14 FUMIGATION FOR THE CITRUS WHITE FLY. 



the practice of some fuinigators who, as has been stated, increase the 

 dosage when the tents and fohage are wet with dew. It seems that 

 the difficulty in handling wet tents is the only consideration for 

 which it is necessary to cease work on foggy nights, everytliing else 

 being favorable. 



SIZE OF TREES AND REGULARITY OF SETTING. 



Wliile it is true that it is possible to place a fumigating tent over 

 any citrus tree regardless of size, the author strongly recommends 

 that orange growers make a practice of pruning large seedling trees 

 so that they will not exceed 28 or 30 feet in extreme height. Such 

 pruning will greatly reduce the cost of labor in fumigating and will 

 be of considerable advantage from the standpoint of picking the 

 fruit. It is probable that the now generally recognized all-around 

 advantage of low-]:)runed fruit trees applies equally well to citrus as 

 to other kinds of fruits. Another consideration of importance is 

 the regularity in the setting of orange groves and the proper spacing 

 of trees. In Florida various factors have resulted in many groves 

 being too crowded or too irregularly set to permit of the easy handling 

 of fumigating tents. Wliile it is well to bear these things in mind 

 to the end that all Florida groves may gradually be adapted to 

 reduce the labor and expense of fumigation, yet even under present 

 conditions it is exceedingly rare that fumigation is rendered abso- 

 lutely impracticable by the size of trees or the irregularity of their 

 setting. 



EQUIPMENT. 



TENTS. 



Styles of fumigating tents. — Two styles of tents are now in use for 

 orchard fumigation, the bell or hoop tent (PI. I.) and the sheet tent. 

 The first is bell-shaped and held open at the mouth by a hooiD of f-inch 

 gas pipe. Tents of tliis style are preferable for use only when the 

 trees in a grove are uniformly less than 12 feet in extreme height. 

 Sheet tents are made in the form of flat octagons and, being adapt- 

 able for trees of all sizes, are in California used almost exclusively. 

 Plate I, figure 3, shows a tree which is 14 feet in extreme height and 

 14 feet in extreme expanse, covered by a hoop or bell tent. When the 

 tent is in position covering the tree the measurements are: Height, 

 13 feet, and diameter, 12 feet. Hoop tents are not always easily 

 placed in jiosition over trees of tliis size, and it is believed that ordi- 

 narily a sheet tent is more desirable for trees of all sizes. A third 

 style of tent which will be found useful in fumigating small trees is 

 the box tent in the form of a rectangular prism. This will probably 

 prove advantageous for trees 5 feet or less in height. The light 

 wooden framework supporting the cloth cover gives a form to the 



