Estimated Yield Loss Assessment of Bread Wheat (Triticumaestivum L.) due to Septoria Leaf Blotch Septariatritici (Roberge in Desmaz) on Wheat in Holeta Agricultural Research Center, West Shewa, Ethiopia

Abstract

Septoria leaf blotch is one of the most important yield limiting diseases of wheat world wide. Yield loss assessment was conducted in Randomized Complete Block Design (RCBD) in pair treatment (sprayed versus unsprayed), with four replications at Holeta Agricultural Research Center experimental field during the main cropping season of 2014. A susceptible bread wheat variety ‘Huluka’ and systemic fungicide Propicanazole, (Tilt-250 E.C), at the rate of 0.5 l/ha was used under natural infections. Evaluation was started from the onset of the disease 62 days after planting (DAP). The initial incidence and severity of disease treated and untreated plots were similar with incidence of 22.5 and 20and Severity of 6.6 % and 5.6 % respectively. However at 110 DAP, the incidence and severity of treated plots were 25and 4.3, while that of untreated plots were 100 and 95% respectively. The effects of Septoria leaf blotch on grain yield was significant (P<0.05) when the treated (5626.kg/ha) was compared with the un treated plots (3324.3 kg/ha). Yield loss in grain yield was estimated to be 41%. Disease parameters like disease incidence, severity and the area under disease progress curves (AUDPC) were negatively correlated with yield and yield components, whereas, yield components were positively correlated with yield. Data on cost benefit analysis showed that, the highest net return benefit was obtained from fungicide treated plots with mean value of 46018.80 Ethiopian birr/ha-1. While the least net return was obtained from untreated plots with a value of 26280.85birr/ha. The marginal value also indicated that, the highest marginal rate of return (926%) was obtained from treated plots when compared with untreated plots. There is a need to assess further pathogen variability’s and subsequently to screen resistant varieties against the Septoria leaf blotch. In absence of other options yet farming communities need to be advised on timely application of efficient fungicides against the pathogen that may lead to utilization of integrated diseases management.