Flutriafol and azoxystrobin: An efficient combination to control fungal leaf diseases in corn crops

Abstract

The performance of a new formulation of fungicide, azoxystrobin and flutriafol (AZXFLT), was evaluated in the control of fungal leaf spots in corn crops in Brazil. Two experiments were realized in the 2nd harvest (late growing season) in 2015 and 2016, and one in the 1st harvest (normal growing season) in 2016/2017. The area under the disease progress curve (AUDPC) was evaluated for the following leaf diseases that occurred in each experiment: northern leaf blight (Exserohilum turcicum), southern corn rust (Puccinia polysora), gray leaf spot (Cercospora zeae-maydis), maize white spot (Pantoea ananatis) and Diplodia leaf streak (Stenocarpella macrospora). The productivity and economic viability of each treatment were estimated. The experimental design was a randomized block with 4 replications. The AZXFLT formulation was evaluated at a dose of 62.5 + 62.5 g active ingredient (a.i.) ha−1 in two applications and 75 + 75 g a.i. ha−1 in one and two applications in the February 2015 and November 2016 planted experiments. In the February 2016 planted experiment, AZXFLT (75 + 75 g a.i. ha−1 in two applications) was evaluated separately and in combination with mancozeb, chlorothalonil, copper hydroxide, copper phosphite, difenoconazole and propiconazole. All fungicides reduced the AUDPC of all diseases and provided an increase in productivity, with positive financial returns when compared with treatment without fungicide. There was a greater emphasis on treatments with AZXFLT in two applications of 75 + 75 g a.i. ha−1. The addition of protective fungicides contributed to increased productivity and economic viability.