In vitro and In vivo Evaluation of Certain Fungicides Against Phytophthora Infestans (Mont.) The Causal Pathogen of Late Blight Disease on Tomato

Abstract

Efficiency of fungicides; Shirlan 50% SC, Ranman 40% SC, Revus 25% SC, Leimay 20% SC, Vegeclean 15% WG and Evito 48% SC against tomato late blight disease was conducted In vitro and In vivo tests. The variation in the aggressiveness of the two isolates of P. infestans could be clearly differentiated to most aggressive one (PhK-2) and least aggressive (PhK-1). Medium effective concentrations (EC 50) of the candidate fungicides indicated that Shirlan 50% SC was the superior fungicides against mycelial growth of PhK-1 and PhK-2 isolates. Revus 25% SC and Ranman 40% SC were less efficiency against mycelial growth of PhK-1 and PhK-2 isolates, respectively. The tested fungicides gave excellent control of tomato late blight disease under greenhouse conditions especially Evito 48% SC and vegeclean 15% WG when applied as protective or curative. The candidate fungicides were used separately at their recommended rates of application against late blight disease on tomato plants during the season of 2015-2016 in two different locations (Fayoum and Sharkia Governorates). In Sharkia Governorate, all the candidate fungicides gave excellent control of late blight disease, which their efficiency ranged between 80.03 and 85.93% except Revus 25% SC gave 63.67% only. Efficiency of Leimay 20% SC and Shirlan fungicides against late blight disease was increased from 63.73 and 65.61% in Fayoum trial to 80.03 and 80.69% in Sharkia trial, respectively. Efficacy percentages of tested fungicides were highly correlated with area under the disease progress curve (AUDPC) values. All candidate fungicides when treated as curative were effective in controlling late blight disease except Revus 25% SC.