540 CITRUS FRUITS AND THEIR CULTURE. 



now attached to the tent at the near edge and the latter 

 pulled to the top of the pole. The rope is then made fast, 

 the guy-ropes pulled, and the tent slid in the same man- 

 ner as with smaller tents. Sometimes the pole is not set 

 at such an angle but nearer the tent, when it will be neces- 

 sary, after sliding the tent part of the way, to again tie 

 the guy-rope and lift the bottom of the pole over; it will 

 then be opposite the trunk, and the tent will be lifted 

 high enough when it is given the final shift. 



When there is fear of breaking the branches in re- 

 moving a tent, the practice is to "skin it off," using a pole 

 of the lifter pattern, and carry the rope around to the far 

 side and attach it to the edge of the tent there. The tent 

 by this method slides over itself and saves the tree to that 

 extent ; it is pulled over on to the next tree as in the pre- 

 ceding methods. Since much of the tent by this method 

 falls to the ground, it is harder on the tree while it is being 

 tented. By this process the tent is reversed each time it is 

 changed." 



Chemicals and Amounts. Only chemicals of high 

 quality should be used, and to this matter particular at- 

 tention must be given. There is much variation in dosage 

 as given by different fumigators. In part, this may be 

 due to climatic and other conditions, but the wide differ- 

 ence may be attributed, in a large measure, to a lack 

 of thorough investigation of the subject. Potassium cya- 

 nide, sulphuric acid and water in the proportion of 2 

 to 3 to 6 will give excellent results. 



Most of the fumigation of citrus trees has been for 

 scale insects. Sufficient work on white fly has been done 

 to justify the conclusion that it requires the same dosage 

 as for scales. 



