Spot Blotch (wheat) - Introduction

Introduction

Foliar blight or Helminthosporium leaf blight (HLB)or foliar blight has been a major disease of wheat (Triticum aestivum L.) worldwide. Foliar blight disease complex consists of spot blotch and tan spot. Spot blotch is favored in warmer environments whereas tan spot is favored in cooler environments such as United States. The tan spot forms of foliar blight appears in United States causing significant yield loss. With changed climatic conditions the disease is supposed to be increasing in cooler parts of the world. Among foliar blights the tan spot, caused by Pyrenophora tritici-repentis, is the most destructive leaf spot disease found in all wheat classes throughout the growing season across North Dakota.

The spot blotch form of foliar blight is severe particularly in warmer growing areas characterized by an average temperature in the coolest month above 17�C.In the past 20 years, HLB has been recognized as the major disease constraint to wheat cultivation in the warmer eastern plains of South Asia. 25 millions of non-traditional wheat growing area are under the pressure of the disease.

See: Knowing the Enemy: Foliar Blight