Estimating grain yield losses caused by septoria leaf blotch on durum wheat in Tunisia

Abstract

Septoria leaf blotch (SLB), caused by Zymoseptoria tritici (Desm.) Quaedvlieg & Crous, 2011 (teleomorph: Mycosphaerella graminicola (Fuckel) J. Schröt.), is an important wheat disease in the Mediterranean region. In Tunisia, SLB has become a major disease of durum wheat (Triticum turgidum L. subsp. durum [Desf.] Husn.) particularly during favorable growing seasons where significant yield losses and increase of fungicides use were recorded over the last three decades. The objectives of this study were to evaluate the effect of SLB severity on grain yield of new elite durum wheat breeding lines and to measure the relative effect of fungicide control on grain yield. Experiments were conducted during 2007-2008 and 2008-2009 cropping seasons. A set of 800 breeding lines were screened for reaction to SLB under natural infection at Béja research station. To estimate the disease effect, correlation between disease severity at early grain filling stage and grain yield was performed. Results showed that susceptible varieties yield was significantly reduced by SLB. Average yield reduction was as high as 384 and 325 kg ha -1 for every increment in disease severity on a 0-9 scale in both seasons, respectively. A negative correlation coefficient varied between -0.61 and -0.66 in both seasons. Treated and untreated trials conducted during 2008-2009 and 2009-2010 showed that yield of treated plots increased by 50% on the commonly cultivated susceptible varieties. The results of this investigation suggested that septoria incidence is related to large grain yield losses particularly on susceptible high yielding cultivars. However, appropriate fungicide application at booting growth stage could be beneficial for farmers. The development and use of more effective fungicide could be sought to alleviate the disease effects and therefore could be considered as a part of the integrated pest management and responsible use strategy on septoria leaf blotch in Tunisia.

Biological control of septoria leaf blotch and growth promotion in wheat by Paenibacillus sp. strain B2 and Curtobacterium plantarum strain EDS

“…High protection levels, 71% and 75%, were conferred against M. graminicola in Alixan and Altigo respectively, as a response to root inoculation with PB2 suggesting the importance of its external root colonization. However, a high correlation has previously been reported between SLB infection levels and wheat grain yield losses (Berraies et al, 2014). In the same way, an increase in wheat grain yield was shown to be correlated with the reduction of M. graminicola DNA in wheat leaves using partially resistant cultivars or fungicides (Didierlaurent et al, 2012;Selim et al, 2012).…”

Improved control of septoria tritici blotch in durum wheat using cultivar mixtures

“…Currently, the two methods to control STB available to Tunisian farmers, fungicides and a few resistant cultivars, are not providing satisfactory levels of disease control. The country experiences serious recurrent epidemics of STB with yield losses reaching up to 40% (Berraies et al ., 2014). A large part of the reason is that many farmers simply do not use either of the two control methods and neglect crop rotation practices.…”

Pérdidas ocasionadas por Zymoseptoria tritici en genotipos de trigo en ambientes de temporal

“…También en trigo duro el comportamiento de la resistencia a Z. tritici es similar como lo reporta Berraies et al (2014) quienes indicaron que en trigo duro las variedades susceptibles llegan a tener pérdidas en el rendimiento de un 50% mientras que en variedades resistentes solo de 8.6%. En Rebeca F2000 se observó el menor porcentaje promedio de pérdidas para la variable BIOMASA (11%), seguida por Triunfo F2004 (17%) y en tercer término Gálvez M87, Salamanca S75 y Verano S91 con una disminución de 29 a 32%.…”

“…El tizón foliar es una enfermedad de trigos harineros (Triticum aestivum L.) y trigos duros (T. turgidum var. durum) causado por el patógeno Mycosphaerella graminicola (anamorfo Zymoseptoria tritici o Septoria tritici) considerada como prevalente en los campos de producción de este cereal (Berraies et al, 2014;Fones y Gurr, 2015).…”