13 



27 SULFUR. 



For Empty Houses. 

 Close the house tightly and burn 200 grams (about 6 oz.) to 1000 

 cu. ft. of space. Keep the house closed at least twelve hours. 



28 SULFUR. 



For Houses unth Gro7i.<ing Plants. 

 Evaporate a small quantity in a kettle over a kerosene stove, tak- 

 ing care that it does not catch fire. Or, better, paint some of the 

 heating pipes occasionally with a mixture of sulfur and oil. 



TREATMENT OF GREENHOUSE PLANTS. 



On general principles the practice of spraying greenhouse plants 

 cannot be recommended, since the control of their diseases is possible 

 to a large extent by maintaining favorable or hygienic conditions. 

 This requires skill obtained from long experience in greenhouse man- 

 agement. When greenhouses are about to be emptied or before 

 replanting, fumigation can be practised to advantage with Nos. 26 

 and 27. 



Red Spiders and Mites. 



Drench the plants with 2 ounces of common salt in a pailful of 

 water. No really satisfactory treatment for these pests has yet been 

 found. 



Plant Lice : Aphids. 



Burn tobacco stems ; when the house is empty, fumigate by any 

 fumngant, such as Nos. 26 or 27. 



Thrips. 



Nikoteen 4 cc. (1 oz.) ) „ u- ( ^ 



,,, ^ ,^'a \ ^ Per 1000 cubic feet. 



\\ ater 150 cc. (5 ri. oz.) s 



Mix and vaporize in the house at night ; will kill most of the 

 thrips. 

 White Fly. 



P'umigate as for Nursery Stock above, No. 25, except that instead 

 of using .2 or .25 gram of cyanid per cubic foot, use .007 to .01 



