Academic literature on the topic 'Phytophthora cinnamomi control'
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Journal articles on the topic "Phytophthora cinnamomi control"
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Benson, D. M., and Frank A. Blazich. "Control of Phytophthora Root Rot of Rhododendron chapmanii A. Gray with Subdue." Journal of Environmental Horticulture 7, no. 2 (June 1, 1989): 73–75. http://dx.doi.org/10.24266/0738-2898-7.2.73.
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Abstract Rooted cuttings of Chapman's rhododendron (Rhododendron chapmanii) in soilless medium were challenged with inoculum of the soi1borne fungus, Phytophthora cinnamomi (Rands). A portion of the plants received a soil drench of Subdue 2EC (metalaxyl) at 0.16 ml/L (2.0 oz/100 gal) at 2 month intervals. Chapman's rhododendron was highly susceptible to P. cinnamomi, but five of six plants treated with Subdue did not develop symptoms of Phytophthora root rot. In the one plant which developed root rot symptoms, P. cinnamomi was recovered in culture.
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Downer, A. J., J. A. Menge, and E. Pond. "Association of Cellulytic Enzyme Activities in Eucalyptus Mulches with Biological Control of Phytophthora cinnamomi." Phytopathology® 91, no. 9 (September 2001): 847–55. http://dx.doi.org/10.1094/phyto.2001.91.9.847.
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A series of samples were taken from mulched and unmulched trees starting at the surface of mulch or soil to a 15 cm soil depth, forming a vertical transect. Saprophytic fungi isolated from the soil samples on rose bengal medium and surveyed visually were most abundant in mulches and at the interface of mulch and soil (P < 0.05). Microbial activity as assayed by the hydrolysis of fluorescein diacetate was significantly greater in mulch layers than in soils. Cellulase and laminarinase enzyme activities were greatest in upper mulch layers and rapidly decreased in soil layers (P < 0.05). Enzyme activities against Phytophthora cinnamomi cell walls were significantly greater in mulch than in soil layers. When Phytophthora cinnamomi was incubated in situ at the various transect depths, it was most frequently lysed at the interface between soil and mulch (P < 0.001). Roots that grew in mulch layers were significantly less infected with Phytophthora cinnamomi than roots formed in soil layers. In mulched soil, roots were commonly formed at the mulch-soil interface where Phytophthora populations were reduced, whereas roots in unmulched soil were numerous at the 7.5 cm depth where Phytophthora cinnamomi was prevalent. Enzyme activities were significantly and positively correlated with each other, microbial activity, and saprophytic fungal populations, but significantly and negatively correlated with Phytophthora recovery.
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Gastañadui, Paul, Rocío Moreno, Patricia Elena Quiroz-Delgado, and Walter Eduardo Apaza-Tapia. "Control of avocado root rot caused by Phytophthora cinnamomi with different Trichoderma strains at Chavimochic Irrigation Project." Peruvian Journal of Agronomy 5, no. 3 (December 30, 2021): 78–86. http://dx.doi.org/10.21704/pja.v5i3.1846.
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Avocado root rot caused by Phytophthora cinnamomi is one of the main problems affecting avocado (Persea americana) cultivation in Peru, especially at the Chavimochic Irrigation Project. The objective of this study was to evaluate the effect of different Trichoderma strains on the control of Phytophthora cinnamomi in Zutano rootstock under greenhouse conditions. Five isolates of Trichoderma were tested: Trichoderma sp. (Chav01); Trichoderma harzianum (Chavo2); Trichoderma harzianum (UNALM01); Trichoderma viride (UNALM02); and a commercial strain of Trichoderma sp. Evaluations were performed at 30, 45, and 60 days. All isolates colonized the rhizosphere of the avocado. No relation was found between the formation of more Trichoderma colonies and Phytophthora improved control. All strains controlled the root rot, but Chav01 and Chav02 showed the greatest diameter of stem, dry matter in the root, and percentage of healthy root in comparison with UNALM01, UNALM02, and the commercial strain. Thus, the native isolates of Trichoderma from the Chavimochic area can be added to the list of potential new Trichoderma species to control Phytophthora cinnamomi.
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Alvarado, Laureano, Sebastián Saa, Italo F. Cuneo, Romina Pedreschi, Javiera Morales, Alejandra Larach, Wilson Barros, Jeannette Guajardo, and Ximena Besoain. "A Comparison of Immediate and Short-Term Defensive Responses to Phytophthora Species Infection in Both Susceptible and Resistant Walnut Rootstocks." Plant Disease 104, no. 3 (March 2020): 921–29. http://dx.doi.org/10.1094/pdis-03-19-0455-re.
