Corn (Zea mays L.) Leaf Angle and Emergence as Affected by Seed Orientation at Planting.

Corn (Zea mays L.) seed orientation at planting can influence emerging leaf angle.  If leaf angle were consistent among plants without leaf overlap, large numbers of these bilaterally symmetrical plants could be arranged to optimize light interception and possibly increase grain yields or maintain grain yield with a lower population.  The objectives were to evaluate the effect of seed orientation in soil on the angle of corn leaves relative to the planted row and on emergence rate.   Seeds were planted 2.5 cm deep in diverse combinations of flat, cotyledon down, cotyledon up, on their side, radicle up, and radicle down.  Each seed orientation was repeated 10 times.  Data for days to emergence and leaf angle were collected.  In three different studies, corn seeds planted flat with the cotyledon up resulted in homogenous and faster emergence, and corn leaves aligned perpendicular to the direction of the corn row. Similar results were achieved with corn seeds planted parallel to the row with the radical down.  Random placement of corn seeds resulted in random orientation of corn leaves, and lower emergence rates.  The effects of controlled leaf geometry could facilitate planting higher populations with the potential for increasing grain yield and/or allow the maintenance of grain yields while reducing seed rates.