Take All Patch

Take all patch is one of the most serious diseases in the UK. Due to the destructive nature of the disease, it is regarded as a potentially serious problem.

The symptoms usually appear during the summer months and progress into late autumn.

Initial symptoms are often saucer shaped, slightly depressed areas which appear bronzed in colour.

These initial patches may only be a few centimetres in diameter but, generally affected areas can be 1 third of a metre across. The grass in the centre of the patch is killed and the area can be overtaken by weeds.

Take-all patch is caused by a fungus that lives in the soil, it does not attack the leaves. The fungus infects and kills the roots and stolons of the grass.

The fungus that causes take-all patch can be found in most soils in the U.K. However, only bentgrass is attacked by the take-all fungus.

If you have ryegrass, fescue or smoothstalk turf it will not develop take-all patch. If your turf is a mixture of grass varieties including bentgrass, then your turf could be affected by take-all patch.

The fungus has been studied a great deal, but it is still difficult for experts to predict when or why the disease develops in a turf.

The fungus is most destructive when the soil is moist, with temperatures between 12-18°C and a soil pH of 7 or above.

Turf growing in sandy soil is more severely attacked than turf rooted in heavier soil.

In general, the disease does not appear in turf for several years after it is laid.

Once it appears, it is likely to reappear year after year for many years. Patches will increase by about 75mm in diameter per year.

As the soil temperature increases above 18°C, the severity of the disease will naturally decrease, but this does not mean take-all patch is gone.

If your soil is pH 7 or above, you are more likely to have severe take-all patch. To reduce the pH of existing soil you can add elemental sulphur, but this can sometimes result in turf damage, and it can take years and repeated applications to achieve a substantial reduction in the pH.

Another means to gradually lower the soil pH in the root zone is to use acidifying fertilisers. Until the soil pH is below 6, you are not going to realise a significant benefit. Whilst we recommend a soil pH of 6 to 6.5, your turf will still grow well at a soil pH below 6. At this level, or below it, will ensure that the take-all fungus is kept weak.

If you are replacing turf that was killed by take-all patch, you need to do at least two soil preparations.

• The first is to check and adjust the soil pH.
• The second is to cultivate the top 150-300mm of the soil after the old turf is removed.

Failure to do this will almost certainly result in the new turf becoming severely diseased.

There are fungicides available for the control of take-all patch, but remember, the use of fungicides should be integrated with the practices described above. Never rely on fungicides alone. If a fungicide is required, it is critical that you apply it when the take-all fungus is starting to become active, in the spring of the year. Follow the manufacturer's recommendations closely.

We recommend that you obtain advice about chemical and non-chemical grass treatment products directly from the manufacturer.

If your turf has developed severe take-all patch, it will require several months for the turf to re-grow sufficiently to heal itself. You can overseed the turf with ryegrass, fescue or smooth stalk. These grasses are not susceptible to the take-all fungus.

Over-seeding with bentgrass will only result in more disease, because the fungus attacks young bentgrass seedlings faster than older grass.