Notes and Brief Articles 



343 



associated poor growth of roots, stems and leaves, failure to form 

 normal terminal buds, and susceptibility to winter injury. 



Chlorosis in western yellow pine at the Pocatello Nursery has 

 been definitely corrected by spraying with ferrous sulphate at 10- 

 day intervals. Similar, though less decisive, results were obtained 

 with Douglas fir. A one per cent, solution in amounts sufficient 

 to wet the tops thoroughly proved the most satisfactory treatment. 

 A two per cent, solution ultimately caused chemical injury to prac- 

 tically all the plants. In a region of more frequent rains the 

 stronger solution might be better. 



The control of chlorosis in jack pine and western yellow pine at 

 the Morton Nursery in Nebraska by spraying with a one per cent, 

 solution of ferrous sulphate has given such evidence of success 

 that it has been adopted as a part of the regular nursery practice. 



" The Relation of Plant Pathology to Human Welfare " was 

 presented by F. L. Stevens as an invitation paper at the Chicago 

 meeting last winter and published in the American Journal of 

 Botany for June, 192 1. The author deals in a very interesting 

 and convincing way with some of the achievements of plant 

 pathology, as well as with some of the problems still to be solved. 

 The following extracts may awaken interest and lead to a careful 

 perusal of the entire paper : 



The magnitude of the annual loss incurred in the United States 

 alone through plant disease in diminution of yield and loss of 

 produce is far greater than it is generally conceived to be. In 

 1919 the total loss with fifteen principal food products is estimated 

 at nearly a billion and a half dollars. Among the late continental 

 arrivals is the pine blister rust, which is under such headway that 

 it seems to be impossible of extermination. The value of the 

 susceptible pines is such that the loss may readily reach a hundred 

 million dollars. The chestnut-bark disease caused a loss of $25,- 

 000,000 from 1904 to 191 1. Much more serious is the loss to be 

 borne as it invades the great chestnut forests of the Appalachians 

 Citrus canker, imported from Japan about 1910-11, bids fair to 

 ruin large industries. As increased long-distance communication 

 gives intercontinental transport to disease, so congestion of crop 



