EXPERIMENT STATION BULLETINS. 287 



infestation of the different plots as compared with their condition in the 

 spring before thej^ were sprayed. As will be seen, the effect upon the 

 sulphur and lime sprayed trees had been very marked. The number of 

 scales upon the branches in the fall was only ten per cent as large as in 

 the previous spring, while in the case of Scalespray the numljer had 

 increased five-fold, with a somewhat smaller number upon the trees 

 sprayed with the other oil mixtures. On the 10th of October the breed- 

 ing of the scale was checked by a severe freeze, which also destroyed all 

 of the crawling larvae and young sets, but in spite of this many of the 

 branches had become very badly encrusted, so that had the last brood 

 developed the trees sprayed with the oil mixtures would have been prac- 

 ticallv covered with the scale. 



No. of Scale, 

 Material Used. Dec 1, 1906. 



(As compared 

 with No. April 1.) Relative Infestation, 



Kil-0-Scale (1-20) 4 40 



Target Brand (1-20) 3 30 



Scalespray (1-20) 5 50 



Scalecide (1-20) 31/2 35 



Kil-o-Scale (1-10) 31/2 35 



Target Brand (1-10) 21/2 25 



Scalespray (1-10) 4 40 



Scalecide (1-10) 3 30 



Sulphur and lime mixture .10 1 



Kerosene and lime (air-slaked) 2 20 



Kerosene and lime (dry-slaked) 2 20 



The above showing for sulphur and lime could only be reached by 

 taking the utmost care to secure thoroughness in making the application. 

 In the case of apple trees it Avould not be possible to secure such a result, 

 as the size of old trees, together with the loose bark upon the branches, 

 would interfere with the results while the fine, hairy growth with which 

 the bark upon the shoots of young trees is covered would prevent the 

 spray from reaching and destroying the scales. 



The work of spraying will be made much easier and the expense will 

 be greatly reduced if trees infested with the wSan Jose scale are thor- 

 oughly pruned before they are sprayed. The amount of cutting back 

 will depend largely upon the size and kind of trees and also upon the ex- 

 tent to which they are infested. If the trees have not been seriously 

 injured by the scale, the pruning need be only such as is necessary to 

 bring them into a compact form for spraying. It will be well then to 

 thin out the tops of the trees, as much as can be done without injuring 

 their form and to head back the ends of the leading shoots as these are 

 not only the ones that are the most likely to escape in spraying, but, 

 where pains is taken to make sure that they are covered, the labor and 

 material will be several times greater than will be required to spray 

 similar areas in the interior of the tree. 



The injury from the San Jose scale is especially noticeable upon 

 branches that are one inch or less in diameter. To such an extent is 

 this true that trees often have all of their branches killed while tht 

 trunk and main limbs have been little, if any injured. Particularly with 

 peach trees, and young trees of all kinds, it will be possible to head back 

 the branches, even when all of the smaller shoots have been killed, and 



