Studies of the Clove Tree, the Effect of the Sudden Death Disease on Water Relations

Abstract

Extensive root disorganization is associated with all recognizable stages of the suddendeath disease of cloves, the final symptoms being those of a rapid wilt. In the early stages of the disease, however, the water status of an affected plant is more favourable than that of a healthy one, in spite of the root disorganization. In the diseased plant, the transpiring power and assimilation rate of the leaves are greatly lowered, probably because of partial closing of the stomata. The consequent reduction in transpiration appears to account for the smaller water deficit found in the earlier stages of the disease. These results are considered to furnish additional evidence in favour of the hypothesis that the disease is caused by a pathogen.