How A Soybean Plant Develops, Special Report No. Emergence The planted soybean seed begins germination by absorbing water in amounts equal to about 50 percent of its weight. VE typically occurs 1 to 2 weeks after planting, depending on soil moisture, soil temperature, and planting depth.
Lateral roots begin to grow from the primary root just prior to emergence.
Shortly after VE, the hook-shaped hypocotyl straightens out and discontinues growth as the cotyledons fold down. Nutrients and food reserves in the cotyledons supply the needs of the young plant during emergence and for about 7 to 10 days after VE, or until about the V1 stage. During this time, the cotyledons lose 70 percent of their dry weight. Loss of one cotyledon has little effect on the young plant's growth rate, but loss of both cotyledons at or soon after VE will reduce yields 8 to 9 percent. After V1, photosynthesis by the developing leaves is adequate for the plant to sustain itself.