The arrival of the much-needed rainfall recently has also unfortunately seen a spike in the risk of the foliar blight form of Anthracnose (Colletotrichum cereale).
Anthracnose attacks grass plants (most commonly Poa annua) when rainfall arrives following prolonged drought stress. It is triggered by environmental stress, low nutrition and compaction which lead to reduced turf vigour. Once this disease reaches basal rot stage, fungicides are no longer effective for control but should be applied to prevent further attack.
PRO TIPS from Aquatrols Europe
Short term strategy:
- Relieve turf stress by raising the height of cut.
- Consider “turf iron” light rolling instead of mowing.
- Ensure that the highest possible quality of cut is maintained.
- Stress can be relieved with applications of Providian @ 20L/Ha.
- Aerate to relieve compaction and to improve oxygen levels.
- Turf should have sufficient available nutrition, in particular Nitrogen. Address this if considered to be required with applications of Super Concentrate Super N @ 20L/Ha.
- Irrigate in the morning to minimize long periods of leaf wetness overnight.
- Use a penetrant wetting agent to move water through the upper soil profile and to keep the surface dry. An application of Dispatch Sprayable @ 1.75L/Ha will do the trick.
- Avoid mechanical cultivations such as verti-cutting and grooming.
- Applications of the Tough Turf tank-mix are beneficial at this time – 10L Ferrosol, 10L Calcium Plus and 10L Premium K/Ha.
- Use fungicides as part of an Integrated Turf Management programme and be aware of causing resistance to one chemical group by its over use.
Longer term strategy:
- Use a slow release liquid fertiliser later in the season to ensure that adequate nutrition is available which will promote recovery of the sward and maintain healthy turf. Applications of Premium N @ 20L/Ha are ideal.
- Implement a programmed approach to water management and plant health with the use of Revolution.
- Reduce the percentage of Poa annua present in the sward.
- Over-seed with suitable, less susceptible varieties.