364 University of California Publications in Agricultural Sciences [Vol. 1 



that the injury which was so marked in series II must be in some 

 way associated with the calcium-magnesium content in solutions 

 which were not properly balanced. No definite calcium-magne- 

 sium ratios can be found which are responsible for the injury 

 which occurred in this series. Twenty different calcium-magne- 

 sium ratios ranging from 0.03^ to 3.54 occur in the series, and 

 both plants which were normal and plants which were seriously 

 injured were found in cultures in which tlie calcium-magnesium 

 ratio was low as well as in cultures where this ratio was high. 

 No definite conclusions can be drawn in this connection, however, 

 since the other variables present complicate the situation so that 

 the injury cannot be said with certainty to be associated with an 

 improper balance between the calcium and magnesium. 



TABLE 3 



Summary of Complete Experiments 



Grouped in such a manner that comparison can be made with special 

 reference to the influence of concentration and balance of the solution 

 upon crop and flower production. The calculation of the per cent total 

 concentration is based on the assumption that the salts are all dissolved 

 in the quantity of water held by 2000 grams of sand when saturated. To 

 get this value in parts per million, multiply the total concentration in 

 grams by 227.2. The real concentration would be much greater than these 

 values would indicate, since the sand was not kept saturated. 



