Influence of cotyledon removal on early seedling growth in Quercus robur L.

The process of resource transfer from seed to growing plant, in terms of dry matter and nitrogen, was studied in Quercus robur L. seedlings. In a factorial experiment, seedlings were subjected to cotyledon excision and shading just after shoot emergence. In another experiment, we removed the cotyledons at emergence and 7, 14 and 21 days later. The transfer of resources from cotyledons to growing plant seemed to be almost complete at a very early stage. Cotyledon excision just after shoot emergence resulted in a significant reduction in seedling growth. Shading had a minor effect during this period. However, the influence of cotyledons on seedling growth declines soon. Their artificial suppression had no significant effect when it was performed later than two weeks after shoot emergence. The consequences of this fact on the relationship between dispersion by jays and seedling growth are discussed.