Drechslera, Curvularia and Pyricularia spp.

Other common names:

Not applicable.

Description:

Spores of Drechslera, Curvularia leaf spot (e.g. C. lunata, C. clavata) and Pyricularia grisea (Grey leaf spot) cause leaf-spotting diseases when the turfgrass is stressed. Curvularia are often irregular shaped patches of green and yellow dappled patterns that extend downwards from the leafblade tip. Affected turf turns brown, then grey as the turf declines and may results in death of affected turf.

Susceptible Turf:

Kikuyu turfgrass, including Drechslera and Curvularia (ASTC, 2016). Green couch and hybrid green couch or hybrid bermudagrass. Some Zoysia varieties will also show occasional leaf spot disease under humid conditions (Loch, 2013). Curvularia clavata on Durban grass (aka sweet smothergrass) as reported by Aldous and Loch (2013). Buffalograss is susceptible to grey leaf spot (Pyricularia grisea) and Curvularia leaf spot (C. lunata). Curvularia leaf spot (C. lunata) has also been identified on QLD blue couch (ASTC, 2019).

Symptoms:

The causal fungi usually first invade the leaves, producing small brown spots. As the disease worsens, the spots on leaf blades expand and produce a dark purplish-red oval border around a tan centre. The spots enlarge until the entire width of the leaf blade is blighted.

References:

• Australian Sports Turf Consultants (ASTC). 2016. Pathological testing of kikuyu turf variety 'Oakridge', Westgate Research Laboratory 16 Feb, PO#ASTC0092.
• Australian Sports Turf Consultants (ASTC). 2019. Pathological testing of 'QLD Blue Couch', Westgate Research Laboratory 27 Sep PO#ASTC0316.
• Aldous, D. and Loch, D. 2013. A REVIEW OF THE BIOLOGY, ADAPTATION AND MANAGEMENT OF DACTYLOCTENIUM AUSTRALE STEUD. DURBANGRASS) AS A TURFGRASS WITH PARTICULAR REFERENCE TO AUSTRALIA, International Turfgrass Society Research Journal, Vol. 12, pp. 135-142.
• Loch, D. (2013) Zoysias: the environmental turfgrass. Australian Turfgrass Management Journal 15(1), 46–49.

Control options:

• Pesticides: See available tabs below for registered products. Use as per label instructions.
• Integrated Pest Management (IPM): Use a combination of approaches listed on this page.
• Cultural: Do not water the turfgrass in the late afternoon or evening.
• Mechanical: Nil.

Disclaimer:

Turf Finder or its developer accepts with no responsibility for any consequences whatsoever resulting from the use of any information or product(s) listed herein. Products are to be applied as per label instructions.