Phytophthora megakarya
Studying 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 Phytophthora megakarya (causal agent of cacao black pod rot disease) upon establishment in 2006 were monitored for presence of disease on a weekly basis from 2009 to 2016. Ripley's ...Recently, a number of researchers have shown interest in finding out the potential of natural substances of plant origin in crop protection. A study was carried out in Yaounde (Cameroon) to test the antifungal activity of extracts of Thevetia
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Phytophthora megakarya is a plant pathogen that causes black pod disease in cocoa trees in West and Central Africa. This pathogen can cause detrimental loss of yield in the economically important cocoa industry. It can damage any part of the tree, causing a wide range in the reduction of yield. A mixture of chemical and cultural controls are ...The only economically important host of Phytophthora megakarya Brasier & Griffin is Theobroma cacao. The pathogen is one of several Phytophthora species causing black pod disease of cacao. Isolates of P. megakarya were grouped taxonomically with P. palmivora isolates until 1979, when it was recognized as a new species (Brasier and …Abstract Black pod rot, caused by Phytophthora megakarya, is the main cause of cocoa harvest losses in Cameroon. Field experiments were carried out over two successive years in two smallholders' plots of cocoa trees, in order to assess the impact of.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 ...La production et la pourriture brune des cabosses du cacaoyer due a Phytophthora megakarya ont ete etudiees durant 3 annees consecutives dans un essai diallele complet, 6 x 6, sans les … Expand. 47. PDF. Save. La pourriture brune des cabosses du cacaoyer au Cameroun: mise en évidence d'un caractère de résistance au champ.Black pod rot or Phytophthora pod rot (PPR) is a serious economically important disease in all cacao-producing regions of the world (Guest 2007).In Central and West Africa, cacao black pod disease is caused by two species of Phytophthora, P. palmivora and P. megakarya, of which P. megakarya is considered the most virulent …Spatial and temporal analysis of a Phytophthora megakarya epidemic in a plantation in the centre region of Cameroon1. 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].Nana WL, Eke P, Fokom R, Bakanrga-Via I, Begoude D, Tchana T et al (2015) Antimicrobial activity of syzygium aromaticum and zanthoxylum xanthoxyloides essential oils against phytophthora megakarya. J Phytopathol 163:632–641. Article CAS Google ScholarPhytophthora megakarya —one of the cocoa black pod disease species, is invasive and probably responsible for the greatest cocoa crop loss in Africa Phytophthora multivora …Phytophthora megakarya and Phytophthora palmivora, Closely Related Causal Agents of Cacao Black Pod Rot, Underwent Increases in Genome Sizes and Gene Numbers by DifferentMechanisms Shahin S. Ali, Jonathan Shao, David J. Lary, Brent A. Kronmiller, Danyu Shen, Mary D. Strem, Ishmael Amoako-Attah, Andrew Yaw Akrofi, B.Phytophthora megakarya and Phytophthora palmivora, closely related causal agents of cacao black pod rot, underwent increases in genome sizes and gene numbers by different mechanisms. Genome Biol Evol. 9(3): 536 – 557. doi: 10.1093/gbe/evx021 , [Web of Science ®], [Google Scholar] Anderson RG, Deb D, Fedkenheuer K, McDowell JM. 2015.Phytophthora palmivora (E. J. Butler) E. J. Butler (1919) is a cosmopolitan pathogen with a wide host range, including some very important economic crops such as cacao, papaya, black pepper, rubber, coconut, and citrus. The center of origin is believed to be southeastern Asia (McHaw and Coffey, 1994). In 1907, Butler originally described a new ...P. megakarya strains, the inhibition of the strains by the extracts, the minimum inhibiting concentration (MIC 50 and MIC 90 ) and the extract characteristic were determined by the usualThe three most important species of Phytophthora worldwide causing black pod disease of cacao are P. palmivora, P. megakarya, and P. capsici. Chemicals are effective in controlling this disease but more natural methods would be preferred. One alternative is to use natural plant extracts. Rosemary and lavender leaf extracts were found to be effective in reducing germination of P. capsici, P ...The three most important species of Phytophthora worldwide causing black pod disease of cacao are P. palmivora, P. megakarya, and P. capsici. Chemicals are effective in controlling this disease but more natural methods would be preferred. One alternative is to use natural plant extracts. Rosemary and lavender leaf extracts were found to be effective in reducing germination of P. capsici, P ...• Premise of the study: Phytophthora megakarya is the agent of black pod disease of cacao and is the main pathogen of this crop in Africa. Population genetic studies are required to investigate how this pathogen emerged. To this end, we developed 12 novel polymorphic microsatellite markers for P. megakarya.The genus Phytophthora has been studied at the cellular level, suggesting that different developmental steps are induced by the expression of some specific genes. However, these studies have only been carried out on certain species, such as Phytophthora infestans and Phytophthora cactorum. ... Phytophthora megasperma and Phytophthora megakarya ...The expansion of the black pod disease (Phytophthora megakarya) during heavy rains is very common in the equatorial rainforest of Cameroon (Opoku et al., 2002; Atangana et al., 2013). A study ...Cross-pollination of suitable genotypes and earlier selection of elite offspring using adequate plants-associated defence markers in plantlets leaves are ...
