Rhizoctonia Patch of Cereals Rhizoctonia solani AG-8
Rhizoctonia is derived from the genus name of the disease.
Patches, that are often circular, up to several metres across with stunted plants. The roots are much shorter than those of healthy plants of the same age. The roots are often pointed or spear shaped at their ends where the disease has rotted them off.
Most species are affected. Barley>Wheat>Oats.
Favoured by wet warm soils.
It is a common soil pathogen that may survive on crop stubble or as sclerotia for long periods.
Spread by movement of infected soil or crop residues.
Cool climate grasses appear to be more susceptible than warmer climate grasses.
Origin and History:
Circular patches in the crop containing stunted plants.
Rhizoctonia causes major yield losses in many crops.
Barley if more affected than Wheat which is more affected than Oats.
Management and Control:
Do a Predicta-B soil test from SARDI Root Disease Testing Service.
Cultivate soil deeper than the planting depth. Avoid zero tillage in affected areas.
Deep rip if necessary to remove compaction layers.
Use adequate fertilizer to reduce effects of the disease.
Avoid the use of sulfonylurea herbicides such as chlorsulfuron and metsulfuron.
Control all weeds before planting.
Don't burn stubble more than one year in three.
Lemon grass extracts reduce the disease (799).
Related and Similar Species:
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