Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Maize southern leaf blight (080)

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  • Worldwide distribution. In tropics and sub-tropics. On sorghum and grasses. Occasional outbreaks have been serious. 
  • Spots merge and cause leaves to dry and die. Spores on undersides of leaves spread in wind and rain splash.
  • The blight survives in debris, and on 'volunteers'.
  • In the 1970s, in the US and elsewhere, a strain of the fungus (Race T), caused an epidemic, and resulted in ear rot, ear drop and lodging, and a large loss of yield. Race O is the common strain in the tropics and causes minor crop loss.
  • Cultural control: resistant varieties; remove volunteers; provide mineral fertilizers or manures; wide spacing to reduce humidity; collect trash at harvest, compost or feed to livestock; plough-in remains; crop rotation.
  • Chemical control: only use if resistant varieties are not available (main control method); use chlorothalonil or mancozeb. Apply when spots first appear.
Common Name

Southern leaf blight, southern corn leaf blight, southern leaf spot, maydis leaf blight

Scientific Name

Cochliobolus heterostrophus; this is the name for the sexual stage; the asexual stage is known as Bipolaris maydis (previously it was Drechslera maydis and before that Helminthosporium maydis). There are different races.

AUTHORS Helen Tsatsia & Grahame Jackson
Information from Souther corn leaf blight. Wikipedia. (; and CABI (2019) Cochliobolus heterostrophus (southern leaf spot). Invasive Species Compendium. (; and Pereira J (2014) Bipolaris maydis. BugwoodWiki. (; and from McKenzie E (2013) Bipolaris maydis: PaDIL -

Produced with support from the Australian Centre for International Agricultural Research under project PC/2010/090: Strengthening integrated crop management research in the Pacific Islands in support of sustainable intensification of high-value crop production, implemented by the University of Queensland and the Secretariat of the Pacific Community.

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