Garden Pests Series: X…

Thoughts and musings

Garden Pests Series: X…

Lewis | May 18, 2015 | 0 Comments

…is for Xylem-invading pathogens.

So here it is! The one you’ve all been waiting for…I bet you’ve been wondering how we would get around the difficult letters of the alphabet when compiling this list of garden pests. But so far, we have very successfully negotiated it to bring you all 26! You still have the letter ‘Z’ to look forward to, which will be the last in the series. But let’s not discuss that now, as for today, a garden nuisance starting with the letter ‘X’ will be discussed. This blog post doesn’t pinpoint an exact pest; it actually covers a number of different diseases and pathogens that affect plants via their xylem, the transport tissue within a plant’s vascular system of which the primary function is transporting water upwards through the plant. So you may have guessed, it is pretty important that the xylem performs it’s function. However, there are organisms that can prevent this, causing the plant to potentially die. So read on to find out more about this silent killer of your garden ornamentals and the ilk.

The featured image for this blog post is how xylem appears under an electron microscope. The tube-like structures, called vessels, transport water as well as some nutrients upwards through the plant, providing plants cells in all areas of the organism with the fundamentals they need to survive. I am currently digging deeply into my Biology A-Level studies (which seems like a lifetime ago!) but after some research toe ensure I am bringing you accurate information, it turns out that my memory isn’t so bad after all! Nevertheless, I do not have to outline excessively that the xylem of a plant is very important to its survival. From a plant’s roots, the xylem transports water to help replenish the water loss that plants love via transpiration and photosynthesis, which is vital when it is remembered that on a dry, warm and sunny day, the leaf of plant can lose 100% of its water weight in just an hour.

Much like many things in life, with something important there are usually entities or external factors that can be detrimental to said something! In this case, there a number of pathogens that can use a plant’s vascular system for their own gain, which can result in wilting of the plant, or even its death. For example, certain bacterial microorganisms secrete compounds called exopolysaccharides, which block the xylem vessels. This slows and evens stops the flow of water through the plant, leading to it’s death. However, perhaps the most infamous diseases that affect a plant’s vascular system is are wilt diseases. There is plenty of information regarding these online, so please read about this.

As far as a bacterial wilt disease is concerned, there is sadly no way to treat a suffering plant once the disease itself is established, as the bacteria in question – Erwinia tracheiphila –  multiplies inside xylem vessels, blocking the water transport system. This particular wilt disease is transmitted by cucumber beetles, so the best you can do is to keep the populations of these species to a minimum using insecticide sprays, as well as careful monitoring of the state of your garden.

So there you go; perhaps the most scientific-based blog post in our Garden Pests Series! We hope you enjoyed it.



Photo credit: <a href=””>AJC</a> / <a href=””>Foter</a> / <a href=””>CC BY-SA</a>