitory concentration of each fungicide for A. carbonarius growth on synthetic medium; and (3) to investigate the effect of several fungicides on A. carbonarius-inoculated grapes. In synthetic medium nine fungicides significantly reduced A. carbonarius growth rate. Meanwhile, 13 fungicides completely inhibited its growth. In general, growth was faster at 30°C than at 20°C, contrary to ochratoxin A production. Fungicides that stopped fungal growth also inhibited ochratoxin A production, but not all the fungicides that reduced growth reduced the ochratoxin A synthesis. In general, fungicides that contained copper or strobilurins reduced both growth and ochratoxin A production, contrary to sulphur fungicides. At the optimum temperature for A. carbonarius growth of 30°C, higher amounts of fungicide were needed to prevent fungal growth than at 20°C. Among the fungicides that inhibited A. carbonarius growth on synthetic medium at the initial doses, cyprodinil seemed to be the active ingredient more effective at stopping fungal growth when testing reduced doses. The fungicide effect on grapes was similar to that on synthetic medium. Both infection and ochratoxin A production were reduced when using cyprodinil (37.5%) plus fludioxonil (25%) and azoxystrobin (25%). Penconazole (10%) also showed a clear reduction in ochratoxin A production at both temperatures, although infection was only reduced at 20°C. Ochratoxin A reduction was strain and temperature-dependent. In general, fenhexamid (50%), mancozeb (80%) and copper hydroxide (80%) plus copper (50%) enhanced infection and ochratoxin A production.

Effect of Several Fungicides on the Leaf Spot of Grapevine Caused by Benzimidazoles Resistant Strains of Pseudocercospora vitis

Effect of Several Fungicides on the Leaf Spot of Grapevine Caused by Benzimidazoles Resistant Strains of <i>Pseudocercospora vitis</i>

Effects of Several Fungicides on Lesion Development of Rice Leaf Blast

Effects of Several Fungicides on Lesion Development of Rice Leaf Blast

Inhibition in pycnidial viability of Phomopsis viticola on canes in situ as an aid to reducing inoculum potential of cane and leaf blight disease of grapevines

The effect of several fungicides and methods of chemical treatment on the viability of the pycnidia of Taxa 1 and 2 of Phomopsis viticola on grapevines was tested. Benomyl, fluazinam, rnancozeb, dithianon and 8-hydroxyquinoline sulphate were effective chemicals, and spraying was shown to be an effective method of application of the chemicals. The importance of these findings in reducing the carry over of inoculum from one growing season to the next is discussed.

Effects of Several Fungicides on Carnation Leaf Spot Caused by Heterosporium echinulatum in Hokkaido

Effects of Several Fungicides on Carnation Leaf Spot Caused by <I>Heterosporium echinulatum</I> in Hokkaido

THE EFFECT OF FUNGICIDE ON THE GROWTH OF APPLE BITTER ROT PATHOGENS

Bitter rot, an economically important disease of apples in the southeastern U.S., is caused by a complex of plant pathogenic fungi. Fruit infection can result in large yield losses. Control of this disease is contingent upon the effectiveness of several commonly used fungicides. Two fungal species, Colletotrichum gloeosporioides (C.g.) and C. acutatum (C.a.), cause bitter rot. Isolates of both species also show a large degree of genotypic variation. The objective of this study was to determine the effect of several fungicides: benomyl (Benlate), Captan, Mancozeb (a combination of zinc ion and manganese ethylene bisdithiocarbamate, Dithane), and zinc dimethyldithiocarbamate (Ziram). Four concentrations (0, 0.5, 1, and 2 ppm) of each fungicide were used. Fungal growth was quantified by measuring colony diameters 3 and 6 days after incubation. Among the fungicides tested, only Benlate and Ziram significantly reduced fungal growth. Average growth reductions of C. gloeosporioides with Benlate and Ziram were 87% and 29%, respectively. In contrast, average growth reductions of C.a. with Benlate and Ziram were 60% and 52%, respectively. In conclusion, Benlate was the most effective fungicide in reducing overall fungal growth, while Ziram was more effective in reducing the growth of C.a.

Effect of Several Fungicides on the Seasonal Occurrence of Rice Sheath Spot, Caused by Rhizoctonia oryzae RYKER &amp; GOOCH

Effect of Several Fungicides on the Seasonal Occurrence of Rice Sheath Spot, Caused by <I>Rhizoctonia oryzae</I> RYKER &amp; GOOCH