56 



DECAY IN HARVESTED APPLES AND ITS CONTROL 



P. I. Bryce, Macdonald College 



The question has suggested itself, " Why should we be interested in the fun- 

 gous diseases or rots of harvested apples ? " 



Much attention and a great outlay of money are being devoted to the sup- 

 pression of diseases of the apple during the growing season. The primary control 

 of disease in the field must ever be the chief interest of the orchardist ; but I shall 

 try to shoAv that something may be done after the apple is ripened and picked to 

 prevent its decay and extend its season. A lack of adequate and suitable supplies 

 in the vdnter months is sufficient excuse for the proposition I suggest. This shortage 

 is due largely to inability to preserve an abundant crop, much of which is sacrificed 

 at low prices in the fall, and a large percentage lost by preventable decay during 

 packing and shipping, or in storage. Should we be paying twenty-five cents a 

 dozen for apples for which the grower received last autumn one dollar per barrel? 



The apples we are buying in this, the late winter season, are of the main 

 Canadian crop, comprising only early and late winter varieties. These also supply 

 the major part of the growing trade with the Western Provinces, and the exports 

 to Great Britain, amounting, in 1910, to 1,523,901 barrels, valued at $4,184,873. 



In these notes are discussed some fungous diseases affecting stored apples, 

 and the means of preventing their occurrence and development. Most of the paper 

 is based on G. T. Powell's bulletin 78, U. S. Bureau of Plant Industry, ''The 

 Apple in Cold Storage," while publications of the Department of Agriculture, 

 Ottawa, were consulted. Full descriptions of the fungous diseases are given in 

 Duggar. 



A few of the many troubles are : The Apple Scab, Venturia pomi (Fr.) Wint ; 

 the Pink Mould, which grows on scab, Cephalothecium roseum Cda ; Brown or 

 Bitter Rot, Glomerella rufomaculans (Berk.) Spaulding and von Schrenk ; Black 

 Rot, Sphaeropsis malorum Pk.; and Soft Rot, or common blue mould, PeniciUium 

 glaucum. All these diseases occur in Quebec Province, but to what extent is not 

 yet known. 



Apple Scab occurs widely in hot, moist summers, and is probably the most 

 widely known fungous pest. Not only destructive by making fruit worthless or of 

 poor quahty, it is followed by other moulds and decays. Growth of scab itself on 

 the fruit may continue after picking, if apples are not kept at low temperatures. 



