How can root diseases of wheat and barley be controlled in zero-till or conservation tillage systems?
The most sure way to control the root diseases of wheat and barley, regardless of tillage system, is to use crop rotation. Unfortunately these pathogens can live up to two years, sometimes longer, in soil in the absence of the roots of wheat or barley. Soils in the northern Great Plains and the inland Pacific Northwest tend to be too cold when wet enough for rapid breakdown of crop residue harboring the pathogens, or too dry when warm enough for rapid breakdown of these residues. Given enough time, however, the “soil will sanitize itself.” The safest way is to use a three-year rotation of wheat one year and crops not related to wheat the other two years. If barley is used with wheat in a three-year rotation, the barley should follow the wheat and the nonhost crop (e.g. lentils, corn, canola, sunflowers) should follow the barley. In barley, the take-all fungus, as well as Rhizoctonia and Pythium, remain confined almost entirely to the roots. In wheat, the take-all fungus and occasionall
