52 INTENSIVE FARMING 



be necessary were it sold on size and condition 

 rather than by the pound. 



In the region where loose lettuce is grown the 

 tomato is a more popular companion crop than 

 cucumbers, although both are used. 



Tomatoes. As has already been pointed out, 

 tomatoes are as a rule grown as a rotation crop 

 with lettuce. This is not true in all cases, for 

 some growers have provided special equipment 

 for the crop. In fact, until the modern general 

 purpose vegetable forcing house was evolved 

 special equipment was necessary for forcing 

 the tomato. The modern house answers well 

 for lettuce, cucumbers, and tomatoes as rota- 

 tion crops. When tomatoes are grown as a 

 forcing crop during midwinter at the North 

 best results are obtained when bottom heat can 

 be applied. This requires special equipment, 

 as the modern vegetable house is not designed 

 for bottom heat. At the time of the year when 

 the crop is usually grown in rotation with let- 

 tuce, the sun heat is increasing instead of wan- 

 ing and bottom heat is of less consequence to 

 the development of the crop. 



The winter tomato crop at the South has 

 more seriously affected the forced crop of to- 

 matoes than has the lettuce crop of the South 

 the forced crop of lettuce. Notwithstanding 



