Effect of satellite-emitted frequency sequences on Phakopsora pachyrhizi control, on soybean nutrition and yield

The obstacles in Phakopsora pachyrhizi management result especially from susceptible soybean genotypes and resistant fungal strains. The objective of the current study was to evaluate the applicability of the emission of extremely low and specific frequencies by Effatha technology in the soybean Asian rust control, nutrition, and its impact on yield. The in-vivo test followed the detached leaves method, with six treatments: frequencies 1 and 2 individually and in association; the conventional chemical treatment (fungicide azoxystrobin + benzovindiflupyr); and witnesses in presence and absence of the fungus. Frequency 1 relates to inhibition of the enzyme succinate dehydrogenase and 2 to ubiquinone oxidase. In the field, frequencies 1 and 2 associated (with the same fungicidal action of the in-vivo study); nutritional frequency; application of azoxystrobin + benzovindiflupyr + mancozeb, and control without application were evaluated. In vivo, the fungicide provided 85% control of the disease symptoms, against 65% of frequencies 1 and 2 in association, which showed a higher efficiency compared to the isolated frequencies. In the field, the rate of increase of symptoms were reduced by all treatments compared to the control. At the end of the soybean cycle, the conventional fungicide resulted in 33% severity against 56% of frequencies 1 and 2 associated, and 69.2% of the control. The emission of the frequency for increased nutrient efficiency stood out positively on yield in relation to all the other ones. The conventional application provided the highest weight of 1,000 grains, possibly a direct reflection of the better control of the disease.

Chemical control of dieback and mango malformation in a semiarid region

The São Francisco Sub medium Valley is a great mango exporter in Brazil. In this semiarid region, diseases such as dieback and mango malformation have reduced the production of this crop. In this work the effectiveness of different active ingredients (flutriafol, methyl-thiophanate, copper hydroxide and fluxapyroxad mixed with pyraclostrobin) was assessed for the control of these diseases in a mango orchard. Monthly assessments of disease incidence were carried out. There was a difference among treatments for the two diseases studied, with flutriafol as the most effective fungicide against dieback and, for the malformation, the mixture of fluxapyroxad and pyraclostrobin and methyl-thiophanate showed the best results.

The Potential Effects of Fungicides on Association of Rhizophagus irregularis with Maize and Wheat

Abstract The effect of different fungicides on mycorrhizal fungi should be investigated in different plants and environmental conditions. Thus, the purpose of this study was to appraise the effect of simultaneous fungicides application (including benomyl, rovral TS, mancozeb, and tilt) on the efficiency of Rhizophagus irregularis in cultivations of maize and wheat. This study was conducted in two separate experiments in the laboratory and greenhouse. The results of the laboratory stage showed that the use of all four fungicides significantly reduced the spore number compared to the conditions of non-use of the fungicide, although only rovral TS and mancozeb led to a significant reduction in root colonization percentage of R. irregularis. In the greenhouse, the benomyl significantly increased root dry weight in maize although tilt significantly reduced root colonization of maize with R. irregularis. The tilt and rovral TS had a positive effect and benomyl had a negative effect on wheat growth traits, but the root colonization of wheat with R. irregularis was not affected by fungicides. Generally, benomyl (2 g L-1) in maize and tilt (2 mL L-1) in wheat and rovral TS in both plants could be recommended with the combined application of R. irregularis inoculants. Therefore, depending on the type of fungicide and the host plant, the effect of the fungicide on colonization and association of mycorrhiza varies.

Modern Fungicides: Mechanisms of Action, Fungal Resistance and Phytotoxic Effects

The establishment of safe and effective methods for controlling fungal diseases is an urgent issue in agriculture and forestry. Fungicide research has provided a wide range of products with new modes of action. Extensive use of these compounds in agriculture enhances public anxiety due to the harmful potential for the environment and human health. Moreover, the phytotoxic effects of some fungicides are already recognized but still little is known about their influence on the photosynthetic apparatus and plant physiology. This review provides an understanding of the mechanisms of action of fungicides, mechanisms of fungicide resistance development, and the phenomenon of phytotoxicity.

Reaction of maize hybrids to Northern corn leaf blight and common rust, and chemical control of Northern corn leaf blight / Reação de híbridos de milho a helmintosporiose e ferrugem comum, e controle químico de helmintosporiose

Northern corn leaf blight (NCLB) and common rust are among the primary fungal diseases affecting maize production. This study aimed to evaluate the susceptibility of ten maize hybrids to NCLB and to common rust and to verify the efficiency of fungicides in the chemical control of Exserohilum turcicum. In the first experiment, hybrids Pioneer (30F53, P1630H, P2530), Monsanto (AG 8045, AG 9045), Dow AgroSciences (2A550, 2A106 and 2B587) and Syngenta (SYN7205 VIPTERA, SW 3949 TL) were used and in the experiment for effectiveness of fungicides in the control of NCLB. The efficiency of fungicides propiconazole, azoxystrobin, cyproconazole + azoxystrobin, prothioconazole + trifloxystrobin, benzovindiflupir + azoxystrobin, cyproconazole + azoxystrobin + mancozeb were tested in the Pioneer P1630H hybrid. In both experiments, the leaf disease severity (%), yield and the weight of one thousand seeds were evaluated. The experimental design was carried out in randomized blocks with four replicates. The hybrids SYN7205, P2530, SW 3949 TL, 2B587, AG 9045, 2A550, P1630H, 2A106 and AG 8025 showed the smallest areas under the common rust severity progress curve. Hybrids AG9045, 30F53, and 2A550 presented the smallest areas under the NCLB progress curve. Hybrids AG8025, 2B587, P1630H, AG9045, 2A106, 2A550, present the highest yields. The fungicides prothioconazole + trifloxystrobin present the highest chemical control efficiency for NCLB and the lowest area under the disease progress curve (AUDPC).(AU)

