When the coleoptile (or spike) breaks through the soil surface and encounters light, coleoptile and mesocotyl elongation stop. The coleoptile ruptures allowing the first leaf to emerge. At this time the location of the growing point and nodal root system is set. With a planting depth of 1½ inches or more, the growing point is set approximately ½ to ¾ inch deep. Floppy or rootless corn can occur when the growing point is too shallow and the nodal root system is initiated on the soil surface. This is often the result of either shallow planting or soil settling or eroding away from the base of the plant after the growing point has been set. A pre-plant application of a growth regulator herbicide like 2,4-D can also cause elongation of the mesocotyl and force the nodal roots to develop above ground, leading to rootless corn syndrome.