Many Phytophthora species have a soil borne phase in their natural life cycles even though disease expression often occurs on aerial plant parts. In Cameroon, black pod rot of cacao (Theobroma cacao L.), is caused by P. megakarya. Primary inoculum ofNana WL, Eke P, Fokom R, Bakanrga-Via I, Begoude D, Tchana T et al (2015) Antimicrobial activity of syzygium aromaticum and zanthoxylum xanthoxyloides essential oils against phytophthora megakarya. J Phytopathol 163:632-641. Article CAS Google ScholarOn the other end, several genome assemblies had high repeat content, namely, P. megakarya, Phytophthora hibernalis, and Phytophthora pinifolia contained 32.94, 32.46, and 33.00%, …PDF | On Jan 1, 2019, Tene Tayo Paul Martial and others published Enhancement of Theobroma cacao Seedling Growth and Tolerance to Phytophthora megakarya by Heat-Treated Oyster Shell Powder | Find ...Background Pathogens of the genus Phytophthora are the etiological agents of many devastating diseases in several high-value crops and forestry species such as potato, tomato, cocoa, and oak, among many others. Phytophthora betacei is a recently described species that causes late blight almost exclusively in tree tomatoes, and it is …
Phytophthora megakarya and Phytophthora palmivora cause black pod rot of cacao. P. megakarya occurs in Africa while P. palmivora is distributed world-wide. P. palmivora has a higher temperature ...Studying 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 Phytophthora megakarya (causal agent of cacao black pod rot disease) upon establishment in 2006 were monitored for presence of disease on a weekly basis from 2009 to 2016. Ripley's ...…
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Dec 11, 2015 · 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 · 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 ...
The virulence of P. megakarya was associated with earlier production of sporangia and an accelerated induction of necrosis, and it remains to be seen whether it can displace P. palmivora from cacao plantations of Ghana as it has in Nigeria and Cameroon. Among the Phytophthora species that cause black pod of cacao, P. megakarya is the …P. megakarya and P. palmivora are closely related among the Phytophthora spp. causing disease on cacao, and are both members of clade 4 of the 10 clade system based on the internal transcribed spacer (ITS) sequences of genomic rDNA commonly used in the genus (Cooke et al. 2000).
Phytophthora megakarya is the most virulent Phytop 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.The impact of environmental factors and microbial and chemical control methods on cacao pod production dynamics and spread of black pod disease caused by Phytophthora megakarya was assessed over three consecutive years in a smallholder's plantation. Significant positive correlations were found between rainfall records and pod rot incidence when assessed after a 1-week lag. Nana et al. (2015) estimated the MIC of clove EO oTwo well-established diseases cause the grea lorsqu'elles infectent les cabosses. Phytophthora megakarya est la plus agressive et peut provoquer entre 60 % et 100 % des pertes de récoltes (Luterbacher et al., 1993, Berry and Cilas, 1994), Opoku et al., 2000), quand les conditions favorisent le développement de la maladie. En revanche, P . palmivora est moins agressif et peut entrainer des Feb 14, 2017 · Plant materials. To identify the c 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 ...1.. IntroductionCocoa black pod rot, caused by oomycetes of the genus Phytophthora, causes substantial yield losses worldwide, particularly in Africa with the species Phytophthora megakarya, which is the most damaging species for the cocoa industry.Although P. megakarya only exists in Africa, the species Phytophthora palmivora and Phytophthora capsici are responsible for the disease in South ... Phytophthora megakarya and Phytophthora palmiPhytophthora palmivora (Butler) is an hemibiotrPhytophthora megakarya (Pmeg) and P. palmivora Phytophthora é um género de protistas que engloba algumas espécies particularmente nocivas para a agricultura e silvicultura, responsáveis por várias doenças em plantas, vulgarmente associadas ao termo "podridão". O termo em latim refere-se, aliás, a esta característica ao aliar o termo grego phyton com phthora . Por vezes, tudo ao que parece, por engano, é frequente encontrar a ...Title / Subtitle: Phytophthora megakarya and P. palmivora on Theobroma cacao: Aspects of virulence and the effects of temperature on growth and resistance to fungicides Subject description: This thesis investigates the dynamics of black pod disease of cocoa caused by Phytophthora megakarya and P. palmivora species in Ghana. Sep 14, 2021 · Phytophthora pod rot disease commonly known as the B (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. Apr 1, 2018 · Phytophthora megakarya and Phytophthora palmi[Black pod, caused by Phytophthora spp. is one of the most importFeb 1, 2000 · A severe black pod disease of Cocoa [Phytophthora megakarya L.]) Septiana 1)* , Suskandini Ratih Dirmawati 1) , Rusdi Evizal 1) 1) Jurusan Agroteknologi Fakultas Pertanian Universitas Lampung, Jl. Prof. SoemantriIn 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 ...