Tracking rust diseases of wheat for better production and
disease management
Berhanu M. Andarge
Graduate Student
Introduction
• Wheat is one of the major food crop grown in the world next to rice,
and maize. It grows in every continent.
• In 2008-2009, 225 Million hectares of land were allocated for wheat
and annually 684 million tones of grain produced (FAO, 2010).
• Of the cultivated wheat area, half is located in less developed
countries (Reynolds and Borlaug, 2006).
• In regions such as North Africa, Turkey, and Central Asia, wheat
provides half of total dietary calories.
Into. Cont.
• Yield progress have been steady increases in productivity since the
green revolution,
– due to genetic improvements in yield potential, resistance to
diseases, adaptation to abiotic stresses, and better agronomic
practices
• Yield progress has been challenged by different factors every year.
• Of those factor Rust diseases caused by fungal pathogens are
considered to be one of the major wheat production constraints
world wide.
• The most common rusts diseases are
– Stem rust or black rust (Puccinia graminis f. sp. tritici),
– Stripe or yellow rust (Puccinia striiformis tritici) and
– Leaf or brown rust (P. recondita).
Intro. Cont.
Strip rust
Stem Rust
Leaf Rust
• Though their optimum environmental conditions are slightly
different, these rusts are present globally, wherever wheat is grown.
• They are often present together in one plant, during different growth
stages of wheat in different severities.
• Since the inception of green revolution majority of world
wheat production was backed by resistance genes
• Therefore, for the last 60 years no major epidemics was
recorded world wide specially from stem rust
• but in 1999 majority of the stem rust resistant genes,
served as a guard for wheat production, were known to
be susceptible because of the occurrence of new stem
rust races
Unique feature of rust (air born) diseases
• Rusts, especially the stem and stripe rusts are considered as the
most important biotic constraint to sustainable wheat production in
developing countries.
– This is due to the ability of the pathogen to evolve rapidly into
new races and to migrate long distances by wind.
Millions of stem rust
spores multiplied in a
susceptible plant and
transported to other
places by wind
• The world has experienced in the 1980’s and 1990’s a series of major
epidemics of wheat yellow rust.
– Unless the field is protected by resistant variety or appropriate fungicide the crop
loss would be reach to 100%.
– healthy crop only 3 weeks from harvest could be reduced to nothing by stem rust.
Picture taken from stem rust wheat Dr.
Current situation of rust disease
• In recent years, leaf rust, stripe rust, and stem rust have been the
most damaging fungal diseases of wheat, causing significant yield
losses worldwide (Singh et al. 2008).
– Of all stem rust is the most feared disease of wheat cause severe
devastation in all continent where wheat is growing.
• In 1999 high severities of stem rust were observed in Uganda on
previously stem rust resistant wheat lines
• This new race, labeled “Pgt-Ug99”, subsequently shown to attack
the stem rust resistance genes, which were previously effective.
• Since then, similar virulences have been confirmed in
– Kenya, Ethiopia, Yemen, and Iran, indicating that this new race, or its
derivatives, has spread within North Africa and into the Middle East.
Importance of tracking rust diseases
• An integrated
– research, communication and outreach approach is needed to combat
the threat of rust disease of wheat production.
– will guide the evaluation of wheat germplasm
– help to develop diagnostic technologies and disease management
systems,
– accelerate the development of new resistant varieties.
– will also outline an effective monitoring, reporting and communication
network. Strategic deployment and use of these resources and
technologies to minimize the impact of new and emerging races of stem
rust.
Application of GPS and GIS on tracking the rust diseases
• A geographic information system (GIS) is a computer program
designed to store, manipulate, analyze, and display data in a
geographic context.
• Wheat researchers can take the advantage of sophisticated
computer software programs to display and analyze spatial data.
• GIS capabilities are ideal for use in infectious disease surveillance
and control, and in outbreak investigation and response. Through
– optimize data collection and management;
– strengthen data analysis;
– strengthen outbreak infrastructure and support;
Application of GPS and GIS on tracking the rust diseases cont.
–
–
–
–
–
map epidemic dynamics in near real-time;
Quickly plan and target response;
Rapidly communicate information;
monitor changes in disease over time;
Aid emergency preparedness by mapping surveillance
data in near-real time for early outbreak detection.
Rust Maper
• Can provide timely, reliable information to wheat researchers and
decision makers in risk countries.
• It was developed by the CIMMYT GIS unit in 2010 by using the
popular satellite-image virtue globe “Google Earth”
• It is a program that tracks
– the stem rust occurrence,
– models, and potential dispersion paths for the pathogen and
– summarizes information on wheat production and susceptibility for
countries in stem rust pathways.
• It displays current rust survey sites, near real-time wind trajectories
from sites reporting stem rust (all races, not only Ug99), major
wheat growing areas and country wheat statistics.
• http://www.fao.org/agriculture/crops/rust/stem/
stem-rustmapper/en/
Thank you