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Clonal rootstocks are one alternative used by the walnut industry to control damage caused by Phytophthora species, traditionally using plants grafted on susceptible Juglans regia rootstock. Vlach, VX211, and RX1 are clonal rootstocks with a degree of resistance to Phytophthora species. The resistance to pathogens in these rootstocks depends on the resistance mechanisms activated by the presence of the pathogen and subsequent development of responses in the host. In this work, we analyzed how plants of J. regia, Vlach, VX211, and RX1 responded to inoculation with Phytophthora cinnamomi or Phytophthora citrophthora isolates obtained from diseased English walnut plants from Chilean orchards. After inoculation, plants of Vlach, VX211, and RX1 showed canopy and root damage indexes that did not differ from noninoculated control plants. In contrast, plants of J. regia, which is susceptible to P. cinnamomi and P. citrophthora, died after inoculation. Vlach, VX211, and RX1 plants inoculated with P. cinnamomi or P. citrophthora showed greater root weight and volume and greater root growth rates than their respective controls. These results suggest that short-term carbohydrate dynamics may be related to the defense mechanisms of plants; they are immediately activated after inoculation through the production of phenolic compounds, which support the further growth and development of roots in walnut clonal rootstocks. To our knowledge, this is the first study that comprehensively characterizes vegetative and radicular growth and the dynamics of sugars and phenols in response to infection with P. cinnamomi or P. citrophthora in walnut rootstocks.
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Andrade-Hoyos, Petra, Omar Romero-Arenas, Hilda Victoria Silva-Rojas, Alfonso Luna-Cruz, José Espinoza-Pérez, Aarón Mendieta-Moctezuma, and José Alberto Urrieta-Velázquez. "Cinnamom verum Plantations in the Lowland Tropical Forest of Mexico Are Affected by Phytophthora cinnamomi, Phylogenetically Classified into Phytophthora Subclade 7c." Horticulturae 9, no. 2 (February 2, 2023): 187. http://dx.doi.org/10.3390/horticulturae9020187.
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Cinnamon is a tree introduced to the lowlands of Mexico in the mid-16th century, but it spread to other places at the beginning of the 20th century due to its important commercial value as an aromatic spice. In the state of Veracruz, symptoms of dieback have been observed in 12-year-old cinnamon plantations cultivated in an agroforestry system, causing concern among producers. For this reason, the present investigation was carried out to determine the causal agent of these symptoms observed in cinnamon trees. Fifty symptomatic plants were recovered from established plantations. One hundred cinnamon root fragments showing dieback were selected and separated; isolates were made from tissue showing crown and root rot on clarified juice V-8 agar medium. After eight days, the growth of whitish coralloid mycelium with characteristics similar to the Phytophthora oomycete was consistently observed. Subsequently, the identity corresponding to P. cinnamomi was confirmed by morphological, taxonomic studies and Bayesian inference of the rDNA internal transcribed spacer. The pathogenicity test was performed on 20 6-month-old cinnamon plants grown in pots by inoculating 2.5 × 104/mL of zoospores around the roots. Control plants were inoculated with sterile distilled water and kept in a greenhouse under conditions controlled. After five weeks, symptoms of root rot were observed in the inoculated plants; however, the control group plants remained healthy. The results showed that P. cinnamomi subclade 7c was responsible for the symptoms observed in lowland cinnamon plantations in Mexico. Our findings suggest that this phytopathogen is a new threat for cinnamon growers; likewise, it is recommended that growers implement management strategies to avoid its introduction into nurseries or new plantations that could be susceptible to this pathogen.
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Agapito Amador, María Eugenia, Víctor David Cibrián-Llanderal, Mónica Gutiérrez Rojas, Daniel Ruiz-Juárez, Betzabe Ebenhezer López Corona, and Edgar Omar Rueda-Puente. "Phytophthora cinnamomi Rands en aguacate." Revista Mexicana de Ciencias Agrícolas, no. 28 (September 22, 2022): 331–41. http://dx.doi.org/10.29312/remexca.v13i28.3287.
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El objetivo de la presente revisión es dar a conocer el estatus epidemiológico de Phytophthora cinnamomi Rands en interacción con Persea americana Mill. y las alternativas de manejo fitosanitario autorizadas. El ensayo se realizó con base en reportes de instancias oficiales y científicas en materia de sanidad vegetal, de brotes epidemiológicos de la enfermedad tristeza del aguacate causada por P. cinnamomi. A nivel mundial, la pérdida de árboles de aguacate fue exponencial, debido a la enfermedad causada por el oomiceto P. cinnamomi quien presentó comportamiento epidemiológico a nivel nacional e internacional. En 1942, en Puerto Rico el patógeno fue aislado por primera vez por Tucker en plantas de aguacate. En México, el primer brote epidemiológico por este patógeno fue en 1952, con pérdidas de 90% de la producción de aguacate, la distribución de la enfermedad se expandió a diferentes partes del mundo. En condiciones favorables afecta la raíz y base de la corona, invade haces vasculares y toma los nutrientes para su desarrollo. La patogénesis es influenciada por la temperatura, precipitación, humedad, pH, disponibilidad de nutrientes y textura del suelo. En campo, la efectividad biológica de las moléculas, para el control del oomiceto, puede presentar limitantes que impactan en la microbiota, flora y fauna; además, de los efectos que se reflejan en la calidad e inocuidad de frutos por la acumulación de moléculas de plaguicidas sintéticos. Dada la situación fitosanitaria que expresa la producción de aguacate es necesario implementar alternativas de manejo sustentable, como la endoterapia, a través de la inyección de productos selectivos en dosis específicas, que controlen a la enfermedad sin afectar la calidad e inocuidad del fruto.
