described as was the deterioration of the mesophyll in the vicinity 

 of the developing apothecium. 



Control of the fungus by cutting out infected trees is out of the 

 question and adequate economical control by the use of fungicide 

 appears almost as impossible. Further trials using the two most 

 successful compounds, Lime-sulfur and Ferbam, might be warranted 

 but it is seriously doubted if the Christmas tree producers would be 

 willing to stand the expense and labor necessary to apply sufficient 

 applications at the proper times. A much more promising approach 

 appears to be that of developing resistant individuals. Wide diver- 

 gences in relative resistance have been observed throughout the 

 Northeast and it is apparent that selection and propagation of these 

 individuals by means of cuttings or grafts will be necessary if 

 Douglas-fir is to be grown successfully in the region. 



Apart from future work involving the fungus-host relationship, 

 more conclusive studies are needed on the economics of spraying. 

 With the continued development of new spray materials it is pos- 

 sible that an effective, less expensive material might be found. As 

 stated above, wide divergences in relative resistance to R. pseu- 

 dotsugae are evident and the selection and propagation of trees 

 showing such resistance seems to be the most obvious and practical 

 approach for future studies. The search for and propagation of, 

 resistant trees will involve a long-term costly program. With the 

 Rhabdocline needle cast disease, however, the basic problem may 

 be not merely a matter of increasing yield or improving a product, 

 as is so often the case, but rather the saving of an entire Douglas-fir 

 Christmas tree industry in the Northeast. 



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