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G. A. SNOW AND A. G. KAIS 



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AIR FLOW 



TIMER 



Figure 1. Apparatus for inoculating pine seedlings. Basidio- 

 spores of Cronartium fusiforme released from telia on oak leaves 

 in the large compartment are carried by a stream of moist air 

 through the connecting tube to the tree in the small compartment. 



We have inoculated up to 200 seedlings with one collection of telia. 

 Oak leaves usually begin shedding sufficient basidiospores within 5 to 

 6 hours after being placed in the system. Inoculation of 200 seedlings- 

 including time for repeated calibration runs--requires 3 to 4 hours. The 

 uniformity of the technique allows us to use fewer plants in an experiment 

 than would be required with a less efficient method. In a recent study, 

 536 pine seedlings were inoculated and all but 3 developed symptoms of 

 fusiform rust. 



LITERATURE CITED 



Snow, G. A. 1968. Time required for infection of pine by Cronartium 



fusiforme and effect of field and laboratory exposure after inoculation, 

 Phytopathology 58: 1547-1550. 



FLOOR DISCUSSION 



Panel leader Patton withheld discussion on this and three other 

 papers covering C. fusiforme inoculation problems and techniques until 

 after the last (R. A. Schmidt) of the papers. Discussion of all four 

 papers will be found there. 



