Evaluation of Bread Wheat (Tritium aestivum L.) Varieties for Rust Resistance at Wolaita Zone, Southern Ethiopia

Abstract

The bread wheat is an important crop of Ethiopia. The average yield of wheat in the country is much behind the potential yield of the improved wheat cultivars. The low yield of wheat is the consequence of many factors including rust diseases that cause yield along with quality losses. Most of breeding programs in the country lack facilities for screening against rust diseases. Usually, selection is done with inadequate rust epidemic or improper pathotypes. As a result, only a few of released cultivars exhibit desired resistance against the prevailing rust diseases. A study was conducted  during 2013 rainy season  at sodo zuria  woreda to provide information on the level of resistance in 20 released  bread wheat varieties against rust diseases. The experiment was conducted using 20 bread wheat varieties and it was arranged using randomized complete block design (RCBD) with three replications. Plots having the size of 2  X 1 m was  prepared. There are 10  rows per plot and the space between rows, plots and replications was  0.2, 0.5 and 1m respectively.  Incidence and severity of  wheat rust diseases were recorded with ten days interval and data on yield and yield components were taken at harvest. Remarkable difference at (P=0.05) were observed in incidence, severity, AUDPC values of the disease and yield component between the twenty varieties. Area under leaf rust progress curve (AULRPC)  was also significantly different at P<0.05 between wheat varieties. The highest of AULRPC values (825%, 616.7 %, 525%,& 378% )  was recorded on  galema, pavon-76,jefarson, and gassay  respectively. Galema, medawelebu, pavon-76 showed the highest area under yellow rust progress curve AUYRPC  with 1092,193.3 and 133.3% respectively. The lowest area under yellow rust progress curve AUYRPC  with 28, 28, 21& 53 % was recorded on the varieties danda, digelu,  hidasie and kakaba respectively. The results indicated that varieties exhibited compatible reaction with prevailing rust diseases of stripe and leaf rust. Varieties danda, hidasie, kakaba and digelu demonstrated  type of resistance against naturally prevailing stripe& leaf rust diseases. Disease severity, incidence and area under disease progress curve (AUDPC) were negatively correlated with wheat yields harvested from four central rows.  More  extensive  studies  for  assessment  of bread varieties  for  specific  regions  and identification of control measures against rust disease would contribute to stabilizing wheat production in  Ethiopia

Keywords: rust diseases, bread wheat varietie