Pasture Diseases - Agriseeds Pasture Site

Pasture diseasesRamularia leaf spotand scald127PASTURECULTIVARSSummarySpecies affectedIdentificationRamularia leaf spotThe fungus Ramularia pusilla causes Ramularia leafspot (RLS), most commonly in spring and autumn,when it can seriously reduce yield and quality.Ryegrass, prairie grass.Rounded leaf spots, grey to brown in colour,sometimes with red edges, appear on the leaf surface.Part of a paddock can appear yellow as infectedleaves become yellow and die.RYEGRASSTRIALSRYEGRASSENDOPHYTEPASTURERENEWALSpreadPreventionandmanagementSummarySpecies affectedIdentificationNumerous small, egg-shaped spores are producedon older lesions. These spores are readily wind borneand can rapidly spread infection to new sites. Thespread of RLS is favoured by wet, humid weather.Pasture should be grazed before becoming longand rank, to reduce the chance of RLS becomingestablished and lower the severity of the disease. Under serious infection, fungicidesmay be economical.ScaldScald, caused by the fungus Rhynchosporiumorthosporum, typically occurs April-October, fromManawatu and Hawke's Bay south.Ryegrass, cocksfoot.Scald causes irregularly shaped lesions or scaldlikeblotches on leaves and leaf sheaths. These arebrown-grey in colour, often appearing grey withbrown edges. Lesions can join to affect most of theleaf. Infected leaves often die from the tip down;heavily infected plants are unpalatable to stock.Ramularia leaf spot onryegrass leaves.PASTUREMANAGEMENTPASTURE PESTS& DISEASESBRASSICACULTIVARSBRASSICAMANAGEMENTBRASSICA PESTS& DISEASESSEEDTREATMENTSpreadSpores produced on dead leaves are splashed,blown or carried to new leaves. The disease thenpersists in cool, sheltered areas. It is most severeduring cool, wet periods in early spring and autumn.Scald on ryegrass leaves.SEEDINFORMATIONPreventionandmanagementSow resistant ryegrass cultivars. All Agriseeds cultivars have good resistance to scald. Ifthe disease is noted in winter conserved feed, timely grazing can reduce losses.WEEDSGLOSSARY