well have been too weak to effect control. A concentration of 1 to 

 40 rather than the recommended summer strength of 1 part concen- 

 trated solution to 50 parts of water was used throughout the course 

 of the Lime-sulfur trials in the present study. 



Indications are that R. pseudotsugae may be controlled using 

 Lime-sulfur sprays, if the first application is made at the proper 

 time in relation to bud burst in spring, and repeated at 7- to 10-day 

 intervals through the initial 2 to 3 weeks of lammas shoot develop- 

 ment. One can immediately foresee the economic and physical prob- 

 lems inherent in such an intensive program. Limiting the applica- 

 tions to two in number with the first at the time of bud burst and 

 the second 10 days later failed to control the disease in the Vermont 

 studies of 1958. These latter tests were not conclusive, however, 

 since a second severe needle cast disease, caused by the fungus 

 Adelopus gaumanni Rohde, was present on the test trees and can be 

 expected to have altered the results of the tests in some way. 



Control of the Rhabdocline needle cast with Ferbam in New 

 York plantations varied from poor to very good. Infection on the 

 lammas branch needles was controlled in all cases. At Camden, of 

 10 trees sprayed with Ferbam in 1956, 2 showed complete control 

 of R. pseudotsugae on spring needles, and on 7 other trees control 

 was good except for the north and northeast sides of the crown. It 

 is conceivable that some type of peculiar temperature-moisture 

 relationship existed on the surface of the northernmost needles 

 causing dilution and subsequent ineffectiveness of the Ferbam. 

 Needles on these sides were lightly to moderately infected. The tenth 

 tree was heavily infected throughout. Needles of the spring shoots 

 at Cortland had light to moderate infection and by comparison with 

 unsprayed needles it was questionable whether any control had been 

 achieved. North and northeast exposures of Ferbam-sprayed trees 

 were not infected at Cortland as they were at Camden. 



Two treatments with Ferbam in the Vermont studies, applied 

 the same days as the Lime-sulfur trials reported above, failed to 

 give any control of R. pseudotsugae in 1958. 



Limited control was obtained with Captan on a single tree with 

 the exception of the north side which was severely diseased. This 

 condition of three-sided control was commonly observed on Ferbam- 

 sprayed trees at Camden. The year-old infected needles which had 

 been sprayed with Captan were very dry and brittle, even more so 

 than Bordeaux-sprayed needles. Older uninfected needles showed 



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