Phytophthora which is responsible for the root rots is also known as jarrah dieback, cinnamon fungus and wildflower dieback.
Most phytophthora species produces three types of spores, zoospores, oospores and chlamydospores. Among these two major types found are zoospores and chlamydospores. Zoospores are formed in sporangium. Each sporangium roughly produces 20-30 zoospores. Production of zoospores occurs normally in moist conditions and around temperature range of 22-28°C. Two flagella helps their motility and they can survive up to four days. On the other hand chlamydospores are produced when conditions are unfavourable. They are also produced from mycelium, but they possess thick cell walls and can survive for years in soil or host tissues. Thus they can wait for the favourable conditions for years.
Phytophthora infections are host specific. So it is highly unlikely that all the species showing advanced stages of dying near Lake Eildon would be infected with phytophthora. However there were few cases where phytophthora infections were found near lake for example near Kent Lake in California several trees were found infected with phytophthora ramorum. There are few characteristics of phytophthora infection through which one can check if it is a phytophthora infection like yellowing of foliage.
There is not any treatment which can cure phytophthora infection, nor there is any way one can stop the spreading of infection once it has infested the area. One can only prevent it from spreading to uninfected areas by taking specific care. To manage phytophthora three risk zones have been identified,
- High risk zone – where by clinical tests its proven that the area is infected
- Moderate risk zone – where its potential to infect are high, but it has not infected
- Low risk zone – where its potential to infect are low.
The following practices would help minimising the risk of spreading phytophthora
- Familiarise