A helmintosporiose e a ferrugem comum estão entre as principais doenças fúngicas que afetam a produção do milho. Os objetivos desse trabalho foram avaliar a suscetibilidade de dez híbridos de milho a helmintosporiose e a ferrugem comum e verificar a eficiência de fungicidas no controle de Exserohilum turcicum. No primeiro experimento utilizaram-se os híbridos Pioneer (30F53, P1630H, P2530), Monsanto (AG 8045, AG 9045), Dow AgroSciences (2A550, 2A106 e 2B587) e Syngenta (SYN7205 VIPTERA, SW 3949 TL), e no experimento de eficiência de fungicidas no controle de helmintosporiose, testou-se a eficiência dos fungicidas propiconazol, azoxistrobina, ciproconazol + azoxistrobina, protioconazol + trifloxistrobina, benzovindiflupir + azoxistrobina, ciproconazol + azoxistrobina + mancozebe, no híbrido Pioneer P1630H. Em ambos os experimentos avaliaram-se a severidade foliar das doenças (%), o rendimento e o peso de mil sementes. O delineamento experimental foi em blocos ao acaso com quatro repetições. Os híbridos SYN7205, P2530, SW 3949 TL, 2B587, AG 9045, 2A550, P1630H, 2A106 e AG 8025 apresentam as menores áreas abaixo da curva de progresso de severidade de ferrugem comum. Os híbridos AG9045, 30F53 e 2A550 apresentam as menores áreas abaixo da curva de progresso de helmintosporiose. Os híbridos AG8025, 2B587, P1630H, AG9045, 2A106 e 2A550 apresentam os maiores rendimentos. Os fungicidas protioconazol + trifloxistrobina apresentam a maior eficiência de controle químico de helmintosporiose e a menor AACPD.(AU)

Effect of Six Fungicides against Fusarium oxysporum and F. solani Associated with Peach Seedlings Decline in Tunisian Nurseries

Aims: This study investigated the efficiency of six fungicides against Fusarium spp. associated to peach seedling decline in Tunisian nurseries. Place and Duration of Study: Department of Biological Sciences and Plant Protection, Higher Institute of Agronomy of Chott Mariem, 4042, Sousse, Tunisia, between March 2016 and June 2016. Methodology: The activity of six fungicides against Fusarium oxysporum and F. solani associated with peach seedling decline in Tunisian nurseries was evaluated in vitro and in vivo. Results: The in vitro test showed that Carbendazim was the most effective at a low dose (10 ppm) against F. solani with 84.39% of hyphal growth inhibition, while it gives 60.55% of growth inhibition against F. oxysporum at 100 ppm. The percent of growth inhibition generated by Mancozeb was between 59.02 and 90.21% at 50 and 100 ppm, respectively. The efficacy of fosetyl-Al was not important in vitro at 10, 25, 50 and 100 ppm against the two tested pathogens. Hymexazol revealed to be effective against F. oxysporumbut without effect on F. solani for all used doses. The Chinosol was effective at different doses against F. oxysporum, with 88% of growth inhibition at 50 ppm for the two tested species. Thus, the fosetyl-Al, hymexazol and chinosol are the most effective on F. oxysporum and F. solani. Carbendazim was moderately effective against F. oxysporum (40. 15%), whereas it was the most effective against F. solani (98.02%). The mancozeb and metalaxyl-M+mancozeb were the lowest effective against the two pathogens tested with percents of inhibition of 27.41% and 28.96% for F. oxysporum respectively, and 48.02% and 42.46% for F. solani, respectively. Results of in vivo test indicated that disease severity parameters of peach seedlings recorded after three months of inoculation by Fusarium spp. showed that the fosetyl-Al and metalaxyl-M + mancozeb reduced significantly root browning induced by Fusarium oxysporum by 62.55%. The mancozeb and carbendazim reduced also the root browning without significant effect. Whereas, all products didn’t reduce the severity of root browning or the vegetative sanitary states index of peach seedlings inoculated by F. solani. For the growth parameters, plants inoculated by F. oxysporum and treated by fosetyl-Al and metalaxyl-M+mancozeb increased the root weight by 34% and 24.89%, respectively. The metalaxyl-M+mancozeb improved also the plant height by 8.05% compared to the control inoculated by F. oxysporum. However, chinosol was the only product that improved plant height by 10.31% and root weight by 9.78% of plants inoculated by F. solani. Conclusion: The fungicides Alliette express (fosetyl-Al), Ridomil Gold (mancozeb+ metalaxyl-M),Dithane-M45 (mancozeb) and Prodazim (carbendazim) were the most effective in vivo against F. oxysporum associated with a peach seedling decline in Tunisian nurseries, whereas Beltanol (chinosol) is the only product that improved the seedling growth inoculated by F. solani. Thus, it will be important to test them in the future against the other genera associated with this disease like Pythium and Phytophthora species. Then, it is necessary to test them against the combination of these pathogens because the causal agent of this disease is a complex.

