EFFECT OF DELAYED EMERGENCE ON CORN GRAIN YIELDS

Abstract

Variable corn emergence results in decreased yields. This study was conducted to determine corn (Zea mays L.) by-plant yield reduction arising from delayed emergence. Treatments included delayed planting of 0, 2, 5, 8, and 12 days at two nitrogen (N) rates. Corn was planted by hand to maintain 17.8 cm plant-to-plant competition. Fifteen plants within a row were divided into five 3-plant sequences (middle plant delayed and 2-adjacent non-delayed plants). Under irrigation, grain yields decreased when the middle plant was delayed 2, 5, 8, and 12 days, by 3, 10, 19, and 25%, respectively. At the rainfed site, grain yields decreased when the middle plant was delayed 2, 5, 8, and 12 days, by 14, 25, 23, and 11%, respectively. Over all sites and years, for each day delay in emergence (one out of every 3 plants), corn grain yields decreased 0.225 to 1.379 Mg ha⁻¹ day⁻¹.

Keywords:

• nitrogen
• precision agriculture
• corn