Wheats are attacked by many fungi and other organisms. Some cultivars are resistant to the various rusts, smuts, and virus diseases. The most important fungal diseases of wheats are the following. Extension agents should be consulted concerning diseases in an area before growing wheat. Also, cultivars should be selected for growing that are resistant to such diseases. Fungal diseases of wheat include Rusts (Stem or Black rust, Puccinia graiminis f. sp. tritici; Leaf or Brown rust, P. recondita; Stripe or Yellow rust, P. glumarum); Smuts (Bunt or Covered smut, Tilletia caries and T. foetida; Dwarf Loose smut, Ustilago tritici); Mildews (Downy mildew, Sclerospora macrospora; Powdery mildew, Erysiphe graminis f. sp. tritici); Root rots (Common root rot, Helminthosporium spp. and Fusarium spp.; Take-all root rot, Ophiobolus graminis; Browning root rot, Pythium spp.); Foot rots (Eye spot, Cercosporella herpotrichoides; Snow mold, Fusarium spp.); Blights and Scabs (Head blight or scab, Fusarium spp.; Rhizoctonia blight, Rhizoctonia spp.; Typhula blight, Typhula spp.; Anthracose, Colletotrichum graminicola; Kernel smudge, Helminthosporium spp., Alternaria spp.); Blotches (Glume blotch, Septoria nodorum; Leaf blotch, S. tritici); Speckled leaf disease, Lepto-sphaeria avenaria f. sp. triticea; Ergot, Claviceps purpurea. Diseases caused by bacteria include the following: Pseudomonas atrofaciens (Basal glume rot or Bacterial black-tip) and Xanthomonas transluscens f. sp. undulosa (Black shaff). Diseases caused by viruses include the following: Wheat mosaic, Wheat streak mosaic, Wheat striate mosaic, and Yellow dwarf. Insect pests encountered in various areas include English grain aphid, the most common aphid affecting wheat, attacking the heads and being very damaging when populations become high prior to the late-dough stage. Other insects and cutworms, darkling beetles, hessian fly, and salt marsh caterpillars may cause damage during the seedling stage. A great number of species of nematodes have been isolated from wheats in various parts of the world. Where nematodes are a problem, the agricultural agent should be consulted (HOE).
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