50 Diseases of Greenhouse Crops 



Table 6 



Plot 



1911 



1911-12 



1912 



1912-13 



Average 





324 



432 



3.33 



332 



3-55 



Straw mulch 



3.06 



301 



2.85 



300 



2.98 



Manure mulch .... 



3.74 



4.61 



4. II 



4.29 



4.18 



Dry 



3.29 



525 



3-86 



4.05 



4. II 



old, well manured soil in the greenhouse. This 

 does not imply, therefore, that it is necessary to 

 renew the soil every year for cucumbers or toma- 

 toes. Soil sterilization, good drainage, and liming 

 will tend to overcome the ill effect of old soils on 

 these crops. 



