HO EXPERIMENTAL FARMS 



1-2 EDWARD VII., A. 1902 

 CONCLUSIONS REACHED UP TO DECEMBER,, 1901. 



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

 to tbe weather for a long time before the eggs 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, which has not been air-slaked. 



8. The most economical and satisfactory formula so far has been found to be, 

 1 lb. lime, 1 gallon water, and 3£ oz. salt, or for a barrel of mixture, 40 lbs. lime, 40 

 gallons water, 8 lbs. salt. This should be sprayed on the tree twice, the second appli- 

 cation being made as soon as the first is dry. The same proportions of lime and 

 water without the salt have given quite satisfactory results also, and the salt is not 

 necessary, but when used the bark of the trees was cleaner and brighter. 



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

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



ASPARAGUS RUST. 



The asparagus rust, Puccinia asparagi, D.C., is a disease which has done much 

 injury to asparagus in the United States during the past five years, and more recently 

 it has effected that vegetable in Canada. This year it appeared at the Central Ex- 

 perimental Farm for the first time. The disease was introduced from Europe to the 

 United States and came into prominence about 1896. It has already spread from 

 the New England States to Kansas and north into Canada. The following descrip- 

 tion of the life history of the disease is quoted from bulletin No. 188 of the New 

 York Agricultural Experiment Station, where extensive experiments have been car- 

 ried on in combating it. 



' The life history of the fungus which causes the disease is marked by three dis- 

 tinct stages, each ending in the production of a crop of spores from which new plants 

 may spring. This profusion of spore-forms may account in a measure for the rapid 

 spread of the disease. 



The first stage of growth of the fungus usually passes unnoticed by the owners of 

 infested asparagus fields ; for from the germination of the spores in the spring till 

 the first fruiting in June, the entire plant is hidden deep in the tissues of its host ; 

 and this fruit-bearing is accompanied by no such change in colour of the asparagus 

 fields as marks the ripening of the second crop of spores. In this first stage, known as 

 the ' spring form,' ' cluster-cup stage,' or, scientifically classified, as the ' acidia] stage,' 

 the spores break through the epidermis of the host plant in clusters of cup-shaped 

 pustules. These cups are greenish-yellow at first but change to orange-yellow as they 

 mature. 



