Boron Response in Corn with Increasing Plant Populations.

High yield management strategies for corn, which include improved stack hybrids and increased plant populations, have increased the need for balanced crop nutrition. Micronutrients such as boron (B) are crucial for cell growth, reproductive development, and to increase yield. The role of B in high stress situations has shown to be beneficial in various studies. The purpose of this study was to investigate the effect of B on corn (Zea mays) grain yield at varying plant populations under traditional and intensive management. The intensive management included hybrids with triple stack technology, planting populations of more than 98,000 plants/ha, fungicide application at R1, and higher nitrogen (269 kg N/ha), phosphorus (112 kg P₂O₅/ha) and potassium (84 kg K₂O/ha) rates. Small plot field experiments were established at 43 locations across the United States in 2011 - 2015. Experiments were conducted in a randomized complete block design with four replications. Another study was conducted at 11 locations in the United States from 2014 - 2015, where corn grain yield response to B was tested at different populations (64,000, 79,000, 94,000, and 109,000 plants/ha) in a factorial treatment structure. Nitrogen fertilizer was split applied (60% at planting and 40% as side dress), and P and K fertilizers were applied preplant broadcast incorporated. Results showed that over 5 years of study, the addition of B increased corn grain yield by 491 kg/ha with a 70% win rate for 43 sites. Response to B increased with increasing plant populations indicating the importance of B and balanced crop nutrition to meet the needs of a dense population in intensively managed corn.