Effect of leaf water potential on cold tolerance of Coffea arabica L.

Young coffee plants from cultivar Mundo Novo of Coffea arabica were grown without irrigation for 32 consecutive days, to evaluate the effect of leaf water potential on damage caused by low temperatures, under controlled conditions. 4 wide range of leaf water potentials were evaluated from -0.45 MPa (wet soil) at the beginning of the experimental period, to -4.8 MPa (severe leaf wilting) at the end. Results showed that under moderate water stress, there was a higher frequency of undamaged plants and lower frequency of severely damaged plants. These results help explain part of the regional variability observed after a frost and stress the importance of new studies associating cold and drought tolerance in coffee.