Blight
Blight is a rapid and complete chlorosis, browning, then death of plant tissues such as leaves, branches, twigs, or floral organs. Accordingly, many diseases that primarily exhibit this symptom are called blights. Several notable examples are:
Fire blight
Besides the historical importance of being the first bacterium proven to be a plant pathogen, it is extremely economically important. Control and loss costs are estimated approximately $100 million a year in the USA. Specifically, in Michigan in the year 2000, $42 million in losses is estimated because of the removal of about 400,000 apple trees. Warm, humid, and wet weather in May resulted in this epidemic. While approximately $68 million is estimated in losses in Washington and northern Oregon. "E. amylovora" is spread all through the USA and worldwide causing severe damage although it is unlikely to cause severe damage in northern Europe. As long as "E. amylovora" is not introduced to Central Asia where wild apple trees still grow, it will not modify any ecosystems. Biodiversity is not impacted either, as no plant species are threatened with extinction due to this pathogen. Growing pears in Emilia-Romagna in Italy is a traditional activity for some families, and fire blight threatens this tradition that has been passed down for several generations. In southern Germany apple and pear trees have been a part of the landscape for a long time, and are difficult to protect. The decline of apple and pear trees from their landscape can be expensive to replace and could have a negative effect on tourism. In the long-run, fire blight is a very important factor of economy and society.