Induced resistance to head smut (Sporisorium reilianum f. sp. zeae) and common rust (Puccinia sorghi) in maize (Zea mays L.)

Abstract

Maize, similar to other crops, is able to efficiently recognize a pathogen and actívate available defense responses, including constitutive and induced, which can avoid or reduce the infection. The defense or induced resistance include inducing substances, such as systemic chemical inducers which increase the recognition and invasión of plant pathogens. The common rust Puccinia sorghi and head smut Sporisorium reilianum f. sp. zeae are a threat to maize production in highlands of Mexico where seeds of susceptible cultivars are planted. The objective of this study was to evaluate the efficiency of six products reported as inducers of  resistance, including Actigard® 50 GS, Alliete®, Consist Max®, ASA, Poncho Votivo® y Serenade® ASO, in two locations in the Mezquital Valley, Hidalgo State, Mexico, to control the common rust Puccinia sorghi Schw. and head smut Sporisorium reilianum f. sp. zeae Kühn, two serious problems for maize production under field conditions. Results showed that Consist Max® (trifloxystrobin+tebuconazol) with 150 % of the comercial dose applied at the V7 stage gave outstanding control of the pathogens under study. For common rust, the area under the disease progress  curve in locations CL and UPFIM were 26.42 ± 0.26 and 78.84 ± 5.77, respectively, against 91.43 ± 2.12 and 198.24 ± 0.73 of the check treatment. Concerning head smut, the lowest incidence was at CL with percentages of infection of 16.83 ± 1.04 against 20.38 ± 1.79 of the check