24 MASS. EXPERIMENT STATION BULLETIN 201. 



cells incites the production of protective cork cells, thus causing the rough 

 russet areas which disfigure the surface of fruits such as apples or grapes. 

 The extent of the injury varies with the hosts, being most severe on peaches 

 and plums, and less so on apples, grapes and potatoes, but varying even 

 here with the variety, weather conditions, stage of development and many 

 other factors. Xo host seems to be immune under all conditions. Ap- 

 parently, continued rainy weather increases injury. According to Hedrick 

 (33) it is not prevented by the use of excess lime. The apple growers of 

 Nova Scotia, however, use an excess lime Bordeaux, 3-10-50, which is 

 found to be effective against scab, while it greatly reduces the russeting 

 of fruit which results from use of the ordinary Bordeaux formula. 



(2) Commercial Bordeaux Preparations. 

 The home preparation of Bordeaux mixture has a number of disadvan- 

 tages: — 



1. It involves a number of distinct operations which require considerable time. 



2. The grower must keep in mind the proportions and various directions for 

 preparation, or always have available the printed directions for the same (con- 

 sidered a nuisance by the average growei). 



3. A number of suitable containers are required and are frequently not at hand 

 when needed. 



4. Few gi'owers keep on hand a supply of quicklime, and even at the store it 

 cannot always be obtained when wanted and of the quality wanted, especially in 

 small quantities. When a barrel of lime is opened, it quickly carbonates, and the 

 merchant in the small place is reluctant to break a barrel for a few pounds; while 

 for the same reason the small grower does not wish to try to keep it at home. 



5. The addition of a suitable insecticide in proper proportions increases the 

 above objections. 



The grower who uses large quantities of material may not hesitate to 

 go to all this trouble, but the grower who operates on a small scale demands 

 a fungicide which can be purchased readj'-mixed, insecticide included, and 

 which needs only to be diluted with water according to the directions on a 

 convenient-sized package to be ready to apply. As early as 1893 — 

 possibly earlier — Leggett & Brother of New York were putting on the 

 market a dry Bordeaux. The Bowker Insecticide Company of Boston 

 sold the concentrated paste "Bodo" at least as early as 1895. Since that 

 time a great number of ready-mixed copper fungicides, usually with the 

 insecticide included, have come into the market: e.g., Pyrox, Caascu, 

 Kiltone, Adheso, Bordo-Lead, Tuber Tonic, etc. 



Guaranties. — In compliance with the insecticide act of 1910, and the 

 various rules and regulations which have been promulgated in interpreta- 

 tion of it, every package of commercial copper fungicide (not materials 

 such as copper sulfate (bluestone), etc.) has on the label a statement of 

 (1) the percentage of metallic copper, and (2) the percentage of inert 

 ingredients which it contains. Thus one well-known commercial brand of 

 dry Bordeaux mixture, typical of most of them, is guaranteed as follows: — 



Active ingredient, metallic copper, not less than 11 per cent. 

 Inert ingredients, not more than 89 per cent. 



