Pathogenecity of fusarium lateritium var. longum as causal agent of collar rot of coffee in Zimbabwe

Abstract

The pathogenecity of the fungus Fusarium lateritium Nees. var. longum Wollenw. causal agent of collar rot of coffee was studied in greenhouse experiments at Coffee Research Station from 1994 to 1997. Artificial inoculation of coffee bushes with the fungus through wounds at the base of the stem resulted in the development of typical collar rot symptoms encountered in the field, but no infection took place through root wounds or undamaged stems. There was no evidence that cotyledon infection of seedlings at the cotyledon stage resulting from seedborne inoculum developed into collar rot of bushes, as such seedlings died shortly after developing symptoms. However, artificial infection of cotyledons of seedlings from the 8th leaf stage onwards sometimes led to mainstem infection which resulted in collar rot of the young seedlings.