Link to home

Fungicide efficacy trials for the management of maize white spot in Paraná, Brazil

Adriano Custodio: Instituto Agronômico do Paraná

<div>In Brazil, maize white spot (MWS) caused by the bacterium <em>Pantoea ananatis</em> was initially described as caused by the fungus <em>Phaeospharia maydis</em>. This is one of the most important diseases for the second crop maize, reducing grain yield up to 60% in susceptible hybrids. Currently, there is evidence that some foliar fungicides of different modes of action (MoA) can also control this bacterial disease. In the present study, we report the field efficiency of fungicides for MWS control in maize hybrid and their impact on grain yield. Eight field trials were carried out in two distinct locations in Paraná, Brazil, during the growing seasons of 2016 and 2017. Ten commercial foliar fungicides were tested. The fungicide treatments showed differences for MWS severity and grain yield. Under less pressure of MWS, only six foliar fungicides were observed lower disease severity and higher grain yield. On the other hand, fungicidal mixtures containing pyraclostrobin + fluxapyroxad + epoxyconazole and trifloxystrobin + prothioconazole resulted in lower disease severity and higher yield under severe MWS pressure. The specifics MoA fungicides were among the most effective for MWS control and to improve maize yield over most of the trials. Additional experiments must be done in order to understand the obtained results. A working group has been organized to determine the field efficacy of fungicides against maize diseases.</div>