<i>Trichoderma harzianum </i>and <i>Aneurinobacillus migulanus </i>were tested separately and in combination as potential biological control agents against <i>F. oxysporum </i>f. sp. <i>gladioli </i>on gladiolus in soil-less culture.  The major secondary metabolites produced by <i>Trichoderma harzianum </i>against <i>F. oxysporum </i>f. sp. <i>gladioli </i>in the treated gladiolus corms as well as in the potato dextrose broth were studied.  The impact of re-application times on the effectiveness of <i>Trichoderma harzianum </i>and <i>Aneurinobacillus migulanus </i>against gladiolus corm rot and Gladiolus production in soil-less culture was examined. Results showed that <i>T. harzianum </i>proved to use different mechanisms against <i>F. oxysporum </i>f. sp. <i>gladioli </i>depending on  the inoculation method. <i>T. harzianum </i>and <i>A. migulanus </i>reduced host defence enzymes.  Also, they increased GA ₃ and IAA content in the corms.  SEM showed that the suppressive mechanisms of <i>T. harzianum </i>and <i>A. migulanus </i>differed <i>T. harzianum </i>appeared to operate through a combination of antibiosis and substrate competition, 6-n-pentyl-6H-pyran-2-one (6PP) and harzianic acid (HA) were found as the main metabolites secreted by <i>T. harzianum.  </i>A significant positive correlation was revealed between qPCR and CFU for both <i>T. harzianum </i>and <i>F. oxysporum </i>f. sp. <i>gladioli.  </i>Multiple applications of <i>T. harzianum </i>and <i>A. migulanus </i>re- application was a successful strategy for suppression of <i>F. oxysporum </i>f. sp. <i>gladioli.  </i>Briefly, <i>T. harzianum </i>was more effective than <i>A. migulanus </i>in <i>F. oxysporum </i>f. sp. <i>gladioli </i>suppression and Gladiolus growth enhancement in soil-less culture. The mixing strategy between <i>T. harzianum </i>and <i>A. migulanus </i>failed.

Para prevenir que el consumidor rechace las bebidas deterioradas por mohos, es importante evaluar la probabilidad de que una determinada bebida sea deteriorada microbiológicamente antes que alcance su vida útil. Los modelos matemáticos, que son capaces de predecir el efecto de diferentes factores sobre el crecimiento fúngico, mejoran la toma de decisiones de la vida útil y optimizan las medidas de control durante la producción, siendo de gran utilidad como herramientas efectivas en el control de calidad de la industria de bebidas. Por esta razón, el objetivo principal de esta investigación fue usar el modelo logístico de la microbiología predictiva para determinar la probabilidad de crecimiento de Fusarium oxysporum en la bebida isotónica sabor mandarina, frente a dos condiciones de temperaturas de almacenamiento: 20 y 30 °C y a dos cargas de inóculo: 100 y 101 esporas/100 mL de bebida isotónica. Los resultados mostraron que el deterioro ocurrió más rápido a 30 °C con una carga de 101 esporas/100 mL de bebida isotónica (con un RMSE “Raíz del Error Cuadrático Medio” = 5.9196) que a 20 °C con 100 esporas/100 mL de bebida isotónica (RMSE = 5.4397) y el tiempo al crecimiento de Fusarium oxysporum decrece en función del incremento tanto de la temperatura de almacenamiento como del tamaño del inóculo. El menor valor de t10% (67.04 horas), que representa el tiempo que da la alerta a la industria de bebidas para recuperar los productos del mercado por un caso de contaminación, se obtuvo con un tratamiento de 101 esporas/100 mL de bebida isotónica a 30 °C. Este estudio logró demostrar que incluso a muy bajas concentraciones de inóculo, la bebida isotónica es deteriorada fácilmente por Fusarium oxysporum y el modelo logístico proporciona a la industria de bebidas un método rápido y de bajo costo para estimar el efecto de la temperatura de almacenamiento y tamaño del inóculo en la bebida isotónica. / Tesis

Thesis (M.S.)--University of Delaware, 2009. / Principal faculty advisor: Kirk J. Cymmek, Dept. of Biological Sciences. Includes bibliographical references.

3 pp. / This publication provides information on the development and management of Fusarium wilt of lettuce. Topics covered include the characteristics of the plant pathogen, disease development, and disease management considerations.

Growth chamber trials were performed to investigate optimal conditions for the small scale production of isolate M12-4A of Fusarium oxysporum on substrate materials that are locally available to subsistence farmers in West Africa. Field trials were conducted in Mali to evaluate the effectiveness of F. oxysporum for the control of Striga hermonthica and to determine the host range of F. oxysporum. F. oxysporum grew and colonized substrates over a range of temperatures (24, 28 and 32 C). Chopped sorghum straw pieces, straw fibres, and glumes supported abundant mycelial growth. Full colonization of the substrates was observed within 10 days. Production of infective propagules (microconidia and macroconidia) was optimum at 28 C. Optimum wetness of the substrates was obtained by soaking straw or glumes overnight. In field studies, the incorporation of 2.6 g of dried ground straw inoculum per sorghum seed pocket (120 cm$ sp2$), at a depth of 5 or 10 cm, resulted in a 60% reduction of emerged S. hermonthica 82 days after sowing. At harvest, biomass of Striga was also reduced by 70% and sorghum grain yield was almost doubled compared with the control. Sorghum, millet, maize, rice, fonio, cotton, cowpea, groundnut, okra and sorrel were immune to isolate M12-4A.