Rust effect estimation in soybean crosses for tolerance to Asian rust / Estimativa do efeito ferrugem em cruzamentos de soja para tolerância à ferrugem asiática

ABSTRACT: Asian soybean rust is an important disease that has deeply troubled farmers and researchers since it was first reported. The causal agent, biotrophic fungus Phakopsora pachyrhizi Sydow & P. Sydow, has found extremely favorable conditions for its dissemination in Brazil. The most characteristic symptom of infection appears in the leaves, initially on the adaxial leaf surface, as small angular points less than 1mm in diameter, together with gray-colored uredospores (spores). Management involves a set of practices that guarantee coexistence between the plant and the pathogen without significant damage to the crop. The objective of this research was to evaluate tolerance to Asian rust by estimating losses caused by natural infection in the field. Experiments with generation F4 (2014/15) plants were established in a randomized blocks design with four replicates, with two types of genotypes (crosses and parents) and two schemes for disease management using fungicides. For analysis of the data, a test was applied on two dependent samples to verify the significance of the estimate of the rust effect. With regard to grain yield and tolerance, the most outstanding crosses were 104 (USP14-01-20 × EMGOPA313) and 149 (USP93-05.552 × EMGOPA313). Crosses 147 (USP93-05552 × PI153.282) and 137 (USP70.108 × PI153.282) were graded as tolerant in the evaluation of both yield reduction and seed size. We found evidence of tolerance to Asian rust in both crosses and parents. The statistical test revealed the significance of the rust effect estimates in soybean.

RESUMO: A ferrugem asiática da soja é a doença que mais tem preocupado os produtores e pesquisadores desde sua primeira evidência. Ela é causada pelo fungo biotrófico Phakopsora pachyrhizi Sydow & P. Sydow que encontrou condições extremamente favoráveis para a sua disseminação no Brasil. O sintoma mais característico apresenta-se nas folhas, inicialmente na face adaxial, como pequenos pontos angulares com menos de um milímetro de diâmetro, juntamente com os uredósporos (esporos) de coloração acinzentada. O manejo se dá por meio de um conjunto de práticas que garanta a boa convivência entre a planta e o patógeno e sem que ocorra danos significativos à lavoura. O trabalho objetivou avaliar a tolerância à ferrugem asiática estimando as perdas causadas pela infestação natural a campo. Os experimentos com a geração F4 (2014/15) foram delineados em blocos ao acaso com quatro repetições. Foram realizadas categorias de experimentos, envolvendo dois tipos de genótipos (cruzamentos e genitores) e dois tipos de manejos de doenças com fungicidas. Para a análise dos dados foi aplicado um teste, para duas amostras dependentes, a fim de verificar a significância da estimativa do efeito ferrugem. Considerando a produtividade e a tolerância, os cruzamentos mais importantes foram 104 (USP 14-01-20 x EMGOPA 313) e 149 (USP 93-05.552 x EMGOPA 313). Os cruzamentos 147 (USP 93-05.552 x PI 153.282) e 137 (USP 70.108 x PI 153.282) foram tolerantes tanto na avaliação de redução da produtividade e do tamanho de semente. Houveram evidências de tolerância à ferrugem asiática nos cruzamentos e nos genitores. O teste estatístico revelou a significância das estimativas de efeito ferrugem em soja.

Sensitivity of two isolates of Phakopsora pachyrhizi to dithiocarmamate, chloronitril, triazoles, strobilurins, and carboxamides fungicides / Sensibilidade de Phakopsora pachyrhizi aos fungicidas ditiocarbamatos, cloronitrilas, triazóis, estrobilurinas e carboxamidas

Asian soybean rust (ASR), caused by the phytopathogen Phakopsora pachyrhizi Sydow & Sydow, is a worldwide distributed fungal disease responsible for causing damages in soybean crops [Glycine max (L.) Merril] of up to 90% of its productive potential. So far, due to limited availability of resistant varieties, fungicide application is the most widely used strategy for ASR control, although some populations of the pathogen have shown reduced sensitivity to certain active ingredients. Several methods have been described to measure the sensitivity of a fungus to a given fungicide, or even the fungitoxicity of a chemical. The most used tests are spore germination in wateragar medium and evaluation of disease severity in detached soybean leaves. Experiments were carried out with Brazilian populations of the pathogen: one from Uberlândia - MG and the other from Chapadão do Sul - MS, following the mentioned methodologies. The results showed the reduction of benzovindiflupyr efficiency in relation to spore germination and disease severity for the MS population, as also did fluxapyroxad, cyproconazole, and tebuconazole. Multisite fungicides (chlorothalonil, copper oxychloride, and mancozeb) may be used in the management of ASR resistance in the fields of Brazil associated with strobilurins, triazoles, and carboxamides. The efficiency of the main active ingredient tested depends on the formulation and others molecules used in the commercial product.

A ferrugem asiática da soja (FAS), causada pelo fitopatógeno Phakopsora pachyrhizi Sydow & Sydow, é uma doença fúngica distribuída mundialmente e responsável por causar danos na cultura da soja [Glycine max (L.) Merril], em até 90% do potencial produtivo. Até agora, devido à limitada disponibilidade de variedades resistentes, a aplicação de fungicida é a estratégia mais utilizada para controlar a FAS, embora algumas populações do patógeno tenham demonstrado menor sensibilidade a determinados ingredientes ativos. Vários métodos foram descritos para medir a sensibilidade de um fungo a um dado fungicida, ou para monitorar sua redução ou perda de eficácia, ou mesmo a fungitoxicidade de um produto químico. Os testes mais utilizados são a germinação de esporos in vitro e a severidade da doença (%) em folhas de soja destacadas. Baseando-se nessas metodologias, foram realizados ensaios com populações do patógeno oriundas de Uberlândia - MG e do Chapadão do Sul - MS. Os resultados mostraram a redução da eficiência de benzovindiflupyr em relação à germinação e à severidade de doença para a população de Chapadão do Sul - MS. O mesmo comportamento foi obtido para os ingredientes ativos fluxapyroxad, cyproconazole e tebuconazole. Os fungicidas multissítios (clorotalonil, oxicloreto de cobre e mancozeb) podem ser utilizados no manejo da resistência à FAS nas lavouras do Brasil associados às estrobilurinas, triazóis e carboxamidas. A eficiência do principal ingrediente ativo estudado depende dos outros ingredientes ativos ou fungicidas associados na formulação comercial.

