348 University of California Publications in Agricultural Sciences [Vol. I 



the groups of a series. Thus I A 5, I B 5. I C 5, and IDS each 

 contained 3 grams NaNO.j, but the content of each pot in KjSOi 

 was 2.4, 1.6, 1.2, and 0.6 grams, respectively; hence the balance 

 between NaNO^ and K.SO4 is very different in each of the four 

 pots. Table 1 shows the distribution of the salts in the three 

 series and the total concentration in grams of the salts in each 

 pot. The total quantity of nutrient salts was added to the sand 

 at the beginning of the experiment. 



The plants were placed in the sand June 15 and were har- 

 vested about November 1, the tops and roots being kept for the 

 determination of dry weight. -° It will lie seen that the plant 

 was allowed sufficient time to complete its natural period of 

 growth, thus permitting certain observations of a quantitative 

 nature as recorded in table 2. 



PHYSIOLOGICAL EFFECT OF XITROGEX 

 DiSTRmuTiox OF Salts in Series I 

 In series I nitrogen as NaNO.. was the salt which was used 

 in the same weights in all of the four groups A. B. C, and D, 

 being present in pots 1 to 5 as follows: 0.01 g. (.001 per cent), 

 0.2 g. (.01 per cent), 1.0 g. (.05 per cent), 2.0 g. (.1 per cent), 

 3.9 g. (.15 per centl. The maximum weights of other salts Avere 

 Ca(H3POj2, 1.2 g.; K,SO„ 2.4 g. ; MgSO,, 0.96 g., in group A, 

 while the minimum quantity of these salts as added in group D 

 was 0.3 g., 0.6 g., and 0.24 g., respectively. The total concen- 

 tration in this series ranged from 1.16 g. in I D 1 to 7.56 g. in 

 I A 5. 



Height ix Series I 

 The height of each plant was measured at two different 

 periods. The first measurement was made when the majority 

 of the plants Avere just beginning to shoAv the first signs of flower- 

 bud formation. The second measurement was taken five or six 

 weeks later, when most of the plants Avere in full bloom. The 

 final height of the five plants in each group is shoAA^n graphically 



20 An accident to the roots while drying prevented the collection of, 

 further data on their dry weight. 



