ECONOMIC VALUE OF FUMIGATION 237 



fruit. It would appear, therefore, that dropping the 

 leaves from the trees is not so apt to work injury to 

 the orange in Florida as in California. We fumigated 

 trees of various sizes from mere bushes up to 30 

 feet in hight and 25 feet in diameter, using various 

 styles of tents. The hoop tent proved most satis- 

 factory for trees not over 12 feet in hight and of 

 equal diameter, but for larger trees we used the bell 

 tent, handling it by means of a new form of derrick. 

 We ceased fumigation work when the trees com- 

 menced to blossom freely, and put the tents away. 



" Several hundred trees were fumigated, and four or 

 five times as many sprayed with resin wash and with 

 a few other materials for comparison. The gas method 

 is the more expensive to begin with, but we are inclined 

 to believe it may be the cheapest in the end. I found 

 that about seventy -five per cent, of the insects were 

 killed by a single spraying with resin wash, but in 

 examining thousands of insects upon many different 

 trees that were fumigated I was able to find but a 

 single living representative. I have no doubt that the 

 practical application of the process to two or three of 

 our orange-growing counties will mean a net profit of 

 $250,000 to $500,000 annually inside of three or four 

 years, if the treatment is generally adopted. We have 

 not worked with deciduous trees, not because we 

 believe it impracticable, but for lack of time up to the 

 present. A number of our nurserymen use the gas in 

 fumigating their nursery stock, and in a more limited 

 way plants and shrubs, upon their premises. Nearly 

 all of our nurserymen doing a large and extensive 

 business have excellent fumigating appliances. 