Caracterización química y evaluación de la actividad antifúngica del aceite esencial foliar de Lippia alba contra Colletotrichum gloeosporioides

El objetivo de este estudio fue caracterizar y evaluar in vitro la eficiencia del aceite esencial foliar de Lippia alba contra Colletotrichum gloeosporioides. Se extrajo el aceite esencial a partir de las hojas mediante el método de hidrodestilación asistida por microondas (MWHD) y se identificaron sus metabolitos mediante una cromatografía de gases acoplada a espectrometría de masas (GC/MS). La evaluación in vitro se realizó empleando 4 concentraciones del aceite esencial (500, 1000, 3000 y 10000 ppm) diluidas en acetona; se utilizó un control positivo con Benomil 1 g/L, un control negativo con acetona y un testigo absoluto; la eficiencia del aceite se midió mediante el porcentaje de índice antifúngico (%I.A). El componente mayoritario en el aceite esencial fue el citral (34.62 a 40.03%) y que el mayor %I.A se encontró a la concentración de 10000 ppm (97.8%), muy similar a la del Benomil (100%). Lo anterior demostraría la eficacia del aceite esencial de L. alba para controlar a C. gloeosporioides, y su posible uso como fungicida biológico.

The aim of this study was to characterize and evaluate the in vitro efficiency of leaf essential oil of Lippia alba against Colletotrichum gloeosporioides. Essential oil from the leaves was extracted by the method of assisted microwave hydrodistillation (MWHD) and metabolites were identified by gas chromatography coupled to mass spectrometry (GC/ MS). The in vitro evaluation was performed using 4 concentrations of essential oil (500, 1000, 3000 and 10000 ppm) diluted in acetone; positive control with Benomyl 1 g /L, a negative control with acetone and absolute control was used; oil efficiency was measured by the percentage of antifungal index (% IA). It was found that the major component was in the essential oil citral (34.62 to 40.03%) and the highest %I.A was found to 10000 ppm concentration (97.8%) very similar to Benomyl (100%). This would demonstrate the efficacy of the L. alba essential oil to control C. gloeosporioides, and its possible use as a biological fungicide.

Sensibilidad in vitro de Trichoconiella padwickii a diversos principios activos usados como fungicidas en el cultivo del arroz / In vitro susceptibility of Trichoconiella padwickii to various active ingredients used as fungicides in the cultivation of rice

El objetivo de este trabajo fue evaluar in vitro la sensibilidad micelial de Trichoconiella padwickii a diferentes principios activos por medio del cálculo de la concentración inhibitoria media (CI50). Para ello se realizaron siembras de discos de inóculo en agar poroto con distintas concentraciones (0,1; 1; 10; 30, 50; 100 y 1.000 mg/l) de diversos fungicidas. A los 7 días se midió el diámetro de crecimiento de la colonia (cm). Los datos obtenidos se ajustaron a modelos de regresión no lineal. La sensibilidad se clasificó utilizando la escala de Edgington. Los resultados obtenidos demuestran que el patógeno es muy sensible a los productos que actúan sobre la cadena respiratoria (quinone outside inhibitors QoI y succinate dehydrogenase inhibitors SDHI) y la membrana celular (multisitio), y moderadamente sensible a los que interfieren en la división celular (metil benzimidazol carbamatos MBC), en la síntesis de ácidos nucleicos (fenilamidas PA) y en la transducción de la señal osmótica (actividad multisitio). Este trabajo es el primer antecedente sobre la sensibilidad in vitro de T. padwickii a principios activos fungicidas.

The aim of this study was to evaluate in vitro the mycelial susceptibility of Trichoconiella padwickii to different active ingredients through average median concentration IC50 calculation. Inoculum disks were seeded on bean agar at different concentrations (0.1; 1; 10; 30, 50; 100 and 1000 mg/l) of various fungicides. After seven days the colony diameter was measured. The data obtained were fitted to nonlinear regression models. Susceptibility was classified using the scale proposed by Edgington. The results show that the pathogen is very sensitive to products that act on the respiratory chain (quinone outside inhibitors QoI and succinate dehydrogenase inhibitors SDHI) and cell membrane (multi-site contact activity), and moderately sensitive to those products interfering with cell division (methyl benzimidazole carbamates MBC), synthesis of nucleic acids (phenylamides PA) and osmotic signal transduction (multi-site contact activity). This work is the first record on the sensitivity of T. padwickii.

