Nov. 16, 2010: Stem rust widespread in both Kenya and Eritrea

Posted on by April 3, 2012

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.

 

Oct. 30, 2010: Zambia rust survey summary – Leaf rust predominates, traces of stem rust recorded

Posted on by June 28, 2012

Wheat rust surveys were undertaken by staff from the ZARI Mount Makulu Research station during the period August to October 2010. The surveys covered the main wheat growing areas in Central Zambia. A total of 27 sites were surveyed using standard BGRI survey methodology. Leaf rust was the predominant rust recorded on the survey, being recorded at 11 widely dispersed sites. Stem rust was only record at 4 sites, all which only had low severity (1-20%) of disease. It should be noted that many of the commercial farmers in Zambia use extensive chemical control on their wheat fields.

Sep. 20, 2010: Survey updates – Caucasus and Central Asia

Posted on by April 3, 2012

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.

Sep. 20, 2010: High Incidence and Severity of Stem Rust in Lowland Zimbabwe

Posted on by April 3, 2012

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.

July 31, 2010: Iran rust survey summary – Yellow rust predominates, but stem rust present in several regions

Posted on by June 26, 2012

Photo Credit: J. Kamali

Extensive wheat rust surveys were undertaken by staff from the Iranian Seed and Plant Improvement Institute (SPII) during the period April to July 2010. Coverage of most of the major wheat growing areas in Iran was achieved, with a total of 185 sites surveyed using standard BGRI survey methodology. yellow rust predominated, being recorded at 48 of the sites visited. The disease was widely distributed, being recorded in most of the survey areas. High or moderate disease severity (>20%) was recorded at 27 sites where yellow rust was present.

Stem rust was recorded at 32 of the survey sites. Stem rust observations were concentrated in two major regions – the Western wheat growing areas and the Caspian Sea areas. High or moderate severity (>20%) of the disease was recorded at 11 sites.

leaf rust was recorded at 16 of the sites visited, quite widely distributed but predominantly in the western areas. High or moderate diseases severity (>20%) was recorded at 8 of the sites with leaf rust.

Barberry species infected with aecia were recorded at four locations – all in the highland areas adjacent to the Caspian Sea. It is currently unknown which rust species are attacking Barberry in Iran, but scientific studies are now on-going to investigate the potential role of Barberry in the region.

July 23, 2010: Survey Updates – East Africa

Posted on by April 3, 2012

Survey updates – East Africa

Kenya: stem rust incidence and severity is very high in Kenya. Recent surveys (June 2010) by KARI,Njoro staff in the Narok region recorded stem rust in 80% of the 109 fields surveyed. Stem rust severity was recorded as moderate (20-40%) or high (>40%) in 33% of the survey fields. Extremely susceptible reactions (80-100S) were recorded in 5% of the survey fields. From the survey, 90% of the fields were considered to have received some fungicide application. Reports from the field indicate that farmers who have not sprayed, sprayed late, or used incorrect dosages are experiencing crop losses. Following above normal rainfall in recent months, conditions appear conducive for disease development.

Uganda: Surveys were undertaken by Buginyanya Zonal Agricultural Research and Development Institute and FAO in July 2010. A total of 25 fields were surveyed in Kapchorwa district (east) and Kabale / Kisoro districts (south-west), Uganda. Stem rust was recorded in 64% of the fields surveyed. Highest incidence and severity was recorded in Kabale district, with only trace amounts and low incidence detected in Kapchorwa district. Bread wheat, barley and triticale were all observed with susceptible reactions; however any losses would be minimal due to the advanced stage of most crops. Current race composition in Uganda is unknown, but samples were collected for future race analysis.

