Phytophthora: The Curious Case of the Pathogen in Your Garden

What is Phytophthora?

Phytophthora is a microscopic organism that causes root, fruit, and stem-base decay in a wide range of trees, shrubs, plants, and vegetable crops. It is a fungus-like organism that attacks the root system and reduces the root area available for water and nutrient uptake, leading to symptoms that often mimic water or environmental stress.

A diagram showing the lifecycle of the Phytophthora pathogen

A leaf displaying symptoms of Phytophthora infection

How is Phytophthora Spread?

Phytophthora is spread in the ground by tiny spores that swim in the water films between soil particles. These spores will travel short distances under their own power, but they are also attracted to susceptible plants by chemicals exuding into the water films from their roots. Phytophthora also produces long-lived resting spores that are released into the soil from decaying roots and can contaminate the soil in the vicinity of an affected plant for several years. It can be spread over long distances through mists, air currents, watercourses, and by animals, tools, equipment, and vehicle wheels.

What Are the Symptoms of Phytophthora Infection?

Symptoms include wilting, yellow or sparse foliage, and branch dieback. In many cases, the symptoms get progressively worse until the plant dies. A common symptom in conifers is a gradual fading in the colour of the foliage, from vibrant to dull green, to greyish, and finally brown.

Do My Plants Have Phytophthora?

Many experts in plant health will be able to recognise Phytophthora signs at first glance. However, relying solely on sight for detection may not be sufficient therefore it’s crucial to determine whether the disease symptoms appearing on your plant or crop are those of Phytophthora.

Our simple-to-use lateral flow tests can quickly identify numerous Phytophthora species in a variety of plants, including potatoes, tomatoes, rhododendrons, oak, and larch.

How Can Phytophthora Be Detected and Managed?

There are often no definitive above-ground signs of infection, particularly in the early stages, so taking samples for laboratory testing has been critical for detection and management. The downside to this is that laboratory testing can be expensive and time-consuming though.

However, the rapid lateral flow tests from Pocket Diagnostic® offer a much cheaper, quicker alternative and can be used in the field for immediate management decisions.

A test tube with a plant sprouting in it

Why Should I Use Pocket Diagnostic Tests?

If you are on the lookout for the presence of Phytophthora you may be aware of the tell-tale signs of its presence and the ideal weather conditions for its survival.

However, you will almost certainly need to provide proof of presence as it may be costly to destroy plants or crops due to an incorrect visual diagnosis. Furthermore, routine management, data collection, exporting purposes, or national/ government plant disease diagnosis protocols may all require confirmation of the presence or absence of Phytophthora.

A Phytophthora rapid test is a quick and easy way to confirm the presence of Phytophthora.

What Are Some Measures to Prevent the Spread of Phytophthora?

Early detection is key to preventing the spread of Phytophthora and other plant pathogens. Pocket Diagnostic® rapid lateral flow tests offer an accessible and efficient solution. With these tests, diagnosis can be made in the field or while pruning your plants, allowing for immediate management decisions.

By identifying an infection early, you can take appropriate measures to reduce the risk of further spread. This is particularly important for those working in, or managing, woods and forests, as well as those involved in large-scale crop production and horticultural activities.

Can Pocket Diagnostic Tests Save My Plants?

Using our in-field rapid tests, you can routinely test for Phytophthora using a simple but effective method. Furthermore, because the test has a high level of detection (the plant only needs to be 0.4% infected), they can serve as an early warning sign in the prevention of a major problem.

Because rapid tests produce in-field results in minutes, management strategies can be implemented faster than if a sample was sent to the lab. This quick decision making could be a clear advantage when attempting to maintain yield, helping reduce the risk of plants lost

A positive Phytophthora lateral flow test in a persons hand

Can Pocket Diagnostic Tests Save Me Money?

Not only will you save money due to reducing the amount of plants lost to disease, but our rapid tests eliminate the need to send every sample to the lab and so the cost per sample can be reduced. For example, if you need to test ten samples, the cost of laboratory testing could cost £100’s whereas testing ten samples with rapid tests could cost less than £100.

Is It Only Phytophthora I Can Test For?

No! We offer rapid tests for Erwinia Amylovora (Fireblight), Potato Virus Y, & Ralstonia Solanacearum (Brown Rot) as well

What Do I Do Now?

Well, you can head to our website to check out our Pocket Diagnostic® range as well as our Biosecurity Kits and two approved disinfectants – Cleankill (water-based) and Propellar (solvent-based) – to help you clean your boots, tools, and other equipment and mitigate the risks immediately.