CALIFORNIA CITRUS CULTURE. 



71 



For young orchards a twenty-foot tent will serve until the trees are 

 about four years old, and the tents can then be enlarged by simply 

 sewing a border around the edges. This border might just as well be 

 made of lighter and less expensive materials. In this way an orchard 

 may be carried over until the ordinary orchard tents can be used. In 

 fact many fumigators do use a large tent upon a small tree by placing 

 a suitable square or triangular frame around the tree to support the 

 tent or if the trees are strong enough to allow them to support the 

 tents unaided. 



FIG. 48. Marked fumigating tent over tree. (After Pierce, P. C. Jr. Ent.) 



For ordinary work forty-five-foot tents are commonly used and meet 

 all requirements of a full grown orchard, except for unusually large 

 trees, many of which require seventy or eighty-foot tents. It is custom- 

 ary, however, to use two or even three tents together when there is only 

 an occasional large tree. 



Materials. The life and nature of a fumigation outfit depends upon 

 the quality and care of the tents. Many materials have been recom- 

 mende.d and tried, army duck and drills of various weights being those 

 most used. Special tight-woven drill tents were recommended by 

 fumigating investigators, but these materials, though allowing but a 

 small escape of gas, have not been able to stand the rough usage. After 



