Phytopthora

Talking Trees with Lily and Jad . Welcome to Talking Trees , your daily exploration into the challenges facing our natural world . In today's episode , we turn our focus to the fungal pathogens of the genus Phytophthora , a serious threat to forests and natural ecosystems around the globe , including in England and Wales .

Welcome back everybody . Today we're going to be taking a deep dive into something that I know is a big concern for all you arborists out there phytophthora it is . It's a pretty big , silent threat to our trees and , you know , as arborists , you're the ones that are really out there on the front lines .

Absolutely .

We've got a couple of research articles today that we're going to be looking at Yep , and also a really interesting overview of phytothor root rot . So let's kind of unpack this a little bit and see what we can figure out and learn today .

Yeah , I think you know . The thing that is so striking about phytothor is that even for seasoned professionals you know , those of us who've been in the industry for quite a while it can completely change the game for us .

Yeah , for sure . And it's not just you know a textbook pathogen we're talking about . You know a genus that can wipe out entire ecosystems , and I'm not being hyperbolic here .

This is the real deal . It's a serious issue .

Yeah . So let's jump right in and talk about a case that I think really shook the arboriculture world Sure , sudden oak death .

Okay .

Caused by Phytophthora remorum .

Yeah , phytophthora remorum is such a fascinating , horrifying but fascinating example , because you're talking about a pathogen that can actually spread through the air . Oh , in coastal regions of North America it's been . You know it's been devastating . It's causing rapid oak mortality , and it's not just oaks that are vulnerable to this .

Over a hundred , yeah , so what does that mean for arborists ? What do they need to be thinking about ?

Well , you know , vigilance is really keyed here , because you could have a tree that seems perfectly healthy one day and then all of a sudden you start seeing these signs of dieback . Phytophthora remorum is , you know , kind of a master of disguise in a lot of ways and its impacts can be very swift and severe .

So knowing the signings is really crucial then .

Oh , absolutely . And this is where it gets really tricky because , you know , the symptoms of phytophthora can vary depending on the host and even the specific phytophthora species that you're dealing with . So you know , we might see root rot , we might see cankers , we might see wilking , but it's not always a very clear cut diagnosis .

Right , and that's just one example .

There are other phytothorous species out there that are wreaking havoc as well in shortleaf pies , and the scope of its impact is really mind-boggling because over 3,000 plant species are known to be susceptible to phytophthora cinnamomi 3,000 .

That's almost impossible to even fathom .

It is and it really speaks to the interconnectedness of our ecosystems .

Yeah .

You know , because when phytophthora cinnamomi infects a tree , it's not just about that one tree You're talking about , you know , disrupting the entire ecosystem , impacting soil , health , biodiversity , even affecting the animals that rely on those trees for habitat and food .

It's like a domino effect .

It is .

One that we , as arborists , really need to understand and be prepared for .

Absolutely .

And to make things even more complex , this pathogen isn't confined to one continent .

Right .

It's present in Europe as well .

Yeah , and the fact that you know Phytothororomorum was first described in Europe before it caused so much devastation in North America really highlights how easily these pathogens can travel .

Yeah .

You know , we live in a globalized world and what happens in one forest can have a ripple effect on another forest on the other side of the planet .

It's a good point that global perspective is really essential for arborists , especially in today's world .

Absolutely , and I think from a practical standpoint you know , understanding the economic impact of phytophthora can be really powerful when you're talking to clients .

OK .

You know we have research here from the Journal of Environmental Management that estimates a staggering 1.446 billion pounds Wow , annual public value at risk in England and Wales alone . Wow , just from the uncontrolled spread of phytophthora remorum and Phytophthora carnovia .

That's not just a number , though .

Right .

What does that translate to in real world terms ?

Think about heritage , gardens , woodlands , heathlands all of these are at risk . Wow , imagine having to explain to a client that their beloved oak tree- that's been the centerpiece of their property for years , has to be removed because of phytophthora . The cost of removal , replanting , the potential decrease in property value it all adds up .

So it's not just about saving trees .

It's about so much more .

It's about protecting investments .

Right .

Preserving these landscapes and really understanding the true cost of inaction .

Exactly Preserving these landscapes and really understanding the true cost of inaction , how serious a threat phytophthora is , both in terms of its ecological impact and also economically . But now I think it's time to shift gears a little bit and talk about what we can actually do about it .

Yeah , because knowledge is great , Right , but you know actually getting out there and

Exactly .

So where do we even begin with something like this ?

Well , it all starts with the basics , and I can't stress this enough Hygiene and sanitation are your first line of defense .

Okay .

I know it sounds really simple , but you'd be surprised how often these fundamental practices are overlooked .

What does that look like in practice ?

Well , think about it , you're moving between job sites . Right , you're dealing with potentially infected trees .

Right .

Every time you touch a branch , use your tools , even drive your truck from one location to another . You could be transporting phytothorous spores .

So we're all potential carriers then ? Essentially yes , unknowingly spreading this microscopic menace .

