The Rhizoctonia Damping-Off of Conifers 



51 



The results obtained with liquid treatments on this species during the 

 season of 1927 are recorded in table 17. The plats of experiment A were 



TABLE 17. Liquid Treatments on Beds of White Pine at the Keene Nursery, 



Season of 1927 



* Treatments 4 and 11 of experiment B are equivalent in mercury content, as are also treatments 5 

 and 12. 



sown on April 21, and those of experiment B on May 13, at the rates of 

 2250 and 1800 seeds, respectively. This seed was of low viability. The 

 final stand on the aluminum-sulfate plats of experiment A show a signifi- 

 cant increase over that of the check, while the increases with the sulfuric- 

 acid treatments were of doubtful significance. 



Unfortunately the results obtained from experiment B were somewhat 

 vitiated by severe bird injury. As a consequence of this and of the low 

 incidence of disease throughout the beds, the figures for final stand are 

 significantly greater than those for the untreated plats, except for treat- 

 ments 6, 11, and 12. All but treatment 9, however, gave greater absolute 

 yields than those of the check. No chemical injury could be detected in 

 any of the plats. 



Seedlings in another experiment, in which 1 gram and 1.75 grams of 

 Semesan and Uspulun, and 0.236 and 0.414 gram of mercuric chloride, 



