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The effects of some selected arbuscular mycorrhizal (AM) fungi, Gigaspora margarita and Glomus mossae on the growth and the role of soluble amino acids of two contrasting cocoa cultivars (ICS84 tolerant and SNK10 sensitive) against black pod disease caused by Phytophthora megakarya were investigated. Root colonization by AM fungi is between 50 and 70% 18 weeks after planting.inoculum of Phytophthora megakarya (causal agent of cacao black pod rot disease) upon establishment in 2006 were monitored for pres-ence of disease on a weekly basis from 2009 to 2016. Ripley’s K(r) function, join count statistics, and Fisher’s Exact test were used to analyze spatial and temporal disease dynamics. Disease distributionAfter 36 months of sampling and baiting, P. megakarya was isolated from the roots of four out of 34 shade tree species examined. The host trees were Funtumia elastica (Apocynaceae), Sterculia ...Phytophthora megakarya, the causative agent of cacao black pod disease in West African countries causes an extensive loss of yield.In this study we have analyzed 4 libraries of ESTs derived from Phytophthora megakarya infected cocoa leaf and pod tissues. Totally 6379 redundant sequences were retrieved from ESTtik database and EST processing was performed using seqclean tool.Phytophthora megakarya (Pmeg) and Phytophthora palmivora (Ppal) are closely related species causing cacao black pod rot. Although Although Ppal is a cosmopolitan pathogen, cacao is the only known ...In P. megakarya infection areas look for canker symptoms mainly on lower parts of the cocoa tree trunk at the beginning of the black pod season (when rains have started). ). This is because the disease mainly lives in theStudying spatial and temporal plant disease dynamics helps us to understand pathogen dispersal processes and improve disease control recommendations. In this study, three cacao plots devoid of primary inoculum of <i>Phytophthora megakarya</i> (causal agent of cacao black pod rot disease) upon establ …The black pod disease caused by Phytophthora megakarya is responsible for 80% of the cocoa production loss in Cameroon. To assess the resistance of cocoa plants against this pathogen, necrotic lesions, phenolic content and qualitative alteration of phenolics were conducted in ICS84 and ICS95 clones (two Trinitario introduced from Trinidad) and ...Phytophthora megakarya and P. palmivora are oomycete pathogens that cause black pod rot of cacao (Theobroma cacao), the most economically important disease on cacao globally. While P. palmivora is a cosmopolitan pathogen, P. megakarya , which is more aggressive on cacao than P. palmivora , has been reported only in West and Central Africa where ...Fungi belonging to the genus Trichoderma have been widely recognized as efficient controllers of plant diseases. Although the majority of isolates currently deployed, thus far, have been isolated from soil, endophytic Trichoderma spp. is considered to be a promising option for application in biocontrol. In this study, 30 endophytic Trichoderma …The negative control using sterile distilled water showed no inhibitory effect on Phytophthora megakarya while 41.00 mm zone of clearance was observed in the positive control test using Metalaxyl ...Phytophthora megakarya was more aggressive than P. palmivora on attached SCA-6 pods, causing expanding necrotic lesions with or without wounding. Phytophthora megakarya is predominant in the Volta region of Ghana and it remains to be seen whether it can displace P. palmivora from cacao plantations of Ghana as it has in Nigeria and Cameroon.Nov 17, 2021 · (From Brasier and Griffin, 1979).P. megakarya is a member of Group II of Phytophthora, as defined by Stamps et al. (1990).It produces caducous papillate sporangia, is heterothallic and antheridia are amphigynous.Sporangia are limoniform, obpyriform or ellipsoid with rounded bases, varying from 20-60 x 13-41 µm, with a length-breadth ratio of 1.2-1.6, and are formed in a sympodium. Phytophthora megakarya is an important pathogen of cocoa in Africa. We used isozyme and RAPD markers to estimate the genetic diversity and structuring among 161 isolates, from the known ...Nov 17, 2021 · Black pod disease of cocoa in West Africa, caused almost exclusively by P. megakarya, still remains one of the most serious constraints on cocoa production. Surveys during the 1978 and 1979 harvest season in Togo revealed losses of up to 80%, when no control measures were taken (Djiekpor et al., 1981). Erwin and Ribeiro (1996) estimated a 20-30 ... Jan 17, 2019 · Phytophthora palmivora is the most common, being present in most of the cacao-growing countries around the world, causing yield losses of 20–30% and tree deaths of 10% annually. Phytophthora megakarya occurs only in West and Central Africa countries but considered to be the most virulent among other species on cacao. Phytophthora megakarya is an increasingly important invasive pathogen of cocoa in West Africa, where it forms part of the black-pod disease complex together with the more widespread, but less aggressive, P. palmivora.Its purported centre of diversity, based on evidence from molecular studies and mating types, lies on the Cameroon-Nigeria border, from where it has spread throughout both ...Phytophthora megakarya is restricted to Cameroon, Nigeria, Togo, and Ghana, causing about 10 percent crop loss. Phytophthora capsici parasitizes cocoa in Central and South America. It is the predominant cause of pod rot in Brazil where it is less aggressive than Phytophthora palmivora. Phytophthora citrophthora also attacks cocoa in Brazil.PDF | On Jan 1, 2019, Simo Claude published Effect of Biofertilizers on the Phenolic Content in a Hybrid Family of Cacao After Leaf Infection with Phytophthora megakarya and Exogenous Application ...Phytophthora species produce a protein that has a similar sequence to the NEP1 of Fusarium oxysporium. Multiple copies of NEP1 orthologues have been identified in a P. megakarya strain and in four other Phytophthora species (P. citrophthora, P. capsici, P. palmivora and P. sojae) (Bae et al., 2005).Phytophthora isolates from coconut plantations in Indonesia and Ivory Coast: characterization and identification by morphology and isozyme analysis. Mycological Research, 98 (12):1379-1389. Google Scholar. Chang HS, Shu IM, 1988. Oospore germination of homothallic Phytophthora species and the identity of Phytophthora hevep isolates from Taiwan.Bioassay of Geniculosporium species for Phytophthora megakarya bPhytophthora megakarya is a devastating oomycete pathogen that causes Black pod rot, caused by Phytophthora megakarya, is the main cause of cocoa losses in Cameroon.A few studies have focused on describing black pod epidemics in cocoa yet numerous questions remain. Here, an epidemiological model describing the temporal evolution of cocoa black pod, taking into account the development stages of pods, is developed and studied. Black pod rot, caused by Phytophthora megakarya, is the m In Cameroon, Phytophthora megakarya is the causal agent of black pod rot of cacao (Theobroma cacao L). Primary inoculum of P. megakarya is located in the soil. With the onset of the rainy season ... Phytophthora megakarya (Pmeg) and Phytophthora palmivora