The Effect of Fungicides on Mycelial Growth and Conidial Germination of the Ginseng Root Rot Fungus, Cylindrocarpon destructans

Ginseng root rot caused by Cylindrocarpon destructans is the most destructive disease of ginseng. Six different fungicides (thiophanate-methyl, benomyl, prochloraz, mancozeb, azoxystrobin, and iprodione) were selected to evaluate the inhibitory effect on the mycelial growth and conidial germination of C. destructans isolates. Benomyl and prochloraz were found to be the most effective fungicides in inhibiting mycelial growth of all tested isolates, showing 64.7% to 100% inhibition at a concentration of 10 µg/mL, whereas thiophanate-methyl was the least effective fungicide, showing less than 50% inhibition even at a higher concentration of 100 µg/mL. The tested fungicides exhibited less than 20% inhibition of conidium germination at concentrations of 0.01, 0.1, and 1 µg/mL. However, the inhibition effect of mancozeb on condium germination of C. destructans was significantly increased to 92% to 99% at a higher concentration of 100 µg/mL, while the others still showed no higher than 30% inhibition.

Management of blight of bell pepper (Capsicum annuum var. grossum) caused by Drechslera bicolor

Abstract Sweet or bell pepper is a member of the Solanaceae family and is regarded as one of the most popular and nutritious vegetable. Blight, in the form of leaf and fruit blight, has been observed to infect bell pepper crops cultivated at the horticulture farm in Rajasthan College of Agriculture, Udaipur, India. Based on disease severity, we attempted to curb this newly emerged problem using different fungicides, plant extracts, bio-control agents, and commercial botanicals against the fungus in laboratory and pot experiments. Bio-control agent Trichoderma viride and plant growth promoting Rhizobacteria (PGPR) isolate Neist-2 were found to be quite effective against bell pepper blight. All evaluated fungicides, botanicals, commercial botanicals, and bio-control agents in vitro were further studied as seed dressers and two foliar sprays at ten days interval in pot experiments. The combinations of Vitavax, PGPR isolate Neist-2, and Mehandi extract were found to be very effective against bell pepper blight followed by Vitavax, T. viride, and Mehandi extract used individually. All treatments in the pot experiments were found to significantly reduce seedling mortality and enhance plant biomass of bell pepper. Thus, these experimental findings suggest that a better integrated management of bell pepper blight could be achieved by conducting field trials in major bell pepper- and chilli-cultivated areas of the state. Besides fungicides, different botanicals and commercial botanicals also seem to be promising treatment options. Therefore, the outcome of the present study provides an alternate option of fungicide use in minimizing loss caused by Drechslera bicolor.

Reduction of white mold level on soybean by fungicide management strategies / Redução do nível de mofo-branco na soja pelo manejo de fungicidas

The objective of this study was to verify the efficiency of the control of white mold on soybean with the use of fungicides applied alone and in rotation, at different growth stages and in a mixture of two active ingredients at three locations: Arapoti, PR, Mauá-da-Serra, PR and Pinhão, PR, Brazil. The fungicides used were carbendazim (Ca), thiophanate methyl (Tm), procymidone (Pr) and fluazinam (Fl). The experiments consisted on 17 treatments and 4 replications in a randomized block design. The analyzed variables were severity, incidence, number of sclerotia and yield. Mauá-da-Serra and Pinhão presented the highest incidences (31% and 29.8% in the control, respectively). At these two locations most of treatments with fungicides decreased the incidence and production of sclerotia, when compared to control; however, no differences in terms of yield were observed. Arapoti presented the lowest incidence (15.8% in the control) where most of treatments with fungicides did not present differences for the variables incidence, production of sclerotia and yield, when compared to the control. No differences were also observed for severity in any of three locations. In conclusion, fungicides applied in soybean areas with historically white mold incidence up to 31% can reduce the disease incidence and sclerotia production levels.

O objetivo deste estudo foi o de verificar a eficiência de controle do mofo-branco na soja com o uso de diferentes fungicidas aplicados isoladamente, alternados, em diferentes estádios fenológicos e em mistura de dois princípios ativos, em três locais: Arapoti/PR, Mauá-da-Serra/PR e Pinhão/PR, Brasil. Os fungicidas utilizados foram carbendazim (Ca), tiofanato metílico (Tm), fluazinam (Fl) e procimidona (Pr). Os experimentos foram compostos por 17 tratamentos e 4 repetições distribuídas em blocos aleatorizados. As variáveis analisadas foram incidência, severidade, produção de escleródios e o rendimento da cultura. Mauá-da-Serra e Pinhão apresentaram as maiores incidências, 31% e 29,8% no tratamento controle, respectivamente, onde a maioria dos tratamentos com fungicidas proporcionou menor incidência e produção de escleródios, quando comparados ao controle, porém sem diferenças quanto ao rendimento. Em Arapoti foi observada a menor incidência, 15,8% no controle, onde a maioria dos tratamentos com fungicidas não apresentou diferenças para incidência, produção de escleródios e rendimento, quando comparados ao controle. Em nenhum dos três locais foram verificadas diferenças entre os tratamentos e o controle para a variável severidade. Como conclusão, fungicidas aplicados em áreas de soja com histórico de incidência de mofo-branco de até 31% podem reduzir a incidência da doença e o nível de produção de escleródios.

