Field evaluation of different fungicides for their effectiveness against cercospora leaf spot (Cercospora sesame Zimm.) of Sesame (Sesamum indicum L.)

Abstract

Sesame (Sesamum indicum) is one of the well known oil crop produced and Ethiopia is one of the major producer country of the crop in the world. The Field experiment was conducted for two years (2015/2017 GC) at Delo-mena site of Sinana Agricultural Research Center (SARC) with the objective of identify effective fungicides for the management of Cercospora leaf spot of Sesame. The trial was arranged in RCB Design with three replication and the treatment fungicides were; Odeon 825 WDG, Mancozeb 80% WP, Natura 250 EW, Ridomil Gold MZ 68 WG, RexDuo, Tilt 250 EC and unsprayed control were included for treatment comparison. The highest Cercospora leafspot disease severity of 41.11% and the lowest (5.00%) were recorded from unsprayed control and Tilt 250 EC treated plots, respectively. Similarly, the highest AUDPC (1474.67%-days) and r (0.038292 units -1 ) and the lowest AUDPC (165.67%-days) and r (-0.004976units -1 ) were similarly calculated from unsprayed control and from Tilt 250 EC treated plots, respectively. Regarding yield and yield related traits; ANOVA has shown significant variations (P<0.05) between treatments for the TKW and grain yield. The highest number of TKW (3.27 g) and grain yield (618.98 kg/ha) were recorded from a plot sprayed with Tilt 250 EC treated plot; while the lowest number of TKW (2.80 g) and grain yield (457.87 kg/ha) were recorded from unsprayed control plot. Simple linear regression of TKW and grain yield with Cercospora leaf spot severity and AUDPC have revealed a significant difference (P<0.05) between treatments; the estimated slope of the regression line obtained for Cercospora leaf spot severity in relation to grain yield was -3.36 and for AUDPC was-0.093. The Correlation of grain yield with Cercospora leaf spot disease severity and AUDPC has depicted that Cercospora leaf spot disease severity and AUDPC has a significant negative correlation with grain yield (r= -0.4821, P<0.05) and (r= -0.4834, P<0.05), respectively. Therefore, based on the result of this study, a fungicide Tilt 250 EC is recommended for the management of Cercospora leaf spot disease on Sesame at both small scale and large scale production level.