Fusarium oxysporum M12-4A fungus is being evaluated for the biocontrol of Striga hermonthica, a parasitic weed of African cereal crops. The production of M12-4A inoculum was assessed in four Malian villages using local technology and substrates. A delivery system using arabic gum to temporarily glue inoculum powder onto the crop seed was tested. In controlled conditions, coating of sorghum seeds with arabic gum and inoculum powder did not affect seed germination or inoculum viability. However, one week at 40°C significantly decreased the viability of the inoculum by 31%. Fungus growth and chlamydospore germination were also reduced by temperatures of 34 and 36°C. M12-4A was susceptible to the fungicide thiram (ED50 = 38.5mug). Field trials were conducted in Mali to evaluate the large-scale efficacy of the seed coating technology. F. oxysporum M12-4A was detected from some S. hermonthica tissue and soil samples using specific primers and Real Time PCR.

Thesis (M. Ag. Sci.) -- University of Adelaide, 1959. / [Typewritten]. Includes bibliography.

Thesis (M.Sc.). / Written for the Dept. of Plant Science. Title from title page of PDF (viewed 2008/12/10). Includes bibliographical references.

Zugl.: Hohenheim, Univ., Diss., 2009

Made available in DSpace on 2014-06-11T19:28:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-04Bitstream added on 2014-06-13T20:58:39Z : No. of bitstreams: 1 silva_jc_me_botfca.pdf: 186787 bytes, checksum: 6b00fb1158e56a1f4a6f91be11738372 (MD5) / A cultura do tomateiro é severamente atacada por diversas doenças, entre elas pode-se destacar a Murcha-de-Fusário. O objetivo do presente trabalho foi o de avaliar a eficiência de isolados de Fusarium oxysporum não patogênicos (Fnp) 233, 233/1, 245, 245/1, 141/3, 251, 251/2, 251/5, 257, originários da Universidade de Torino, Itália, no controle da Murcha-de-Fusário, causada por Fusarium oxysporum f. sp. lycopersici raças 1 e 2 (Fol). Os isolados patogênicos CA4A (Fol - 1), C-21A (Fol - 2), TO11 (Fol - 2) e TO245 (Fol - 2), bem como os isolados não patogênicos, foram cultivados em meio de cultura BD (batata-dextrose) durante 10 dias à 25ºC, com agitação constante de 150rpm. Para se obter estruturas de resistência do fungo 500 ml de inóculo líquido de cada isolado de Fnp foram adicionados em 1000 g de talco e incubados durante 30 dias. Com o intuito de verificar a patogenicidade dos isolados CA4A, C-21A, TO11 e TO245, plântulas de tomateiro cv. Viradoro foram transplantadas para substrato infestado com inóculo líquido nas concentrações de Fol de 103, 104, 105 e 106 conídios mL-1. Após 35 dias do transplante, as mudas foram avaliadas quanto a severidade da doença (Notas variando entre 1 a 6, onde: 1 planta sadia e 6 planta morta), a altura e as massas secas do sistema radicular e da parte aérea das plantas. As concentrações de 106 e 105 conídios mL-1 dos isolados de Fol promoveram a maior severidade da doença, quando comparadas com a testemunha não inoculada. Após determinar a concentração do patógeno, verificou-se a atividade não patogênica dos isolados de Fnp em plantas de tomateiro onde, raízes foram imersas em uma suspensão de conídios dos... . / The tomato is severely is affected by several diseases, among them may be detached the Fusarium wilt. The objective this present research was to evaluate the efficacy of the nonpathogenic Fusarium oxysporum strains (Fnp) 233, 233/1, 245, 245/1, 141/3, 251, 251/2, 251/5, 257, from the University of Torino, Italy, on the control of Fusarium wilt, caused by Fusarium oxysporum f. sp. lycopersici (Fol) races 1 and 2. The pathogenic strains CA4A race 1, C-21A race 2, TO11 race 2 and TO245 race 2, as well the nonpathogenic strains were growing in liquid media PD (potato-dextrose) during 10 days at 25ºC, with constant agitation at 150 rpm. To obtain resistant structure of the fungi 500 mL of the liquid inoculum with each the Fnp strain were mixed in 1000 g of talc and incubated for 30 days. To evaluate the pathogenic activity of the strains: CA4A (Fol - 1), C-21A (Fol - 2), TO11 (Fol - 2) e TO245 (Fol - 2), tomato seedlings cv. Viradoro susceptible to race 2 of the pathogen were transplanted into the infested substrate with inoculum suspension in the concentrations of Fol 103, 104, 105 e 106 conidia mL-1. After 35 days of the seedlings transplantation were evaluated the disease severity (Notes between 1 and 6, where: 1 health plant e 6 died plant), the height plants and the weight dry material of the root system and aerial part of the plants. The concentrations 106 e 105 conidia mL-1 of the strains de Fol increased the higher severity, when compared with non inoculated plants. After determination the concentration of the pathogen, observed the nonpathogenic activity of the Fnp strains in tomato plants where, roots were dipped in a conidial suspension in the concentration of the 106 conidia mL-1. The plants were growing into pots for the 500 mL capacity of the substrate and after 35 days of the growing in greenhouse were realized the evaluations. The plant... (Complete abstract, click electronic address below).