That's right , but the good news is we can break that chain . It's all about being mindful and implementing some simple but effective biosecurity measures .

Okay , so give us some specifics . What could arborists do to you know ? Stop those spores from hitting a ride .

Well , start with your toolers .

Okay .

Make sure they're cleaned and disinfected between every single job .

Okay .

Think about the soles of your boots , your truck tires anything that comes into contact with soil or plant material could be harboring phytophthora .

So it's kind of like creating a clean slate before you move on to the next site .

Exactly .

No one wanted souvenirs .

Precisely . And another important step is sourcing your plants from reputable nurseries that prioritize biosecurity . Don't be afraid to ask questions about their practices , their inspection protocols . You want to be confident that the trees you're planting are healthy and disease-free .

It's all about due diligence .

Absolutely .

Protecting your clients and their investments .

Exactly , and remember we talked earlier about the importance of early detection and reporting . Right , you're the eyes on the ground . If you see something suspicious , don't hesitate to reach out to your local plant health authorities .

Okay .

Or diagnostic labs .

So if a tree is showing symptoms , we shouldn't just assume it's something else .

Right .

Better to get confirmation .

Exactly . A proper diagnosis is key . They can identify the specific phytophthora species , which can then guide your treatment decisions .

Okay . So let's say we've got a confirmed case of phytophthora

Okay .

What happens next ?

Well , the next steps depend on a variety of factors , sure , the severity of the infection , the species of the tree , the site conditions . But in many cases removing and destroying infected plant material is necessary to prevent further spread .

Removal . That sounds a little drastic . I know , are there less extreme options ?

Sometimes , if the infection is caught early enough and depending on the overall health of the tree , preening affected branches or roots might be an opaline .

So kind of like a surgical approach .

Exactly Just targeting the diseased area , that's right , but it's important to emphasize that this must be done with extreme care .

Okay .

And in conjunction with other management strategies . You don't want to create more wounds that could become entry points for further infection .

Right , it's all about minimizing the risk of spreading those spores .

Precisely , and another important aspect of control is managing the site conditions to make them less favorable for phytophthora .

Okay , how do we do that ?

Well , we know that this pathogen thrives in moist , poorly drained soils , so think about improving drainage , avoiding overwatering , mulching appropriately .

So it's about playing defense , creating an environment that's not a phytophthora paradise .

That's a great way to put it . You're essentially tweaking the environment to give the trees a fighting chance .

And this is where an arborist's expertise really comes into play .

Absolutely .

Right Understanding the specific needs of the trees and the site conditions .

You're not just treating the symptoms .

Right .

You're creating a holistic management plan that considers the entire ecosystem .

And speaking of tools in the toolbox , yes , we talked earlier about phosphonates , as what's the latest on those ?

Well , phosphonates can be a valuable weapon against phytophthora .

Okay .

Especially in severe cases or when you're dealing with highly valuable trees . They work by boosting the plant's natural defenses and inhibiting the pathogen's growth .

But like with any chemical treatment , there are some potential downsides to consider .

There are , and responsible use is really key . One concern is phytotoxicity .

Okay .

Essentially damage to the treat itself Right If the phosphonates are applied incorrectly or at too high a concentration .

So knowing the right dosage and application method is crucial .

Absolutely . And another issue is the potential for resistance development in phytophthora populations if they're repeatedly exposed to the same chemical treatment .

So it's a balancing act then . It is Using these tools strategically while minimizing the risks . Exactly what's the best way for arborists to stay informed about the latest research and guidelines on phosphonate use ?

That's a great question .

Right .

So continued education is really fruitful . Organizations like the Forestry Commission and FARA are excellent resources . They publish research findings , best practice guidelines and they even host workshops .

So staying ahead of the curve is really essential in this battle .

It is .

It's not just about knowing what to do . It's about knowing the latest and the most effective methods .

Exactly and don't underestimate the power of networking .

Okay .

Talk to other arborists , share experiences , attend conferences Right the collective knowledge and expertise within the arboriculture community is invaluable .

Powerful stuff . I think you know a lot of arborists feel that deep connection to the trees that they care for . It's more than just a job , Absolutely , it's a passion .

I couldn't agree more , and that passion is what's going to drive us forward .

Yeah .

Even in the face of challenges like Phytophthora .

Well , as we wrap up this deep dive , I want to thank you for sharing your expertise and insights with us today .

Oh , the pleasure was all mine .

It's been a really eye-opening journey into the world of Phytophthora .

Yeah , it's a fascinating and complex topic , for sure .

For sure To our listeners out there . We hope this deep dive has equipped you with the knowledge , sparked some new ideas and fueled your passion for protecting our trees .

Absolutely . Stay curious stay informed and keep up the amazing work you do , because together we can make a difference . Couldn't have said it better myself the amazing work you do , because together we can make a difference .

Couldn't have said it better myself . Thank you for joining us on today's episode of Talking Trees . We've delved into the critical threat posed by phytophthora pathogens . As we continue to navigate these complex issues , we hope you take away the importance of proactive prevention and control measures in safeguarding our forests and natural ecosystems .