What are plant health elicitors?

In recent years, we’ve seen the introduction of a new type of crop protection product - plant health elicitors. But what are they, and how do they work? Most importantly - are plant health elicitors beneficial for growers? One of the most well-known elicitors is IODUS, from UPL’s Natural Plant Protection range. That should give you a clue as to what a plant health elicitor is.

Eliciting a response from the plant

A plant health elicitor does what it says on the tin. It elicits a response in the plant to protect its own health. IODUS, for example, works by stimulating a response from the plant’s own defence mechanisms. It encourages - triggers - the plant to protect itself from harmful pathogens.

How do plant health elicitors work?

The easiest way to understand how plant health elicitors like IODUS work is to think about them preparing a plant for a fungal pathogen attack. They prime the plant’s defences by mimicking the kind of degraded cellular material that would normally come from a fungal attack. The plant thinks it's being attacked, and raises its defences. These defences are then ready to act faster when a real fungal attack happens. You could also think of them like a vaccine. A vaccine’s job is to introduce a safe version of a virus or disease to your cells so that they can learn how to fight it. Then if they do detect the real infection, they’re well prepared to shut it down quickly.

The science behind plant health elicitors

Plant health elicitors work by tapping into a plant’s natural ability to protect themselves against pathogens. Normally, a plant’s defences are triggered when it detects an attack, BUT, this takes time. Sometimes it takes up to 48 hours for the defences to be fully active, by which time, a fungal infection like Septoria has often taken hold.

In a typical defence process:

A pathogen attacks a plant, and cells are compromised.
The diseased, compromised cells release degradation products which become elicitors
The elicitors tell other cells to raise their defences, effectively putting a barrier around their cell walls to keep the pathogen out.
But, this process takes 48 hours.

A plant health elicitor:

Mimics the degraded cell products to make the plant think it's under attack
These elicitors tell other cells to raise their defences
Cells put up their defence barriers AHEAD of a pathogen attack
The warning messaging is carried throughout the plant cells - including newly formed tissues

Three important things to remember about plant health elicitors

They’re not an alternative to conventional fungicides

Elicitors like IODUS do not replace fungicides, they don’t directly fight fungal pathogens. Instead, they help a plant put up its own defences, giving growers more flexibility with fungicide applications.

They prime a plant’s natural defense mechanisms

Elicitors work by stimulating a natural response from the plant. They encourage its cells to effectively protect themselves. This gives growers more time between T0 and T1 sprays, knowing their crop has some protection.

They support effective Integrated Pest Management

You’ll get best results from plant health elicitors like IODUS by using them in conjunction with conventional fungicides at T1. By combining biological and chemical protection, you’ll have a more effective IPM programme.