RESULTS OF SUB-IRRIGATION. 77 



irrigated beds. " The lettuce rot, which appeared to a 

 marked extent in the surface-watered beds," he writes, 

 "was apparently absent in the sub-irrigated beds. The 

 disease was first noticed at time of marketing, at which time 

 it could not be detected in the other beds. During the 

 growth of the second crop it became very troublesome, and 

 some of the varieties in the surface-watered beds required 

 marketing before they were fully grown, while in the under- 

 surface-watered beds the disease was completely held in 

 check." 



Rane also found " marked superiority " in sub-irrigation 

 for tomatoes, "no marked difference" in turnip-rooted 

 radishes, "very beneficial" effects in long-rooted radishes, 

 "a slight difference" in earliness in spinach, "no marked 

 difference" in turnip rooted beets, and "very marked" 

 gain in maturity of parsley from seed but " no perceptible 

 difference in its growth " after the plants in the surface- 

 irrigated soil "once reached maturity." 



Conclusions. Green makes the following points of ad- 

 vantage of sub-irrigation in glass houses : 



"Watering by sub-irrigation in the greenhouse is more 

 cheaply done than by the ordinary method. 



"Watering by sub-irrigation in the greenhouse is more 

 efficiently done than by the ordinary method. 



"Where sub-irrigation is practiced in the greenhouse, 

 the soil does not become compacted as by surface water- 

 ings, but retains its original loose, friable condition, even 

 without frequent stirring, nor does it become mossy, water- 

 logged and sour. 



' ' Plants are less liable to suffer from over watering 

 and diseases by sub-irrigation than where the water is 

 applied to the surface. 



"All classes of plants which may be grown upon 

 greenhouse benches thrive better by sub-irrigation than 

 by the ordinary method of watering." 



Rane writes as follows: "The saving of labor through 

 sub-irrigation is almost inestimable. The expenditure of 



