Abstract only

Climatic conditions and virulence changes have significant effects on the occurrence of wheat rusts in Nepal. Stripe rust is the most important and epidemics are frequent. The most recent epidemics were in 2004, 2005 and 2007 with losses up to 50%. Frequently identified pathotypes (7E150, 7E158, 15E158, 46S119 and 71E32) are virulent on the widely grown cultivars RR 21 (Sonalika), Annapurna-1, Annapurna-4 and Nepal 297. Frequent rainfall and prolonged winter conditions lead to epidemics during mid-February to mid?March; infection may even begin at the seedling stage. Genes Yr5 Yr10, Yr15, Yr24, Yr26 and Yrsp remain effective. Although leaf rust is important, it is managed through incorporation Lr34/Yr18, Lr46/Yr29 and other adult plant slow rusting resistance genes. Sources of resistance to leaf rust and stripe rust include Tonichi 81, Parula, Pavon 76, Pastor, Amanda, Tukuru, Kukuna, Genaro 81 and Seri 82. Stem rust occurs during late May in local and late maturing genotypes, but epidemics have not developed in recent years. Lines carrying Sr14, Sr25, Sr28, Sr36, Sr38 and Srdp-2 are susceptible. Barberry may also have a role in epidemiology. Berberis aristata was earlier reported as an alternate host of Pgt. Aecia were recently found on B. asiatica at Godavari near Lalitpur. Detailed study on barberry needs to be done in order to establish its role as an alternate host for both Pgt and Pst.

Text in English

CIMMYT Staff Publications Collection