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Sumida, Ciro Hideki, Lucas Henrique Fantin, Karla Braga, Marcelo Giovanetti Canteri, and Martin Homechin. "Control of root rot (Phytophthora cinnamomi) in avocado (Persea Americana) with bioagents." Summa Phytopathologica 46, no. 3 (September 2020): 205–11. http://dx.doi.org/10.1590/0100-5405/192195.
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ABSTRACT Despite the favorable edaphoclimatic conditions for avocado production in Brazil, diseases such as root rot caused by the pathogen Phytophthora cinnamomi compromise the crop. With the aim of managing root rot in avocado, the present study aimed to evaluate chemical and biological control with isolates of Trichoderma spp. and Pseudomonas fluorescens. Thus, three assays were conducted to assess: (i) mycelial inhibition of P. cinnamomi by isolates of Trichoderma spp. and P. fluorescens from different crop systems; (ii) effect of autoclaved and non-autoclaved metabolites of P. fluorescens, and (iii) chemical or biological treatment of avocado seedlings on the control of root rot under field conditions. The isolates of Trichoderma spp. from maize cultivation soil and the commercial products formulated with Trichoderma presented greater antagonism (p <0.05) to the pathogen P. cinnamomi in the in vitro tests. Similarly, non-autoclaved metabolites of P. fluorescens presented antagonistic potential to control P. cinnamomi. Under field conditions, the fungicide metalaxyl and the bioagents showed effectiveness in controlling P. cinnamomi, as well as greater root length and mass. Results demonstrated potential for the biological control of avocado root rot with Trichoderma spp. and P. fluorescens.
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Saiz-Fernández, Iñigo, Ivan Milenković, Miroslav Berka, Martin Černý, Michal Tomšovský, Břetislav Brzobohatý, and Pavel Kerchev. "Integrated Proteomic and Metabolomic Profiling of Phytophthora cinnamomi Attack on Sweet Chestnut (Castanea sativa) Reveals Distinct Molecular Reprogramming Proximal to the Infection Site and Away from It." International Journal of Molecular Sciences 21, no. 22 (November 12, 2020): 8525. http://dx.doi.org/10.3390/ijms21228525.
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Phytophthora cinnamomi is one of the most invasive tree pathogens that devastates wild and cultivated forests. Due to its wide host range, knowledge of the infection process at the molecular level is lacking for most of its tree hosts. To expand the repertoire of studied Phytophthora–woody plant interactions and identify molecular mechanisms that can facilitate discovery of novel ways to control its spread and damaging effects, we focused on the interaction between P. cinnamomi and sweet chestnut (Castanea sativa), an economically important tree for the wood processing industry. By using a combination of proteomics, metabolomics, and targeted hormonal analysis, we mapped the effects of P. cinnamomi attack on stem tissues immediately bordering the infection site and away from it. P. cinnamomi led to a massive reprogramming of the chestnut proteome and accumulation of the stress-related hormones salicylic acid (SA) and jasmonic acid (JA), indicating that stem inoculation can be used as an easily accessible model system to identify novel molecular players in P. cinnamomi pathogenicity.
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D'Souza, Nola K., Ian J. Colquhoun, Bryan L. Shearer, and Giles E. St J. Hardy. "The potential of five Western Australian native Acacia species for biological control of Phytophthora cinnamomi." Australian Journal of Botany 52, no. 2 (2004): 267. http://dx.doi.org/10.1071/bt03089.
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Five Acacia species native to Western Australia were assessed for their potential to protect the highly susceptible species Banksia grandis Wield from infection by the plant pathogen Phytophthora cinnamomi Rands. In a rehabilitated bauxite pit at Jarrahdale 55 km south-east of Perth and in a glasshouse trial, B. grandis planted either alone or with A. pulchella R.Br., A. urophylla Benth., A. extensa Lindl., A. lateriticola Maslin or A. drummondii Lindl., was soil inoculated with P. cinnamomi. It could only be shown that A. pulchella significantly protected B. grandis from P. cinnamomi infection in the rehabilitated bauxite pit trial up to 1 year after inoculation. This confirms the potential of this species for biological control of the pathogen in infested plant communities. The observed protection was not the result of a decrease in soil temperature or moisture. Protection was not emulated in a glasshouse trial where optimum environmental conditions favoured P. cinnamomi. Despite a delay in infection of B. grandis planted with Acacia spp., none of the five species definitively protected B. grandis from P. cinnamomi. However, in the glasshouse trial, A. pulchella, A. extensa, A. lateriticola and A. drummondii did significantly reduce the soil inoculum of P. cinnamomi, indicating a possible biological control effect on the pathogen. The mechanisms of biological control are discussed and the implications for management of rehabilitated bauxite mined areas and forests severely affected by P. cinnamomi are considered.
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Onsando, J. M., and C. N. Gathungu. "CONTROL OF AVOCADO ROOT ROT CAUSED BY PHYTOPHTHORA CINNAMOMI." Acta Horticulturae, no. 218 (January 1988): 351–54. http://dx.doi.org/10.17660/actahortic.1988.218.45.
