REPORT OF THE HORTICULTURIST. 12; 



SESSIONAL PAPER No. 16 



CONCLUSIONS REACHED UP TO NOVEMBER 1900. 



1. Lime slaked in water and sprayed on apple trees infested with the oyster-shell 

 bark-louse has the effect of loosening the scales. 



2. The scales, when loosened, are removed from the trees by rain, ice, wind, and 

 probably by other means. 



3. As the scales contain the eggs from which the young insects hatch about June 

 1, it is necessary, in order to get the best results, that the trees be sprayed as soon as 

 possible after the leaves fall in autumn, so that the loosened scales may be exposed 

 to the weather for a long time before the Gggs hatch. 



4. The lime appears to have no injurious effect on the eggs within the scales. 



5. Lime used in various proportions in the several experiments had no apparent 

 injurious effects on apple or peach trees. Even when the leaf buds were opening no 

 injury occurred. 



6. As the action of the lime seems to occur soon after the trees are sprayed, it 

 is not necessary to use any substance other than water to help bind it to the tree. On 

 the contrary, it would appear that such substances counterbalance the effects of the 

 lime, for a time, by glueing the scales to the trees. 



7. It is important to use good stone lime, whicl^ has not been air-slaked. 



8. As no experiments were conducted in the autumn of 1899, to determine what 

 proportion of lime was necessary to get satisfactory resixlts, and as it has been found 

 that spraying in late winter or early spring is not a very good time, it is not possible 

 yet to say what is the most economical formula to use. As nearly all the scales were 

 removed from some of the trees, which were sprayed with 1 pound lime to 1 gallon 

 water in March, 1900, it is quite likely that satisfactory results will be obtained by 

 using that mixture in the autumn. 



9. It is necessary to make at least two applications, as those scales with which the 

 mixture does not come in contact will not be effected by it, and it is not possible to 

 do the work thoroughly with one spraying. 



10. The lime mixture applied in winter evidently has no effect on the San Jose 

 or I^Tew York scales. 



11. The bark of trees sprayed with the lime mixture is much brighter afterwards 

 than on trees not sprayed, and it is possible that many fungus germs are destroyed. 



COVER CROPS. 



The importance of cultivating orchards has for ten years or more been impressed 

 upon fruit growers in America, on every possible occasion. It has been found, how- 

 ever, after several years' experience that the constant stirring of the soil lessens the 

 amount of humus in it to such an extent that in districts where droughts occur 

 frequently it becomes a burning question how to restore humu? cheaply to the soil ; 

 for as soil with plenty of humus holds moisture better than soil with little of it, the 

 amount of moisture conserved by cultivation is becoming less every year where humus 

 is not restored. Of late years there have been some severe winters, when fruit trees 

 were root-killed by the thousands, and thus another question arose as to how best to 

 protect the roots of the trees sufficiently to save them. Thus developed the value of 

 the so-called ' cover crop,' which, although it had been grown by many fruit growers 

 for years back, did not become a prominent feature in Canadian horticulture until the 

 last six or seven years. 



At the Central Experimental Farm the importance of cover crops has been fully 

 recognized, and experiments have been conducted with them since 1895, and in the 

 horticulturist's reports for 1896, 1897, 1898 and 1899, the experience which had been 

 obtained concerning the different plants used for this purpose, and other matters con- 

 cerning them, was published. 



