April, '13] ESSIG: SAN JOSfi SCALE CONTROL 271 



present time, I believe that success depends entirely upon four 

 factors: (1) the chemicals used; (2) the dilution necessar}'; (3) the 

 methods of application, and (4) the time of application. 



1. The chemicals used: As previously stated, lime-sulphur spray is the 

 proper remedy for the Pernicious Scale. All early experimental work 

 with this spray was necessarily made with the home-made products, 

 and it was several years before commercial spray companies began 

 to turn out first-class and dependable insecticides. In the meantime 

 all published investigations and extension work were based upon the 

 home-made solutions. In fact, we must come down to the last few 

 years to find any number of station bulletins or reports recommend- 

 ing the commercial product. Consecjuently the growers have been 

 slow to accept anything but those first recommended, and it is little 

 wonder that such proves to be the case. Those of you who have made 

 a special study of the preparation of this spray know that it is difficult 

 to always get a like and satisfactory product, and it is not strange then 

 that the preparations made by the average grower are not only un- 

 satisfactory but often worthless. Practically all of the failures in the 

 control of this scale may be traced directly to these worthless sprays, 

 and I feel confident that success begins with the use of a thoroughly 

 reliable commercial product. 



Spray manufacturers are becoming keenly alive to the possibili- 

 ties of efficient sprays and are now employing the best experts and 

 machinery in the manufacture of their products. The results are so 

 much better than those obtained by even the best home-made solu- 

 tions that they are being gradually supplanted by the commercial 

 sprays. However, in many sections of our own state the home-made 

 product is still used, and I dare say that a few farmers still persist in 

 adding the salt also. In order to reap the benefits of large purchases 

 the growers of a community should unite in buying the prepara- 

 tions by the carload lot. This is becoming common practice in many 

 parts of California with the result that the growers are now enjoying 

 prompter service and lower prices than they could ever hope to get as 

 individuals. 



2. The dilution necessary: Too often good material is wasted by im- 

 proper dilution. The prime considerations are always cost and effi- 

 ciency; neither of which should be sacrificed for the other. We find 

 one grower applying a spray much too strong at a big cost, while his 

 neighbor is doing the opposite. Of course the extent of infestation, 

 the relative openness and the size of the trees must be taken into con- 

 sideration. Some growers always make their sprays just strong enough 

 to meet the most favorable conditions, while others aim to provide 

 against all unfavorable factors, and this latter class is certainly more 



