F. KiDD AND C West 



21 



Accounts of the treatment of seeds with solutions of various salts 

 with the object of testing the effect upon final yield are to be found 

 scattered through the literature, but although sweeping conclusions are 

 occasionally drawn, the experimental data upon which these conclusions 

 are based are in the majority of cases completely inadequate. Two or 

 three examples may be given. 



In discussing the results of a long series of pot-culture experiments 

 extending over a number of years, carried out at the Woburn Experi- 

 ment Station with the primary object of testing the manurial value of 

 small quantities of the so-called rarer constituents of ash, Voelcker(40) 

 observes (p. 325) that "certain metallic salts have either a toxic or a 

 stimulating effect upon vegetation, the particular effect depending upon 

 the quantity of the metal present. At what stage of the plant's life are 

 these influences exerted? The evidence so far adduced, leads strongly 

 to the belief that it is during the germination of the seed, rather than at 

 the later stages of the plant's growth, that these influences are exercised." 



The substances tested by Voelcker were in most cases applied to the 

 soil, but in a few experiments the only application of the substances was 

 to the seeds, which were soaked in solutions for a short time before 

 sowing. It was found that in some cases this treatment gave very 

 favourable results, and in other cases it produced a moderately good 

 result, whereas when the same substances were applied to the soil in 

 various amounts, the results obtained were always negative. Some of 

 the results obtained by Voelcker (37, 38, 39, and 40) are collected together 

 in the following table (Table XV). 



Kind of seed used 

 Winter Wheat 

 (White Chaff Bro\vick) 



Wheat 



Barley 



N.B. In a later series of experiments it was found that soaking the seed for 20 mins. 

 in NaT or NaBr (1, 10, and 20 % solutions) did not give beneficial results. 



* All the seeds were steeped in hot water for 10-15 minutes before treatment in order 

 to kill smut. 



