GENERAL CHAKACTEKS OF THE Sl'KAYS TESTED. 1G5 



Milk of lime appears to ])C practically harmless when applied to 

 dormant trees or to trees in leaf; hence any injurious action resulting 

 from the use of sprays containint;- lime should he charged to the other 

 ingredients or to the lime as altered or moditied through combination 

 with such other constituents. 



ADVANTAGES OP DISCERNIBLE AND INDISCERNIBLE SPRAYS. 



Reference has been made in a brief way to the advantages possessed 

 by certain sprays in forming a visible deposit upon the surfaces 

 sprayed. While sprays forming such a visible deposit are decidedly 

 advantageous for all winter work, those leaving no such distinct deposit 

 are most desirable for the treatment of fruit, especially when approach- 

 ing nraturity. The advantages of white sprats in the winter treat- 

 ment of deciduous trees are obvious, it being possible with such sprays 

 to clearly see what portions of the plant have been thoroughly and 

 properly covered. This advantage may even make the difference 

 between success and failure in the work. 



Some recent experiments in applying whitewash or sprays contain- 

 ing large amounts of lime have tended to show that th(> opening of the 

 buds may be somewhat retarded by such winter treatment. The theory 

 is that whitening the trees prevents, to some extent, their absorption 

 of heat from the sun's rays, and tliat this aids in keeping the trees in 

 a dormant condition somewhat later than would otherwise be the case. 

 Whether this will prove of enough importance to warrant the outlay 

 for spraying remains to be shown. An illustrated article on this sub- 

 ject appeared in the Canadian Horticulturist for January, 1890.^ 



All spra3''s, both copper and sulphur, which contain lime are adapted 

 to the purposes here considered. The Bordeaux mLxtures and sulphur 

 spra3^s used in the work described are distinctly observable upon the 

 trees when applied, and after drying for a ver}^ short time the treated 

 trees become decidedly white. The greater the amount of lime the 

 whiter the trees. (PI. XXIII.) 



In the summer treatment of trees and plants having fruit approach- 

 ing maturity, the use of clear sprays is often most to be recommended. 

 The spray now best adapted for this purpose is the ammoniacal 

 copper carbonate. A stronger spray, though making less showing 

 than Bordeaux mixture, is the modilied eau celeste. As this is apt 

 to cause injury in some cases, it is desirable to use Bordeaux mixture 

 for summer work up to a date when the fruit is approaching maturity, 

 and then to adopt the ammoniacal copper carbonate. The time at 

 which the summer use of Bordeaux mixture should be discarded for the 

 ammoniacal copper carbonate will depend largely upon the amount 

 of summer rams in the locality where used. In New York State, for 

 instance, where summer showers are frequent, the lime-containing 



^Orr, W. M., 1. c, pp. 18-20. See further remarks on this subject on p. 150. 



