Tree species are indispensable to human needs. Due to their long life cycle and environmental sensitivity, breeding trees for sustainable production is a formidable challenge on order to meet the demands of growing human population and industries. Fruit crops such as apple, cocoa, mango, citrus, litchi, pear, dates, and coconut or industrial crops including rubber and tea, improving yield under the optimal, sub-optimal and marginal areas call for a unified worldwide efforts. Tree breeding is the application of genetic, reproductive biology and economics principles to the genetic improvement and management of forest trees. In contrast to the selective breeding of livestock, arable crops, and horticultural flowers over the last few centuries, the breeding of trees, with the exception of fruit trees, is a relatively recent occurrence. This book provides a balanced, up-to-date and comprehensive account of the developments in the field of breeding tropical and subtropical fruits.