GEAPE-SPBAYING EXPERIMENTS IN MICHIGAN IN 1909. 



11 



system of plats caused by the blowing or carrying over of a fungicide 

 from one plat to another is negligible. However, the counts to get 

 the percentage of rot on each plat were made on the inner rows, while 

 in irettino; the average number of berries on a bunch counts were 

 made on all the rows. 



The percentage of rot on the difl'erent plats was as follows: 



Table IV. — Results of spraying experiments on thirteen plats in Mr. Tattle's 



vineyard, near Paw I'aio, Mieli., 1900. 



Fungicide used. 



4-4-50 Bordeaux mi.xluie 



4-3-f)0 Bordeau.x mixture 



4-3-50 Bordeaux mixture, with 2 pounds of iron 



sulphate 



1-3-50 Bordeaux mixture, with 2 pounds of resin- 



fishoil soap for 5 applications 



4-2-50 Bordeaux mixture 



Check, unsprayed, outer row 91.2 per cent 



Check, unsprayed, middle row 90.2 per cent 



3-2-50 Bordeaux mixt ure 



Ammoniacal copper carbonate 



Neutral copper acetate 



Self-boiled lime-sulphur 



Commercial lime-sulphur 



4-3-50 Bordeaux mixture 



4-3-.50 Bordeaux mixture 



4-3-.50 Bordeaux mixture, with 2 pounds of soap in 



fifth application 



Amount 

 of rot. 



Per rent. 

 35. 

 40.0 



40.7 



35.0 

 37.2 



90.7 

 38.4 

 72.4 

 40.1 

 54.3 

 45.2 

 8.0 

 10.9 



4.3 



Yield in baskets. 



8 pounds. 20 pounds. 



105 

 iOl 



97 



85 

 90 



None. 

 108 



None. 



None. 



None. 



20 



205 



210 



210 



18 

 27 



25 



21 

 16 



None. 

 21 

 24 

 49 

 33 

 13 

 8 

 •5 



Neutral copper acetate was used in the sixth spraying on plats 

 10 and 11 and in the seventh application on all plats sprayed at that 

 time except No. 8. 



Many of the buds were destroyed by climbing cutworms in the early 

 spring before they opened. This, together with the poor condition of 

 the vineyard, is probably the reason for the light crop. In this vine- 

 yard, as in that of Mr. Giddings, the various Bordeaux mixtures 

 proved to be the most efficient, and there was no injury to the vines 

 and not so much damage from rot in most cases as with the other 

 fungicides. In the first six plats sprayed with Bordeaux mixtures 

 there was very little difference in the amount of rot. The addition 

 of iron sulphate as a '' sticker " did not seem to improve the mixture, 

 as the percentage of rot on this plat was the highest of any sprayed 

 with Bordeaux mixture, while in the case of plat 4, where resin-fishoil 

 soap w^as used as an adhesive, the grapes were in slightly better con- 

 dition. However, the iron sulphate has been used only one season 

 and should be more thoroughly tested before it is abandoned. The 

 3-2-50 Bordeaux mixture compares very favorably with the others, as 

 it did on Mr. Giddings's vineyard. 



In plats 12 to 14, sprayed with Bordeaux mixture, there was not 

 much damage from rot. These were on the opposite side of the 



[Cir. 0.')] 



