Rhizoctonia root rot

Description

The symptoms of rhizoctonia are often very easy to see: uneven crop growth leaves weak or bare patches with a defined edge between the affected plants and healthy ones. These distinct patches, which develop once the seminal roots are established, can be up to several metres in diameter. Diseased plants will be severely stunted and have short roots with pinched ends known as ‘spear tips’ – a characteristic symptom that helps distinguish rhizoctonia from other soil-borne diseases.

Control

Rhizoctonia can’t be eliminated, but it can be suppressed to the point where it doesn’t cause significant yield loss.

The most effective method of reducing disease pressure is cultivation, which breaks up the rhizoctonia ‘web’– a network of filaments in the top 10 cm of the soil. Now that most growers are minimising tillage, other management practices have taken on greater importance. They include sowing cereal crops as early as conditions allow (so they get off to a more vigorous start in warmer conditions), and frequent rotation to less susceptible crops like canola.

One big advance in recent years has been the release of EverGol® Prime, a seed treatment and in-furrow fungicide that is more effective than the previous industry standards, and the innovative seed treatment EverGol Xtend.