Olive tree diseases and their control

Listed are the four main diseases which can affect olive trees in Cyprus and the Mediterranean area:

Olive Knot - (Pseudamonas Savastanoi) are rough swellings caused by bacterial infection and which can develop on wounded area on the trees branches, trunk or leaves. Cut out any diseased area at the first signs of the disease. This disease and all the others mentioned can be reduced by providing good growing conditions and by regular pruning to maintain airflow and sunlight entry to all parts of the tree. Avoid pruning if wet weather is expected and ensure all pruning tools are disinfected before use.

Olive Fruit Fly - fruit fly larvae feed on olives, if you want organic olives you have to accept some damage or the alternative is inorganic chemicals. However, there are some experiments currently being undertaken to develop biological traps which will suit organic growers.

Brown or Black Olive Scale - caused by insects which excrete a sticky and shiny scale on leaves which reduces the trees productivity. Cut out damaged areas and burn and deter the insects by pruning to keep an open and airy structure to the tree. This problem is however very rare in healthy well pruned trees.

Peacock Spot also known as Olive Leaf Spot - A common disease caused by a fungus which leaves sooty blotches on leaves which turn into black circular spots, causing the leaves to prematurely fall. Burn all diseased leaves and ensure you collect all fallen leaves to burn.