Deposit of pesticides without and with adjuvants on citrus seedlings following different intervals of artificial rain / Depósito de caldas fitossanitárias sem e com adjuvantes sobre mudas de citros com diferentes intervalos para incidência de chuva artificial

ABSTRACT:For a crop protection product to achieve its goal, the product must be applied and remain on the leaves until it is absorbed. This situation may be compromised due to rainfall after spraying, thus necessitating reapplication which increase the overall cost. Application technology research has focused on alternatives and solutions to mitigate this effect through the use of adjuvants. The objective of this research was to evaluate the deposit of spraying liquid on citrus seedlings using the products spirodiclofen, propargite, imidacloprid, lambda cyhalothrin, copper oxychloride, and copper hydroxide with water mixed with the adjuvants polydimethylsiloxane and phosphatidylcholine. Seedlings were subjected to simulated rains of 10mm at intervals of 1, 6, 12 and 24h after spraying, and the remaining deposits of spraying liquid per leaf area were analyzed by spectrophotometry by assessing a metallic marker previously added in the spraying liquids. Variables were subjected to analysis of variance and Tukey's test (P<0.05). The rains that occurred soon after spraying resulted in decreased spraying liquids deposits on citrus leaves. Adjuvant phosphatidylcholine promoted the greatest retention of spraying liquid on citrus leaves after rainfall.

RESUMO:A aplicação de um produto fitossanitário deve assegurar que ocorra sua chegada e permanência das gotas sobre folhas até que sejam absorvidos para manifestação do efeito biológico. Essa situação pode ser comprometida pela ocorrência de chuvas após a pulverização, necessitando de reaplicações que elevam os custos. A tecnologia de aplicação busca alternativas e soluções para amenizar esse efeito, como o uso de adjuvantes. Objetivou-se, neste trabalho, avaliar o depósito de caldas fitossanitárias pulverizadas sobre mudas de citros, com os produtos espirodiclofeno, propargite, imidacloprido, lambida cialotrina, oxicloreto de cobre e hidróxido de cobre apenas com água e em mistura com os adjuvantes polidimetilsiloxano e fosfatidilcoline antes e após chuvas artificais de 10mm, com intervalos de 1, 6, 12 e 24 horas após a pulverização. Os depósitos de caldas remanescentes por área foliar foram analisados por espectrofotometria, considerando um marcador metálico previamente adicionado nas caldas. As variáveis foram submetidas à análise de variância e ao teste de Tukey (P<0,05). As chuvas ocorridas mais próximas do momento das pulverizações resultaram em menores depósitos de calda sobre as folhas de citros. O adjuvante fosfatidilcoline manteve a maior quantidade das caldas sobre folhas de citros, quando da ocorrência de chuvas após a pulverização.

RICHNESS, CELLULOLYTIC ACTIVITY, AND FUNGICIDE SUSCEPTIBILITY OF FUNGI FROM A BIRD BIOLOGICAL COLLECTION / Riqueza, actividad celulolítica y susceptibilidad a fungicidas de hongos de una colección biológica de aves

Biological collections in natural history museums serve important purposes to the scientific community and the general public, however, their value and utility might be diminished by biodeterioration. We studied a biological collection that represents more than sixty years of avifauna sampling of Colombia, the country with the highest bird diversity. An initial inspection of the collection showed that the general appearance of some specimens was compromised by mold-like growth on their surfaces. We aimed at (i) identifying the taxonomic affiliation of these fungi, (ii) evaluating their cellulolytic activity, and (iii) probing chemical agents that could be utilized to control their growth. The most common fungi genera were Aspergillus, Penicillium, Chaetomium, and Trichophyton, most of which can degrade cellulose. Zinc chloride and salicylic acid showed to be effective fungicides. Based on this, we propose some actions to control the fungi-pest in this biological collection of birds.

Las colecciones biológicas en los museos de historia natural juegan un papel importante tanto para la comunidad cientifica como para el público en general. Sin embargo, su valor y utilidad pueden verse afectados por la biodeterioración de sus ejemplares. Se estudio una colección biológica de aves que representa más de sesenta anos de esfuerzo de muestreo de la avifauna del pais más rico en aves. Una inspección inicial mostró que la apariencia general de algunos de los especimenes de la colección se encontraba afectada por hongos. Los objetivos de este estudio fueron (i) identificar la afiliación taxonómica de los hongos, (ii) determinar la actividad celulolítica y (iii) probar agentes químicos que puedan ser utilizados para controlar su desarrollo. Los géneros de hongos más comunes fueron Aspergillus, Penicillium, Chaetomium y Trichophyton, de los cuales la mayoria presentan la capacidad de degradar celulosa. Adicionalmente, el cloruro de zinc y el ácido salicilico actuaron como fungicidas efectivos. De acuerdo con en estos resultados proponemos algunas acciones para controlar la contaminación por hongos en la colección de aves.

Advance in study on plant essential oils for their inhibitory effects on fungal growth and mycotoxin synthesis / 中草药

Fungi and mycotoxins contamination in food, fruits, and vegetables, Chinese herbal medicines and agricultural commodities has not only led to a huge waste of resources and economic losses, but also posed the potential threats for human's safety and health, which has been widely concerned in the world. The researchers are trying their best to look for the scientific and effective methods to control the fungi growth and mycotoxins production in these matrices. Although some synthetic chemicals have been usually used as fungicides, they were still prohibited owing to the disadvantages of residues, public hazards, drug resistance, and so on. Many plant essential oils (PEOs), because of their advantages including broad-spectrum antifungal activity, high volatility, short degradation period, minimal residues, non-toxicity or low toxicity, friendly to human and environment, have the attractive attention of scientific community towards the development of eco-friendly botanical fungicides. The paper reviewed the distribution of PEOs, together with their inhibitory effects on fungal growth and mycotoxins production, antifungal spectrum, safety assessment, and antifungal mechanism to provide the scientific evidences for developing effective green fungicides.

