High temperatures also cause chlorosis and burning (scald) in coffee leaves (Cannell 1985; Wrigley 1988). Excluding the effect of light, chlorosis caused by high tempeatures in coffee leaves resembles that caused by iron deficiency (Franco 1970). The phenomenon is also a consequence of high temperature and/or water deficits (Da Matta and Rena 2001). In general, photo-oxidative damage causesleaf chlorosis that rapidly evolves into tissue necrosis ( Fig. 1) leading to leaf abscission. It is believed that in this case, the loss of water by transpiration is faster than its reposition in the local cells. There is fading and the cells tend to die. In general, these symptoms are visualized on the leaves’ extremities and this type of damage frequently appears in plants that are shaded and are rapidly exposed to full sunlight and,consequently, high temperatures. Thus, it is common to observe this problem in coffee seedlings not adequately adapted prior to be taken to the field (Franco 1970).