Abstract

MARISCAL-AMARO, Luis A. et al. Effect of fungicides on agronomic traits, yield and leaf blights in rainfed wheat in Mexico. Rev. fitotec. mex [online]. 2020, vol.43, n.1, pp.71-78.  Epub Dec 28, 2020. ISSN 0187-7380.  https://doi.org/10.35196/rfm.2020.1.71.

Wheat (Triticum aestivum L.) planted under rainfed conditions hosts fungi that cause spots and leaf blight that reduce yield by up to 60 %. Given the lack of varieties resistant to these diseases and the yield losses that they cause in the current varieties planted under these conditions, chemical control is used as a complementary alternative in this cereal. Currently, there is little information on the effect of fungicides with different active ingredients on the severity of these diseases and other agronomic traits. The objective of this study was to test the effectiveness of foliar fungicides on the severity of the disease measured as the damaged leaf area and to observe their effect on agronomic traits and yield. The study was carried out at three locations of the highlands of central Mexico, where eight systemic and three contact fungicides were tested. Fungicides only had a highly significant effect on days to maturity where azoxystrobin + propiconazole delayed plant maturity by up to 8 d compared to the control. All fungicides reduced the damaged leaf area by up to 63.3 % and increase grain yield by up to 56 %. Azoxystrobin-based fungicides and those of the triazole family induced the stay-green (delayed foliar senescence) effect and improved plant health. A positive correlation was observed between days to maturity and grain yield, and a negative one between the percentage of damaged leaf area and grain yield. The application of foliar fungicides for the management of leaf spots and blights on wheat is recommended as an alternative to protect the crop and increase the yield in wheat.

Keywords : Triticum aestivum; Septoria tritici Desm.; fungicides; leaf blights; yield.

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