Pflanzcnkraukheiten. 319 



Ballard, W. S. and W. H. Volck. Winter spraying with 

 Solutions of nitrate of soda. (Journ. Agr. Res. I. p. 437 — 444. 

 pl. 50—51. 1914.) 



Dormant fruit trees sprayed with a nitrate of sodacaustic potash 

 Solution came into bloom about two weeks earlier than the un- 

 sprayed checks and gave a larger yield for the two succeeding 

 seasons. To determine if this effect were caused by the nitrate as 

 a fertilizer this substance was added to the soil but gave no response 

 similar to that produced by the spray. The nitrate in an acid Solu- 

 tion gave similar results as regards early blooming as did the 

 alkaUne Solution. Other substances also produced the same effect. 

 No explanation for this phenomenon is offered, but its similarity 

 to the results obtained by various investigators on treating dormant 

 twigs with certain Solutions is pointed out. 



M. C. Merrill (St. Louis). 



Mancy, T. J., The effect of potato scab treatment on seed 

 vitality. (la. Agr. Exp. Sta. Bull. 148. p. 319—334. f. 1—3. 1914.) 



Formaldehyde gas is shown to be injurious to the germinating 

 power of the potato. A Solution of formaldehyde in the proportion 

 of 1 pint formaldehyde to 30 gallons of water of corrosive Sublimate 

 2 ounces to 16 gallons of water for periods of 2 — 6 hours gave no 

 evidence of injury. M. R. Ensign (St. Louis). 



Lipman, C. B. and P. S. Burgen. Studies on ammonifica- 

 tion in soils by pure cultures. (Univ. of Cal. Pub. Agr. Sei, 

 L p. 141-172. 1914.) 



Results are given showing the marked differences in the am- 

 monifying efficiency of fifteen organisms in pure culture. There 

 were used three different types of soils and four common fertilizers 

 as sources of nitrogen. The character of the soil as well as the 

 character of nitrogenous material was found to modify markedlj»- 

 the ammonifying power of an organism. Interesting comparisons 

 with Marshall's work are made. M. R. Ensign (St. Louis). 



Lipman, C. B. and P. S. Burgen. The effects of copper, 

 zinc, iron, and lead salts on ammonificationand nitri- 

 fication in soils, (Univ. of Cal. Pub. Agr. Sei, I. p. 127—139. 1914.) 



Copper, zinc. iron, and lead salts were found to exercise a 

 slight toxic effect on the ammonifying flora of a sandy soil at all 

 concentrations employed, while these same salts showed a marked 

 Stimulation to the nitrifying flora if the concentrations were not too 

 weak. Lead sulphate was the only salt that did not stimulate nitri- 

 fication up to 0.15 per cent concentration. 



M. R. Ensign (St. Louis). 



Reed, H. S. and J. S. Cooley. The effect of Gytnnosporangium 

 on the transpiration of the apple trees. (Va. Agr. Exp. 

 Sta. Rep. p. 82-90. 1911 — 12.) 



This paper gives a comparative study of the transpiration rate 

 in diseased and healthy apple shocts as compared with those affec- 

 ted by Gymnosporangmm Jtiniperi-virginianae. The method used 



