Clorose das folhas do cafeeiro excelsa

Abstract

A type of leaf chlorosis is shown by plants of excelsa coffee growing in nursery beds in a lath house at the Instituto Agronômico, Campinas. Tests made with various elements showed that this type of chlorosis is due to iron deficiency. Seedling plants of arabica coffee growing in the same beds do not show chlorosis, but these symptoms are exhibited by arabica scions grafted on some excelsa rootstocks. Scions from chlorotic excelsa plants recover the normal color when grafted on arabica rootstock. Likewise, arabica scions that had become chlorotic after being grafted on excelsa rootstock recovered when transferred onto an arabica rootstock. Other grafting tests indicated that no pathological cause seems to be associated with this type of chlorosis, and that it is probably due to genetical characteristics of the excelsa root system that prevents the plants from absorbing enough iron from the soil imder marginal conditions.