Suggestions about Spraying. 251 



quantity of lime to neutralize it is very important. Added at the rate 

 given above, however, it seems to be perfectly safe. 



As we frequently have inquiries concerning powdered Bordeaux- 

 mixture, it seems best to state that, having given it a fair trial, we arc 

 not warranted in recommending it for use as a substitute for Bordeaux 

 mixture. The adhesive properties of such material are often poor, 

 and, on the whole, they have given very meagre results in comparison 

 with liquid Bordeaux. The results obtained at other experiment sta- 

 tions seem to confirm the results of the work at this station. 



Certain modifications of Bordeaux mixture have been made at the 

 New Jersey Agricultural College Experiment Station,* which compare 

 favorably with the usual formula for Bordeaux. In one of these modi- 

 fications, termed " Soda Bordeaux," caustic soda was used instead of 

 lime to neutralize the copper sulphate ; the quantity of caustic soda 

 recommended is 1. 1 pounds for every five pounds of copper sulphate. 

 A second modification substitutes caustic potash for the lime, three 

 pounds of the potash being used to neutralize five pounds of copper 

 sulphate. In this case, however, potash, such as is obtained in bulk, 

 is referred to, and, as this contains varying proportions of impurities, 

 the quantity (in weight) required to neutralize the copper sulphate will 

 also vary, so in using this formula, as also the one for soda Bordeaux, 

 it is advisable to test with red htmus paper. Add the caustic soda or 

 potash solution to the copper sulphate until upon inserting into it a 

 little piece of red litmus paper a faint tinge of blue appears ; when the 

 blue tinge begins to show, enough has been added. These modified 

 Bordeaux mixtures, in somwhat extended trials, seemed to be nearly 

 if not quite as effective as the common form, and in certain cases, per- 

 haps, present some advantages. They do not clog the nozzle. 



Apply the proper remedy at the right twie. — One of the essential 

 features of successful spraying, and one often overlooked, is to apply 

 the proper remedy at the right time. To know what to apply, and 

 when to apply it, is generally not a difficult matter if a few facts be 

 kept in mind. Practically all insect enemies of plants, for which 

 s[)raying is a specific, may be divided into two classes with respect to 

 their habits of feeding, and the remedy to be applied will depend upon 

 these habits. The insects of one class, of which the potato bug and 



Ninth Ann. Rep., 1896 (Report of Botanist). 



