NURSERY PRACTICK IN PENNSYLVANIA 765 



ing eliminates it for the beds sown at that time. The method of seed- 

 covering and careful drainage keeps it under control in spring-sown 

 beds. Acting on a hint from Professor Coville, the writer has been 

 experimenting with a natural acid treatment. It is noted that Clearfield 

 and Pump Station have little "damping-off" and that their soils test 

 acid. It was assumed that a natural acid condition would stop the 

 trouble. For two years acid soil was brought into the nursery and used 

 in comparative work. This last year not only was this done, but also- 

 acid leachings from leaves were applied to ordinary nursery beds. Un- 

 fortunately, owing to the departure of the senior carrying on the work, 

 only incomplete data are available for the latter portion of the experi- 

 ment. Results so far secured are as follows : 



Per cent of survival 



Year Species r '^— \ 



Acid Check 



1915 White pine 80.7 



1916 Spruce 83 . 5 56 



Pitch pine 92 62 



White pine 78 30 



1917 Spruce 70 42 



Spruce watered with acid leachings 79 72 a 



a Not complete. 



As a result of these experiments it is recommended that no lime be 

 used in the Mont Alto Nursery, and that raw humus be used as a fer- 

 tilizer to some extent. 



Much experimentation with various fertilizers has been done in the 

 past few years in some of the nurseries. The general results were pub- 

 lished in the 1914-1915 Report of the Pennsylvania Department of 

 Forestry. At Mont Alto a careful effort was made to analyze these 

 results carefully and to follow out some suggested leads. The original 

 experiment called for a test of seven chemical fertilizers, lime, and 

 stable manure in many different combinations. Altogether 28 beds of 

 single and double applications were used. Each bed had a surface area 

 of 100 square feet. Single applications gave the following actual plant 

 food : .75 i)ound actual N ; i pound P2O5 ; i pound k"0 ; i pound CaO. 

 To secure these the following fertilizers were used : Nitrate of soda, 

 sulphate of ammonia, dried blood, acid phosphate, bone meal, floats, 

 sulphate of potash, pure hydrated lime, burnt lime. A tabulation of 

 the combinations and the results follows : 



