Dr. Phyto

Couch grass

Elymus repens

Diseases & pests on this plant

• brown rust of wheat + ryePuccinia recondita

  Small orange-brown round pustules scattered on upper leaf surfaces (smaller + more random than yellow rust stripes), severe infection causes premature leaf senescence, reduced photosynthesis lowers thousand-grain weight, late-season teliospores form black pustules on dying leaves.

• ergot of rye + cerealsClaviceps purpurea

  Hard purple-black curved sclerotia (5-30mm long) replacing kernels in cereal heads (very distinctive — looks like a black banana stuck in the head), honeydew (sticky yellow exudate) on flowering heads during infection phase, sclerotia drop to ground at harvest + survive winter, contaminated grain dangerous for human + animal consumption.

• crown rust of oatPuccinia coronata

  Bright orange-yellow pustules on leaves with characteristic crown-shaped teliospores in late season, severe infection causes premature leaf death + lodging, kernels do not fill properly leading to shrivelled grain, in epidemic years 50%+ yield loss with poor grain quality.

• Take-all patchGaeumannomyces avenae

  Roughly circular, sunken patches 5–60 cm across, at first orange-bronze then bleached straw to grey, with the worst symptoms on bentgrass. The centre often recovers and is colonised by weeds or other grasses, giving a 'frog-eye' ring. Roots are blackened, rotted and pull away easily; worst on alkaline, sandy or newly limed soils 1–3 years after establishment.

• Leaf spot and common root rotBipolaris sorokiniana

  Small dark brown to black leaf spots, often with a yellow halo, that enlarge and merge to blight whole leaves in warm, humid weather; on close-mown turf this becomes a general thinning and bronzing. Below ground the same fungus causes a brown rot of roots, crowns and stem bases, so plants are easily pulled up and the turf melts out in diffuse, irregular brown areas. Most damaging in warm summer spells on stressed, thatchy lawns.