Influência da adubação nitrogenada, época de plantio e aerosporos sobre a severidade da mancha de grãos em arroz de terras altas

Silva-Lobo, V. L.; Lacerda, M.D.; Filippi, Marta Cristina Corsi de; Silva, Gisele Barata da; Prabhu, A. S.

doi:10.1590/s0100-54052011000300005

Cited by 7 publications

(14 citation statements)

References 6 publications

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“…The RGDP values found show that the disease is distributed throughout all rice-cropping regions of Corrientes province. Similar studies performed in different parts of Brazil have informed that RGDP has increased and that RGD has become an economically important disease due to the susceptibility of most of the cultivars used and to the fact that predominant pathogens vary according to the region and meteorological conditions of each campaign, even within each region (da Silva-Lobo et al, 2011;Malavolta et al, 2007;Soave et al, 1984).…”

Section: Discussionmentioning

confidence: 79%

“…More complex weather variables such as DPrecTRH and DWet1, which need relative humidity daily records (that are not always available in historical weather data) for their calculations, decreased slightly their correlations with RGDI. Several authors agree that high relative humidity subserve RGDI and disease severity (Baite et al, 2020;Chhabra & Vij, 2020;da Silva-Lobo et al, 2011), while others have found no correlation between relative humidity and RGDI (Rawte, 2007). Concerning precipitation, although it is widely mentioned as an influential factor, information regarding the amounts required to incentivize infection is scarce (Baite et al, 2020;dos Santos et al, 2009;Huang et al, 2011a).…”

Section: Discussionmentioning

confidence: 99%

“…The most economic and sustainable method to control RGD would be through resistant varieties; however, to date, no immune or highly resistant varieties are known, and semi‐dwarf high‐yielding varieties seem to be more susceptible than conventional ones (Castaño Zapata, 1985). In addition, rice genetic improvement programmes have not yet been successful due to the fact that RGD pathogens affect other parts of rice plants earlier in the crop cycle, and predominant pathogens vary according to the location and environmental conditions (da Silva‐Lobo et al, 2011). Although fungicides applied at heading or at early flowering stage could help in controlling RGD or preventing economic losses due to the disease, their effectiveness depends on the pathogens involved, and according to this, to the type of fungicide used, application timing, etc.…”

Section: Introductionmentioning

confidence: 99%

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Modelling of the effects of environmental factors on rice grain discoloration incidence in Corrientes province, Argentina

Dirchwolf

Moschini

Gutiérrez

et al. 2022

Journal of Phytopathology

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Rice grain discoloration (RGD) is a disease of complex aetiology for which there are no resistant varieties. Due to the need to better define the environmental conditions that favour the disease, the aims of this work were to (i) identify the predominant fungi associated, (ii) determine the meteorological variables most closely related, and (iii) develop preliminary weather‐based models to predict binary levels of RGD incidence. After analysing 123 rice grain samples under natural infection conditions from rice‐cropping regions throughout Corrientes province, Argentina, we found that RGD was mainly associated with Alternaria padwickii (14.2%) and Microdochium albescens (13.7%). The strongest associations between weather variables and RGD incidence were observed in a susceptible critical period (Scp) that extended from the rice flowering stage until 870 accumulated degree days (Scp lasting 32 days, ±7 days). The binary response logistic model including the weather variables DPrecT (which combined the effect of the simultaneous daily occurrence of precipitation lower than 12 mm and air temperature between 13 and 28°C), and DDMnT (sum of the exceeding amounts of daily min temperature from 23°C), was the most appropriate, showing prediction accuracy (PA) values of 84.6%. The univariate model that included DPrecT presented a PA of 82.1%. The logistic regression techniques here used to develop weather‐based models to estimate the probabilities of occurrence of binary levels of RGD can not only help to clarify and quantify the environmental effect on the development of RGD but also be useful tools to be included in future management strategies.

