Corn planter performance measures based on spatial and temporal corn (Zea mays L.) emergence

Non-uniform plant spacing and uneven seedling emergence of corn ( Zea mays L.) may reduce grain yield. Practically acceptable levels of deviation in spacing and emergence need to be determined so that growers can properly evaluate planter performance. Investigations consisted of three experiments established to examine the influences of planter design and planting speed on plant growth, development, and grain yield through their effect on plant spacing and emergence variability under two tillage systems. All experiments were carried out at two locations in south central Ontario, Canada, during a 2-year period. The results indicate that corn growth and grain yield are more responsive to plant emergence variability than plant spacing variability, and there is no significant interactions on plant growth and grain yield between the two kinds of variability. Grain yield is little influenced by the variation in spacing, but is influenced substantially by delays in emergence. Yield decreased by 4% and 8% when one out of six plants emerged 2-leaf (12 days) and 4-leaf (21 days) stage late, respectively. The planter design and its adjustment along with planting operations under different tillage management can have a large impact on stand uniformity. The degree of impact and the consequences on grain yield may vary with individual planters and field conditions.