162 EFFECTS OF REACTION OF SUBSTRATE ON FUNGI 



Alkaline fungicides. In the lio-ht of observations that fungi 

 generally grow better in acid than in basic media, various attempts 

 have been made to utilize this fact in wood preservation and the 



800 



700 - 



600 - 



CO 



§> 500 



s 



I 400 



0) 



s 



CtH 



o 



£ 300 



.SP 



200 - 



100 - 



5 6 



Reaction of medium 



8 



9 



Fig. 25. Growth of certain Basidiomvcetes at 25° C in peptone nutrient solu- 

 tions with varying initial reactions. Comparison with Fig. 23 shows that 

 nutrition is also a factor in growth. (After Wolpert.) 



prevention of decay in fruits. Stains of sapwood can be largely 

 prevented if the lumber is dipped into an alkaline bath immedi- 

 ately after it is sawn [Scheffer and Lindgren ( 1 940 ) | . Such 

 treatment gives protection until the water content of the lumber 

 can be reduced to 20% or less, at which point lack of moisture 

 inhibits the growth of sapwood-staining species. 



