VIEW ARTICLE

The Quantitative Relationship Between Late Blight of Potato and Loss in Tuber Yield. W. C. James, Plant Pathologist, Ottawa Research Station; C. S. Shih(2), W. A. Hodgson(3), and L. C. Callbeck(4). (2)Statistician, Statistical Research Service, Canada Department of Agriculture, Ottawa, Ontario; (3)Plant Pathologist, Research Station, Canada Department of Agriculture, Fredericton, New Brunswick; and (4)Plant Pathologist, Research Station, Canada Department of Agriculture, Charlottetown, Prince Edward Island. Phytopathology 62:92-96. Accepted for publication 4 August 1971. DOI: 10.1094/Phyto-62-92.

Data for 96 disease progress curves with corresponding tuber yields, from 11 experiments representing three locations and two cultivars in eastern Canada during the period 1953-1970, were used to develop a method for estimating the loss in tuber yield caused by late blight. A multiple regression equation was derived using the increase of disease during 9 weekly periods as the independent variables and yield loss as the dependent variable. The empirical equation can be used to estimate the yield loss associated with any given progress curve. The difference between estimated loss, computed from the equation, and actual loss, derived by weighing, was less than 5% in nine cases out of 10.