14 HATCH EXPERIMENT STATION. [Jan. 



The growing of carnations in sterilized soil, according to 

 our limited experiments, shows a slightly beneficial effect on 

 the plant, although others who have had more extensive 

 experience have noted very little difference as the result of 

 this practice. It is especially applicable to carnations in 

 eliminating the wet stem rot caused by the fungus Rhizoc- 

 tonia. In our opinion, there is little reason to believe that 

 sterilizing would succeed in preventing the dry rot caused by 

 Fusarium. With carnations, soil sterilization possesses some 

 advantao^e in the cutting bed where cuttings are affected 

 with Rhizoctonia and the dami)ing-off fungus (Pt/thiiun De 

 Baryanum, Hesse). In our rather extensive use of ster- 

 ilized soil we have never observed any detrimental influence 

 on the soil itself; we have, however, always made use of 

 a tolerably rich soil, well supplied with organic matter. 



The principal forms of appliances now used for this pur- 

 pose are similar, with some modifications, to those which 

 have been employed for five or six years. Perforated iron 

 pipes made up into frames, 10 to 12 feet long and 8 to 10 

 feet wide, are most generally used. The harrow form of 

 apparatus, known as the Sargent sterilizer, is also largely 

 used, and consists of an iron frame, 4 or 5 by 8 or 10 feet, 

 provided with i)erforated teeth about 10 or 12 inches apart 

 and 1 foot long. The teeth are thrust into the soil, and the 

 steam is turned on. With this form of apparatus it is not 

 necessary to shovel the soil, hence the process is cheap. 

 The latter type requires a high pressure of steam, and not so 

 great a volume ; while the former apparatus requires a large 

 volume of steam, and can be operated to advantage with 15 

 or 20 pounds of steam pressure. 



The Influence of Electrical Potential on the 

 Growth of Plants.^ 

 In our last report we gave results of experiments showing 

 the effects of current electricity upon the growth of plants, 

 also the results of subjecting plants and moist seeds to dif- 

 ferent electrical potentials. We shall give here the results 



' These experiments were conducted by N. F. Monalian. 



