Although the rainfall here and there is welcomed, the changeable mild weather of late has also unfortunately seen a spike in the risk of the foliar blight form of Anthracnose (Colletotrichum cereale).
Anthracnose attacks grass plants (normally only Poa annua) when they are under environmental 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. Time to make a plan of attack!
PRO TIPS from Aquatrols Europe
Short term strategy:
- Relieve turf stress by raising the height of cut.
- Alternating mowing with rolling has been seen to result in less damage.
- Ensure that the highest possible quality of cut is maintained.
- Fortnightly tank-mix applications of TurfRx K+ Micro Crystal @ 4.5kg/Ha and TurfRx Ca @ 5L/Ha will improve abiotic stress defences and cell wall strength while conditions persist.
- 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 minimise long periods of leaf wetness particularly 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 as these can cause further stress to the grass plant.
- Applications of the Tough Turf tank-mix are beneficial at this time – 10L Ferrosol, 10L CalSea Xtra 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.
- Fortnightly tank-mix applications of TurfRx OxyCal @ 4.5kg/Ha and TurfRx NatureCur @ 10L/Ha can be used to promote recovery once disease activity has abated
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.
- Reduce the percentage of Poa annua present in the sward.
- Implement a programmed approach to water management and plant health with the use of Revolution or Zipline.
- Over-seed with suitable, less susceptible varieties.