Leaf Spot/Melting Out

Symptoms	A yellow or paling of leaves with spots or lesions will develop. This will depend on the grass species.
Grass Species that are susceptible	All species of grass are susceptible. This disease is the most common disease in perennial ryegrass on football pitches.
When does it appear?	In the growing season.
Climate Conditions	Moist grass leaves, overcast and warm weather.
Turf condition	General turf stress, excessive thatch, excessive nitrogen, poor air movement due to shading and leaf wetness.

leaf spot

Causes

Leaf Spot is a fungal disease that attacks the leaf of mainly Rye (Lolium spp) but can sometimes be found on Fescue (Festuca spp) and Bent (Agrostis spp).

It occurs during warmer seasons, high humidity, drought conditions, wet foliage, high shade levels.

Moves across the surface on water film.

Often found in a stadium environment due to lack of air movement.

Leaf Spot is just on the leaf it does not usually damage plants significantly.

If left untreated it will infect the crown, this then turns yellow and die as temperatures increase; this is referred to as the melting-out phase of the disease.

Cultural Control

Minimise surface wetness.

Increase airflow.

Balanced nutrition promotes harder turf more resistant to disease attack.

Remove excess thatch in an integrated programme.

Use resistant cultivars.

Raise height of cut to avoid stress if less than 50mm.

Chemical Controls

Apply Heritage Maxx (Azoxystrobin), Dedicate (Tebuconazole and Trifloxystrobin) or Medallion TL (Fludioxonil), depending on time of year, last fungicide applied and temperatures.

Always add Prestige Super Recovery to each fungicide application.

Notes:

Heritage Maxx has been withdrawn from sale and distribution. You have until the 24th March 2024 for the disposal, storage and use of existing stock

Use fungicides as part of an IPM programme and be aware of causing resistance to one chemical group by its regular use.

Use plant protection safely. Always read the label and product information before use