Phytophthora megakarya Brasier & Griffin, is one of the Oomycete pathogens reported on Theobroma cacao, and it is the most virulent of the Phytophthora species that causes black pod disease.Phytophthora megakarya was first reported as the causal agent of black pod disease in 1979 after the reclassification of Phytophthora species recovered from infected cacao tissues.Phytophthora palmivora (Butler) is an hemibiotrophic oomycete capable of infecting over 200 plant species including one of the most economically important crops, …Cocoa (Theobroma cacao L.) black pod rot, caused by oomycetes Chromista Phytophthora megakarya is the major constraint to cocoa production in Cameroon, causing substantial yield losses (up to 100%). As mean to alter the yield shortage, priority is given to chemical fungicides, though Arbuscular Mycorrhizals Fungi (AMF) have been pointed out to ...Nyassé, S., Despréaux, D., Cilas, C., Validity of a leaf inoculation test to assess the resistance to Phytophthora megakarya in a cocoa (Theobroma cacao L.) diallel mating design, Euphytica 123 (2002) 395 – 399. CrossRef Google Scholar

Jun 1, 2023 · 1. Introduction. Black pod disease, caused by Phytophthora megakarya, is one of the major diseases of cocoa that small-scale farmers are facing in West and Central Africa. In Cameroon, severe economic losses in cocoa production, which ranged from 30% to 80% were caused by this disease in all cocoa-growing regions where no proper control measures were applied [1], [2], [3]. Phytophthora megakarya, a Causal Agent of Black Pod Rot in Africa 1 Introduction. Phytophthora megakarya (Brasier and Griffin 1979 ), one of several ……

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs. PDF | On Oct 1, 2014, J.B. Mbarga and others published A new o. Possible cause: Phytophthora Megakarya: a review on its status as a pathogen on cacao i.