Meeting the Challenge of Yellow Rust in Cereal Crops - ICARDA

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Figure 1. Locations of yellow rust monitoring nurseries planted in different wheat
growing areas of Pakistan
Results and discussion
Changes in climate, especially rainfall intensity and pattern, have greatly
affected yellow rust development in the past. Heavy rainfalls from 1991 to 1995
resulted in a favourable environment for yellow rust development. As a result
of heavy inoculum build-up during these years, yellow rust appeared in
epidemic form, particularly in NWFP and Northern Punjab during 1994/95
and 1995/96. This havoc was mainly due to the appearance and build up of
race 134E150 (Anonymous, 2001b). This race was capable of overcoming
resistance in wheat varieties with gene Yr9 (Ahmad, 2000). The series of heavy
rainfall years were followed by a period of drought throughout Pakistan, and
yellow rust infection remained low and restricted to a few areas of Punjab and