Full textDissertations / Theses on the topic "Phytophthora cinnamomi control"
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Finlay, Annabelle Ruth. "Microbial suppression of Phytophthora cinnamomi." Thesis, Queen's University Belfast, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317116.
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Dunne, Christopher Philip. "Control of Sudden Death in Cultivated Proteas from the Southwest of Western Australia." Murdoch University, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20041207.140807.
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Phytophthora cinnamomi Rands is a common and devastating pathogen of cultivated proteas worldwide. Webb (1997) described a Sudden Death plant disease of proteas in Western Australia (WA) protea plantations. Proteas that suffer the syndrome display symptoms such as stunted growth, wilting, chlorosis and often death. In the current study, a number of protea plantations in the southwest of WA were visited to quantify the extent that P. cinnamomi was attributing to deaths of cultivated proteas. The survey indicated that P. cinnamomi is the major cause of Sudden Death in proteas. A range of other fungi (Fusarium, Botryosphaeria, Pestalotiopsis, Alternaria) and pests (nematodes, mealy bug, scale insects) were also identified to be contributing to protea death and decline in WA plantations. In many cases the factors contributing to protea disease appeared complex, with a range of physical factors or nutritional imbalances commonly associated with these pathogens and pests. As P. cinnamomi was the major cause of death of cultivated proteas the remainder of the experiments described in this dissertation investigated its control in horticultural plantings.
Biofumigation has the potential to become an important technique in an overall integrated management approach to P. cinnamomi. In this thesis, biofumigation refers to the suppression of pathogens and pests by the incorporation of Brassica plants into the soil. Two biofumigants (Brassica juncea (L.) Czern., B. napus L.) were screened for their effect on the in vitro growth of five common Phytophthora species (P. cinnamomi, P. cactorum (Lebert & Colin) Schroeter., P. citricola Sawada, P. cryptogea Pethyb. & Laff. and P. megasperma Drechsler). Growth was determined by the measuring dry weight and radial growth of vegetative hyphae. B. juncea was found to be superior in its suppressive effect compared to B. napus. There was also significant variation in the sensitivity of the Phytophthora species to the suppressive effects of the biofumigants. P. cinnamomi was the most sensitive of the five species investigated. Where the rates of the biofumigant were sufficient to suppress growth of Phytophthora, the suppressive effect was mostly fungicidal.
To determine how B. juncea and B. napus affect the infective ability and survival of P. cinnamomi, their effects on sporangia and chlamydospores production in soil was investigated in vitro. P. cinnamomi colonised Miracloth discs were added to soil amended with the two Brassica species, before being removed every two days over an eight day period for the determination of sporangia production, chlamydospore production and infective ability. Only the soils amended with B. juncea significantly reduced sporangia production in P. cinnamomi. Both Brassica species increased the percentage of aborted or immature sporangia and reduced the infective ability of the pathogen. Neither Brassica species had any effect on zoospore release or chlamydospore production in P. cinnamomi.
Soil cores and soil leachate were collected from biofumigant-amended field soils to determine the inoculum potential and infective ability of the pathogen under glasshouse conditions. Amending the soil with both Brassica species had an immediate suppressive effect on the inoculum potential and infective ability of the P. cinnamomi. However, after this initial suppression there was a gradual increase in the recovery of the pathogen over the monitoring period of four weeks. To determine if the suppression would result in decreased disease incidence in a susceptible host, Lupinus angustifolius L. seeds were planted in the biofumigant amended soil. B. juncea amended soils reduced the disease incidence of P. cinnamomi by 25%. B. napus had no effect on disease incidence in L. angustifolius.
Although the current study had demonstrated that biofumigants could suppress the growth, sporulation and infection of P. cinnamomi, it was unclear if this would equate to a reduction in disease incidence when applied in the field. A field trial was conducted on a protea plantation in the southwest of Western Australia that compared biofumigation with B. juncea to chemical fumigation (metham sodium) and soil solarisation. The three soil treatments were used in an integrated management approach to control P. cinnamomi that included the use of a hardwood compost, mulch and water sterilisation. All treatments were monitored during their application to ensure the treatments were conducted successfully. The three soil treatments significantly reduced the recovery of the pathogen and the infective ability of the pathogen to a soil depth of 20 cm. Metham sodium was the most suppressive soil treatment and soil solarisation was the least suppressive treatment. Only the metham sodium treatment resulted in a significant reduction in the incidence of root rot in Leucadendron salignum P.J. Bergius x laureolum (Lam.) Fourc (c.v. Safari Sunset) over the monitoring period of three years.
Another field trial was conducted on the same protea plantation to compare the effectiveness of B. juncea and B. napus, without the use of other control strategies, to reduce the incidence of P. cinnamomi infection of Leucadendron Safari Sunset. The concentration of isothiocyanates was monitored for seven days after the incorporation of the biofumigants. Although both Brassica species reduced the recovery and infective ability of the pathogen, neither biofumigant reduced the incidence of root rot in Leucadendron Safari Sunset.
