<p>We hypothesize that South African medicinal plants contain compounds that can act in synergism with synthetic antifungal compounds. Four fungicides - Sporekill&trade / , Rovral&trade / , Terminator&trade / and Teldor&trade / at doses 0.1, 0.2, 0.4 and 0.8 mL L-1 and plant species Galenia africana, Elytropappus rhinocerotis and Tulbaghia violacea were tested aloneand in different combinations for their potency (efficacy) on radial growth inhibition of Botrytis cinerea strains on potato dextrose plates. Four doses of plant extract for each of the respective plant species were used. A total of 48 combinations were tested for each strain. Mixtures of plant extracts were far more effective in controlling strains compared to the individual components alone, representing significant levels of in vitro synergistic interactions. Combinations of these components represent an attractive future prospect for the development of new management strategies for controlling B. cinerea. Since the in vitro tests of these mixtures showed inhibitory activity, the mixtures were tested for activity in assays on Granny Smith apples. In vitro tests can be used to screen mixtures to obtain information on their inhibitory activity on a pathogen, however, the environmental conditions of the fruit and the ability of the pathogen to grow into the fruit cannot be simulated in vivo. A series of two-fold doses of medicinal plant extracts were combined with fungicides to conduct decay inhibition studies. The incidence of gray mold was significantly reduced by mixtures of plant extracts and fungicides. Under conditions similar to those in commercial storage, a drench treatment with G. africana and Rovral&trade / significantly (p=0.05) inhibit gray mold on the apples and was more effective than the plant extract and fungicide alone. The treatments exerted synergistic effects and were markedly better than the components applied alone. The wound colonization assay was used for optimal decay control. In a drench, much higher volumes of the treatments are used to ensure that the components of the suspension are deposited evenly over the entire fruit surface. Drenching of fruit to apply other chemicals is an established practise in the pome (fleshy) fruit industry, and simplifies the commercial application of the mixtures, as no additional infrastructure at commercial packing houses will be required. This approach not only makes it possible to reduce fungicide concentrations while maintaining adequate decay control, but also ensures a reduction of the chemical residue on the fruit.</p>

Gray mold, caused by Botrytis cinerea is the major cause of postharvest loss in strawberries. Detection of flower and fruit infections enables producers to make intelligent management decisions. A plate-trapped ELISA protocol using a Botrytis-specific monoclonal antibody (BC-12.CA4) was developed for the detection of Botrytis cinerea in strawberry flower receptacles and red fruits. Horseradish peroxidase, was chosen as enzyme conjugate because it gave lower background absorbance in disease-free samples. B. cinerea reference antigen (RAg) was isolated from strawberry. BC-12.CA4 was very sensitive to the RAg, detecting up to 6 mug/ml of RAg when mixed with strawberry extracts. The MAb did not show any reaction to Rhizopus sp., Mucor sp. and Penicillium sp. associated with strawberry. B. cinerea could be detected in receptacles two days after inoculation. Treatment of inoculated receptacles with paraquat speeded-up detection. Inoculated red fruit infection could be detected after three days of incubation. Disease in commercially-produced receptacles and red fruits were assessed visually and by ELISA. The ELISA detected B. cinerea in 95% of commercial flower samples, whereas the traditional visual method detected only 50 to 70%. No dramatic differences between methods were found for red fruits.

<p>We hypothesize that South African medicinal plants contain compounds that can act in synergism with synthetic antifungal compounds. Four fungicides - Sporekill&trade / , Rovral&trade / , Terminator&trade / and Teldor&trade / at doses 0.1, 0.2, 0.4 and 0.8 mL L-1 and plant species Galenia africana, Elytropappus rhinocerotis and Tulbaghia violacea were tested aloneand in different combinations for their potency (efficacy) on radial growth inhibition of Botrytis cinerea strains on potato dextrose plates. Four doses of plant extract for each of the respective plant species were used. A total of 48 combinations were tested for each strain. Mixtures of plant extracts were far more effective in controlling strains compared to the individual components alone, representing significant levels of in vitro synergistic interactions. Combinations of these components represent an attractive future prospect for the development of new management strategies for controlling B. cinerea. Since the in vitro tests of these mixtures showed inhibitory activity, the mixtures were tested for activity in assays on Granny Smith apples. In vitro tests can be used to screen mixtures to obtain information on their inhibitory activity on a pathogen, however, the environmental conditions of the fruit and the ability of the pathogen to grow into the fruit cannot be simulated in vivo. A series of two-fold doses of medicinal plant extracts were combined with fungicides to conduct decay inhibition studies. The incidence of gray mold was significantly reduced by mixtures of plant extracts and fungicides. Under conditions similar to those in commercial storage, a drench treatment with G. africana and Rovral&trade / significantly (p=0.05) inhibit gray mold on the apples and was more effective than the plant extract and fungicide alone. The treatments exerted synergistic effects and were markedly better than the components applied alone. The wound colonization assay was used for optimal decay control. In a drench, much higher volumes of the treatments are used to ensure that the components of the suspension are deposited evenly over the entire fruit surface. Drenching of fruit to apply other chemicals is an established practise in the pome (fleshy) fruit industry, and simplifies the commercial application of the mixtures, as no additional infrastructure at commercial packing houses will be required. This approach not only makes it possible to reduce fungicide concentrations while maintaining adequate decay control, but also ensures a reduction of the chemical residue on the fruit.</p>

