Pakistan Yellow Rust Severity 2013 vs 2012

Very extensive rust surveys were undertaken throughout the main wheat growing regions of Pakistan during February-April 2013. The survey were coordinated by Dr. Atiq ur Rehman Rattu, NARC, Islamabad but were undertaken by a wide range of different institutes within Pakistan. Surveys in 2013 covered 232 locations throughout Pakistan, an increase of nearly 50% on the previous year. All three rusts were encountered on the surveys, but stripe (yellow) rust predominated being recorded at 53% (n=124) of the locations. Leaf rust was the second most widely observed rust in 2013, recorded at 33% (n=77) of the locations. stem rust was observed at 15% (n=34) of the survey locations in 2013.
Conducive climatic conditions for rusts, especially stripe (yellow) rust, occurred in Pakistan in 2013 and these conditions were mirrored in many other countries in the CWANA region. These favourable conditions were reflected in an increased frequency (compared to 2012) of high (>40%) or moderate (>20%) severity ratings for  all three rusts in Pakistan in 2013. This increasing trend of higher severity was particularly pronounced for stripe (yellow) rust. Distinct spatial distribution patterns were observed for each of the three rusts in 2013, highlighting the distinct environmental niches present in the Pakistan wheat growing areas. Stripe (yellow) rust predominated in the cooler northern-central wheat areas of Punjab, North-west Frontier, and Azad Jammu and Kashmir. Leaf rust was the most cosmopolitan rust distributed from north to south, but with higher occurrence in the central to southern areas. Stem rust was concentrated in the warmer southern regions of Sindh, with only isolated observations in the southern Punjab and one report of stem rust from a trial at Chakwal in the north. Extensive sampling of all three rusts was undertaken in Pakistan in 2013, with over 170 samples collected, and race analysis is on-going.