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Rust Report - Stem (Black) Rust

Regularly updated situation reports on cereal rusts based on information provided by a global network of rust workers. It is important to note that not all reports of stem rust relate to Ug99 or variants - other local races are also included.

Stem Rust Situation Update: Stem rust widespread in both Kenya and Eritrea

16 Nov 2010

Survey updates – East Africa

Kenya: Stem rust incidence and severity remains high in Kenya. Expanded surveys (Aug-Sept 2010) by KARI, Njoro staff in the Central and North Rift regions recorded stem rust in 70% of the 122 fields surveyed. Stem rust severity was recorded as moderate (20-40%) or high (>40%) in 29% of the survey fields. From the latest surveys, 75% of the fields were considered to have received some fungicide application.

All of the surveys undertaken in Kenya this year have found stem rust at high incidence and severity. The disease is widespread throughout the wheat growing regions and farmers are very reliant on fungicides for control.  

 

Eritrea: Repeat annual rust surveys were undertaken by NARI, Eritrea staff throughout the Central Highland wheat growing areas in Oct. 2010. In stark contrast to the previous year, stem rust incidence and severity was high. Stem rust was widespread in all the areas surveyed (c.f. complete absence during the Sept. 2009 surveys). Favourable environmental conditions during the current season were undoubtedly a key factor. A total of 92 fields were surveyed and stem rust (both wheat and oat) was recorded at 84% of the sites. Excluding infected oat fields, wheat stem rust was recorded at 49 sites out of 63 (78%). Of these wheat / barley sites, 37 (40%) had moderate (20-40%) or high (>40%) stem rust severity. Extensive sampling was undertaken as part of the Eritrean surveys and race analysis will be undertaken by AAFC, Canada.

 

Details of all surveys can be found in the country survey maps.

   

Wheat Stem Rust Situation Update: High Incidence and Severity of Stem Rust in Lowland Zimbabwe

20 Sep 2010

Survey updates – Southern Africa

Mozambique: Wheat rust surveys were undertaken by IIAM, Mozambique and FAO in the key wheat growing areas of Manica and Tete provinces, Central Mozambique during the period 26th August - 1st September 2010. Wheat in Mozambique is grown in dispersed, small plots typically in remote highland areas. The Tsangano region bordering Malawi contained the highest density of fields. A total of 24 wheat fields were surveyed using standardized methodology. Wheat stem rust was not widespread and only positively recorded at one site; Rotanda, in Sussendenga district. Here a tall local wheat variety (Sitsonko) showed a highly susceptible reaction. It was noteworthy that virtually all farmers in Mozambique were growing the same variety; SC Nduna.

Zimbabwe:  Wheat rust surveys were undertaken by the Crop Breeding Inst, SeedCo and FAO in the key wheat growing areas of Zimbabwe during the period 4th-9th September 2010. A total of 27 wheat fields, distributed throughout the main agro-ecological zones, were surveyed using standardized methodology. Wheat stem rust was recorded at 12 of the 27 survey sites, being much more prevalent and widespread than in the previous 2009 season. Stem rust was widespread in the Lowveld, with 8 out of 9 Lowveld sites (elevation below 800m) recording the disease. High or moderate stem rust severity (>20%) was recorded at 6 of these Lowveld sites. Highly susceptible reactions were observed on improved varieties such as SC Stallion. Very high incidence and severity of stem rust was recorded at Chisumbanje Research Station (Photo). Trace amounts of stem rust were also recorded at 4 highveld sites (Gwebi VTC, Rattray Arnold, Kadoma, Nyanga). Stem rust samples were collected at all sites where the disease was present. Until completion of the laboratory analysis the actual identity of stem rust pathotypes present in Zimbabwe is unknown. Given the recent (2009) confirmation of Ug99 lineage race PTKST (combined virulence to both Sr31 and Sr24) in South Africa, identification of the Zimbabwe pathotypes is a high priority. 

 

Survey updates - Caucasus and Central Asia

Additional survey data were received from Azerbaijan and Tajikistan. In Azerbaijan, stem rust was absent from 24 fields surveyed in April 2010. In Tajikistan, 39 fields were surveyed using standard methodology in May 2010. Stem rust at high severity was recorded at 2 sites close to the border with Uzbekistan. Stem rust pathotypes present in Tajikistan are currently unknown.

 

Details of all surveys can be found in the country survey maps.

   
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Rust SPORE is developed by FAO and partners as part of the Borlaug Global Rust Initiative (BGRI) to mitigate the threat of wheat rust diseases (stem rust, leaf rust and yellow rust).

Disclaimer

The designations employed and the presentation of material in this information product do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations (FAO) concerning the legal or development status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.

Latest Updates

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2010 Rust Surveys - Stem Rust Severity (Click to access smart PDF)
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