The number of nodes per plant varies depending on the plant variety and environmental conditions. Leaves are fully developed when the edges of the leaves are fully unrolled and no longer touching each other. Stage VE begins when recently germinated seedlings protrude through the ground. It may take the seedlings anywhere from 5-15 days after planting to reach this stage, depending on soil type and temperature, moisture, and planting depth. After emergence, two cotyledons develop and the stem begins to straighten, marking the initiation of the VC stage.
Cotyledons are unifoliate, and are small relative to subsequent leaves.
These cotyledons supply food and nutrients to the developing plant for 7-10 days, or until V1 when photosynthesis is initiated. The first leaves to develop on soybeans are unifoliate. Stage V1 is assigned to plants where these unifoliate leaves and the trifoliates on the node above them are completely mature. During V2 the root nodulation begins to produce the plant's nitrogen requirements. Nitrogen fixation is accomplished through the symbiotic relationship with the bacterium Rhyzobium japonicum .