EPIDEMIOLOGY AND CONTROL OF WHEAT LEAF RUST DISEASE IN EGYPT

Abstract

of disease component Leaf rust caused by Puccinia triticina is an epidemic disease. The present study was concerned with the epidemiology and control strategy of wheat leaf rust disease in Egypt during 2014/16 growing seasons. Spore traps were conducted in four locations in Egypt, i.e, Kafr El-Sheikh, Sharqia, Beni Suef and Alexandria. The highest number of spores were found in March at Kafr El-Sheikh, where 1700 and 2576 spores/ month in the two growing seasons, respectively. While the lowest number was 607 spores in March at Beni Suef in the second season. Spore traps were located at four different distances, radiating from each of eight directions (E, NE, N, NW, W, SW, S, SE). In directions E, SW, S and SE, the dimensions of the spore trap did not allow the installation at the largest distances. While, in directions NW, W, N and NE, the dimensions of the spore trap more allow the spores installation at the largest distances. A total of 37 and 90 virulence phenotypes were respectively described in the three Governorates under greenhouse conditions. The two most common virulence phenotypes were BBBB and BBBT that found with high frequencies throughout the tow growing seasons. The most common race group was DK-- (13.51%) followed by race group TT-- (10.81%) in 2014-15. On the other hand, race group BB-- (23.33%) was the highest frequency in 2015/16. Virulence frequency was very high against Lr 1, 2c, 10, 11, 16, 17, 21, 24 and 26. In contrast, virulence occurred at relatively low frequency against Lr 2a, 2b, 3, 3ka, 9, 18 and 30. To study the effect of climatic factors on leaf rust incidence, ten wheat genotypes were screened against leaf rust, under field conditions at Kafer El-Sheikh, Sharqia and Beni Suef governorate. All the tested cultivars were susceptible showing terms of infection types of different levels of final rust severity. The values of final rust severity FRS%, r-value and AUDPC of most cultivars at Sharqia location were higher than in the two other locations. In general, the wheat genotypes Gemmiza-7, Sids-1, Thatcher and Morocco showed higher values of final rust severity %, R-value and AUDPC. However, the two resistant genotypes Giza-168 and Sakha-94 showed lower level of susceptibility and exhibited lower values