Fungal pathogens of the Prunus species in Malta

Abstract

The purpose of this project was to investigate the fungal diseases of the Prunus species. The investigation was carried out between July and September 2002. Ten samples were collected from ten different fields located in different localities as follows: three from Mgarr, three from Siggiewi, one from Rabat, one from Dingli, one from St.Lucija and from Ghammieri. The field samples, which were infected by the fungal pathogen, were immediately transferred to a plastic bag and stored in a refrigerator. These were then taken to the plant health laboratory for analysis microscopically to detect any fungal hyphae or fruiting bodies. These infected leaves were then sectioned and transferred on a culturing medium such as water agar. The medium was prepared in the laboratory by dissolving 15grams in 1000ml of distilled water. It was sterilised in an autoclave, left to cool to a temperature of 45°C and then poured in plastic sterilised petri dishes. After they solidified, the infected plant tissues were transferred on the agar plates for culturing. After one week they were examined under a high powered microscope and diagrams were made of the specimens identified. In all ten different fungi were identified through the use of fungal keys. The study revealed that the most common obligate pathogen was powdery mildew while the second most important was the shot hole disease.