Does Narrow-Row Corn Production Influence Plants’ Response to Foliar Inputs?

Abstract

Little information exists on the use of foliar inputs in corn grown in narrow‐row systems. Foliar N increased yield in narrow rows but did not change partial economic returns. Foliar N plus fungicide did not increase yield compared with fungicide alone in narrow rows. Future evaluation is needed in systems with elevated disease severity. Intensive management to increase corn (Zea mays L.) yield may involve multiple practices moving forward. Although the effects of foliar fungicide and foliar fertilizer applications on corn yield have been evaluated in past research, little is known concerning the impact of these foliar applications in narrow‐row corn. The objectives of this study were to determine if disease or N demands increase in plants grown in narrow rows (15‐inch spacing) compared with conventional row spacing (30 inches), and if intensive management involving application of foliar N at R1 with or without a fungicide can help increase grain yield in narrow‐row systems. A field study was conducted with two hybrids during 2016–2018 at two Ohio locations. Plants were rated for foliar fungal disease [northern corn leaf blight (Exserohilum turcicum) and gray leaf spot (Cercsopora zeae‐maydis)] injury before and after foliar application, and plots were harvested for grain yield. Partial returns were also assessed for each foliar treatment. Although the weather was favorable for fungal foliar diseases in some site‐years, disease incidence was low. Inclusion of foliar N increased yield in narrow rows in the absence of a fungicide but did not increase the partial economic return compared with the untreated control. The addition of foliar N alongside fungicide did not impact yield in 15‐inch rows but increased yield at 30‐inch row spacing. However, partial returns were similar for each row spacing and foliar treatment.