RED DEER, Alta. – Leaving some trash on the land every fall may keep the soil from blowing eastward, but that straw and chaff may contribute to crop diseases in the spring.
Minimum or zero-till systems leave plant residue on the land that is a perfect host for fungi and bacteria, said Kelly Turkington of Agriculture Canada.
The disease triangle that consists of a pathogen, the environment and the host was explained by Turkington at the recent Alberta Conservation Tillage Society meeting in Red Deer.
Read Also
Going beyond “Resistant” on crop seed labels
Variety resistance is getting more specific on crop disease pathogens, but that information must be conveyed in a way that actually helps producers make rotation decisions.
“As we leave more crop residue on the surface we tend to see an increase in net blotch in barley,” he said.
However, crop residue is only partly to blame if a farmer decides to grow the same crop on the same field every year. Continuous cropping of cereals such as barley exacerbates net blotch problems and other yield lowering diseases, he said.
Another disease caused by poor rotation is blackleg. If canola is grown on the same field year after year, this residue borne disease increases. A fungus can survive in soil for up to 11 years.
“Rotation will be the cornerstone of most disease management programs,” said Turkington.
Besides rotation, use of disease resistant varieties and a balanced fertilizer program also improves a plant’s ability to stave off disease.
