Yield Loss Associated with Soya Bean Rust (<i>Phakopsora pachyrhizi</i> Syd.) in Uganda

Kawuki, Robert; Adipala, E.; Tukamuhabwa, Phinehas

doi:10.1046/j.1439-0434.2003.00668.x

Cited by 54 publications

(38 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In Uganda, Kawuki et al (2004) showed that rainfall, especially during mid-growth period of the crop, was important for examining soybean cultivar reactions. For example, the authors did not observe any differences among soybean cultivars and their reaction to ASR during a rainy season, when the highest ASR severities and infection rates were observed.…”

Section: Overall Effects Of Meteorological Factors On Field Epidemicsmentioning

confidence: 99%

Meteorological factors and Asian soybean rust epidemics: a systems approach and implications for risk assessment

Ponte

Esker²

2008

Sci. agric. (Piracicaba, Braz.)

View full text Add to dashboard Cite

Favorable meteorological and environmental conditions are critical components that affect Asian soybean rust (ASR), caused by Phakopsora pachyrhizi, the most damaging fungal disease of soybean. In this review, we used available knowledge on the effect of meteorological factors affecting the disease to construct a systems-based approach to understand the risk of ASR epidemics. The systems approach is based on a hierarchical framework where relevant environmental factors that affect the key stages of the ASR disease cycle are identified and this included both aerobiological and epidemiological components. The formal framework we used examined the following epidemic characteristics: spore release, spore dispersal, spore deposition, infection efficiency, latent period and spore production. It provided the ability to identify the most important meteorologicalrelated factors along with relevant knowledge gaps from which the implications for disease forecasting were described. This is new information that can be used as a guide for further epidemiological research and especially to develop and improve upon both local and regional risk models. Key words: Phakopsora pachyrhizi, plant epidemiology, risk prediction, climatology, plant diseases FATORES METEOROLÓGICOS E AS EPIDEMIAS DE FERRUGEM ASIÁTICA -UMA ABORDAGEM SISTÊMICA E IMPLICAÇÕES NA AVALIAÇÃO DE RISCORESUMO: Condições meteorológicas e ambientais são componentes críticos nas epidemias de ferrugem asiática da soja (FAS), doença causada pelo fungo Phakopsora pachyrhizi e que causa o maior dano na cultura da soja. Nesta revisão, o conhecimento sobre o efeito de fatores meteorológicos que influenciam nas epidemias foi usado para construir uma abordagem sistêmica para compreender o risco de epidemias de FAS. Esta é baseada em uma estrutura hierárquica onde os fatores relevantes que afetam os estágios chave no ciclo da doença foram delineados, incluindo os componentes aerobiológicos e epidemiológicos. As seguintes características epidemiológicas foram avaliadas: liberação de esporos, dispersão de esporos, deposição de esporos, eficiência de infecção, período latente e produção de esporos. O conhecimento sobre os fatores meteorológicos que afetam cada um dos componentes foi revisado, sendo identificados os fatores mais importantes e as falhas de conhecimento, bem como as implicações para a previsão da doença. A informação é importante para orientar a pesquisa epidemiológica futura e especialmente desenvolver e melhorar modelos de risco da doença em níveis locais a regionais. Palavras-chave: Phakopsora pachyrhizi, epidemiologia de plantas, previsão de risco, climatologia, doenças de plantas

show abstract

Section: Overall Effects Of Meteorological Factors On Field Epidemicsmentioning

confidence: 99%

Meteorological factors and Asian soybean rust epidemics: a systems approach and implications for risk assessment

Ponte

Esker²

2008

Sci. agric. (Piracicaba, Braz.)

View full text Add to dashboard Cite

show abstract

“…bras., Brasília, v.43, n.10, p.1277-1286, out. 2008 podem ser de até 100% (Hartman et al, 1991;Kawuki et al, 2003;Yorinori, 2006).…”

Section: Introductionunclassified

Análise multivariada dos componentes da resistência à ferrugem-asiática em genótipos de soja

Koga

Canteri

Calvo

et al. 2008

Pesq. agropec. bras.

