10 



Diseases of Truck Crops 



Plat No. i Stable manure. 



Plat No. 4 Sodium nitrate. 



Plat No. 5 A complete fertilizer, PKN. 



Plat No. 6 Nothing, check. 



The effect of these treatments is briefly surnmarized 

 in Table 4. 



Table 4 



Colonies per Gram of Dry Soil 



The above Table shows that although sodium ni- 

 trate or a complete fertilizer increases the soil 

 flora, neither one can be compared to manure in 

 efficiency. 



Structure and Life History of Fungi 



Besides bacteria of all sorts, our cultivated soils 

 are also teeming with fungi. The true function of 

 the latter remains to be studied. There seems no 

 doubt, however, that certain fungi like certain bac- 

 teria in the soil work on the organic and the mineral 

 matter to make it available as plant food. Parasitic 

 fungi depend for their food on living plants alto- 

 gether. Examples of these are the Uredinales, the 



