Webinar #1 - A path to plant biosecurity, water and environmental sustainability: SCRI project overview (October 2013)

By: Project Team

Webinar Recording

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Polls included in this webinar included:

Questions Options
Which of the following best describes you (select ONE)? Grower
Private consultant
No vote
What is your principal concern about irrigation water? (Check ALL that apply to your facility) Cost of irrigation systems
Cost of quality water
Pathogen contamination of water
Water availability
Do you capture any or all surface runoff and recycle it for irrigation (select ONE)? No
No vote
What is your principal water treatment method to control waterborne pathogens (select ONE)?

Chlorine dioxide
Other tech (Copper ionization, Heat pasteurization, Ozonation, Slow sand filtration, Surfactant, OR Ultraviolet light)
No vote

Beside water treatment, have you used any other means as a major approach to reduce pathogen spread via irrigation systems (select ONE)?

Yes (please indicate what they are in the Chat box on the bottom right)
No vote


Hello, everyone! Can you hear me ok?

My name is Chuan Hong. I’m a professor of plant pathology at Virginia Tech. On behalf of the team, I would like to welcome you ALL to the Webinar.

If you have NOT checked in at the ATTENDEES poll (P1) yet, please do so now. We will close this poll shortly. In the meanwhile, I would like to make THREE quick comments.

First is about OUR PLAN for the webinar.

This webinar will begin with a 35- to 40-minute presentation, followed by a discussion session until 1 o’clock. So we will have plenty of time at the end for questions and answers.

For those who are NOT familiar with the software (Adobe Connect) we are using for this webinar, there is a CHAT box in the bottom right of your computer screen. If you have a question during the presentation, you can type your question in the space BELOW that CHAT box, then click SEND icon on the right to submit the question. We will answer your questions as soon as possible.

Please mute your phone when you are NOT talking. Thanks!

My second comment is about WHO WE ARE.

Discuss the Poll #1 results here

One economist: Dr. Jim Pease, my colleague at Virginia Tech
Two horticulturists: Drs. John Lea-Cox and Andrew Ristvey from University of Maryland
Three plant pathologists: Drs. Gary Moorman from Penn State and Warren Copes from USDA-ARS, plus myself, and
My IT colleague, Carl Estes. He set up this meeting room, is working behind the scene today, and will provide continuing support for future webinars.

My third comment is about OUR GOAL for this first webinar.

Here is a to-do list for this webinar. We will:

Our goal is to make you ALL aware of these issues and their potential impacts on the horticulture industry, and begin to think creatively about what may be done in a specific production facility to put the businesses on A PATH TO SUSTAINABLE GROWTH.

With that, I would like to turn the presentation to Dr. Gary Moorman now.

Hi, everyone. While I'm telling you about myself, please take a couple of quick polls (2 and 3) on your computer screen.

I'm a professor of plant pathology at Penn State where I've been working on plant pathogens in irrigation water for several years. In particular, I've been working on Pythium in greenhouse crops. Some species of Pythium are plant pathogens that can cause significant losses in greenhouse crops. And Pythium can produce swimming zoospores that can be dispersed by irrigation water. That is one part of the SCRI project.

Another major part of the project is Phytophthora, particularly Phytophthora in nursery irrigation water. Phytophthora too produces swimming zoospores that can be dispersed by irrigation water. Chuan and his research group at Virginia Tech work on that.

Discuss the results of Poll 2 and Poll 3 here

To deal with disease problems effectively, we must look at the pathogens and the plants we grow, AND we must keep the BIG picture in mind.

One of the major dimensions in this big picture is emerging ornamental plant pathogens of global significance.

Recent examples are:

These pathogens pose a serious threat to the nation’s horticulture industry and the natural environment.

Once they are introduced into a nursery or greenhouse production system they can be dispersed in that system through irrigation water.

And once we have infected plants, there is the possibility that those plants could be sold, distributed, and planted throughout North America.

So this is a plant disease issue, a water use issue, a plant production issue, and an environmental issue all rolled into one.

It is also an economic issue because losses in crops and grower reputations could wipe out a business.

The second dimension is water scarcity. Water is a precious commodity, essential to agriculture.

A prolonged drought in Virginia and mid-Atlantic Region in 2007 resulted in many irrigation ponds drying up as shown here on the right of this slide.

Some producers rely heavily on municipal water sources. During a drought, agricultural uses of scarce water can be curtailed.

The third dimension is water pollution. Ornamental crop production can generate substantial amounts of runoff water.

If nutrient-rich runoff is not contained, our streams, rivers, lakes and ponds water may soon look like “Pea-soup”.

We must make every effort to reduce our environmental impact.

One way to deal with water is to capture and reuse it.

Runoff containment ponds and water recycling systems reduce our impact on the environment and generate an alternative water resource for irrigation.