View full text Add to dashboard Cite

Resumo -O objetivo deste trabalho foi detalhar os ciclos de infecção da Phakopsora pachyrhizi Syd. & P. Syd. em genótipos de soja, para o estabelecimento de grupos de genótipos mais promissores para o uso como fontes de resistência à ferrugem. Os componentes do ciclo de infecção foram quantifi cados em 48 genótipos. Foram avaliados: tipo de lesão, intensidade de esporulação, severidade, número de lesões e de urédias e produtividade de urediniósporos. Pela análise de agrupamentos, formaram-se quatro grupos: A -desenvolveu a maior quantidade de doença; B -desenvolveu a menor quantidade de doença; C -baixa resistência inicial e D -alta resistência inicial. Os genótipos dos grupos B, C e D apresentaram lesões RB ("redish-brown") e variaram quanto à resistência inicial, resistência tardia, intensidade de esporulação, estabilidade da resposta qualitativa, produtividade de urediniósporos e número de dias para atingir 50% da severidade máxima. Entre as variáveis analisadas, as que apresentaram importância prática foram as avaliações das respostas qualitativas e as de severidade. Esta última refl ete os efeitos combinados de resistência sobre todos os componentes da infecção e apresentam importância prática na diferenciação de genótipos, quanto à resistência à doença. Os genótipos dos grupos B, C e D manifestaram resistência qualitativa e quantitativa, em diferentes graus, e promissores para serem utilizados como fontes de genes de resistência à ferrugem-asiática-da-soja.Termos para indexação: Glycine max, Phakopsora pachyrhizi, epidemiologia, número de lesões, número de urédias, resistência horizontal e vertical, resistência quantitativa e qualitativa. Multivariate analysis of resistance components to Asian rust in soybean genotypesAbstract -The objective of this study was to detail the infection cycles of Phakopsora pachyrhizi Syd. & P. Syd. in soybean genotypes, in order to establish a group of the most promising genotypes for use as sources of resistance to Asian soybean rust. The infection cycle components were quantifi ed in 48 genotypes. The assessments consisted of: type of lesion, intensity of sporulation, severity, number of lesions and uredinias, and productivity of urediniospores. The cluster analysis formed four groups: A -developed the highest amount of disease; B -developed the lowest amount of disease; C -low initial resistance; and D -high initial resistance. All the genotypes of groups B, C and D had RB (redish-brown) lesions and varied for initial resistance, delayed resistance, intensity of sporulation, stability of the qualitative response, productivity of urediniospores, and number of days to reach 50% of the maximum severity. Qualitative responses and disease severity evaluations refl ect the combined effects of resistance on all the infection components and show practical importance in genotypes differentiation, regarding disease resistance. The genotypes of groups B, C and D presented qualitative and quantitative resistance, in different degrees, and they are promising genotypes as sources of res...

show abstract

“…P. pachyrhizi is an invasive fungal disease that can signiÞcantly reduce soybean yield (Kawuki et al 2003, Miles et al 2003. In the absence of P. pachyrhizi, inconsistent but positive yield responses are possible with the application of fungicide (Hanna et al 2008) through control of various (or multiple) fungal pathogens present in North America soybean (Dashiell and Akem 1991).…”

mentioning

confidence: 99%

Probability of Cost-Effective Management of Soybean Aphid (Hemiptera: Aphididae) in North America

Johnson

O’Neal

Ragsdale

et al. 2009

View full text Add to dashboard Cite

Soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is one of the most damaging pests of soybean, Glycine max (L.) Merrill, in the midwestern United States and Canada. We compared three soybean aphid management techniques in three midwestern states (Iowa, Michigan, and Minnesota) for a 3-yr period (2005)(2006)(2007). Management techniques included an untreated control, an insecticidal seed treatment, an insecticide fungicide tank-mix applied at flowering (i.e., a prophylactic treatment), and an integrated pest management (IPM) treatment (i.e., an insecticide applied based on a weekly scouting and an economic threshold). In 2005 and 2007, multiple locations experienced aphid population levels that exceeded the economic threshold, resulting in the application of the IPM treatment. Regardless of the timing of the application, all insecticide treatments reduced aphid populations compared with the untreated, and all treatments protected yield as compared with the untreated. Treatment efficacy and cost data were combined to compute the probability of a positive economic return. The IPM treatment had the highest probability of cost effectiveness, compared with the prophylactic tank-mix of fungicide and insecticide. The probability of surpassing the gain threshold was highest in the IPM treatment, regardless of the scouting cost assigned to the treatment (ranging from $0.00 to $19.76/ha). Our study further confirms that a single insecticide application can enhance the profitability of soybean production at risk of a soybean aphid outbreak if used within an IPM based system. Keywords IPM, break-even analysis, gain threshold Disciplines Agriculture | Entomology CommentsThis article is from Journal of Economic Entomology 102 (6) ABSTRACT Soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is one of the most damaging pests of soybean, Glycine max (L.) Merrill, in the midwestern United States and Canada. We compared three soybean aphid management techniques in three midwestern states (Iowa, Michigan, and Minnesota) for a 3-yr period (2005Ð2007). Management techniques included an untreated control, an insecticidal seed treatment, an insecticide fungicide tank-mix applied at ßow-ering (i.e., a prophylactic treatment), and an integrated pest management (IPM) treatment (i.e., an insecticide applied based on a weekly scouting and an economic threshold). In 2005 and 2007, multiple locations experienced aphid population levels that exceeded the economic threshold, resulting in the application of the IPM treatment. Regardless of the timing of the application, all insecticide treatments reduced aphid populations compared with the untreated, and all treatments protected yield as compared with the untreated. Treatment efÞcacy and cost data were combined to compute the probability of a positive economic return. The IPM treatment had the highest probability of cost effectiveness, compared with the prophylactic tank-mix of fungicide and insecticide. The probability of surpassing the gain threshold was highe...

show abstract

Yield Loss Associated with Soya Bean Rust (Phakopsora pachyrhizi Syd.) in Uganda

Cited by 54 publications

References 4 publications

Meteorological factors and Asian soybean rust epidemics: a systems approach and implications for risk assessment

Meteorological factors and Asian soybean rust epidemics: a systems approach and implications for risk assessment

Análise multivariada dos componentes da resistência à ferrugem-asiática em genótipos de soja

Probability of Cost-Effective Management of Soybean Aphid (Hemiptera: Aphididae) in North America

Contact Info

Product

Resources

About