SOLARIZATION OF PEAR AND APPLE TREES TO ERADICATE BACTERIA IN FIRE BLIGHT CANKERS

Solarization of entire trees under "tents" of clear polyethylene was used as a means to stop the progress of fire blight infections and eradicate Erwinia amylovora from infected tissues.
High temperatures and reduced water and nutrient availability are reported to stop disease progress but growers are usually unable to control these factors.
Elevated temperatures obtained through solarization of soil have been shown to reduce inoculum of pathogens.
Apple and pear trees with active cankers were completely covered with a 10 x 10 m polyethylene tarp left in place for 4 to 7 days in the summers of 1993 and 1994. Temperatures at 3 heights inside the tent, and ambient temperatures were recorded.
Results were variable depending on tree species, ambient temperatures, and the year.
In many solarized trees, canker expansion was stopped and no viable E. amylovora were isolated from cankers, while cankers on untreated trees continued to expand.
Several consecutive days of ambient temperatures near 33°C in 1994 raised temperatures inside the tents to 56°C, resulting in complete eradication of the pathogen and death of tops of the trees.

VII International Workshop on Fire Blight

S.V. Thomson

https://doi.org/10.17660/ActaHortic.1996.411.68