Field Based Assessment of Spot Blotch (Bipolaris Sorokiniana) Disease of Wheat (Triticum Aestivum L.)

Abstract

Wheat, the third major staple crop of Nepal has suffered from many diseases. Various diseases are the major limiting factors of considerable wheat production, one of them is Spot blotch. Spot blotch caused by Bipolaris sorokiniana is a major disease of wheat in warm and humid regions of Nepal. The fungus has a worldwide distribution but as a pathogen, it is the most aggressive under the conditions of high relative humidity and temperature associated with the low fertility of soils in South Asia, South America, Africa, and Australia. The yield loss due to the disease is very significant in Nepal. This experiment was conducted to identify the genotypes having a good level of resistance against spot blotch. The experiment set was received from CIMMYT comprises 52 entries and arranged in alpha lattice design with two replications in 2017/18 at Regional Agricultural Research Station, Parwanipur, Bara, Nepal. Each plot size was 8 rows of 2 meters long. Three times disease scoring was done in the double-digit method and calculated the Area under the disease progress curve (AUDPC). Heading days, days to maturity, plant height, number of grains per spike (NGPS), number of tillers per meter square (NTPM), mean AUDPC, thousand-grain weight (TGW), and grain yield were found highly significant. The genotype 8HLBSN24 was found the highest yielder (4999kg/ha) with a 208 mean AUDPC value. The grain yield and mean AUDPC was a strong negative correlation (-0.96). However, NGPS and NTPM found a positive correlation to grain yield. Keywords: Foliar blight, AUDPC, Wheat, Genotype