ARS | Publication request: MODELING OF CEREAL RUST EPIDEMICS IN RUSSIA: CONCEPT OF MODELING, ACCUMULATION OF INOCULUM IN DISEASE FOCI

Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: June 1, 2006
Publication Date: July 1, 2006
Citation: Sanin, S.S., Ibragimov, T.Z., Babina, F.A., Chen, X. 2006. Modeling of cereal rust epidemics in russia: concept of modeling, accumulation of inoculum in disease foci. APS Abstracts 96:S102. Jul 29-Aug 2, 2006, Quebec City, Quebec, Canada.

Technical Abstract: The most damaging cereal diseases in Russia are rusts, leaf rust of wheat (Puccinia triticina) and rye (P. dispersa), stripe rust of wheat (P. striiformis f. sp. tritici), and stem rust of wheat and rye (P. graminis). D'pending on the region, rust epidemics occur 2-5 times every decade. Special experiments and analytical studies were conducted to develop mathematical models for epidemic development in time and space. Epidemics of diseases caused by local and outside sources of pathogen inoculum were studied. Each of these epidemic types consists of 6 periodical stages in the disease cycle: 1) accumulation of inoculum in the source, 2) emission of inoculum into the air, 3) transportation of spores by airflow, 4) settling of spores on crops, 5) infection at settling site, and 6) development of the disease on the crops. At the first stage, reproduction potential of rust fungi on intact plants in the field was directly determined. Spore production depended on the growth stage of the plants, their resistance, density of the canopy, and development of the pathogen. On a hectare of infected crop, P. triticina produced 3.0 ' 1010 to 1.2 ' 1013; P. graminis produced 6.0 ' 1010 to 2.4 ' 1013; and P. striiformis produced 4.4 ' 1010 to 1.8 ' 1013 urediniospores during a 24 h period.