8 



NUTRITION OF FUNGI 



TABLE 3 

 Growth Responses of Phymatotrichum omnivorum on Combinations of K2HPO4, 



MgSC>4, AND KC1 AFTER INCUBATING FOR 21 DAYS AT 28° C 



(All solutions had 4% glucose, 0.0125 M NH4NO3, and 2 ppm of Fe, of Mn, and 



ofZn.) 



1 These figures represent averages of the number for pH of each of the replications 

 and are not, of course, the average pH. 



These observations furthermore indicate that a proper balance 

 between K 2 HP0 4 and AIgS0 4 in the growth of P. omnivorum is 

 equally as important as the direct effect of either salt. This proper 

 balance is maintained without significant change in the amount 

 of mycelial growth even though the concentration of K 2 HP0 4 

 and A'1jtS0 4 is decreased one-half or increased fourfold. If the 

 concentration of either salt is increased, however, the concentra- 

 tion of the other must be increased accordingly to maintain this 

 proper balance. The potassium ion is of more imoortance in main- 

 taining balance than is the phosphate radical. 



