STUDIES ON STEM RUST OF WHEAT AND ITS CONTROL

Abstract

Wheat (Triticum aestivum L.) is one of the most important food crops in Egypt and world. This crop is liable to be attacked by many diseases particularly the rusts. The present investigation is dealing with studying stem rust disease and it's control in Egypt. The study included the following topics:

Disease survey was carried out in the northern governorates of Egypt i.e. Kafr El-Sheikh; Dakahlia and Dumyatt. The traditional method of Stakman eta/. (1962) was applied and resulted in the identity of five physiologic races i.e. 11, 15, 17, 19 and 39. The common race was no (11) which represented (76.13% and

39.71%) of the total races during 1994/95 and 1995/96, respectively. In addition to 40 and 65 virulence formulae of P. graminis tritici the causal agent of wheat stem rust, which were derived from 88 and 68 stem rust single pustule. Likewise, Sr's (9e and 8a), (9e and Gt) proved their effectiveness during the same abovementioned seasons.

On the other hand, the recent method ofRoelfs and Martens (1988) in which 12 wheat stem rust monogenic differentials were used throughout the two seasons i.e. 1994/95 and 1995/96. This procedure gave evidence to the inclusion . of isolates i.e. RTT (37.3%), RRT (22.6%), TRT (9.04%), TTT (4.52%); JTT, RQF, RRM, RTP and STT with a frequency of(l.l3%) each, were included in race (11) which rated (79%) of total isolates. The isolates RRT (7.9%) and RTT (2.3%) were included in race (17) which represented (10.2%) of the total isolates. Isolates (KTT, STT, TTT), RRT, TQT, TRT) and (GRP, RRT, RTT) each represented (1.13%) of race (15, 19 and 39) respectively, with a frequency of (3.4%) for each race during growing season 1994/95. However, in 1995/96 the isolates TTT (7.35%), RTK (4.41%), RTT (2.94%), MTT (2.94%), RPP (2.94%). However, isolates BBG, GFT, GKG, PRM, RFK, RKP, RTP, SKR