This practice, however, could spread destructive pathogens including Phytophthora, Pythium, Cylindrocladium, and Ralstonia.

Thus, all these issues are interconnected.

A key reason for our doing the SCRI project is our belief that managing pathogens in water is key to plant bio-security as well as water and environmental sustainability.

AND we realize that there are serious economic implications for growers.

We are approaching these interconnected issues from different angles to make sure that we do NOT create new and bigger problems when solving the existing problems.

Teams of plant pathologists are working with horticulturists to develop a better understanding of water quality dynamics and pathogen aquatic biology then use this knowledge to develop protocols to help farmers design better water recycling systems and modify existing systems for pathogen risk mitigation.

As I said, Chuan's team at Virginia Tech focuses on Phytophthora pathogens in nursery crops while here at Penn State we are focusing on Pythium and greenhouse crops.

John Lea-Cox, Andrew Ristvey, and their group at the University of Maryland are looking at water use, nursery designs that conserve water, mitigate water runoff, and foster good water quality.

A team of economists at Virginia Tech has been assessing the potential benefits of implementing the protocols developed by the pathologists and horticulturists.

Of crucial importance to this project is an advisory committee made up of nurserymen and greenhouse operators who have helped us set research priorities and assess the importance of our results.

A team of information technology scientists has been helping us at every step, to communicate among the research teams and with the grower advisory group. They are also helping us develop and online knowledge center where our results and recommendations will be made available to whoever needs them... growers, scientists, extension educators and policy makers.
And now the IT people are helping us to present to you this webinar series.

The total project team wants to produce real solutions to help the green industry.

If you like to learn more details about the SCRI project, please visit the project website at www.irrigation-pathogens.info.

Here is a snapshot of the homepage of the website with a number of tabs to help you get to the contents of the greatest interest as soon as possible. If you have any questions, we would like to hear them. The tab on the far right is Webinar; all info related to this webinar series including the recordings will be posted under this Tab.

But what about the webinar series?

In this 14-session series, I will be doing three separate webinars, each dealing with some specific aspects of plant pathogens in water.

When pathogens are found in irrigation water, the most frequently-asked question is “what are my water treatment options?” Please complete the Poll 4 to indicate the PRINCIPAL water treatment method you have used in your production facility. Another EQUALLY, IF NOT MORE IMPORTANT BUT OFTEN BEING NEGLECTED question is whether and how WATERBORNE pathogen risk may be mitigated without water treatment? If you used any, please check YES in Poll 5 and indicate what it was or what they were in the CHAT box on the bottom right of your computer screen. The two questions will be the central focus of next six webinars.

Discuss the results of Poll 4 and Poll 5 here

Two of these webinars will be presented by Drs. Andrew Ristvey and John Lea-Cox, professors of horticulture in the University of Maryland. They can’t be with us today and asked me to present their slides. These two webinars have the same goal and that is to produce healthy crops to reduce amount of pathogens in runoff water returning to irrigation reservoirs or entering recycling irrigation systems.

Andrew’s webinar will focus on substrate management.

We recognize that, often, management of pathogens is either reactive in the case of dealing with an active infection or preventative, where applications of fungicides are used to prevent the start of an infection. In the case of preventative applications, over-use of some fungicide chemistries is possibly creating resistant strains of pathogens which then end up in the landscape. So for a nursery manager, the first consideration for growing plants in containers is the substrate. The characteristics of any substrate will determine how to manage irrigation to better manage nutrients and pathogens.

This webinar will focus on best horticultural substrate management to minimize pathogen problems. It will be split into four sections. The first is Physical Properties: Air and Water Management. We will discuss Component Materials and how different ratios of components affect Water Holding Capacity, which is the volume of water held by a substrate after irrigation and drainage and Air-Filled Porosity, which is the volume of air held by a substrate after irrigation and drainage. We also will discuss how these components affect Water Availability and how easily a substrate releases the water contained within the pore spaces.
Following that we will discuss Substrate Chemical Properties. This section will include information about pH and Buffering, Nutrient Availability and Salinity Stress Management.
We will brush upon Biological Factors which affect pathogen survivability, and lastly we will discuss issues of Storage and Handling Management, both before potting and after potting.
Grasping these concepts, the nursery manager will get a better understanding of how to manage the plant system including irrigation and nutrient use to aid in minimizing disease problems.

John’s webinar will discuss a number of inter-related factors that influence daily irrigation water scheduling decisions, building upon the substrate management principles that were outlined by Andrew Ristvey in his webinar.

Good irrigation management is one of the essential disease management practices in both nurseries and greenhouses. The principle is to create and maintain a dry, antagonistic environment to reduce, or if possible, eliminate pathogen development and transmission.

