Usually caused by soil-borne fungi that attack plants when conditions are unfavorable. The same fungi cause root rots of older plants. Different fungi are favored by different weather conditions.
Seedling blights
Seedling blight may cause very poor stands which require re-seeding. The photo available here is a late seedling blight caused by Rhizoctonia. Notice girdling at the base of the stem.
Seedlings die before emergence. Shortly after emergence, stem bases become pinched off and seedlings die (damping-off). Older seedlings show wirestem symptoms in which the stem below the ground and upper tap root are constricted and rot. Plant seed with high vigor into a firm seeded. Pack soil to bring moisture in good contact with the seed and ensure rapid emergence. Seed treatments help reduce seedling blights.
Helix® Vibrance® protects canola's genetic potential, producing more vigourous emergence and healthier root systems. The result: enhanced crop establishment and higher yields.