Corn vegetative growth stages are designated by a V with a number following representing fully developed, emerged leaves. Only those leaves which have a leaf collar visible are fully developed and count as an appropriate growth stage. After corn plants reach the V5 or V6 growth stage, the first leaf is normally torn from the stalk as the stem elongates and nodal root development increases. Harsh environmental conditions, such as sand-blasting or hot, dry wind can also kill and dislodge lower leaves. However, every leaf, regardless of whether they are dead or even no longer attached, must be counted to determine appropriate growth stage. The plant height of corn plants at a given growth stage may vary a little depending upon planting date and growing conditions. Later-planting and favorable conditions will generally enhance height.