Need for proactiveness in fighting Fire-Blight


Fire blight is one of the most devastating diseases which affects apple and pear orchards. One of the reasons for this is the difficulty in controlling the disease once infection is present in orchards. The disease has no cure, hence prevention is key. This is one of the key reasons why it is necessary to be proactive in preventing and mitigating fire blight events.


When fire blight occurs, it results in:

  • Death of apple trees sometimes numbered in thousands
  • Diminishes production capacity of surviving trees
  • Financial loss due to lost revenue from affected orchards, sanitation costs and orchard replacement cost


There are various known control methods for managing fire blight; horticultural practices, sanitation and use of bactericide sprays such as copper and streptomycin. Sanitation activities like pruning during the growing season could yet contribute to spread of disease. None of these methods quantitatively describes severity of fire blight risk. Although the above methods of control are not 100% effective, however, they could help prevent severity of the disease.


In a growing season, there are usually about 5 high risk infection events. Some of the chemicals mentioned above have a limited number of applications per growing season, because of their effect on the environment. Hence, there is a need to adequately plan for the measure of control to be taken for high risk events.


Due to climate change, there is now an increased risk of traumatic events taking place. These include hurricanes, high winds, storms and rainfall. Unanticipated events result in worse problems for growers.  Periods of bloom and rapid growth are the times in which the disease becomes more prevalent. In addition, the higher temperatures experienced now during critical growth stage is a valid reason why growers need to be proactive about quickly identifying conditions contributing to high risks.


Fire blight management has always been about managing the increasing population of pathogens. Once pathogens spread internally into the orchard, external control becomes ineffective. Some of the spraying done is also ineffective if not applied directly to pathogens. Also, excess application of nitrogen fertilizers could also make it easy for disease propagation. Not taking proactive measures towards fighting fire blight will result in losses for growers. Unfortunately, the full extent and cost of damage is still not totally known. This is proof that identifying fire blight risk ahead of infection is very key to protecting grower investments.