{"id":13392,"date":"2014-01-21T13:06:23","date_gmt":"2014-01-21T18:06:23","guid":{"rendered":"https:\/\/extension.umaine.edu\/publications\/?page_id=13392"},"modified":"2024-05-22T09:27:16","modified_gmt":"2024-05-22T13:27:16","slug":"1015e","status":"publish","type":"page","link":"https:\/\/extension.umaine.edu\/publications\/1015e\/","title":{"rendered":"Bulletin #1015, Barley Scald"},"content":{"rendered":"\n

Bulletin #1015, Barley Scald (PDF)<\/a><\/p>\n\n\n\n

By Steven B. Johnson, Extension Crops Specialist, University of Maine<\/em><\/p>\n\n\n\n

For information about UMaine Extension programs and resources, visit extension.umaine.edu<\/a>.<\/strong>
Find more of our publications and books at extension.umaine.edu\/publications\/<\/a>.<\/strong><\/p>\n\n\n

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\"barley<\/a>
Barley leaf scald. Photo by Steven B. Johnson<\/figcaption><\/figure><\/div>\n\n\n

Barley scald is a common disease on barley in Maine as well as worldwide. It is caused by the fungus Rhynchosporium secalis<\/i>. The pathogen can also attack rye and some other grasses. Scald is a fungal disease which can affect all above-ground portions of the plant. Most common in wet seasons, scald is potentially damaging to barley as it can prematurely kill leaves. Yield loss is primarily owing to reduced kernel weight, but the number of kernels and number of heads per plant may also be affected. Decreased photosynthetic area on the flag and second leaf of the infected plant may result in reduced seed weight and yield loss.<\/p>\n\n\n\n

Biology<\/strong><\/h3>\n\n\n\n

The scald fungus overwinters on barley residue, grain, and some grasses. In spring, spores are produced mainly from barley residue left on the soil surface from the previous year. Spores are transported to barley plants by raindrops and wind. The contribution of scald-infected seed as a source of disease spread in barley is not well understood. The disease is favored by cool (40\u00b0F to 75\u00b0F), rainy weather and dense crop canopies where leaves remain wet for prolonged periods. Optimal temperatures for sporulation and infection are 60\u00b0F to 68\u00b0F. If the disease appears and spreads early in the season, such as during tillering, yield losses may be expected owing to flag leaf infection. Late-season disease appearance rarely results in appreciable yield loss.<\/p>\n\n\n\n

Symptoms<\/strong><\/h3>\n\n\n
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\"barley<\/a>
Barley leaf scald, top to bottom: stem lesion; leaf lesion; leaf lesions starting to coalesce. Photo by Steven B. Johnson<\/figcaption><\/figure><\/div>\n\n\n

Large water-soaked spots, grey-green in color, appear on the leaves. These spots enlarge to lesions that are oval in shape with dark brown margins. The lesions become a bleached tan in the center. As the lesions enlarge, they coalesce to give a \u201cscalded\u201d appearance. Hot, dry weather halts disease progress.<\/p>\n\n\n\n

Management<\/strong><\/h3>\n\n\n\n