Fungicide use in the turf industry - prevention or cure?

A recent trend in the turf industry has been one of prevention is better than cure and this appears to have been driven by a combination of chemical manufacturers together with their suppliers. I am not arguing that this is an admirable approach and one that could lead to a reduction in some problems developing. However, there are three issues I have with this.

Firstly, surely if prevention is better than cure this should be taken literally and not be based entirely on liberal applications of chemicals, on the off chance that it will prevent any potential disease or pest infestation from occurring?  Surely you wouldn’t pump antibiotics or other medications into your system on the off chance that you might get an infection, would you?

The second issue is one of pure economics. If prevention is better than cure surely the starting point for this is the health and nutrition of the plant (and the soil) rather than a blind reliance on chemicals for this? In the same way, a balanced diet reduces the likelihood of disease, and managing turf health appropriately will do likewise. Our industry appears, to some extent, to have forgotten this for several reasons, the main one being chemical companies (in the same way as pharmaceutical companies do) have large marketing budgets and their message is drummed into us that this is the sensible approach to take, regardless of any potential side effects.

The third issue is that of the side effects, for example, many fungicides that are applied have unwanted (nontarget) impacts and side effects that lead to other issues developing. One of the severe examples would be the effects on beneficial organisms or an unexpected growth regulatory effect.

In a 2013 article by Harold Winter, he states…’’ Illness does not occur with 100% certainty, but instead with some probability’’… and this holds true for turf management. In reality, the aim must be to reduce the probability of disease occurring and the key starting point for this is not a chemical application but instead a combination of cultural practices and getting your plant health and nutrition right!

This situation is not peculiar to the turf industry, the same situation exists in mainstream agriculture where we are now totally reliant on chemical fertilizers and crop protection chemicals to grow food. Unfortunately, this gradual change has been to the detriment of food quality, soil health, and ultimately human nutrition. And much like turf management practices, the increasing use of chemical solutions, (which is having a huge impact on the level of nutrition that is now available to us), has occurred so gradually that their real impact has largely gone unnoticed.

In my years of working in the turf industry, one example of this sticks out clearly in my mind. I remember a turf manager having major issues with dollar spot. No matter what chemicals were applied it would not go away. Every sales rep under the sun suggested applying this or that fungicide to counter this but to no avail.

A closer examination revealed that his nutritional program was based entirely on applying every month 50kg/Ha sulphate of ammonia which equated to 0.105g/N/m2 per month. Bearing in mind that dollar spot is a low nutrition disease, simply increasing either the frequency or rate of application would have alleviated this disease pressure.

Being a cynic you do wonder if sometimes simple solutions are overlooked for whatever reason!?

Chemical companies are in the business to supply chemicals and I am sure that they would be the first to admit that. Other factors such as cultural practices or the correct nutrition are not really their thing. When was the last time you were asked by a chemical company or supplier about your practices or what you are feeding with etc.? Not often if at all I would guess.

So bearing the above in mind, Yes prevention is better than cure, but the cornerstone of any preventative programme has got to be your cultural practices, your nutritional inputs, and monitoring and maintaining soil and plant health. Get these right and the likelihood of disease and pest infestation occurring is reduced significantly.

Optimizing the quality of turf (or in fact any plant) relies on an ability to balance minerals and beneficial microbes in the soil, with minerals in the plant, whilst maintaining the plants’ efficiency to convert sunlight into carbohydrates and extract nutrients from the soil.

Tips to Prevent Fungal Diseases

1. Irrigate as needed not as a habit (do not overwater!) The increasing acceptance of soil moisture probes such as the TDR 300 can be extremely cost-effective.

2. Reduce shade.

3. Maintain airflow.

4. Manage your nutrition accordingly. For example, dollar spot is a low fertility disease, and Pythium sp the direct opposite.

5. If adopting a preventative fungicide program select the appropriate one for the job. They do not all achieve the same results or work the same way.

7. Make fungicides part of the solution not the basis of any programme. Other options such as cultural and a good IPM strategy should be given serious consideration.

Options such as silica (granular or liquid), salicylic acid, cytokinins, and disease-resistant cultivars should all be given consideration as they have a role to play in this approach. The bottom line is a healthy plant is less likely to have disease issues.

 For more information on this topic and the use of biostimulants in turf.