In conclusion, P. cinnamomi is the most common and devastating pathogen in WA protea plantations. The current study demonstrated that P. cinnamomi is sensitive to the suppressive nature of biofumigants. Biofumigants can suppress the in vitro growth, sporulation, infective ability of P. cinnamomi and reduce the incidence of the disease caused by the pathogen in the glasshouse. Of the two Brassica species investigated, B. juncea was superior in its ability to control P. cinnamomi compared to B. napus. When applied in the field, biofumigation using B. juncea was found to be more suppressive that soil solarisation, but not as effective as metham sodium.
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Dunne, Christopher P. "Control of sudden death in cultivated proteas from the Southwest of Western Australia /." Access via Murdoch University Digital Theses Project, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20041207.140807.
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Bekker, Theo Frederik. "Efficacy of water soluble silicon for control of phytophthora cinnamomi root rot of avocado." Diss., Pretoria : [s.n.], 2007. http://upetd.up.ac.za/thesis/available/etd-09172007-084901.
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Aberton, Michael J., and lswan@deakin edu au. "The use of phosphite as a control for Phytophthora cinnamomi in southeastern Victorian vegetation communities." Deakin University. School of Biological and Chemical Sciences, 2005. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20060921.150649.
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One of the major aims of the research presented in this thesis was to assist managers of native vegetation communities in southeastern Australia in understanding the dynamics of P. cinnamomi with an important ecological species, Xanthorrhoea australis. It trialed the use of phosphite in large-scale field applications to establish the usefulness of this management option for the first time on Victorian flora.
This thesis describes the process of disease development within mature X. Australia plants. For the first time it was shown that within X. australis plants, secondary disease symptoms are related to the percentage of stem that has been infested by the disease. It was evident that after initial invasion the pathogen moves via root xylem and throughout the plant within vascular to the stem, especially within the desmium. The research shows that the pathogen could not be isolated consistently even though it was considered to be responsible for disease symptoms.
Trials of a control fungicide (Foli-R-fos 200) shows that protection occurs in many susceptible plants when 2 and 6g a.i./L phosphite is applied. Phytotoxicity occurred in native plants at Anglesea and within controlled environment trials when using ≥ 6g a.i./L. It will be shown that 2g a.i./L phosphite controls disease in sprayed plots within heathlands at Anglesea and a recently burnt coastal woodland community at Wilsons Promontory. The proportion of healthy X. australis plants treated with phosphite was significantly higher than the proportion in control plots without phosphite. The research shows that phosphite was recovered from leaves of three species treated with Foli-R-fos 200 in the field. For the first time it has been shown that seed germination was reduced in two species when high concentrations of phosphite were applied. The first documentation of the effect that phosphite has on soil properties showed that nitrogen and oxidised organic carbon were the only parameters to alter significantly.
This thesis provides answers to some important questions, answers that can now be used by managers in formulating better policies and actions at an operational level. There has been a dire need in Victoria to address many issues regarding P. cinnamomi and this thesis provides relevant and informative approaches to disease control, and a better understanding of the disease progress.
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Favas, Melissa. "The role of active compounds produced by actinomycetes in the control of Phytophthora cinnamomi." Thesis, Favas, Melissa (1994) The role of active compounds produced by actinomycetes in the control of Phytophthora cinnamomi. Honours thesis, Murdoch University, 1994. https://researchrepository.murdoch.edu.au/id/eprint/32819/.
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The overall aim of this project was to screen actinomycetes for the ability to produce antibiotics inhibitory to P. cinnamomi in vitro. Some of the more promising isolates were then screened in vivo in a glasshouse pot-trial. The actinomycete isolates used had been previously isolated from jarrah forest soils suppressive to P. cinnamomi, ie. areas where P. cinnamomi was present in the soil but there was little evidence of disease. They had been isolated using dry heat pretreatments ( 120°C for one hour) designed to select for less frequently isolated actinomycetes especially the genus Microbispora.
Isolates were screened against P. cinnamomi in vitro for the production of secondary metabolites inhibitory to this pathogen. Of the isolates screened 40% caused strong inhibition of P. cinnamomi , 13% caused medium inhibition and 46% caused no inhibition of P. cinnamomi. Of the 40% of isolates that caused inhibition in vitro only ±4.0% of those tested for inhibition of P. cinnamomi in the pot-trial showed a potential for inhibiting P. cinnamomi in soil.
The pot-trial was performed using actinomycete isolates that had shown different levels of inhibition in vitro. Eight actinomycetes that had produced an antibiotic inhibitory to P. cinnamomi in vitro were tested in the pot-trial, 6 showing strong inhibition and 2 medium inhibition, but only 2 of these isolates a Streptomyces, isolate 97, and a maduromycete, isolate 55A, suppressed P. cinnamomi in vivo. In addition 2 of the 4 isolates with no in vitro inhibition of P. cinnamomi showed some activity against P. cinnamomi in the pot-trial. The results emphasised the fact that the production of an antibiotic in vitro does not automatically mean that the isolate will have the ability to control the pathogen in vivo.
The actinomycete isolates 97 and 55A which had shown strong inhibition in the in vitro screening were also screened against a range of fungal plant pathogens from different taxonomic groups. The fungal pathogens included representatives from the ascomycetes, hyphomycetes, basidiomyeetes and oomycetes. Eight other species of Phytophthora were also included. Isolate 97 showed the ability to strongly inhibit all of the fungal pathogens except Pythium ultimum which was only partially inhibited. Isolate 55A did not have the ability to inhibit Pythium ultimum but did inhibit all other pathogens to different degrees. Both isolates though showed that the antibiotics they produced were active over a range of different fungal taxonomy groups.