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2004. / Härtill 4 uppsatser.

Orientador: Ben-Hur Mattiuz / Resumo: As doenças fúngicas são as principais causas de perdas na pós-colheita do tomate, e são controladas por manejo cultural e fungicidas aplicados na pré-colheita. O tratamento hiperbárico na pós-colheita é um métodos físico, com potencial uso comercial na redução da deteriorização por fungos. Neste trabalho, a eficiência das pressões hiperbáricas para controlar o desenvolvimento das podridões de Botrytis cinerea e Alternaria sp. in vitro e em tomates ‘Débora’ foram avaliadas, bem como a atividade das enzimas antioxidantes e as relacionadas a defesa do vegetal. Os experimentos foram realizados em um sistema de pressão hiperbárica do Laboratório de Tecnologia Pós-colheita da FCAV-UNESP, Câmpus de Jaboticabal, utilizando as pressões de 100 (controle), 200, 400, 600 e 800 kPa à temperatura de 23±1°C, durante 3 e 6 dias. No ensaio in vitro as placas com os fungos permaneceram nas pressões e depois foram incubadas até que a colônia do controle atingisse a borda. No experimento in vivo, tomates inoculados com os fungos foram mantidos por 3 e 6 dias sob o tratamento nas pressões, com posterior armazenamento por mais 2 e 4 dias em condição de ambiente (23 °C, 50% UR, 100 kPa) para simular a comercialização. Avaliou-se o crescimento micelial, a taxa de germinação dos conídios dos fungos, incidência e severidade das podridões nos frutos, o metabolismo antioxidante (teor de licopeno e polifenóis totais) e a atividade das enzimas relacionadas à defesa dos tomates (peroxidase (POD), fenilalan... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Fungal rots are one of the major causes of postharvest losses in tomatoes, and they are controlled by cultural management and fungicidal applied in preharvest. The postharvest hyperbaric treatment is a physical method that it have potential to be used in commercial for reducing fungal decay. In this work, the efficiency of hyperbaric pressures to control rot development of Botrytis cinerea and Alternaria sp. in vitro and ‘Debora’ tomatoes were evaluated, also the activity of antioxidant and defense-related enzymes.The experiments were carried out in a hyperbaric pressure system at FCAV-UNESP Postharvest Technology Laboratory, Campus de Jaboticabal, using the pressures of 100 (control), 200, 400, 600 and 800 kPa at a temperature of 23 ± 1 ° C for 3 and 6 days. In vitro assay the Petri dishes with the fungi were kept at pressures after they were incubated until the control colony reached the edge. In vivo assay, tomatoes inoculated with the fungus were kept at 3 and 6 days under the treatment pressures, after they were stored for more 2 and 4 days at ambient conditions (23 °C, 50% RH, 100 kPa) to simulate the commercialization. It was evaluated the mycelial growth, germination rate of fungal conidia, incidence and severity of fruit rot, antioxidant metabolism (lycopene content and total polyphenols) and activity of defence-related enzymes (eroxidase (POD), phenylalanine ammonia-lyase (PAL), β 1,3 glucanase (GLU), superoxide dismutase (SOD) and catalase (CAT)). The hyperbaric pr... (Complete abstract click electronic access below) / Doutor

