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Water management photos


Water management photo gallery

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Phytophthora can spread from cull piles where diseased plants are disposed of, especially if the site is muddy with standing water. Spores can be tracked throughout the nursery on vehicle tires and workers shoes.Ensure that runoff from cull piles is directed away from areas such as roads, growing beds, soil components and mixing areas, and especially from areas containing high-risk host plants to prevent contamination by spores. Cull Pile
Avoid overhead irrigation. If you use overhead irrigation, ensure that leaf wetness of 12 hr or more is minimized. Irrigate in the morning to allow leaves to dry as soon as possible. smConifer Inoculum Production Study 035
Drip irrigation saves water and reduces the chances of infection. However, if the soil or media stays wet and in contact with the plant, infection may result.

Drip irrigation
Drip irrigation
Dirt roads are prone to flooding in the wet climate of the Pacific Northwest.Standing water in roadways is a good environment for Phytophthora and Pythium, whose spores can be spread on vehicle tires. Managing Water
To prevent flooded areas where waterborne diseases can accumulate, a level, graveled road is the best option. Level Graded Road
Avoid letting water accumulate under or around blocks of containerized nursery stock. Allowing plants to stand in water increases the chances for Phytophthora root infection. Plants in standing water
These plants are set out on a sloped area, allowing water to run off rather than accumulate.However, water should be diverted from hillsides populated with P. ramorum host plants since spores move in water. Place these plants at the bottom rather than the top of the slope.

sloped area
Plants on a sloped area
Disease can be spread throughout a nursery in recycled irrigation water.Irrigation water from any source other than well or municipal water should be monitored for P. ramorum if the pathogen is detected in or near the nursery grounds.

Dangers of recycled irrigation water
Dangers of recycled irrigation water
Retention ponds should be tested periodically for presence of Phytophthora and Pythium species. It is a good idea to monitor for Phytophthora species in general to reduce damage caused by these diseases.

Retention Pond Testing
Retention Ponds should be tested regularly
Water in ponds can be treated with chemicals, such as sodium hypochlorite, to eliminate disease organisms. Water Treatment
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Contact: Gary Chastagner, 253-445-4528 | WSU Puyallup Research & Extension Center, 2606 West Pioneer, Puyallup, WA, 98371-4998 USA
Last updated January 2, 2013

Containers


Containers

Disease can be transmitted in a nursery via used containers, which may harbor spores in potting media and plant debris. It is important to use clean containers for high risk host material, such as Rhododendron, Camellia, and Viburnum, to prevent infection of new plants.Containers on mat

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Incoming Plant Material


Incoming Plant Material

Keep diseases out of your nursery by purchasing clean nursery stock from a trusted supplier. Monitoring incoming plant material is especially important in Washington since most is grown out of state.

Click here to see photos of situations involving plant material in nurseries.

Check plant material for disease symptoms before integrating it into the rest of the nursery stock using this guide to symptoms of Phytophthora ramorum and look-alikes on important PNW host plants.

High risk hosts in Washington are Rhododendron, Camellia, Viburnum, Pieris, and Kalmia species. Recently Vaccinium and Gaultheria spp. have been found with P. ramorum. These hosts are sold and planted in large quantities and have been connected to outbreaks of P. ramorum.

If you suspect P. ramorum on plant material, isolate it from other host plants. This key will help you determine the likelihood of P. ramorum infection. You can submit a sample to the WSU plant clinic for analysis.

Symptom ID and Scouting -Presentation from the Best Management Practices workshops in 2014

Click here to view the most recent APHIS list of regulated and associated hosts for P. ramorum.

Lists of certified shipping nurseries for the Pacific Northwest:

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Sanitation


Sanitation

Many Phytophthora diseases, including P. ramorum, can survive and be transmitted in soil, potting media, and leaf litter. Good sanitation is important in reducing the amount of disease in the soil. Once the soil becomes infested with Phytophthora, it is very difficult to eradicate.

Photos – Management of soil and potting media, as well as sanitation techniques.

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

USDA-APHIS approved methods for treatment and disinfection in nurseries (Appendix 8, Confirmed Nursery Protocol 2007)

Biosecurity measures for nurseries (Appendix 9, Confirmed Nursery Protocol 2007)

Articles

Dart, N.L., Chastagner, G.A., Rugarber, E.F., and K. L. Riley. 2007. Recovery Frequency of Phytophthora ramorum and Other Phytophthora spp. in the Soil Profile of Ornamental Retail Nurseries. Plant Disease 91: 1419-1422

Shishkoff, N. 2007. Persistence of Phytophthora ramorum in soil mix and roots of nursery ornamentals. Plant Disease 91: 1245-1249.

Tjosvold, S. A., D. L. Chambers, E. J. Fichtner, S. T. Koike, S. R. Mori. 2009. Disease Risk of Potting Media Infested with Phytophthora ramorum Under Nursery Conditions. Plant Disease 93:4, 371-376

Steam boilers and soil steam sterilization systems. MSD AG (Möschle-Seifert-Dämpftechnik).

Steam Treating for Weed Control. Whitney Ridout, American Nurseryman 2012

Using heat to eradicate soil-borne plant pathogens from nursery potting media (“soil sterilization”). Elizabeth Bernhardt and Ted Swiecki, Phytosphere Research

Soil environmental factors and their relation to avocado root rot by John A. Menge and Lawrence J. Marais, Citrus Research Board

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Water


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.

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Managing Phytophthora diseases in the nursery


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


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


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


Regulations

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

Click here to see map of quarantine and regulated areas.

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. ramorumdetected 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.

State

Washington State Department of Agriculture (WSDA)

Federal

USDA-APHIS