26 MASS. EXPERIMENT STATION BULLETIN 326 



Tomatoes 



Tomatoes are more sensitive to naphthalene fumigation than cucumbers and 

 should be given this treatment only when pest infestation is extremely severe. 

 As with cucumbers, the disagreeable odor and flavor of the chemical is absorbed 

 and retained by the fruit, especially after it begins to color. Injury first appears 

 as a marginal foliage burn on tender new growth. 



COST OF NAPHTHALENE FUMIGATION 



Naphthalene fumigation is not an expensive operation. After the equipment 

 for fumigating a greenhouse unit is available, the cost compares favorably with 

 that of other effective fumigation treatments. 



Permanent equipment consists of vaporizing units and a gas mask of some 

 kind, but with ordinary care this equipment should last for 10 years or more, 

 thus distributing the initial cost over a long period. 



Practical vaporizing stoves can be purchased for $2.00 or $2.25 each, or 

 satisfactory units can be assembled at home at a cost of 50 cents or more each, 

 depending upon the ability and ingenuity of the individual. The only wearable 

 parts in the stoves are the wicks, which should last for two or three years. Gas 

 masks should be considered a convenience rather than a necessity since many 

 operators do not use them. Furthermore, they have other uses and are valuable 

 safety equipment for many emergencies. 



Commercial flake naphthalene costs 8 to 12 cents per pound retail, and 2 to 

 3 ounces for each 1,000 cubic feet are used in a fumigation. 



It is probable that some additional fuel will be necessary to maintain the 

 required temperature but this will be variable and is difficult to estimate. 

 Based on approximate figures in the experimental greenhouses, it would require 

 in the coldest weather approximately 37 gallons of fuel oil at 6 cents per gallon, 

 or J^ ton bituminous coal at $7.00 per ton, to raise the temperature 15° to 

 25° F. above normal temperatures for a 6-hour fumigation period; while in 

 cool weather about 12 1 2 gallons of fuel oil at 6 cents per gallon, or 1/10 ton of 

 bituminous coal at $7.00 per ton, would be sufficient. 



Most fumigations are managed by the grower or his most reliable regular 

 help so that no additional labor is necessary, but if additional labor is necessary 

 an expense of 6 hours labor at 30 cents an hour should be charged to the fumi- 

 gation. 



An estimate of the cost for fumigating with naphthalene in a greenhouse 200 

 feet long, 30 feet wide, and 10 feet high (average), containing 60,000 cubic 

 feet is as follows: 



Initial Cost 



Maximum Minimum 

 Stoves, 1 for each 7,000 cu. ft.: 



9 at $2.25 (purchased) $20.25 



9 at .50 (homemade) . . $4.50 



Gas Mask 5.00 None 



Totals $25.25 $4.50 



