Bio-control pesticides… not to be confused!

As environmental stewards, greenkeepers need to produce the highest quality turf, while retaining a healthy environment for people and wildlife. Greenkeepers also face the challenge of increasingly stringent environmental regulations and a dwindling armoury of products to help deliver truly outstanding grass.  With the game-changing development, Harmonix Turf Defense, recently announced, here we zoom in on the phrase ‘Bio’ and why it is important to understand its many guises, particularly as we see the introduction of bio-control fungicide.

By definition, the term ‘Bio’ simply means connected with life and living things.

That’s easy… and vague. The confusion starts when we start to add words on to the end.

In the turfgrass industry there are a wide range of products that begin ‘Bio’ – let’s review that and try to separate the key details of what some of them are.

 

What is a bio-control pesticide?

High performance turf surfaces suffer frequent attacks and high mortality rates from various pests (weeds, insects, and fungal diseases), collectively called “natural enemies.” Bio-control or biological pesticides use natural enemies or agents to manage these pests. The ultimate goal of bio-control is to suppress or reduce pest population and damage with reduced synthetic pesticide use. Natural enemies are utilised differently depending on the target pest, host, environmental condition, and pest life cycle. Bio-controls are products derived from nature that contain living organisms such as bacteria, fungi, or viruses, that control or reduce pests or diseases. They can also help support the health and resilience of plants.

A bio-control pesticide, first and foremost, must have a direct effect on the pest (i.e., fungicidal). They can also work in secondary non-direct ways such as colonising the plant or soil, so outcompeting or antagonizing harmful organisms, or by stimulating the plant's natural defense mechanisms.

An additional important point worth remembering is that when a product comes with some control/reduction claims, it means data backed evidence. To say that a product controls or reduces a pest means we must register it as an approved plant protection product. This involves years of research to prove any efficacy claims alongside a detailed environmental and safety report. That means turf managers can confidently make the correct and safe choice when they have a pest/disease problem.

Harmonix Turf Defense, the UK’s first and only registered bio-control fungicide, is a unique, patented strain of bacteria, Bacilus amyloliquefaciens. During production, the bacteria create vast quantities of fungicidal lipopeptides that have contact action on fungal pathogens. In addition, Harmonix Turf Defense primes plants to defend themselves against disease attack via Systemic Acquired Resistance and Induced Systemic Resistance. Harmonix Turf Defense also forms a mutual relationship with the plant roots, preventing soil diseases and assisting with nutrient assimilation.

 

What is a Biostimulant?

This is more of a challenging definition because it encompasses so many products. The Health and Safety Executive (HSE) classify biostimulants using the following definition:

A plant biostimulant contains substances and/or microorganisms that stimulate natural plant processes. The effect will be independent of its nutrient content and will improve one or more of the following characteristics of the plant, or the plant rhizosphere:

• Nutrient-use efficiency
• Tolerance to environmental stress
• Quality traits
• Availability of nutrients in the soil or rhizosphere

 

They can be derived from natural (biological) or synthetic sources and are often used in combination with other products.

Biostimulants will have an indirect effect on the control of any pest (weeds, insects, or disease). This does not mean that biostimulants cannot reduce disease or other pests. It simply means the product is not directly active on the pest and instead is contributing to the reduction via other mechanisms.

If they have any claimed direct pesticidal activity they should be reclassified as a (bio)pesticide, put through the required testing scheme, and have a Ministerially Approved Pesticide Product (MAPP) number.

A confusing example:

Beneficial bacteria or fungi that are derived from nature (biological) but may have an indirect effect on a fungal pathogen infecting a plant. Mycorrhizae products may increase turf health through various indirect mechanisms thereby reducing severity of disease outbreaks. That is an example of a natural (fungus) product that may have an in-direct effect on fungal disease. Under the most recent guidelines from HSE, EU Regulation 1107/2009, mycorrihizae could be classified a biostimulant with accompanied efficacy and other data requirements.

 

Summary

Tighter environmental legislation and the drive towards improving sustainability dictates that bio-control pesticides will play a pivotal role in the future when it comes to managing turf disease and other pests. Biostimulants will also play a part in that future. However, understanding that these products are very different will be even more important as more “bio’s” are introduced to the market.   

Be aware that the effectiveness of bio-control pesticides and biostimulants can vary depending on the type of turf, conditions, and application methods. The success of establishing an economical, effective, and sustainable turf management plan is to investigate an integrated approach that will form an overall pest management plan. For further information, get in touch today.