COST OP EQUIPMENT. 57 



The cost of the sheet tents would be considerably reduced by the 

 use of one or two widths of 6i-ounce drill, sewed around the margin 

 as a skirt, as described under the subject of construction of fumigat- 

 ing tents. The difference between the cost of tent materials in Cali- 

 fornia and in eastern citrus-growing States, owing to the greater 

 distance of the former from the factories, should result in a reduction 

 of from 2 to 5 per cent in the cost of an outfit at any point in the 

 Gulf States. In Florida the season for fumigating against the white fly 

 extends over from seven to ten weeks. During this time a fumigating 

 tent, used between thirty-five and fifty days on an average of eight 

 hours per day with forty-five minute exposures, would be used to 

 cover between 280 and 400 trees. A tent large enough to cover the 

 largest trees should ordinarily not cost over SI 10. It has been 

 stated that the tents used in the author's experiments in January 

 and February, 1907, have not deteriorated appreciably. With 

 proper care tents should last several seasons, whether untreated 

 or mildew-proofed. If such a tent as referred to above should be 

 used for only three seasons, and be used to cover only between 280 

 and 400 trees each season, the cost of the wear and tear of the tent 

 would amount to only from 9 to 12 cents per tree. Even taking into 

 consideration interest on the money invested, the cost per tree 

 would not exceed 15 cents. This is fully twice the cost of a tent 

 large enough to cover trees of average size. 



In many cases it would not be advisable for an orange grower to 

 invest several hundred dollars in fumigating tents for his exclusive 

 use, although many with extensive groves would doubtless prefer 

 to do this. When possible individual ownership of an outfit is desir- 

 able. In some citrus fruit growing countries where fumigation is 

 practiced against scale insects several growers form a club and 

 share the cost of the fumigating outfit, which is left at the disposal 

 of each of the members in turn. . Such a plan might be followed in 

 many cases in Florida. It is especially to be recommended where 

 several groves constitute a naturally isolated group, and cooperation 

 has all the advantages of individual ownership of a single isolated 

 grove. A few citrus growers with a crop worth on an average $25,000 

 would not be put to unreasonable expense in the joint ownership of 

 an outfit costing $1,200 or $1,500. The rapid growth of the idea of 

 orange growers' associations in Florida during the past few months 

 leads to the hope that a means is at hand for providing for systematic 

 campaigns against citrus pests. In some cases associations for this 

 purpose have already been organized. Fuinigation by the contract 

 system, as it is now done to a large extent in California, may also 

 come into use in Florida. The plan which can be most strongly rec- 

 ommended is for the work to be done by the various counties. Each 



