534 CITRUS FRUITS AND THEIR CULTURE. 



ronio system of lemon pruning, are well adapted to spray- 

 ing. All dead wood must be pruned from the interior of 

 the tree before spraying is commenced. 



Trees with dense, thick heads, as already noted, are 

 much more easily fumigated than sprayed. The mass of 

 branches prevents the spray from penetrating thoroughly 

 and efficient work cannot be done except by fumigating. 



SPRAYING. 



In spraying trees for scale and allied insects, it will 

 be found that, to secure the best results, the work must 

 be thoroughly done. A liberal application should be 

 given. Ten to fifteen gallons will be required for trees 

 from fifteen to twenty feet high, while those from twenty 

 five to thirty-five will require about half a barrel. 



For spraying large areas, a gasoline or steam engine 

 (see Plate 34), a strong pump carrying three or four leads 

 of hose and a tank holding about three hundred gallons 

 will prove most satisfactory. For smaller areas, hand 

 pumps may be used and of these there are a number of 

 good ones on the market. The Gould, Deming, Stahl. 

 Friend and Field pumps may be mentioned here as giving 

 good satisfaction. 



To hold most insects in check, two or three winter 

 sprayings and one or two summer sprayings will be 

 necessary. As a general rule the armored scales must be 

 sprayed during the immature stages, as they are not easily 

 destroyed when their hard covering is fully developed 

 White-fly must be attacked during the larval and pupa 

 stages, while the mites must be sprayed whenever active. 

 Resin wash and similar mixtures should not be applied 

 to trees when the fruit is only partially grown. Serious 



