The Tobacco Slug. 



37 



and not be carried about the farm, where either the poison itself or 

 the vessels in which it was contained may be a danger to animals 

 and men. When put on plants it causes severe injury, if not complete 

 destruction. Arsenate of lead is also an animal poison, but it is 

 much less virulent; of course, it must not be used carelessly. It is 

 insoluble in water, and, therefore, the mixture must be frequently 

 stirred during- its application to plants. The simplest method of 

 applying the spray is probably that of sprinkling by means of a 

 small broom, as carried out by Mr. Geo. lleid, of Piet Retief. 

 He states that when the plants are about a foot high, in his expe- 

 rience the most important time to spray, two plants can be treated 

 with one dip of the broom, and the method is effective and compara- 

 tively rapid and economical of material. It seems doubtful whether 

 this method can be recommended for large plants. 



Knapsack pumps should prove to be the most popular under our 

 conditions. Bucket pumps are rather slow and laborious for field 

 work. A garden syringe should not be used, as a spray cannot be 

 properly applied with it. 



Fig. 3. — ^A field sprayer for treating tobacco. The attachments for spraying 

 the undersides of the leaves, although desirable, are not absolutely necessary 

 when spraying for the tobacco slug, and may be omitted. 



The most economical apparatus in time and labour will uo doubt 

 be a proper field sprayer. As far as is known, such an implement is 

 not at present for sale in South Africa ; but it is possible to have 

 one made by fixing nozzles at suitable intervals along a lengih of 

 metal pipe and attaching this to a barrel pump mounted on wheels. 

 I'or all the pumps used it would be necessary to have nozzles which 

 throw a fine spray to get the poison evenly distributed. 



