The graphical presentation of the Fire Blight models is best to use with values aggregated on the daily base. The graph shows the climate values related to this disease. The Cougar Blight result named Fire Blight DIV and the Blossom Blight results. To interpret the Cougar Blight results the graph is underlaid by 5 different colours. The distribution of this colours is made on base of the settings on the first blight history of the orchard. The 5 colours are indicating the risk class for the DIV values.

Interpretation of values (in dependance of the fire blight occurrence the last years, basic set up):

Potential for Pathogen PresenceLowModerateHigh Extreme
No fireblight past two years0-350350-500500-800800+
Fire blight in local area two seasons0-300300-500500-750750+
Fire blight in locals area last year0-250250-450450-700700+
Fire blight in orchard last year0-200200-350350-500500+
Acitve cankers present nearby0-100100-200200-350350+

Action threshold:

Control is advised if a high or extreme risk infection period is detected. Factors determining the damage are : numbers of flowers, tree aged, vigor and variety,... too.


The opportunity of an Blossom Blight infection is displayed by a bar from 0- 1 (so all conditions are met or not).


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Aim of the Fire Blight models is it to assess the probability of infections by Erwinia amyloflora in the orchard.

The Mary Blight model which is evaluating for blossom blight is very well indicating infection situations of high economic impact. By this reason it is quite frequent used to indicate the use of antibiotics against this pathogen. Cougar blight is giving information about the risk of fire blight infections do to the overall propagation possibilities of the pathogen. Its weighting done by the history of an orchard is very helpful to indicate us how carefully we have to check the orchards for fire blight symptoms even in situations where Mary Blight will not indicate an infection. 


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