Esterase isozymes patterns of grape vine (Vitis vinifera L) are altered in response to fungicide exposure / Padrões de isozimas Esterases de videira (Vitis vinifera L) alterados em resposta à exposição a fungicidas

Current analysis characterizes the effect of different fungicides often applied for pest control on α−and ß-esterase patterns of four economically important table-wine grape cultivars (Italia, Rubi, Benitaka and Brasil) of Vitis vinifera. The α- and ß-esterase patterns in bud leaves of the cultivars were assessed by native PAGE analysis. Cabrio Top® compound inhibited EST-2, EST-5, EST-6, EST-7, EST-8, EST-9 and EST-10 carboxylesterases, whereas EST-4, EST-11, EST-12, EST-13, EST-14 acetylesterases and EST-16 carboxylesterase were detected as weakly stained bands. Carboxylesterases and acetylesterases were also detected as weakly stained bands when exposed to fungicides Orthocide 500®, Positron Duo® and Folicur PM®. No changes in α- and ß-esterase patterns were reported when the vines were exposed to the fungicides Rovral SC®, Kumulus DF®, Curzate M®, Score® or Cuprogarb 500®. The evidence of functional changes in carboxylesterase and acetylesterase levels in current study is a warning to grape producers on the dangers inherent in the indiscriminate use of potent and modern fungicides extensively used in agriculture. The inhibition effect of fungicides on esterase isozyme molecules seems to be independent of the fungicide chemical.

O presente estudo caracterizou o efeito de diferentes fungicidas comumente aplicados como medidas de controle de pragas sobre padrões de α- e ß-esterases de quatro importantes cultivares de uva de mesa (Itália, Rubi, Benitaka e Brasil) de Vitis vinifera. Os padrões de α- e ß-esterases de brotos foliares das cultivares foram avaliados por PAGE. O composto Cabrio Top® inibiu as carboxilesterases EST-2, EST-5, EST-6, EST-7, EST-8, EST-9 e EST-10, enquanto as acetilesterases EST-4, EST-11, EST-12, EST-13, EST-14 e a carboxilesterase EST-16 foram detectadas como bandas fracamente coradas. As carboxilesterases e acetilesterases também foram detectadas como bandas fracamente coradas quando expostas aos fungicidas Orthocide 500®, Positron Duo® e Folicur PM®. Não foram observadas alterações nos padrões de α- e ß-esterases quando as videiras foram expostas aos fungicidas Rovral SC®, Kumulus DF®, Curzate M®, Score® ou Cuprogarb 500®. A evidência de alterações em nível funcional em carboxilesterases e acetilesterases, apresentada neste estudo, pode servir como um alerta aos produtores de uva dos perigos inerentes ao uso indiscriminado de fungicidas potentes e modernos amplamente utilizados hoje na agricultura. O efeito dos fungicidas sobre as enzimas esterases parece ser independente do grupo químico ao qual pertence o fungicida.

Analysis of a suppressive subtractive hybridization library of Alternaria alternata resistant to 2-propenyl isothiocyanate

Background Isothiocyanates (ITCs) are natural products obtained from plants of the Brassicas family. They represent an environmentally friendly alternative for the control of phytopathogenic fungi. However, as it has been observed with synthetic fungicides, the possibility of inducing ITC-resistant strains is a major concern. It is, therefore, essential to understanding the molecular mechanisms of fungal resistance to ITCs. We analyzed a subtractive library containing 180 clones of an Alternaria alternata strain resistant to 2-propenyl ITC (2-pITC). After their sequencing, 141 expressed sequence tags (ESTs) were identified using the BlastX algorithm. The sequence assembly was carried out using CAP3 software; the functional annotation and metabolic pathways identification were performed using the Blast2GO program. Results The bioinformatics analysis revealed 124 reads with similarities to proteins involved in transcriptional control, defense and stress pathways, cell wall integrity maintenance, detoxification, organization and cytoskeleton destabilization; exocytosis, transport, DNA damage control, ribosome maintenance, and RNA processing. In addition, transcripts corresponding to enzymes as oxidoreductases, transferases, hydrolases, lyases, and ligases, were detected. Degradation pathways for styrene, aminobenzoate, and toluene were induced, as well as the biosynthesis of phenylpropanoid and several types of N-glycan. Conclusions The fungal response showed that natural compounds could induce tolerance/resistance mechanisms in organisms in the same manner as synthetic chemical products. The response of A. alternata to the toxicity of 2-pITC is a sophisticated phenomenon including the induction of signaling cascades targeting a broad set of cellular processes. Whole-transcriptome approaches are needed to elucidate completely the fungal response to 2-pITC.

Chemical control of phytophthora wilt in tomatoes / Controle químico da murcha de fitóftora no tomateiro