Memoria para optar al Título Profesional de Ingeniero Agrónomo / Botrytis cinerea Pers. causa niveles importantes de pudrición, los que pueden superar el 10% en peras de exportación en Chile, principalmente en la variedad Packham’s Triumph. La enfermedad postcosecha más importante producida por B. cinerea en peras almacenadas en frío corresponde a la pudrición calicinal, cuyo control se realiza en floración, período en que el hongo produce infecciones latentes que se manifiestan en pudrición tras la madurez de la fruta. En años con primaveras húmedas se ha observado un aumento de la incidencia de la enfermedad, lo cual ha generado cuestionamientos acerca de los tratamientos de control e incertidumbre sobre la capacidad del patógeno de infectar los frutos durante su crecimiento. Los objetivos del presente estudio fueron determinar la ocurrencia de infecciones en campo durante el período de crecimiento de frutos bajo condiciones artificiales de alta humedad con y sin inoculación del patógeno, y determinar el nivel de infección en precosecha para evaluar la efectividad de las medidas de control realizadas por los productores en dos huertos comerciales de la zona central de Chile. En uno de los huertos estudiados se determinó que las inoculaciones lograron generar infecciones en el período de crecimiento de frutos, lo que permite concluir que el patógeno efectivamente puede infectar peras cv. Packham’s Triumph durante el crecimiento de los frutos. Por otro lado, el patógeno fue recuperado desde la cavidad calicinal de fruta no inoculada en crecimiento en ambos huertos, observándose también pudrición calicinal en postcosecha, lo que sería consecuencia de la inefectividad de las aplicaciones de fungicidas realizadas en floración por los productores. Este trabajo establece una base para la realización de estudios en campo en pudrición calicinal de perales en Chile. / Botrytis cinerea Pers. causes significant levels of postharvest decay that may be over 10% in pear fruit in Chile, especially in the cultivar Packham's Triumph. Calyx-end rot is the most important postharvest disease caused by B. cinerea in stored pears, and its control is achieved in the flowering period, when the fungus produces latent infections that manifest in fruit decay after ripening. It has been observed that there is an increased incidence of the disease in years with humid and rainy conditions during spring and summer, which has raised questions about control treatments and pathogen's ability to infect fruit during its growth under these conditions. The objectives of this study were to determine the occurrence of infections in the orchard during fruit growth under artificial high humidity conditions with and without pathogen inoculation, and to determine the level of preharvest infection in order to evaluate the efficacy of control measures taken by the growers in two commercial orchards of central Chile. In one of the studied orchards, inoculations resulted in infections during fruit growth, leading to the conclusion that the pathogen can effectively infect Packham's Triumph pears during this period. Moreover, the pathogen was isolated from the calyx cavity of non-inoculated fruit during the growth period, and postharvest calyx-end decay was also observed, which would indicate the inefficacy of fungicide applications performed by the growers. This work provides basic information for further field studies on calyx-end rot of pears in Chile.

Tesis para optar al Grado de Magíster en Ciencias Agropecuarias, Mención Producción Frutícola

Made available in DSpace on 2014-06-11T19:33:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-04-16Bitstream added on 2014-06-13T19:23:49Z : No. of bitstreams: 1 000739516.pdf: 1650325 bytes, checksum: a1b57134d48fa771d7c3cfd4a0dce580 (MD5) / As espécies de Trichoderma spp. e Clonostachys rosea são bastante estudadas atualmente para o controle biológico de doenças de plantas. O objetivo deste trabalho foi avaliar o potencial dos antagonistas, Trichoderma asperellum (LQC96) e Clonostachys rosea (LQC62), no controle biológico das principais doenças fúngicas de begônia (mofo cinzento, mancha de Mirotécio e podridão do colo). A etiologia da podridão do colo em begônias foi estudada por meio das análises de suas características morfológicas e moleculares. Foram realizados ensaios in vitro a fim de verificar os mecanismos envolvidos no controle biológico dessas doenças, avaliados por meio da produção de compostos voláteis e compostos solúveis com ação inibitória aos patógenos, além da capacidade hiperparasítica dos antagonistas. A metodologia para avaliar os compostos voláteis consistiu em posicionar dois fundos de placas de Petri sobrepostas, contendo em uma delas cultura do antagonista e em outra, do patógeno. Para avaliar os compostos solúveis, foram utilizadas duas metodologias, o método em cultivo sobre o papel celofane para LQC96 e o método do filtrado da cultura líquida para LQC62. O hiperparasitismo foi avaliado por meio de culturas pareadas. Verificou-se a colonização e a supressão da esporulação em discos e em hastes de begônias. Após a análise do potencial in vitro, foram realizadas ensaios em casa de vegetação, a fim de verificar o controle dessas doenças em cultivo comercial de begônia. Nos ensaios in vitro, verificou-se que os antagonistas tiveram atividade antagônica contra esses patógenos, com a produção de compostos voláteis e solúveis, além de demonstrar a capacidade hiperparasítica de ambos antagonistas. Ambos agentes de controle biológico avaliados foram capazes de colonizar os discos e hastes de begônia e a aplicação preventiva na concentração de... / Currently the species of Trichoderma spp. and Clonostachys rosea are widely studied for biological control of plant diseases. The aim of this study was to evaluate the potential of these isolates these antagonists (T. asperellum LQC96 and C. rosea LQC62) in the biological control of major fungal diseases of begonia (gray mold, Myrothecium leaf spot and stem rot). The etiology of stem rot was studied using morphological and molecular analysis. In vitro assays were performed to verify the mechanisms involved in the biological control of these diseases, measured by the production of volatile and soluble compounds with an inhibitory effect on pathogens and the ability of antagonist hyperparasitism. The methodology for assessing the volatiles consisted of placing two Petri dishes superimposed on one culture containing the antagonist and another pathogen. To evaluate soluble compounds, two methods were used, the cultivation on cellophane for LQC96 and and the culture liquid filtrate method for LQC62. The hyperparasitism was assessed using paired cultures. There colonization and suppression of sporulation was evaluate on leaf disks and stem of begonias. After analysis of the potential in vitro assays, were performed in a greenhouse in order to verify the control of these diseases in commercial cultivation of begonia. In vitro assays was found that the antagonists were antagonistic activity against these pathogens, producing volatile and soluble compounds, and demonstrate the ability of hyperparasitism. Both biocontrol agents evaluated were able to colonize the leaf discs and stem of begonia and preventive application in concentration of 1x107 conidia mL-1 proved to be the most effective in suppressing pathogen sporulation on leaf discs and stem of begonia. The essay on commercial cultivation decreased the incidence of diseases with weekly application of antagonists. For control of gray mold and ...

