to "be infected with the yellow blister rust, leredenniun 

 fil^mentosum. 11 of the 2-0 yellow pine inspected, 

 ana the visibly infected seedlings - bout 4 per cent - 

 culled and burned, i thorough exsmination of the territory 

 surrounding the beds rc^. rge patch of C^stilleie 

 miniata growing on the edge of a lodge pole pine stand near 

 the creek bank, directly northeast of the infected seedling 

 beds, and not more then 00 1 istent. The records of 

 the weather station here show that the prevailing winds 

 blow northc v/est, which is an important factor 



in spore distribution between the two hosts* These winds 

 sweep northeast from th. How pine beds over the 

 Castille: tch, and in i-evercinft, blow southwest from 

 the Gristilleia ares to the seedling beds. In this manner 

 the aeciospores from the infected yellow pine are distri- 

 buted to the Ot stilleie p] and the sporidia borne on 

 the Oastilleia leaves < re transmitted to the young trees 

 in the beds. 



The scare from t ^ridermium infection had 

 hardly subsided, v/hen a seemingly more serious disease 

 appeared on both the 2-0 yellow pine and I ' te 

 pine seedlings, The seedlings were affected with a dying 

 of the tops or "Purple Top. T The heaviest infection 

 appeared in the beds on the west border of the groun 

 whore the soil conditions r.re the more moist, and. decreased 

 in the beds to the e st, being only 15 per cent fatal in 



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