Red Thread and Poa Annua

August 7, 2020

Red Thread is also referred to as pink patch and is probably the most common and troublesome disease on domestic lawns. It is easily identified as reddish or pink threads or fungal filaments attached to the top of the leaves of temperate grasses. Red thread is most often a problem from autumn until late spring.

Is primarily indicative of nitrogen deficiency.
In some instances, potassium may also be a useful treatment when combined with Nitrogen.
Restrict movement to avoid transferring fungal spores across the lawn.
Mow only when the grass leaf material is dry.
Ensure that mower blades are sharp
Plants will recover after the disease has run its course
Apply the fertiliser Nitrex at 4.0kgs per 100m2 of lawn. Ensure this is watered after application. Approximately 14 - 21 days later apply Finelawn Gold at the same rate.

‍Poa annua is an annual grass weed from the large Poa family that tends to act as an annual grass in irrigated situations. This species which is sometimes referred to as “annual winter grass” or “green-keepers curse” is endemic in soils throughout temperate parts of the world. It is a relatively small grass plant which is light green to yellow-green in colouration and it seeds prolifically throughout the year. The seeds are white in colour and the leaf blades are soft and often crinkled when young.

Control

Ryegrass, Tall fescue, N.Z. Browntop, Kentucky Bluegrass

Apply ethofumesate (sold in New Zealand as Ethopro, EXPO 500, Ethosin, Claw, Nortron) at 40mls per 100m2.

Water this onto the soil surface
Re-apply in 14 - 28 days
Allow this treatment to dry on the plant leaves
Repeat application every 3 - 4 months if the infestation is bad

Fine Fescue lawns

Apply Hasloxyfop-P-Merthyl (sold as Ignite or Gallant) at label rates from September through until April. It is advisable not to use this product in winter as it does have a tendency to discolour the fescue.