Orientador: Antonio de Goes / Coorientador: Marcelo Augusto Boechat Morandi / Coorientador: Káthia Fernandes Lopes Pivetta / Banca: Rita de Cássia Panizzi / Banca: Edson Luiz Furtado / Banca: Adelmo Golynski / Banca: Helson Martins do Vale / Resumo: As espécies de Trichoderma spp. e Clonostachys rosea são bastante estudadas atualmente para o controle biológico de doenças de plantas. O objetivo deste trabalho foi avaliar o potencial dos antagonistas, Trichoderma asperellum (LQC96) e Clonostachys rosea (LQC62), no controle biológico das principais doenças fúngicas de begônia (mofo cinzento, mancha de Mirotécio e podridão do colo). A etiologia da podridão do colo em begônias foi estudada por meio das análises de suas características morfológicas e moleculares. Foram realizados ensaios in vitro a fim de verificar os mecanismos envolvidos no controle biológico dessas doenças, avaliados por meio da produção de compostos voláteis e compostos solúveis com ação inibitória aos patógenos, além da capacidade hiperparasítica dos antagonistas. A metodologia para avaliar os compostos voláteis consistiu em posicionar dois fundos de placas de Petri sobrepostas, contendo em uma delas cultura do antagonista e em outra, do patógeno. Para avaliar os compostos solúveis, foram utilizadas duas metodologias, o método em cultivo sobre o papel celofane para LQC96 e o método do filtrado da cultura líquida para LQC62. O hiperparasitismo foi avaliado por meio de culturas pareadas. Verificou-se a colonização e a supressão da esporulação em discos e em hastes de begônias. Após a análise do potencial in vitro, foram realizadas ensaios em casa de vegetação, a fim de verificar o controle dessas doenças em cultivo comercial de begônia. Nos ensaios in vitro, verificou-se que os antagonistas tiveram atividade antagônica contra esses patógenos, com a produção de compostos voláteis e solúveis, além de demonstrar a capacidade hiperparasítica de ambos antagonistas. Ambos agentes de controle biológico avaliados foram capazes de colonizar os discos e hastes de begônia e a aplicação preventiva na concentração de ... / Abstract: Currently the species of Trichoderma spp. and Clonostachys rosea are widely studied for biological control of plant diseases. The aim of this study was to evaluate the potential of these isolates these antagonists (T. asperellum LQC96 and C. rosea LQC62) in the biological control of major fungal diseases of begonia (gray mold, Myrothecium leaf spot and stem rot). The etiology of stem rot was studied using morphological and molecular analysis. In vitro assays were performed to verify the mechanisms involved in the biological control of these diseases, measured by the production of volatile and soluble compounds with an inhibitory effect on pathogens and the ability of antagonist hyperparasitism. The methodology for assessing the volatiles consisted of placing two Petri dishes superimposed on one culture containing the antagonist and another pathogen. To evaluate soluble compounds, two methods were used, the cultivation on cellophane for LQC96 and and the culture liquid filtrate method for LQC62. The hyperparasitism was assessed using paired cultures. There colonization and suppression of sporulation was evaluate on leaf disks and stem of begonias. After analysis of the potential in vitro assays, were performed in a greenhouse in order to verify the control of these diseases in commercial cultivation of begonia. In vitro assays was found that the antagonists were antagonistic activity against these pathogens, producing volatile and soluble compounds, and demonstrate the ability of hyperparasitism. Both biocontrol agents evaluated were able to colonize the leaf discs and stem of begonia and preventive application in concentration of 1x107 conidia mL-1 proved to be the most effective in suppressing pathogen sporulation on leaf discs and stem of begonia. The essay on commercial cultivation decreased the incidence of diseases with weekly application of antagonists. For control of gray mold and ... / Doutor

