666 , INSECTS AFFECTING VEGETATION 



The heating pipes of greenhouses are frequently painted with 

 flour of sulphur made into a paste with water for the production of 

 fumee, which act to prevent various diseases. Fumes irom burning 

 sulphur may -be used to disinfect empty greenhouses, storage houses, 

 and outbuildings. 



Caution. Fumes from burning sulphur are destructive to plant 

 life and should never be used to disinfect inclosures containing live 

 plants or fresh fruits and vegetables, as they will kill them wholly or 

 in spots. 



Corrosive Sublimate. Corrosive sublimate (mercuric chlorid) 

 is used at the rate of 1 part to 1,000 parts of water to disinfect the 

 knife or other tools used in cutting out pear-blight. Convenient- 

 sized tablets of this substance can be purchased at a drug store and 

 kept in a bottle. One of these tablets may be added to a bottle con- 

 taining the required quantity of water (usually a pint), and a 

 sponge or cloth saturated with this solution may be used to wipe the 

 tool after each cut. It is also advisable to disinfect in this way the 

 wound made by the removal of the blighted wood. 



Caution. Taken internally, corrosive sublimate is a deadly 

 poison and should be handled as such. 



DIRECTIONS FOR THE PREPARATION OF SELF-BOILED LIME-SULPHUR 



WASH. 



The standard self-boiled lime-sulphur mixture is composed of 8 

 pounds of fresh stone lime and 8 pounds of sulphur to 50 gallons of 

 water. In mild cases of brown-rot and scab a weaker mixture con- 

 taining 6 pounds of each ingredient to 50 gallons of water may be 

 used with satisfactory results. The materials cost so little, however, 

 that one should not economize in this direction where a valuable 

 fruit crop is at stake. Any finely powdered sulphur (flowers, flour, 

 or commercial ground sulphur) may be used in the preparation of 

 the mixture. 



In order to secure the best action from the lime, the mixture 

 should be prepared in rather large quantities, at least enough for 200 

 gallons of spray, using 32 pounds of lime and 32 pounds of sulphur. 

 The lime should be placed in a barrel and enough water (about 6 

 gallons) poured on to almost cover it. As soon as the lime begins 

 to slake the sulphur should be added, after first running it through 

 a sieve to break up the lumps, if any are present. The mixture 

 should be constantly stirred and more water (3 or 4 gallons) added 

 as needed to form at first a thick paste and then gradually a thin 

 paste. The lime will supply enough heat to boil the mixture several 

 minutes. As soon as it is well slaked water should be added to cool 

 the mixture and prevent further cooking. It is then ready to be 

 strained into the spray tank, diluted, and applied. 



The stage at which cold water should be poured on to stop the 

 cooking varies with different limes. Some limes are so sluggish in 

 slaking that it is difficult to obtain enough heat from them to cook 

 the mixture at all, while other limes become intensely hot on slaking, 

 and care must be taken not to allow the boiling to proceed too fur. 

 If the mixture is allowed to remain hot for 15 or 20 minutes after 



