Fire Blight symptoms

As we have mentioned on previously PhageFire GA: 958645 is a project funded by European Commission with 2,969,643.50 € allocated to framework Horizon 2020. In this project we are looking for a cure and a management tool against the Fire Blight so today we will speak about the symptoms over pear trees.

First infections appear in spring during the blossom period. Flowers, shoots and young fruit are the most sensitive parts. If conditions are favourable for the bacterium it will spread along the inside of the plant and the infection can reach the whole tree rapidly. Pear trees, among all the crops affected by Erwinia amylovora, is the specie that shows the most impressive symptoms. Parts of the tree infected get a black colour that looks like if the tree would have been burned, that is where the name of the disease comes from.

Over the parts mentioned above it can appear other symptom too, the ooze. This ooze looks like brownish mucilaginous drops. These drops contain a huge amount of new bacteria.

It is necessary to observe the trees paying attention because some symptoms can be mix up with symptoms of other disease or even pests like: Pseudomonas (necrosis of young tissues), phytoptora (cankers), Janus compressus (shepherd crook) or long dry periods are some examples.

In the region of our partner Denominación de Origen Protegida Peras de Rincón de Soto it happens a curious thing: the most critical period is not the main blossom period, like in other productive areas, but the secondary blossoms which are happening during these days and they will happen again at the end of the season. But why this happens? Well, Erwinia amylovora develops between 18ºC to 29ºC with high humidity conditions, these conditions during the main blossom period do not usually happen although it is important to follow the warnings of the monitoring services because these conditions could happen occasionally. However, at the current moment these weather conditions happen more often so the risk of infection is very high. On the pictures you can check some of the symptoms.