NOTES AND ABSTRACTS. 



645 



of washing soda. Heat to boiling, taking care to prevent the tobacco 

 from rising to the surface. Allow to cool. After 24 hours run off the 

 extract and add sufficient water to make 300 gallons of liquid. The 

 wash does not keep long. A powerful spray must be used. — S. E. W. 



Tomato, Disease of, in Louisiana. By C. W. Edgerton and 

 C. C. Moreland [U.S.A. Exp. Stn., Louisiana, Bull. No. 142 ; Oct. 

 1913). — A popular bulletin to help tomato-growers in identifying and 

 controlling the various diseases of tomato plants, more especially the 

 tomato wilt {Fusarium Ly coper sici) and early blight {Alternaria Solani). 

 These two diseases seem to be doing considerable damage in Louisiana. 



Fusarium Lycopersici lives over from year to year in the soil, and 

 is consequently very difficult to control. The disease affects the 

 vascular tissue of the root and stem, the growth is stunted, the leaves 

 turn yellow, and the plant eventually dies. 



Rotation of crops is advised, also extreme care in removing and 

 burning all infected plants or parts of plants. 



Alternaria Solani, being a disease of leaves and fruit, can be 

 controlled by spraying with Bordeaux mixture. — D. M. C. 



Transpiring Power of Plants. By A. L. Bakke {Jour. Ecol. 

 vol. ii. No. 3, pp. 145-173 ; 2 figs.). — In this important paper the 

 author describes a method for determining the transpiring power 

 of different plants by means of standardized cobalt-paper. He gives 

 tables of results obtained by this method in the study of the daily 

 march of transpiration, the relation of position on the plant and 

 age of the leaves to their transpiring power, the relation of night 

 to day transpiring power, and so on, for a large number of plants 

 experimented with. The method gives remarkably interesting results, 

 but perhaps the most important outcome of his studies is the 

 conclusion that the method offers an adequate and simple means 

 of classifying plants in a scale of xerophytism or of mesophytism 

 according to their index of foliar transpiring power, while experiments 

 made with cultivated plants indicate that the method may be of great 

 practical value in determining the relative resistance to drought of 

 different crops or different varieties utilized in horticulture and 

 agriculture — a problem which the author considers might be better 

 approached by this method than by any other as yet devised. For 

 instance, the magnitude of the foliar transpiring power, as thus 

 determined, may prove valuable in predicting the need of irrigation 

 long before the occurrence of actual wilting. — F. C. , 



Trees, The Artificial Production of Vigorous. By A. Henry 

 (Jour. Dep. Agr. Tech. Ins., Ireland, xv. 1914 ; plates and 

 figs.). — The author describes the method of crossing such trees as 

 poplars, walnuts, ash, and the like, and comments upon the extra- 

 ordinary vigour of some of the hybrids which have been raised, 

 especially among poplars (see p. 341, and Populus x generosa, p. 636). 



F. J. C. 



