2 GEORGE V. SESSIONAL PAPER No. 16 A. 1912 



PART I. 



PLANT DISEASES IN 1910. 



During the past year, a large number of diseases have been dealt with by this 

 Division. Owing, however, to the fact that our work in this direction is as yet not 

 sufficiently known, these cases, though over one hundred and fifty in number, are not 

 cited as giving a comprehensive review of the plant diseases of Canada, but merely to 

 serve as a record of the various outbreaks reported to, or observed by, us. The close 

 proximity of some of the United States Experiment Stations encouraged a number of 

 associations or private individuals to seek assistance in those quarters, and, partly for 

 this reason and, partly, owing to the indifference of some growers towards the first 

 outbreak of disease, our records are much less complete than they would otherwise be. 



The following are some of the diseases that have been investigated during the 

 year. 



DISEASES OF CEREAL CROPS. 



RUST. 



This is a constant enemy of the grain grower throughout the Dominion. No pro- 

 gress in our knowledge of the control of this disease can be recorded. The eradication 

 of the barberry or other alternate hosts of the parasite is generally advised, though 

 even in countries where the destruction of these plants is carried out under legis- 

 lative measures, the results have not been altogether encouraging. It has been found, 

 for instance, in Denmark, that the compulsory destruction of these carriers of the 

 fungus, extending over the last decade, haa brought no reduction in the severity of 

 rusts. The selection of rust-resistant varieties appears to be the only practicable 

 means of control, with our present knowledge. Such selection work should, however, 

 be carried on in the particular locality where the seed is to be used, since it ha3 been 

 found that the same variety may diminish appreciably in its resistance when trans- 

 ferred to another region. Probably the best method available to the farmer is the 

 selection for seed purposes of the plump, full-weight grain to be found in a crop which 

 has suffered from rust during a season when the disease has been severe. Such grain 

 is the produce of individual plants which have been rust-resistant to a marked degree, 

 and the plants grown from these seeds will most probably inherit this property. 



SMUT. 



Stinking smut of wheat, in spite of the ease of its control, continues to seriousl.v 

 reduce the yield in some quarters. The smuts of oats, and covered smut of barley are 

 likewise easy to control, yet a tax caused by these is voluntarily paid by the farmer 

 in the form of a diminished yield, of a value which would excite a very vigorous 

 protest if levied in the orthodox manner. 



Loose smut of wheat and barley are advancing slowly in the western provinces. 

 These latter kinds of smut are not affected by the seed treatments so successful with 

 the forms just mentioned, and ignorance on the part of farmers of this difference in 

 their nature has led some to question the value of seed treatment for any form of the 



