U of I Professor Darin Eastburn recently reported that cereal rye and rapeseed were most successful at warding off diseases than the other two cover crops studied – brown mustard and winter canola.  But all four crops tested prevented root rot and other diseases from getting any worse during the three years.

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And more on Peter Gary Field Note report on covers http://harvestpublicmedia.org/content/study-cover-crops-can-ward-soybean-diseases#.UtQO5rSNP2p