Effect Of Foliar Fungicides Applied At Silking On Stalk Lodging In Corn

Stalk lodging in corn (Zea mays L.) leads to harvest complications and yield losses. Farmers who apply a foliar fungicide to manage leaf diseases have also observed reduced lodging. The goal of this study was to evaluate the effect of a foliar fungicide applied at silking on percent lodging. Field trials were established on Iowa State University Research Farms in 2016 and 2017. Treatments evaluated were foliar fungicide application (with or without) and harvest date (corn harvested at weekly intervals for up to 5 weeks); a split plot design was used with four complete blocks. Across all locations and years, a fungicide application significantly reduced mean lodging (P < 0.0001) by 9.3% and increased yields (P = 0.0043) by an average of 258.3 kg/ha (4.1 bu/acre). Percent lodging increased as harvest was delayed (P < 0.0001). This study demonstrated that foliar fungicides applied at silking reduced lodging and thus confirmed observations of farmers. Applying a fungicide to reduce lodging and favor harvest, however, is not recommended due to risk of fungicide resistance development and the lack of efficacy on stalk rot pathogens.