ENVIRONMENT AND WHITE PINE BLISTER RUST INFECTION 



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Figure 7. Pattern of airflow that controls rust spread around 

 a swamp edge. 



45 H ASPEN 





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SEEDLING CHECKS 

 GRAFT CHECKS 

 RESISTANT TREES 



Figure 8. Numbers of blister rust cankers per 100 white pine 

 seedlings (2-3 ft tall) in a forest opening at Whyte, Minn. 

 Legend boxes show average infection rates. Graft check plot 

 values have been multiplied by 16.7 to arrive at a corrected 

 infection index for the graft canker plots. 



