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WSU Puyallup Ornamental Plant Pathology
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Water

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Water Management

Since Phytophthora diseases are waterborne, good water management practices are key in preventing plant losses.

Water management photos  – Examples of water management situations in nurseries in the Pacific Northwest.

Water Management for Nurseries -Presentation from the Best Management Practices workshops in 2014

Water Sampling Protocol (Appendix 7, Confirmed Nursery Protocol 2007)

The Water Education Alliance for Horticulture at the University of Florida has a comprehensive website on water management, mainly chemical and other treatments for water.

 Irrigation Pathogens and Water Quality – Learn how to recycle water without recycling pathogens at this Virginia Tech site.

A Short Introduction to Water Recycling for Plant Nurseries – this presentation provides a good summary of water treatments for nurseries, to prevent disease spread and reduce pollutant runoff.

Facts and Myths About Irrigation Water An overview of irrigation water treatments and uses in nurseries.

Back to Managing Phytophthora diseases in the nursery

Managing Phytophthora diseases in the nursery

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Managing Phytophthora diseases in the nursery

Four critical control points have been identified to prevent the entry of waterborne diseases such as Phytophthora and Pythium into nursery production. These are:

By preventing or managing disease outbreaks at these points in the production cycle, you can minimize the damage and loss of product, and grow clean, healthy plants.

More information:

Vivero de Demostración Virtual Oomycete

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Bienvenido al Vivero de Demostración Virtual Oomycete

Los Oomycetos son un grupo de organismos similares a los hongos, entre los cuales se incluyen especies de Phytophtora y Pythium que son patogénicas de plantas nativas y exóticas. Estos organismos se parecen a los hongos en cuanto a su apariencia y comportamiento, pero están más relacionados con las algas marrones(por ej alga marina). Al igual que las algas marrones, los Oomycetos necesitan agua para desarrollarse y dispersarse. Así es como muchas estrategias de manejo efectivas para los Oomycetos, en efecto, están basadas en restringir su acceso al agua. Tenga esto presente mientras usted visite este vivero y observe cuántas de las prácticas de manejo son esencialmente estrategias de manejo de la humedad. Un segundo tema importante observado a través de este vivero virtual es la higiene.

Hay varias razones que le explicaran porque es una buena idea el manejo contra especies de Phytophthora and Pythium en su vivero. Muchos de estos organismos causan daños a las hojas y pudrimiento de las raíces, lo cual devalúa la mercadería de horticultura. Algunos de estos organismos son exóticos y tienen el potencial de impactar negativamente nuestro ambiente ya que matan y reducen el vigor de los árboles y otras plantas que no han desarrollado defensas contra estos. También algunas de estas plantas patógenas, incluyendo Phytophthora ramorum están reguladas por el gobierno federal. Si Phytophthora ramorum fuera detectada en su vivero durante las inspecciones de viveros del Departamento de Agricultura, las medidas de mitigación le costarían a su vivero más de un promedio de $12,000 en el estado de Washington.

Disfrute su visita y piense sobre como las estrategias observadas en la Demostración de Viveros Oomycetos Virtual de WSU podría ser adaptada para su vivero de venta al público o viveros mayoristas y hasta su jardín personal en la casa.

Comience la visita presionando en un item numerado en el mapa de abajo…

Virtual Oomycyete Demonstration Nursery

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Welcome to the Virtual Oomycete Demonstration Nursery

Oomycetes are a group of fungal-like organisms which include important native and exotic plant pathogenic species of Phytophthora and Pythium. These organisms resemble fungi in appearance and behavior but are more closely related to brown algae (e.g. sea kelp). Like brown algae, Oomycetes need water to thrive and disperse. Thus many effective management strategies for Oomycetes in effect restrict their access to water. Keep this in mind as you tour this nursery and see how many of the management practices are essentially moisture management strategies. A second important theme observed throughout this virtual nursery is sanitation.

There are several reasons why it is a good idea to manage against Phytophthora and Pythium species in your nursery. Many of these organisms cause leaf blights and root rots which devalue horticultural merchandise. Some of these organisms are exotic and have the potential to negatively impact our environment by killing and reducing the vigor of trees and other plants that have not evolved defenses against them. Also some of these plant pathogens, including Phytophthora ramorum are regulated by the federal government. If Phytophthora ramorum is detected in your nursery during department of agriculture nursery inspections; mitigation measures will cost your nursery over $12,000 on average in Washington State.

Enjoy your visit and think about how the strategies observed in the WSU Virtual Oomycete Demonstration Nursery could be adapted for your retail or wholesale nursery and even your personal home garden.

Start the tour by clicking on a numbered item on the map below…

Regulations

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Regulations

Federal regulations for Phytophthora ramorum are developed by the United States Department of Agriculture – Animal and Plant Health Inspection Service.

Distribution

The entire states of California, Oregon, and Washington are regulated to limit the spread of P. ramorum from nurseries. Each state has their own set of regulations.

The entire state of California and one county in Oregon (Curry) are under quarantine.

Click here to see map of quarantine and regulated areas.

Important Updates

3/31/14

APHIS Revises Phytophthora ramorum Domestic Quarantine Regulatory Requirements for Certain Host Nurseries –

As of March 31, 2014, APHIS will no longer impose P. ramorum regulatory requirements for the interstate movement of host nursery stock from certain nurseries located in the regulated areas of California, Oregon, and Washington. Nurseries that have not had P. ramorum detected in annual surveys since March 31, 2011 will not be required to be inspected and certified in order to ship regulated and associated host plants interstate. Also, nurseries located in regulated areas that do not contain, and that do not ship nursery stock listed as proven host taxa or as associated plant taxa are no longer required to comply with 7CFR 301.92. APHIS will, however, continue to regulate all interstate shipping nurseries located inquarantine areas of California and Oregon, including those that contain only non-host nursery stock.

Read the full document here.

Resources

State
Federal