Southern Corn Leaf Blight Infection Model

This disease needs free water (leaf wetness) to infect plant tissue. Therefore conditions for starting an infection are : leaf wetness and temperatures warmer than 15°C. The infection will be finished after we can accumulate 100 degreehours (temperature and leaf wetness hours).


Southern corn Leaf Blight(Bipolaris mayidis) Infection model

START SCLBinfection: if leaf wetness > 0 and air temperature >= 15 then begin

INCREASE of INFECTION: SCLBinfection acutal hour =SCLBinfection former hour + (air temperature * leaf wetness period in minutes)

STOP: if conditons are not given (no leaf wetness, temperature below 15°C), or if SCLBinfection > 100*60 °C (= degreeminutes) then SCLBinfection = 100*60 (in sum 6000 degree minutes or 100 degreehours (wich is for example about 6hours leaf wetness at 15°C or 5hours leaf wetness at 18°C),  of leaf wetness at a temperature higher than 15°C is the maximum). 
(If Temperature is higher than 15°C and leaf wetness for more than 100*60°C accumulated Temperature per minute infection is complete)

This models have been designed following the Report on Plant Diseases 202 - Common Leaf Blights and Spots of Corn by Mohammad Babadoost.

Extension Specialist in Fruit and Vegetable Diseases, Department of Crop  Sciences, University of Illinois at Urbana-Champaign.