Morphological and pathogenic characterisation of fungi associated with berry necrosis on robusta coffee in Uganda

Abstract

Morphological and pathogenic characterisation of fungi associated with berry necrosis on robusta coffee in Uganda from highly infected coffee berries was studied in a laboratory Experiment at Makerere University, a total of 33 fungal isolates representing the highly infected major coffee producing region of Uganda was studied on the basis of cultural, morphological, and pathogenic characterization. The isolates differed significantly on their colony diameter growth, colony texture, colony color, there were statistically significant differences in length and width of conidia among the 33 isolates, spore size varied significantly at (p≤0.05) within and among isolates ranging from 2.4 to 5.9 um and 8.0 to 37.3 um in mean width and length respectively and conidial shapes, mycelial characteristic varied significantly. The dominant forms of conidia were cylindrical and round at both ends followed by cylindrical acute at one and round at the other ends, elongated among others, based on the conidial shape, Colletotrichum and Fusarium spp. are among the most likely fungi common on coffee berries with necrosis symptoms, in general, the study showed that coffee berries with necrosis symptoms harbors several types of fungi that are diverse in cultural characteristics and Some fungal isolates caused significant berry necrosis on young, mid-aged and old coffee berries, hence could be causal pathogens of coffee berry and lateral necrosis on robusta coffee in the study area. Therefore, the study should be repeated to confirm the current findings, Molecular characterization of the highly necrotic isolates be done to identify them to species level and Field level inoculations with suspected pathogenic isolates be made on robusta coffee to test their reaction in the real growth conditions and environment in order to design desirable effective management options which may enhance sustainable coffee production in the country hence improvement in the economy.