Memoria para optar al Título Profesional de Ingeniero Agrónomo / El control de enfermedades de poscosecha es una problemática constante en la producción de uva de mesa, siendo Botrytis cinerea y Penicillium expansum, dos de los patógenos más importantes. El cuestionamiento a la cantidad máxima de residuos de agroquímicos permitidos en la fruta en los mercados de destino y la acotada cantidad de fungicidas disponibles en el mercado, han llevado a la búsqueda de alternativas a los fungicidas sintéticos, la cual se ha enfocado a productos naturales, amigables con el medio ambiente y libres de residuos. El principal objetivo de este estudio fue evaluar la actividad de 15 extractos de macrohongos en el control de ambos patógenos. Los macrohongos fueron colectados desde su ambiente natural, posteriormente secados, triturados y macerados en alcohol al 95%, y los extractos resultantes fueron utilizados en bioensayos de inhibición in vitro e in vivo. Para el control in vitro se enmendó agar papa dextrosa con cada extracto en etanol al 1% donde se sembró micelio y conidias de los patógenos. El control in vivo se realizó sobre bayas de uva de mesa del cv. Red Globe sometidas o no a desinfección previa con NaClO (0,5%). A las bayas se les realizó una herida y luego se aplicaron los extractos 1 y 24 horas antes de la inoculación con conidias de los patógenos. Los extractos con mayor efectividad inhibitoria in vitro del crecimiento miceliar de B. cinerea fueron Suillus luteus, Agarical sp. y Amanita sp. los que inhibieron en un 92,9, 71,0 y 69,4%, respectivamente. Para el control in vitro de P. expansum los dos extractos que tuvieron un mayor efecto fueron los de Agarical sp. y Agaricus arvensis con un 35,3 y 34,6% de inhibición del crecimiento miceliar, respectivamente. Los extractos con mayor efectividad en la inhibición de la germinación de conidias fueron: Agarical sp. y Macrolepiota rhacodes, para B. cinerea, y Agaricus arvensis y Laetiporus sulphureus para P. expansum. En el control in vivo solo el extracto de Amanita sp. tuvo un efecto en la inhibición de la pudrición causada por B. cinerea sobre las bayas, aplicado 24 horas antes de la inoculación, e igualmente en bayas sin desinfectar inoculadas con P. expansum. / Postharvest rots of table grapes are a constant problem for the industry with Botrytis cinerea and Penicillium expansum as the most important pathogens. Restrictions on the maximum amount of pesticide residues allowed on the fruit, and the limited number of fungicides registered in the markets have prompted the look for alternatives to the traditional chemical fungicides, focusing mainly on natural products environmentally friendly and free from residue restrictions. This study was aimed to evaluate the activity of 15 extracts of mushrooms in the control of both pathogens. The mushrooms were collected from their natural sources, dried, grounded and macerated in ethanol 95%, and the extracts obtained were evaluated in vitro and in vivo. Potato dextrose agar media was amended with the ethanol extracts at a rate of 1%, for the in vitro tests with mycelia or conidia of the pathogens. In vivo assays were conducted on Red Globe berries that were surface disinfected with NaOCl (0,5 %) or not disinfected at all. The berries were wound inoculated with a spore suspension of each pathogen 1 or 24 hours after the extracts treatments. The extracts that gave the greatest inhibition of the mycelial growth of B. cinerea were those of Suillus luteus, Agarical sp. and Amanita sp, which gave a 92.9, 71.0 and 69.4 % inhibition, respectively. While the extracts with the higher inhibition of the mycelial growth of P. expansum were those of Agarical sp. and Agaricus arvensis with 35.3 and 34.6 % inhibition, respectively. The extracts with the higher inhibition of the conidia germination were those of Agarical sp. and Macrolepiota rhacodes, for B. cinerea, and Agaricus arvensis and Laetiporus sulphureus for P. expansum. Only the extract of Amanita sp. reduced the rot caused by B. cinerea when applied 24 hours before berry inoculation and the rot caused by P. expansum on berries that were not disinfected.