344 Report op thb Horticultural Departmjbnt of the 



yield from boxes having 20 per ct. manure combined with com- 

 mercial fertilizers. These remarks hold good also for the loose 

 lettuce though not in the same degree. The loose lettuce seemed 

 to be less affected by the excessive use of manure and to the eye 

 the entire crop appeared more uniform and less influenced by 

 the differences in the treatment of the soil than did the head 

 lettuce. The head lettuce was harvested Jan. 14, when the earli- 

 est maturing heads were ready to be cut. The loose lettuce was 

 cut Jan. 31. 



RE3SULTS AS SHOWN BY THB WEIGHTS OF THE THREE LETTUCE CiROPS. 



The average weight per plant, both of the head lettuce and of 

 the loose lettuce, is shown below for each crop and each separate 

 treatment. The number of plants from which the average yield 

 is deduced is stated and also the ratio of that average to the 

 average of corresponding untreated, or check, plants, the latter 

 being always considered as a unit. It should be remembered 

 that the value of the unit or check for the clay loam differs from 

 that of the sandy loam with each crop; it also differs on the same 

 kind of loam with the different crops. 



