TY  - PRO
AU  - Boshoff,W.H.P.
AU  - Van Niekerk,B.D.
AU  - Pretorius,Z.A.
ED  - Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT), Addis Ababa (Ethiopia)
TI  - Stripe rust:  a new threat to wheat production in South Africa
SN  - 92-9146-058-3
PY  - 1999///
CY  - Addis Ababa (Ethiopia)
PB  - CIMMYT
KW  - Breeding methods
KW  - AGROVOC
KW  - Disease control
KW  - Food production
KW  - Plant diseases
KW  - Puccinia striiformis
KW  - Rusts
KW  - South Africa
KW  - Triticum aestivum
KW  - Plant breeding
KW  - CIMMYT
N1  - Abstract only
N2  - Stripe (yellow) rust, caused by Puccinia striiformis Westend. f. sp. tritici Eriks., is one of the most important diseases of wheat (Triticum aestivum L.). Yield losses as high as 84% have been recorded under severe epidemic conditions. During August 1996, stripe rust was observed for the first time on bread wheat in the Western Cape, South Africa. Ensuing surveys during 1996 indicated that stripe rust spread to most of the wheat producing areas in the winter rainfall region of the Western, Southern and Eastern Cape and to irrigated wheat in the summer rainfall area south of Kimberley. In 1997 the disease was observed early in the season in the Western Free State from where it spread to the rest of the province, KwaZulu-Natal, Gauteng, the North West and Northern province. In the Southern Cape and Eastern Free State the pathogen over-summered successfully on volunteer wheat plants. Infected grass species, serving as accessory stripe rust hosts, were also observed in the Western Cape and Eastern Free State. The rapid dispersal of stripe rust during the 1996 and 1997 wheat seasons, the ability of P. striiformis to over-summer in both the winter and summer rainfall regions, susceptibility of several wheat cultivars, favourable climatic conditions in many wheat growing areas in South Africa, and additional costs of fungicide application, qualify stripe rust as a damaging disease with strong impact in local wheat production. A low percentage of both winter and spring cultivars expressed complete resistance, presumably controlled by race-specific genes, towards pathotype 6E 16 of P. striiformis f. sp. tritici. The high mutation potential of the stripe rust pathogen could drastically alter the current resistance status in these cultivars. Future breeding efforts should be directed towards strategies to obtain effective and durable resistance against stripe rust. The release of cultivars containing only race-specific resistance genes should be strongly discouraged. Selection of resistance sources for application in breeding programs should focus almost entirely on genotypes with known durability
ER  -