ABSTRACT
Both pear and quince belong to the Rosaceae family and along with the apple and some lesser known fruits, the subfamily Pomoideae. The pear belongs to the Pyrus genus of which there are several primary species. Pear is well adapted to many of the environmental stresses experienced in its native range. The wide geographical range of commercial cultivation is evidence that species of pear evolving in nature or varieties of pear developed by breeding are adapted to a wide range of climatic and edaphic conditions. An understanding of the environmental factors such as irradiance, temperature, and water on physiology can improve yield and fruit quality in current areas of production and may facilitate the further expansion of pear to new geographical regions. The adverse effect of shading on fruit size and quality of pear has been demonstrated.
