156 



BOTANICAL GAZETTE 



[august 



tures with creatinine, an increase of 17 per cent. In the cultures 

 with no nitrate creatinine produced an increase of 36 per cent. 



Effect of creatinine in cultures with larger amounts of nitrate 



It has been shown that creatinine was very beneficial in cultures 

 which contained no nitrates. In a group of cultures, composed of 

 mixtures of phosphate and potash in different proportions, creatinine 

 increased the growth 36 per cent. It has also been pointed out 

 that the beneficial effect of creatinine was not so great in cultures 

 containing a small amount of nitrate. In a second group of 

 cultures, composed of mixtures of potash, phosphate, and 8 ppm. 

 of NH 3 as nitrate, creatinine increased the growth only 17 per cent. 



In table III are given the results of growth in cultures with and 

 without creatinine, composed of mixtures of phosphate, potash, 

 and nitrogen having 16 ppm. NH 3 as nitrate. The green weights 

 of the creatinine cultures given in the last column of the table are 

 slightly larger than the normal cultures, as shown in the fifth 

 column. The total green weight of the cultures without creatinine 

 was 25.516 grams against 27.573 grams for the cultures with 

 creatinine, an increase of 8 per cent. 



TABLE III 



Showing the effect of creatinine in cultures containing 16 ppm. of NH 3 



as nitrate 



No. 



I 



2 



3 



4 



5 

 6 



7 

 8 



9 



PPlf. OF FERTILIZER INGREDIENTS IN CULTURE 



SOLUTION 



PaO 



O 



8 



16 



24 



3 

 40 



48 



56 

 64 



NH, 



16 

 16 

 16 



16 



16 



16 

 16 

 16 

 16 



K,0 



64 



56 

 48 



40 



32 



24 

 16 



8 





Green weight of cultures 



in grams 



Without 

 creatinine 



2.200 

 3.200 



3 097 

 3-250 

 3.228 



2-975 

 2.626 



1.440 



With 

 creatinine 



2.570 

 3.720 



3-SOO 



3.702 



3-250 



3-3°° 

 3.240 



2-55 1 

 1.740 



comDosed of the 



P,Oc. NH 



5' 



3' 



NH 



nitrate, 



creatinine increased growth only 2 per cent. Its effect in cultures 



