18U7.] PUBLIC DOCUMENT— No. 33. 65 



But in the case of decorative plants, even if the Bordeaux 

 mixture effectually prevented disease, its use would involve 

 a serious disadvantage. Imagine a fine palm or Ficus cov- 

 ered with blue whitewash ! It would certainly be more 

 disfigured than by any disease. We have, however, other 

 fungicides which have given very satisfactory results in the 

 treatment of plant diseases, and which, being clear solutions, 

 leave no stain on the plant. Among these the so-called 

 ammoniacal copper carbonate solution is one of the best. 

 It is prepared by dissolving one ounce copper carbonate in 

 strong ammonia (26°), of which about one pint will be re- 

 quired. The copper carbonate should be jiut into a wooden 

 pail with sufficient water to make a thick paste, and the 

 ammonia then added. The resulting solution is then diluted 

 with about nine gallons of water. 



But, aside from any method of spraying, much can be done 

 for the eradication of spot diseases by removing and destroy- 

 ing all affected leaves, etc. This must be done promptly 

 and thoroughly, in order to be effectual. As soon as a leaf 

 is seen to be spotted, it should be removed and burned. 

 This will certainly lessen the extent of the disease, and will 

 in many cases entirely eradicate it, if the plant be kept in 

 good growing condition. We would recommend, however, 

 that all plants which have been or are liable to be attacked 

 by such diseases should be sprayed with the above-described 

 solution, the frequency of the operation varying with cir- 

 cumstances. A plant which has been diseased should be 

 sprayed three or four times, at intervals of about two weeks. 

 If then no further indications of the disease appear, spraying 

 may be discontinued altogether, or the whole house may be 

 thoroughly wet down with the solution every month or two, 

 as a general precaution. (If the house contains any particu- 

 larly delicate or valuable plants, it may be well to try the 

 solution on a small scale on them before applying it gen- 

 erally. We have experimented with quite a variety of com- 

 mon greenhouse plants, and have experienced no harmful 

 results. The solution should be diluted to the full extent 

 recommended.) Spraying apparatus can be obtained of any 

 dealer in agricultural implements. 



But, after all, the perfection of spraying methods, however 



