Occurrence of yellow rust of wheat, its impact on yield viz-a-viz its management

Abstract

Investigations conducted on yellow rust (Puccinia striiformis f.sp. tritici) of wheat revealed that it has started appearing in higher proportions on widely grown cultivar PBW 343 in Punjab during recent years. Intensive monitoring and analysis of samples collected from various locations revealed that Yr 27 virulence (78 S 84) which was detected in the year 2001 was virulent on PBW 343 and its frequency increased slowly. Rust was observed in certain farmeris fields in the districts of Hoshiarpur, Ropar and Nawan Shahar upto 50 per cent and in Gurdaspur, Jalandhar upto 40 percent and upto 20 per cent in Kapurthala and Ludhiana during 2006–07. Higher severity (upto 70%) of yellow rust at many places was also recorded late in the season during 2007–08. It became wide spread during 2008–09 throughout the Punjab state and severity was as high as 80 per cent in the most of the fields in the districts of Hoshiarpur, Nawan Shahar and Ropar and caused yield losses upto 62.94 per cent in experimental plots and upto 61.84% in farmeris fields in variety PBW 343. Due to breakdown of resistance of PBW 343, an integrated management strategy including replacement of PBW 343 with resistant varieties for cultivation in disease prone areas, intensive monitoring early in the season to identify focal points and application of fungicide was worked out for its management during 2009–10. The analysis of the samples collected from various locations during 2009–10 also revealed the prevalence of Yr 27 virulence (78 S 84) on PBW 343. The foci of infection were timely identified and Tilt 25 EC was sprayed which checked the disease effectively.