July 23, 2010: Survey updates – Middle East, Caucasus, and Central Asia

Posted on by December 2, 2011

Surveys were undertaken in Azerbaijan (May/June 2010 – 38 fields), Lebanon (May 2010 – 16 fields) and Uzbekistan (May 2010 – 56 fields). In each country, isolated occurrences of stem rust were detected in farmer’s fields. In Lebanon, occurrence of stem rust at 11 of the 16 survey sites was considered slightly unusual. In Azerbaijan, stem rust at two on-farm sites (score 20SMS, 40SMS) on the Caspian Sea was noteworthy. In Uzbekistan, stem rust (score 40MS) was recorded at a single site in the Fergana Valley. In all cases races involved are currently unknown. Increased surveillance effort may be one factor leading to increased detection, but regular future monitoring and confirmation of races involved is considered important.

July 1, 2010: Iraq rust survey summary – Yellow rust at near epidemic levels

Posted on by June 26, 2012

Extensive wheat rust surveys were undertaken throughout the wheat growing regions of Iraq during April to June 2010. A total of 218 sites were surveyed using standard BGRI survey methodology. Conditions in 2010 were extremely suitable for rust development. Yellow rust was observed in nearly 70% of the fields visited (n= 149) and a large proportion of these fields (n=89) had disease severity greater than 20%. All the areas surveyed were affected by the disease.

leaf rust was also widespread, being recorded at 84 of the sites visited. Most reports of leaf rust came from the Central and Southern areas of the country. Moderate severity (20-40%) of leaf rust was reported from nearly half the sites where leaf rust was present.

Stem rust was recorded at 45 of the sites visited. Most reports were clustered around Erbil in the North-east. Virtually all the records related to low severity (<20%) of disease. Which pathotypes were present is currently unknown.

June 30, 2010: Syria rust survey summary – Major yellow rust epidemic with mega-cultivar Cham-8 very susceptible

Posted on by June 26, 2012

Following early indications of a major yellow rust outbreak and high susceptibility of meg-cultivar Cham-8, the Syrian Agricultural Research Programme in collaboration with ICARDA undertook a massive rust survey effort in 2010. A total of 546 fields were surveyed, covering all the major wheat growing areas in the country. Yellow rust was recorded on 235 of the fields surveyed, with moderate or high severity (>20%) reported on more than 50% of these fields. The disease was widespread, but high incidence and severity was apparent in the North-east adjacent to the Turkish and Iraqi borders and also in the areas around Aleppo.

Conditions in 2010 were favourable for rusts in general, with leaf rust also widespread. Leaf rust was recorded on 245 fields. Highest incidence and severity was observed in the western areas.

Stem rust was recorded on only 11 fields, predominantly in western coastal areas, west of Hamah and Homs.

June 30, 2010: Morocco rust survey summary – Leaf rust and yellow rust both widespread

Posted on by June 26, 2012

Extensive surveys were carried out by Dr Ramdani, the INRA cereal pathologist, during the second fortnight of April and the first week of May 2010. The surveys covered the major wheat growing areas and were conducted when the growth stage of wheat ranged from anthesis to physiological maturity. The data recorded were host species and its growth stage, visual assessment of grain yield and incidence and severity of the main diseases. A total of 72 fields were surveyed using standard BGRI methodology, of these 53 fields were Bread Wheat and 19 fields Durum Wheat. The surveys covered all the major diseases of wheat and not just rusts.

This survey revealed that the most prevalent diseases on both bread and durum wheats were Septoria-like diseases, leaf rust, yellow rust and at some extent root rot complex. Powdery mildew and common bunt were less prevalent and were detected both on bread wheat and on durum wheat, whilst stem rust was observed on some fields of durum and loose smut on some fields of bread wheat. On the whole, 91 and 79% of bread wheat and durum wheat fields respectively were infected by SLD, whilst leaf rust was detected on 75 and 58% respectively. Yellow rust was detected on 64 and 32% of bread wheat fields and durum fields respectively. The severity of SLD ranged from zero to 100% with Gharb being the area where Septoria was most severe followed by Zemour and Pré-Rif areas. The coefficient of infection for leaf rust ranged from zero to 50 with the highest infection observed in Sais area. That for Yellow rust ranged from zero to 80 with the highest infection observed in Sais, Tadla and Middle Atlas.