Meta‐analysis of fungicide efficacy on soybean target spot and cost–benefit assessment

Target spot of soybean has spread in Brazil, the southeastern United States and Argentina in the last decade. A collaborative network of field Uniform Fungicide Trials (UFT) in Brazil was created in 2011 to study the target spot control efficacy of fungicides, including azoxystrobin + benzovindiflupyr (AZ_BF), carbendazim (CZM), fluxapyroxad + pyraclostrobin (FLUX_PYRA), epoxiconazole + FLUX_PYRA (EPO_FLUX_PYRA), mancozeb (MZB) and prothioconazole + trifloxystrobin (PROT_TRIF). Network meta‐analysis was used to conduct a quantitative synthesis of UFT data collected from 2012 to 2016 and to evaluate the effects of disease pressure (DP, low ≤ 35% target spot severity in the nontreated control < high) and year of experiment on the overall mean efficacy and yield response to each of the tested fungicides. Based on mean percentage control of target spot severity, the tested fungicides fall into three efficacy groups (EG): high EG, FLUX_PYRA (76.2% control relative to the nontreated control) and EPO_FLUX_PYRA (75.7% control); intermediate EG, PROT_TRIF (66.5% control) and low EG, MZB (49.6% control), AZ_BF (46.7% control) and CZM (32.4% control). DP had a significant effect on yield response. At DPLow, the highest response was due to PROT_TRIF (+342 kg ha−1, +12.8%) and EPO_FLUX_PYRA (+295.5 kg ha−1, +11.2%), whereas at DPHigh, EPO_FLUX_PYRA and FLUX_PYRA outperformed the other treatments, with yield responses of 503 kg ha−1 (+20.2%) and 469 kg ha−1 (+19.1%), respectively. The probability of a positive return on fungicide investment ranged from 0.26 to 0.56 at DPLow and from 0.34 to 0.66 at DPHigh.

Instituto de Patología Vegetal

Fil: Edwards Molina, Juan Pablo. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; Argentina

Fil: Paul, Pierce A. Ohio State University. Department of Plant Pathology. Ohio Agricultural Research and Development Center; Estados Unidos

Fil: Amorim, Lilian. Universidade de São Paulo. Departamento de Fitopatologia e Nematologia; Brasil

Fil: da Silva, Luis Henrique Carregal Pereira. Agro Carregal, Rio Verde; Brasil

Fil: Siqueri, Fabiano Victor. Fundação Mato Grosso; Brasil

Fil: Borges, Edson Pereira. Fundação Chapadão; Brasil

Fil: Campos, H.D. Universidade de Rio Verde; Brasil

Fil: Nunes Júnior, José. Centro Tecnológico para Pesquisas Agropecuárias, Goiânia; Brasil

Fil: Meyer, Maurício Conrado. Embrapa Soja; Brasil

Fil: Martins, Mônica Cagnin. Círculo Verde Assessoria Agronômica e Pesquisa, Luís Eduardo Magalhães; Brasil

Fil: Balardin, Ricardo Silveiro. Universidade Federal de Santa Maria; Brasil

Fil: Carlin, Valtemir José. Agrodinâmica, Tangará da Serra; Brasil

Fil: Grigolli, José Fernando. Fundação MS, Maracajú; Brasil

Fil: Belufi, Luana Maria de Rossi. Fundação Rio Verde, Lucas do Rio Verde; Brasil

Fil: Godoy, Claudia Vieira. Embrapa Soja; Brasil