Areolate Mildew Confirmed in North Carolina
go.ncsu.edu/readext?546880
en Español / em Português
El inglés es el idioma de control de esta página. En la medida en que haya algún conflicto entre la traducción al inglés y la traducción, el inglés prevalece.
Al hacer clic en el enlace de traducción se activa un servicio de traducción gratuito para convertir la página al español. Al igual que con cualquier traducción por Internet, la conversión no es sensible al contexto y puede que no traduzca el texto en su significado original. NC State Extension no garantiza la exactitud del texto traducido. Por favor, tenga en cuenta que algunas aplicaciones y/o servicios pueden no funcionar como se espera cuando se traducen.
Português
Inglês é o idioma de controle desta página. Na medida que haja algum conflito entre o texto original em Inglês e a tradução, o Inglês prevalece.
Ao clicar no link de tradução, um serviço gratuito de tradução será ativado para converter a página para o Português. Como em qualquer tradução pela internet, a conversão não é sensivel ao contexto e pode não ocorrer a tradução para o significado orginal. O serviço de Extensão da Carolina do Norte (NC State Extension) não garante a exatidão do texto traduzido. Por favor, observe que algumas funções ou serviços podem não funcionar como esperado após a tradução.
English
English is the controlling language of this page. To the extent there is any conflict between the English text and the translation, English controls.
Clicking on the translation link activates a free translation service to convert the page to Spanish. As with any Internet translation, the conversion is not context-sensitive and may not translate the text to its original meaning. NC State Extension does not guarantee the accuracy of the translated text. Please note that some applications and/or services may not function as expected when translated.
Collapse ▲
False/Areolate Mildew caused by Ramularia areola on cotton. (Photo courtesy of Terri Thomas)
Areolate mildew (Ramularia areola syn. Ramularia gossypii) has been confirmed on samples collected from Halifax County, North Carolina. This is likely not the only field given recent wet weather conditions. Symptoms of this disease including white mildew covering parts of or entire leaves. These symptoms appear at the lower portion of the canopy and work their way upwards, in some cases very rapidly. Hyphal mats or white strands of the fungus can be observed when examined closely.
Should you suspect the presence of this disease, contact your local county agent and samples should be sent to the NC State University Plant Disease and Insect Clinic for confirmation. To submit a sample, send several detached leaves in a plastic bag, along with a damp paper towel to prevent desiccation (if mailing a sample, leave the paper towel dry). If the sample can’t immediately be sent to the clinic, it should be refrigerated until it can be sent.
There’s little information about this disease in the United States. It has been observed in Georgia, Alabama, South Carolina, and now North Carolina. There’s not much information to suggest that it causes significant yield losses, but a fungicide application (e.g. Priaxor, Headline, Quadris, Topguard, etc.) may be warranted with continued conducive environmental conditions.
Based on recommendations in other states, if cotton is currently within the 6th week of bloom or earlier, and the disease is prevalent in large proportions of the field with a weather forecast conducive to further disease development (cloudy/damp/wet conditions and saturated soils), a fungicide application may be necessary. For fields that are beyond the 6th week of bloom, fully cutout with fairly mature bolls, and within 4 weeks or so from defoliation, a fungicide application may not be warranted. Before any fungicide sprays, it is important to submit samples to the disease clinic to confirm the presence of this disease and rule out other less destructive pathogens.
Lastly, if the NC State University Plant Disease Clinic confirms areolate mildew in one or more of your fields, this presents a great opportunity for on-farm research, since this disease is relatively new to NC and there is little data to determine when fungicide applications may be warranted. If you are interested in participating in a simple field trial, please contact your county agent immediately so that we can establish a simple field trial to help answer these questions on your behalf.