THE AUTHOR 



R. J. HOFF is principal plant geneticist with the Intermoun- 

 tain Research Station's Forestry Sciences Laboratory in 

 Moscow, ID. He received a B.A. degree in biology from 

 Western Washington State University and a Ph.D in 

 botany from Washington State University. 



RESEARCH SUMMARY 



In 1985 a needle cast caused by Lophodermium 

 baculiferum Mayr severely infected a provenance test and 

 a progeny test of ponderosa pine located in northern 

 Idaho. Populations of ponderosa pine from northern Idaho- 

 northeastern Washington and western Montana differed in 

 their susceptibility to needle cast. Geographic area ac- 

 counted for most of the variation among populations; 

 elevation accounted for very little. The populations in the 

 north-central portion of the collection area were most 

 resistant, and these were connected with the more sus- 

 ceptible southern populations by gentle dines. Family 

 heritability was 0.60; for individuals it was 0.45. 



February 1988 



Intermountain Research Station 

 324 25th Street 

 Ogden, UT 84401 



