Climate favourability to leaf rust in Conilon coffee

Abstract

The Brazil is the second largest producer of Conilon coffee (Coffea canephora), being the state of Espirito Santo responsible for producing 9.7 million bags of Conilon coffee. The biology of Hemileia vastatrix, etiologic agent of leaf rust, the main disease of this culture, is not well understood under the environmental conditions of Espirito Santo, Brazil. This study determined the ideal temperature and leaf wetness ranges for in vitro germination and infection of leaf discs in this pathosystem. For this, regression analyses with differents temperature and leaf wetness ranges were performed. The results showed that a climate characterized by mild mean temperatures (between 21.6 °C and 23.6 °C) with foliar wetness associated with high relative humidity (>80 %) is the most favorable condition for the infection of Conilon coffee by H. vastatrix. The knowledge of the optimal temperature and moisture conditions for the infection can also be useful for developing systems to predict the occurrence of the disease in C. canephora from Brazil.