The metabolites from Streptomyces isolate 97 which showed strong activity against a range of fungal pathogens were extracted and purified from a broth culture filtrate. The antibiotic compound did not lose its ability to inhibit P cinnamomi through the extraction or purification process. Two antibiotic compounds were extracted, YB1 and YB2, both of which were inhibitory to P cinnamomi although YB2 was the stronger of the two. Antibiotics YBI and YB2 were also inhibitory to a few bacterial plant pathogens increasing the range of pathogens that could be inhibited by isolate 97.
Due to the wide range of pathogens inhibited by Streptomyces isolate 97 and its metabolites an attempt was made to further identify the isolate to species. There was not sufficient time to determine all the data required to identify the isolate by numerical classification, which requires data from 139 unit characters but a simple outdated key was used in the attempt. The use of the older key did not result in the identification of the isolate but the isolate was characterised morphologically and with respect to carbon source utilisation.
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D'Souza, Nola Kim. "Biological control of Phytophthora cinnamomi: The potential of Western Australian native legumes to protect susceptible plant species." Thesis, D'Souza, Nola Kim (2001) Biological control of Phytophthora cinnamomi: The potential of Western Australian native legumes to protect susceptible plant species. Honours thesis, Murdoch University, 2001. https://researchrepository.murdoch.edu.au/id/eprint/32764/.
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ABSTRACT The plant pathogen Phytophthora cinnamomi is having a major negative impact on the biodiversity of native ecosystems in the south west of Western Australia. Acacia pu/chella has previously been shown to suppress P. cinnamomi in the jarrah forest of Western Australia and protect susceptible species from infection. This has management implications for the control of P. cinnamomi in rehabilitated bauxite pits infested with the pathogen and severely diseased forest areas. The objective of this thesis was to determine if other Western Australian native legume species have the potential to biologically control P. cinnamomi.
In a rehabilitated bauxite pit trial, five Acacia species were planted with Banksia grandis, to determine their ability to protect this highly susceptible species against P. cinnamomi infection. A. pulchella protected B. grandis from infection for over a year. This protection was not the result of a decrease in soil moisture or soil temperature, as was previously suggested. A. urophylla, A. extensa, A. latericola and A. drummondii did not protect B. grandis in this trial. The trial was replicated in the glasshouse under conditions conducive to the pathogen. The infection of B. grandis by P. cinnamomi was delayed for up to 7 weeks by all of these Acacia species; however, none of them protected B. grandis from eventual mortality.
In a glasshouse soil inoculation trial, native legumes other than A. pulchella were able to reduce the soil inoculum potential of P. cinnamomi. Based on these findings, the species with the greatest potential for biological control of P. cinnamomi along with A. pulchella were A. extensa, A. stenoptera and A. a/ata. 11 By assessing the roots of soil inoculated native legumes from the glasshouse trial, P. cinnamomi was found to asymptomatically infect fine lateral roots of some species and sporulate from them. These species can potentially harbour the pathogen and allow for an inoculum increase when environmental conditions are favourable. A. urophylla and Viminaria juncea were the species with the least potential for biological control of P. cinnamomi due to this finding.
A possible management tool for bauxite pits in infested areas and in severely diseased forest areas is the ability to influence the density and composition of species used for rehabilitation, by manipulating the seed mix ratio. The implications of this study would be to increase seed in a seed mix of those legume species with the potential for biological control and decrease seed of those species that can harbour the pathogen. However, before rehabilitation management practices are adjusted, further investigation is required to understand how P. cinnamomi suppression occurs and whether it is transferable to a natural environment. The actions of P. cinnamomi suppression by legume species and future research directions are discussed.
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Auckland, Clare. "The dilution of phosphite in rapidly growing plants and how soil and plant phosphate levels interact with phosphite and its ability to control Phytophthora cinnamomi." Thesis, Auckland, Clare (2002) The dilution of phosphite in rapidly growing plants and how soil and plant phosphate levels interact with phosphite and its ability to control Phytophthora cinnamomi. Honours thesis, Murdoch University, 2002. https://researchrepository.murdoch.edu.au/id/eprint/32633/.
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The soil borne plant pathogen Phytophthora cinnamomi has irreversibly altered the make-up and diversity of the plant communities found in Australia. Recently, the fungicide phosphite has been used to effectively reduce the impact of this pathogen in natural plant communities. However, little is known (a) about how rapidly phosphite is diluted in the tissues of rapidly growing plants and (b) how soil and plant phosphate levels interact with phosphite and its ability to induce host-resistant responses when challenged by P. cinnamomi. This study examined the effects of different phosphite rates (0, 24 and 48 kg/ha phosphite) applied as a mist application on three size classes of Banksia grand is, as well as the interaction of phosphate status on two Eucalyptus marginata forest vegetation types differing in soil phosphate status with phosphite. It also examined, under controlled glasshouse conditions, the effects different soil phosphate levels had on in planta phosphite and phosphate levels in B. hookeriana, and the subsequent control of P. cinnamomi.
