3G0 University of California ruhlications in Agricultural Sciences [Vol. 1 



The influence of total concentration is again plainly seen in 

 this series. Plate 13 shows plant 1 of each of the groups A, B, 

 C, and D. As the total concentration decreases from A to C 

 there is a steady increase in the vigor of the plant as judged by 

 height. Curves in figure 9 indicate this general tendency to an 

 increase of height with a decrease in the total concentration of 

 the solution. 



Dry Weight in Series III 

 As in series I and II, the dry-weight curves (fig. 10) do not 

 correspond w^ith the height curves (fig. 8). The greatest dry 

 weight of any plant was that of III A 4, which was not so tall as 

 the other plants of like number. The low dry weight of III B 4 

 is especially noticeable. A comparison of the two dry-weight 

 curves for the A and B groups shows a very peculiar effect of 

 KoSO^ in solutions of different balance. In each case where the 

 group A curve is high, the group B curve is low, a fact which 

 also applies to plants 3, 4, and 5 in the A and C groups. That 

 this should occur with such regularity is rather remarkable and 

 no satisfactory explanation can as yet be found to account for 

 this situation. It is evident that the physiological balance of 

 salts in the solution is dependent upon the concentration, as has 

 been shown by McCool,-^ Gile,-" Tottingham,-' and Shive.-^ 



Flower Production in Series III 

 The more vigorous growth of plants in this series gave a 

 greater total yield of flowers than either of the other two series. 

 This was to be expected from the result of series I and II, where 

 the flower yield was shown to be definitel.y related to the general 

 vigor of the plants. The production of flowers in this series 

 differs, however, from that in the other series. An increase of 

 K2SO4, wiiile in general depressing the total height of the plant, 

 when added in excess of .01 per cent gave a higher flower yield. 

 Thus in group C there is steady increase in the number of flowers 

 produced which corresponds to the increase of K0SO4. The 



25 MeCool, Cornell Agric. Exp. Sta. Mem., vol. 2, pp. 121-170, 1913. 



26 Gile, Porto Eico Agric. Exp. Sta. Bull. 12. 



27 Loc. cit. 

 2S Loc. cit. 



