Streptomycin has been withdrawn, we spray copper year after year, and the copper load in soils keeps growing. There are few targeted tools against bacterial plant diseases today, while new pathogens keep appearing: bacterial wilt of bean (Curtobacterium) was recently detected in Hungary too. There is an option that has long been known yet is hardly used in crop protection: the bacteriophage.

What is a bacteriophage?

A bacteriophage is a virus that infects and destroys bacteria. Unlike an antibiotic it acts in a targeted way: each phage attacks only certain bacteria and leaves the rest alone. It enters the bacterium, multiplies inside it and then bursts the cell – and it can be effective even against multi-resistant bacteria.

What do the trials show?

In field trials abroad, phage cocktails were used against fire blight (Erwinia amylovora) in apple and pear orchards, against black rot of potato tubers (Dickeya solani), and against Xanthomonas campestris The results are encouraging, and phage-based products against fire blight are being developed in Hungary too.

Why aren’t we using them yet?

Phages are sensitive to UV radiation, they don’t stick to every leaf surface, and bacteria can outwit them over time. The biggest obstacle, however, is not biological: in the EU every single phage must be registered as a separate active substance, with a full toxicological and environmental risk assessment.

Four questions if you have a bacterial disease on your farm

1. Exactly which bacterium causes the symptoms – confirmed by a lab?
2. How much copper have you applied in recent years, and how much more can the soil take?
3. What haven’t you used yet in prevention: seed, rotation, hygiene?
4. What approved biological options are there in your crop?

With bacterial diseases, the right decision rarely comes down to a single product.

In detail

I wrote about the trial results, the Hungarian development work and how promising I think phages are in Parasztvakítás: Mivel védekezzünk a bab kurtobaktériumos hervadása ellen? (for subscribers).

How I can help

I work as an independent plant doctor: I don’t sell plant protection products and I take no commission from distributors. My advice is guided by one thing only: what pays off for your farm.

• Phone consultation: a quick, well-founded answer to a specific question, followed by a written summary.
• Consulting for the whole season: systematic support so that problems come to light in time.

Request a callback, and let’s see what this means for your farm.