The most effective disease management method for yield reducing diseases affecting tomatoes is the use of fungicides. This study evaluated the efficacy of chemical control on three Phytophthora sp. isolates, pathogenic to tomatoes. The effect of fungicides on mycelial growth of Phytophthora sp. and on tomato wilt was evaluated in vitro and in vivo. Two tests were done in Petri plates, and one on seedlings, in completely randomized design as a 4x3 factorial, with 5 replications. In vitro tests were done in growth chamber, at 25°C. The experimental unit consisted of a 5-mm diameter fungal mycelial plug placed 30 mm away from a filter paper disk, of similar size, soaked in fungicide, over cornmeal agar. The first test evaluated four commercial products registered for the control of potato blight: chlorothalonil+metalaxyl (Folio Gold® 742.5 WP); propamocarb chloridrate (Infinito® 687.5 CS), metalaxyl-m+mancozeb (Ridomil Gold® 68 WP), cymoxanil + manconzeb (Curzate® MZ 72 WG), at the recommended doses. The other assays evaluated three doses of Infinito (0.125%, 0.150% or 0.175%) and Ridomil. In vivo test was done in the greenhouse, and the experimental unit consisted of one pot, containing one tomato seedling, cultivar Alambra F1. Fungicide was drenched on the seedling soil one day prior to inoculation with 50,000 zoospores per pot. Data of mycelia growth inhibition by fungicide were submitted to analysis of variance and the averages compared by the Tukey test at 5% significance; efficacy was determined as a function of Ridomil®, the standard fungicide. In the first test, regardless of isolate, Infinito® presented performance similar to Ridomil® with efficacy of 98.5%, while Folio Gold® presented efficacy of 57.3% and Curzate® had no fungicide effect. Growth of isolate PP3 was smaller in all fungicides. In the second in vitro test, all three doses of Infinito® had efficacy above 82%. The best control was observed on isolates PP3 and PP4. In the third test, in vivo, no significant differences were observed in root matter among the standard fungicide and the doses of Infinito®; however, efficacy of Infinito® at 0.175% was 14% greater than that obtained with Ridomil®. It can be concluded that Infinito® is one more option for the control of tomato wilt.

O método mais efetivo no manejo das doenças fúngicas que afetam o tomateiro e reduzem a produtividade significativamente é o uso de fungicidas. Este trabalho avaliou a eficiência do controle químico sobre três isolados de Phytophthora sp. patogênicos ao tomateiro. O efeito de fungicidas no crescimento micelial de Phytophthora sp. e na murcha de tomateiro foi avaliado in vitro e in vivo, respectivamente. Foram realizados dois testes em placa de Petri e um teste em mudas, em delineamento experimental inteiramente casualizado (DIC), como fatorial 4x3, com 5 repetições. Os testes in vitro ocorreram em câmara de crescimento, a 25°C. A parcela experimental correspondeu a um disco de micélio fúngico disposto a 30 mm de um disco de papel embebido com solução de fungicida, ambos com 5 mm de diâmetro e dispostos sobre meio sólido a base de milho. O primeiro teste avaliou quatro produtos comerciais indicadas para o controle da mela ou requeima no tomateiro: clorotalonil+metalaxil (Folio Gold® 742,5 PM); propamocarbe (Infinito® 687,5 SC), metalaxil-M+mancozeb (Ridomil Gold® 68 PM), cimoxanil + manconzeb (Curzate® MZ 72 WG), nas dosagens recomendadas. Os demais ensaios avaliaram três doses de Infinito (0,125%, 0,150% e 0,175%) e Ridomil. O teste in vivo foi realizado em casa de vegetação, sendo a parcela experimental representada por um vaso, contendo uma muda de tomate, variedade Alambra F1. Fez-se "drench" para aplicação do fungicida no dia anterior à inoculação de 50.000 zoósporos por vaso. Dados de inibição do crescimento micelial por fungicidas foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey a 5% de significância; e a eficácia foi calculada em função do Ridomil®, fungicida padrão. No primeiro ensaio, independentemente do isolado, Infinito® apresentou desempenho semelhante ao Ridomil® com uma eficácia de 98,5%, enquanto Folio Gold® apresentou eficácia de 57,3% e Curzate não apresentou efeito fungicida. O crescimento do isolado PP3 foi menor em todos os produtos. No segundo teste in vitro as três doses de Infinito® tiveram eficácia superior a 82%. O melhor controle foi observado sobre os isolados PP3 e PP4. No terceiro teste, in vivo, não houve diferença significativa na massa de raízes, entre o padrão e as doses de Infinito®, no entanto, a eficácia de Infinito® a 0,175% foi 14% maior que a obtida para o Ridomil®. Conclui-se que Infinito® é mais uma opção para controle da mela em tomateiro

Detection of endogenous bacteria of Gardenia seed and comparative study of chemical treatments / 中国药学杂志

OBJECTIVE: To study the endophytic fungi in the seeds of Gardenia from different regions, identy the strains carried by the seed surface and interior, and compare the treatment effects of different fungicides, to provide reference for the antibacterial treatment before gardenia seed sowing and fungal disease control. METHODS: Plate method was used for the surface and internal detection of Gardenia seeds from 15 countries in China, method of seed dressing was used for seed treatment and disinfection effects of 6 kinds of fungicides is done. RESULTS: Main flora in surface of the seed are genus Fusarium, Mucor, Penicillium, Aspergillus and Rhizopus, Penicillium and Aspergillus are the dominant species.There is no significant difference in this 5 species of the seeds from different places, but significant difference in isolation frequency.Load capacity of the spore range from (6.7±11.5) to (1333.3±230.1) per seed. There is significant difference in spore load from different places.Endophytic fungi inside the seeds are mainly Aspergillus, Penicillium, Mucor, Rhizopus and etc.There is significant difference in seeds of these fungi, it ranges from (1.7±2.9)% to (58.3±17.6)%. Carrier rate and species of fungal among different habitats are significantly different, discrete frequency of Aspergillus is the highest. CONCLUSION: The six antiseptics provided all have kill and inhibition to Gardenia seed fungus in some extent. Bactericidal effects of carbendazim fernasan and carbendazim are the poorest, and fernasan ziram and oxadixyl mancozeb and evil frost are the best, which can achieve above 95.0%. Suggestion is made to choose fernasan ziram and oxadixyl mancozeb as inhibiting fungus agents of Gardenia seed disinfection treatment.