Cause: Cochiobolus sativus (Bipolaris sorokiniana) Occurrence: September - June, during periods of moisture. Key Symptoms: Brown to black lesions on primary and secondary roots and subcoronal internode. Brown discoloration of crowns. Yellowing of plants in spring. Poor tillering. Scattered pockets of dead and dying plants in April. Spindly plants with small heads. Symptoms usually more acute on wind-prone hills and knobs.
· Plant adapted varieties for your geographic area.
· Plant into a firm, mellow seedbeds (loose seedbed promote disease).
· Control weeds in summer fallow land (weeds deplete soil moisture which predisposes plant roots to infection in the fall.
· Always plant good quality seed (bin-run seed is at higher risk).
· Plant at the recommended date for your geographic area. Early planting or extended, warm fall weather promotes disease.
· Cultural practices recommended for crown and root rot also reduce the risk of winter injury.
· Seed treatment fungicides provide an early window of protection in the fall against common root rot.
· When selecting a seed treatment product, pick one that has activity against common bunt and loose smut as well as common root rot.
Vitavax Extra (carboxin + imazalil + thiabendazole)
Dividend XL (difenoconazole + mefenoxam)
Raxil XT or MD (tebuconazole + metalaxyl)
Raxil MD Extra (tebuconazole + metalaxyl + imazalil)
RR, Flo-pro, NuZone (imazalil)
Baytan (tridimenol)
· Uniformly coat the seed when applying the seed treatment product.
· For drill box application, fill the drill box 1/3 full of seed, sprinkle 1/3 of the fungicide over the seed and mix. Repeat until the proper amount of fungicide has been added and mixed.
· Read and follow all label directions for mixing and application.
Categories: Small grains, Diseases, Common Root Rot
Date: 09/11/2004