Advancement toward New Spot Blotch Resistant Wheats in South Asia

Spot blotch, caused by Cochliobolus sativus , is a constraint to wheat ( Triticum aestivum L.) production in South Asia. A set of genotypes was grown in Bangladesh, India, and Nepal to assess the current status of genetic resistance across locations. This study examined spot blotch resistance and agronomic performance of 24 wheat genotypes through regional trials in 2003, 2004, and 2005 and the estimated reduction in yield caused by spot blotch. We analyzed the area under the disease progress curve (AUDPC) and AUDPC d −1 to assess spot blotch severity, and recorded grain yield, 1000‐kernel weight (TKW), days to heading, and plant height. Disease severity differed in the 3 yr. The highest AUDPC d −1 in 2005 was associated…