Firstly, something that everyone can do right now is ensure that your irrigation system is working correctly, since if it is not applying water uniformly, then large parts of the production area are most likely being overwatered.
Irrigation uniformity is one of the keys to reducing overwatering and that can greatly reduce the chance of pathogen movement.
As Andrew mentioned, the substrate physical properties contribute to how water is retained in the container.

If the substrate is to fine, water-logging and lack or aeration will lead to poor root growth.

If the substrate is too coarse, then it will not retain enough water, and you will have to irrigate very frequently, to compensate.

Another essential factor is knowing exactly when to irrigate. John will illustrate how growers are using sensors to provide very precise irrigation control by measuring soil moisture. In this way, growers now have good tools to provide them with real-time information when water is needed by a crop, and more importantly, how long to irrigate. What we have learned to date is that very often we are irrigating when in fact the plant has plenty of available water in the root zone.

Now I am turning the presentation back to Chuan.

Thanks, Gary.

Built on the Andrew and John’s webinars, I will use two sessions to show you what else may be done to reduce waterborne pathogen risk WITHOUT water treatment.

In one webinar, we will ask whether and how a grower may build an irrigation system that RECYCLES WATER BUT NOT PLANT PATHOGENS? We will present the data from several case studies and discuss:

The goal of this webinar is to help growers build crop health into their water recycling systems.

My second webinar will take a step FURTHER, and discuss the importance of SITE SELECTION for new production facilities. Building a new production facility is like investing in real estate, the primary considerations are LOCATION, LOCATION, and LOCATION. As school district for real estate properties, WATER AVAILABILITY and WATER QUALITY should be a premier factor in selecting sites for new production facilities.

Site selection, better system designs, and best management practices are ALL important, but they may NOT completely prevent ALL pathogens from entering irrigation systems at EVERY production facility. Therefore, it is equally important to know the latest about water treatment options. My next webinar focuses on chlorination, which is by far the MOST COST- EFFECTIVE water treatment method available today.

In this webinar we will ask:

The goal of this webinar is to help growers make the MOST out of their chlorine dollars.

There are quite a few other disinfestants on the market that are not as commonly used by the horticultural industry. These will be covered in another webinar by Dr. Warren Copes. Warren has done a lot of research on chlorine dioxide which will be a major focus of his webinar. Chlorine dioxide (ClO2) is a chlorine product, but it behaves differently from the common chlorine products such as bleach, chlorine gas and tablets. Specifically, Warren will:

• Present the efficacy responses unique to ClO2, such as biocidal activity over a broad pH range and low reactivity to many compounds in the water, such as ammonia
• Discuss some general issues that affect the activity of this disinfestant, such as water temperature, and
• Present two types of ClO2 delivery systems. Unlike other chlorine products, ClO2 is not a stable product, it CANNOT be shipped, and it MUST be generated on site.

This seminar will finish with a quick review of some additional disinfestant products, such as hydrogen peroxide products.

Besides plant pathogens, WATER QUALITY is another issue of major concern associated with water recycling practice and that is the focus of next two webinars. We have been working with the groups at University of Maryland and USDA-ARS on this issue for quite a few years.

In one webinar, I will show you:

In the second webinar, we will focus on water pH and discuss:

Now, I am turning the presentation to Dr. James Pease, a professor of Ag Economics at Virginia Tech.

The Economics Team’s objectives for the “Irrigation Pathogens and Water Quality” project are to determine potential price premiums that could be gained from marketing certified “environmentally friendly” ornamental products and which could generate profits that finance investments in healthier and more water efficient practices.

The potential for price premiums has been examined by our student, David Hartter, who conducted a survey of retail consumers’ willingness-to-pay higher prices for selected plant types that could be certified as “disease-free” or “water conserving.” Analysis suggests that consumers are willing to pay more for certified plants, and we’ll be discussing these results in the final webinar of this series.

The willingness of horticultural producers to adopt recapture and reuse irrigation water has been studied by our student Alyssa Cultice. She surveyed ornamental producers in Pennsylvania, Maryland and Virginia to determine irrigation and disease management practices. In order to lay the groundwork for the webinar series discussion of these practices, results of the survey will be discussed in the second webinar of this series.

In order to disseminate information concerning the costs and benefits of new plant disease research produced by the project, we will seek cooperation by participating Mid-Atlantic nurseries as we develop case studies of both small and large ornamental producers and their search for cost-effective disease management, and describe costs and benefits that some nurseries have encountered by adopting systems that recapture and recycle irrigation water.

Now, I am turning the presentation back to Chuan

Thanks, Jim.

Before concluding this project overview presentation, I would like to encourage those of you in the audience who are extension educators and private consultants to bring subsequent webinars to the attention of your clientele.

Thanks and now we shall be happy to answer any questions from the audience. When you ask your first question, please introduce yourself: who you are and where you are calling from. Thanks.