This study was the first to look at the role of phosphate in the soil and the plant, and its interaction with phosphite and the subsequent control of P. cinnamomi in planta. Results from the field trial indicated that phosphate in the soil did not play a role in the reducing the uptake of phosphite by the plant. It did suggest that stem and root colonisation was increased when phosphate in the soil was more plentiful. Further research is needed into this area.
This study was also the first to look at the distribution of phosphite in planta. The highest concentration of phosphite was in the leaves, followed by the stem and then roots. Ph9sphite in the plant tissue was found to increase as the phosphite applied to 5 the plants increased. Plants classed as seedlings showed more phytotoxic symptoms than the intermediate and semi-mature plants. The concentration of phosphite in the roots of the intermediate sized plants was more than double the amount found in the seedling and semi-mature plants. The concentration of phosphite in the whole plant, as well as in the leaves and stems per plant, increased as the plant size increased. This was supported by results that showed that as the dry weight of the leaves increased so did the amount of phosphite in the leaves. The same was seen with the dry weights of the stems and roots that correlated with phosphite in the stem and the roots, respectively.
Lesions and P. cinnamomi colonisation in the stems of non-phosphite treated plants were more than double those in stems of plants treated with 24 and 48 kg/ha phosphite. There was very little difference in the visible lesion lengths and P. cinnamomi colonisation between plants treated with 24 and 48 kglha of phosphite even though plants sprayed with 48 kg/ha phosphite had significantly more phosphite in their tissues than plants sprayed with 24kg/ha phosphite. This suggests that the phosphite in the plant may have been metabolised into another substance and that this substance was acting on the pathogen and/or the plant to reduce colonisation. This was further supported by no observed correlation between phosphite in the plant tissue and the extent of colonisation or visible stem lesion caused by P. cinnamomi. This was contradictory to other results in this study (Chapter 2) that clearly showed that phosphite did restrict the colonisation of the pathogen. Further research is needed into the mode of action of phosphite.
In the glasshouse trial, a non-invasive inoculation technique failed to infect B. hookeriana plants with the pathogen. However, this is likely due to very high ambient temperatures experienced during the trial, since a preliminary trial 18 days earlier resulted in extensive colonisation of all plants inoculated. As phosphate levels increased, stem colonisation by the pathogen increased in the presence of phosphite. There was no difference in the concentration of phosphite in the leaves. As phosphite applied increased, so did the concentration of phosphite in the root tissue.
This study shows that phosphate does interact with phosphite and the subsequent expression of P. cinnamomi, and as phosphate levels increased in planta so did the extent of colonisation by the pathogen. The exact nature of this interaction is still unknown and further research is required to better understand the nature of this relationship.
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Sampaio, Ana Rita Brito Chedas. "Selecção de plantas com efeito alelopático para controlar Phytophthora cinnamomi." Master's thesis, ISA/UL, 2017. http://hdl.handle.net/10400.5/13857.
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Mestrado em Engenharia Agronómica - Protecção das Plantas - Instituto Superior de Agronomia - ULO declínio dos Montados de sobro e azinho é uma doença que tem sido descrita desde a década de 80 do século passado e é influenciada pela interacção de factores bióticos e abióticos. Inúmeros estudos mostram uma associação entre espécies do género Phytophthora e o declínio dos Montados, sendo que Phytophthora cinnamomi é a espécie isolada com mais frequência nos solos desses ecossistemas. P. cinnamomi é um patogénio do solo, da classe Oomycota, que causa podridão radicular e, consequentemente, a morte da planta. A sua erradicação dos solos é muito difícil. Os produtos fitofarmacêuticos utilizados até ao momento não apresentam eficácia no seu controlo, pois o patogénio encontra-se disseminado nos solos e apresenta uma elevada gama de hospedeiros. Tais condicões favorecem a sua sobrevivência. Dado que a luta química para o controlo de P. cinnamomi tem-se mostrado ineficaz, é necessário procurar alternativas mais sustentáveis. Este trabalho teve como objectivo apresentar um primeiro contributo para a selecção de plantas com um efeito alelopático sobre P. cinnamomi. Para tal, seleccionaram-se doze espécies das seguintes famílias: Fabaceae, Poaceae, Lamiaceae e Brassicaceae. Avaliou-se a susceptibilidade das espécies selecionadas a P. cinnamomi em ensaios em estufa, tendo-se observado que três espécies foram infectadas. Realizaram-se ensaios in vitro de modo a testar os extractos aquosos radiculares das plantas e determinar os seus efeitos na actividade do patogénio através do seu crescimento micelial, produção de esporângios e clamidósporos bem como da viabilidade e germinação de zoósporos. Como resultado, seleccionou-se as espécies Eruca sativa e Raphanus raphanistrum por inibirem quase totalmente o crescimento e desenvolvimento do patogénio, O efeito inibitório total fna actividade do patogénio foi observado no extracto combinado das duas espécies. Por outro lado, os extractos de gramíneas, em particular de Lolium rigidum, tiveram um efeito promotorr do patogénio
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Martins, Maria de Fátima Tomé. "Caracterização do gene gip de Phytophthora cinnamomi Rands associado à doença da Tinta do castanheiro e pesquisa de novos fitofármacos no controlo da doença." Master's thesis, Instituto Politécnico de Bragança, Escola Superior Agrária, 2010. http://hdl.handle.net/10198/5817.