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Section: Discussionmentioning

confidence: 79%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Modelling of the effects of environmental factors on rice grain discoloration incidence in Corrientes province, Argentina

Dirchwolf

Moschini

Gutiérrez

et al. 2022

Journal of Phytopathology

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“…Alrededor de 35 especies de hongos han sido identificados como agente causal del manchado del grano en arroz (Rivero et al, 2012). Especies de los géneros Alternaria, Curvularia, Fusarium y Pyricularia han sido identificados como patógenos potenciales en el cultivo de arroz (da Silva-Lobo et al, 2011). La pigmentación de grano contaminado es de color gris, marrón y negro (Figura 1), reduciendo el rendimiento alrededor de 19% y calidad de semilla (Baite et al, 2020;Rivero et al, 2012;Dirchwolf et al, 2018).…”

Section: Manchado De Grano De Arroz Causados Por Hongos Fitopatógenosunclassified

“…Existe dispersa información sobre la relación entre la tolerancia a patógenos y nutrición mineral en el cultivo de arroz. Los hongos Rhizoctonia (Schurt et al, 2015), Alternaria, Fusarium, Curvularia Pyricularia has sido demostrados como patógenos potenciales en el cultivo de arroz (da Silva-Lobo et al, 2011). El manuscrito discute la relación entre la nutrición mineral y la incidencia/severidad de hongos fitopatógenos potenciales que afectan al cultivo de arroz.…”

Section: Introductionunclassified

Incremento de la patogenicidad de hongos en arroz bajo condiciones de desbalance nutricional

2022

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El presente artículo discute los hongos fitopatógenos potenciales que afectan al cultivo de arroz en condiciones de desbalance nutricional. A nivel mundial el arroz es considerado como el tercer cultivo alimentario de mayor importancia. Sin embargo, es afectado por diversos hongos fitopatógenos que ocasionan daños en hojas, tallos, panículas y granos del cultivo. La incidencia de estos hongos se debe a factores como la temperatura (25-37 ºC), humedad relativa (70-76%), humedad en el suelo, el viento y desbalance nutricional. El género Rhizoctonia causa manchas con forma elíptica de coloración marrón, pudrición de tallos y panículas, lo que reduce el 19% del rendimiento. Por otra parte, los hongos que se encuentran dentro de los géneros Alternaria, Fusarium, Curvularia y Pyricularia provocan manchas de color café y disminuyen la germinación, rendimiento, peso específico del grano (g L-1). Aunque existen investigaciones acerca de los hongos que afectan al cultivo del arroz, la asociación entre el desbalance nutricional y la incidencia de patógenos aún está por evaluarse en germoplasmas superiores a 100 variedades de arroz en condiciones óptimas y de desbalance nutricional.

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Efficiency of bacterial isolates on suppressing brown spot in rice plants

Ajulo,

Bezerra,

de Oliveira

et al. 2024

Journal of Phytopathology

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Many fungicides can control brown spot, caused by Bipolaris oryzae in rice (Oryza sativa L.), although searching for beneficial microorganisms for biocontrol will improve sustainable integrated pest management. The aim of this investigation was the selection of natural suppressors of the brown spot disease in rice. We performed biochemical (E1), molecular antagonism (E2) and severity suppression (E3) studies under laboratory and greenhouse conditions. The E1, E2 and E3 assays were performed with 21 isolates. The experimental design was completely randomized with three replicates. E1 characterized all 21 isolates for the production of extracellular enzymes, siderophores, biofilm, indole‐3‐acetic acid (IAA) and phosphate solubilization. E2 was conducted to test the in vitro antagonism between the 21 isolates and B. oryzae, and E3 was conducted under greenhouse conditions, where seeds of the rice cultivars BRS‐Primavera and Esmeralda were sown in plastic trays containing 3 kg of fertilized soil. After 45 days, rice leaves were sprayed and inoculated with a mixed suspension of bacterial cells (1 × 108 CFU) and B. oryzae. All of the 21 bacterial isolates produced lipase, N‐fixation, siderophore, IAA, biofilm and solubilized phosphorus. Bacillus cereus, Priestia megaterium, Stenotrophomonas nitritireducens, Serratia marcescens and Serratia nematodiphila reduced radial colony growth of B. oryzae and suppressed brown spot severity by up to 90%. This indicates the potential of these isolates for biocontrol of brown spot in rice as a component of rice disease management.

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Influência da adubação nitrogenada, época de plantio e aerosporos sobre a severidade da mancha de grãos em arroz de terras altas

Cited by 7 publications

References 6 publications

Modelling of the effects of environmental factors on rice grain discoloration incidence in Corrientes province, Argentina

Modelling of the effects of environmental factors on rice grain discoloration incidence in Corrientes province, Argentina

Incremento de la patogenicidad de hongos en arroz bajo condiciones de desbalance nutricional

Efficiency of bacterial isolates on suppressing brown spot in rice plants

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