The productivity of the sweet potato (Ipomoea batatas (L.) Lam.) is influenced by, among others,the relationship between the source potential and the sink capacity. The total dry matter of the tuberous roots depends on the photosynthetic activity of the leaf canopy (source) and the capacity of the tuberous roots to capture or accommodate the assimilates. Increasing the activities of the source and the sink and maintaining them for long periods of time could lead to higher economic yield. The source strength and sink capacity consist of two major components, namely the size and activities of the source and sink. The clarification of the relative importance and relationships of the source-sink characteristics is the first priority in analyzing the physiology of yield in the sweet potato. The evaluation of the source potentials is simple because sweet potato has a simple source-sink relationship, and source can easily be exchanged by reciprocal grafting. In this book, an investigation into the source-sink relations in six locally available clones of sweet potato was carried out, with the aim of selecting genotypes with a balanced source-sink potentials that could lead to higher yield.