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Uma característica notável da interacção entre plantas e microrganismos patogénios de espécies de Phytophthora é a produção de proteínas inibidoras de glucanases (GIP) relacionadas com a doença da Tinta do castanheiro.
Dada a grande importância do castanheiro (Castanea sativa Mill) ao nível da economia e ecologia na região do Nordeste Transmontano, tornou-se necessário melhorar o conhecimento sobre os mecanismos de infecção de Phytophthora cinnamomi Rands, através do estudo da proteína GIP como mecanismo de resposta a proteínas hidrolíticas, endo-β-1,3-glucanases por parte da planta.
Este estudo, teve como objectivo clonar o gene gip e avaliar a expressão por gel de SDS-PAGE em diferentes tempos de indução e determinar em qual dos substratos naturais utilizados existe maior expressão por RT-qPCR. Paralelamente foram efectuados biotestes com plantas Castanea sativa Mill e com Phytophthora cinnamomi de modo a estudar a capacidade antimicrobiana de óleos essenciais extraídos de Mentha pulegium L. Os resultados deste estudo revelaram que a clonagem foi bem sucedida após a visualização em gel de agarose 0.8 % (v/v) de uma banda de 5369pb e outra de 940pb corresponde ao vector pET-28a(+) e á ORF do gene gip. A expressão da proteína verificou-se às 8 horas de indução pela presença de uma banda 31kDa observada por gel SDS-PAGE. A análise da expressão por RT-qPCR indicou que a expressão do gene gip é maior quando o patogénio cresce na presença de serrim 0.2 % (p/v) como substrato indutor. Os ensaios com óleos essenciais extraídos de Mentha pulegium L revelaram que a P. cinnamomi é inibida a uma concentração de 80 % (v/v), na qual a planta se mantem viavel e a sua sobrevivencia não é afectada. Desta forma o uso deste produto natural como agente activo é de grande importância, especialmente nas regiões que têm soutos como recursos naturais, de grande valor económico, podendo vir a ser uma alternativa ao controlo de P. cinnamomi.A remarkable characteristic of the interaction between plants and pathogen microorganisms of Phytophthora species is the production of inhibitory proteins of glucanases (GIP) related with the chestnut ink disease. Due to the great importance of the chestnut (Castanea sativa Mill) at economical and ecological levels in the Nordeste Transmontano region, became necessary to improve the knowledge about the infection mechanisms of Phytophthora cinnamomi Rands, through the study of GIP proteins, as a response mechanism to hydrolytic proteins, endo-β-1,3-glucanases, by the plant. In the present study was intended to clone the gene gip and to evaluate the expression by SDS-PAGE gel in different induction times and to determine in which natural substrates used there is a higher expression for RT-qPCR. At the same time were carried out bioassays with Castanea sativa Mill plants and Phytophthora cinnamomi in order to study the antimicrobial activity of the essential oils extracted from Mentha pulegium L. The results obtained revealed that the cloning was well succeeded after the visualization in a agarose 0.8 % (v/v) gel of two bands of 5369pb and 940pb corresponding respectively to the vector pET-28a(+) and to the ORF of the gip gene. The protein expression was observed at 8 hours of induction by the presence of a band of 31kDa in a SDS-PAGE gel. The analysis of expression by RT-qPCR shown that the expression of the gip gene is higher when the pathogen grows in the presence of 0.2 % sawdust (w/v) as a inductor substract. The essential oils extracted from Mentha pulegium L. revealed that P. cinnamomi is inhibited in a concentration of 80 % (v/v), in which the plant remains viable and its survival is not afected. By this way the use of this natural product as an active agent if of great importance, specially in the regions that have chestnut orchards as natural resources, with high economical value, and may ultimately be an alternative way in the control of P. cinnamomi.
Books on the topic "Phytophthora cinnamomi control"
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Shearer, B. L. Jarrah dieback: The dynamics and management of Phytophthora cinnamomi in the jarrah (Eucalyptus marginata) forest of south-western Australia. Como, W.A: Dept. of Conservation and Land Management, 1989.
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Hardy, Giles E. St. J., ed. The potential of the fungicide phosphite to control Phytophthora cinnamomi in native plant communities associated with mining. East Perth, WA: MERIWA, 2000.
Find full textBook chapters on the topic "Phytophthora cinnamomi control"
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Ávila Murillo, Mónica Constanza, Erika Andrea Plazas Gonzales, Wilman Antonio Delgado Ávila, and Luis Enrique Cuca Suarez. "Lauráceas como fuente de control de enfermedades de frutas tropicales. Modelo Phytophthora cinnamomi, “tristeza del aguacatero”." In Gulupa (Passiflora edulis), curuba (Passiflora tripartita), aguacate (Persea americana) y tomate de árbol (Solanum betaceum) Innovaciones, 229–49. Centro editorial Facultad de Ciencias, 2019. http://dx.doi.org/10.36385/fcbog-1-13.
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