.png)
Causal Pathogen: Ophiosphaerella korrae (previously known as Leptosphaeria korrae)
Commonly found impacting Green Couch and Hybrid Green Couch turfgrass surfaces around Australia.
Summary, Symptoms and Favourable Conditions
Visual signs of Spring Dead Spot in the field are circular areas of dead or bleached grass, that are most visible when the couch resumes growing following dormancy. The damaged areas will often reappear in the same place over a number of years and will grow in size.
The Damage is Done During the Cooler Months
While the visual symptoms of Spring Dead Spot are clearly visible during the warmer months, the damage is done during the cooler months.
Spring Dead Spot is most active when soil temperatures are below 21°C. These temperatures coincide with the Autumn, when couch is entering dormancy and Spring, when couch is coming out of dormancy. This enables the disease to flourish while turf growth is slow and the root system is vulnerable. Wet weather conditions and excessive levels of thatch are also favourable for the disease to flourish.
Preventative Fungicide Applications in Autumn
A Useful Management Tool for Spring Dead Spot Control
Preventative fungicide applications made to susceptible turfgrass surfaces from January to April are an important part of the management strategy for combatting Spring Dead Spot. The applied chemistry will gain control of the disease before the symptoms are visibly noticeable and before environmental conditions favour disease activity.
Apply the first application of a preventative fungicide (eg. propicanazole) for Spring Dead Spot when soil temperatures reach 21°C. Make a second preventative fungicide application before soil temperatures fall below 15°C.
Fungicide Use and Renovation Timing
Couch growth can be slow to recommence in Spring following Autumn applications of a Group 3 Fungicide. Ensure that turf treated with a preventative fungicide from Group 3 has resumed active growth before carrying out renovations.
Ensure turf that has been renovated is fully recovered post-renovation before treating with a Group 3 Fungicide.
Products to Consider for your Spring Dead Spot Control Program Include:
Contact us for information on these products and many more.
|Management is achievable|
Comentarios