Management of wheat rusts at different growth stages using Nativo 300 SC (trifloxystrobin 100g/L+tebuconazole 200g/L) fungicide

Abstract

Rusts (stem, yellow and leaf) remain the most important diseases of wheat worldwide due to their ability to cause severe yield losses in susceptible varieties. Timing of fungicide application in the integrated management of rusts on wheat is critical. This study was conducted to determine the wheat growth stage at which fungicide application can effectively control/reduce the damages caused by rust diseases. Field experiments were conducted in 2013 and 2014 in three locations; Njoro, Eldoret and MauNarok. Three doses of Nativo 300 SC (trifloxystrobin 100g/L+tebuconazole 200g/L) fungicide were applied at seven different growth stages of wheat variety Duma as split plot arrangement using a randomized complete block design with three replications. Results showed significant (P<-0.01) differences among growth stages for stem rust infection, grain yield, grain and test weights. Area Under Disease Progress Curve (AUDPC) was significant for stem and yellow rusts in MauNarok and for leaf rust in Njoro. Significant (P<-0.01) effects of environments and fungicide were observed on grain yield, grain and test weights. Environment growth stage interaction were significant (P<-0.01) on AUDPC for stem rust, grain yield, grain and test weights. Fungicide application at tillering and flowering growth stages (GS) increased grain yield by 66.3%, grain weight by 41.6% and test weight by 17.27%. Therefore, wheat rusts can effectively be controlled by applying fungicide at tillering and flowering growth stages.