1913.] PUBLIC DOCUMENT — No. 31. 213 



treatment of the two Howe plots was that Plot A was sprayed 

 three times during 1911, while Plot C, as well as the other 

 plots, was sprayed only twice. 



Where two checks were laid out for the same plot (as noted 

 in the above table) they were in every case located on opposite 

 sides of the sprayed area. The berries were all picked with 

 scoops. It should be borne in mind that the increases recorded 

 above were obtained in spite of considerable mechanical injury 

 done in the process of spraying. The spraying was done with 

 a 30-gallon wheeled-barrel outfit, and the injury was much 

 greater than it would have been had a power outfit been used, 

 it being serious enough to be plainly noticeable on the vines, on 

 parts of the plots, at picking time. 



It should be noted here that the fungus plots showed no in- 

 crease in quantity of fruit over their checks last year, and this 

 may perhaps be taken to indicate that the effects of annual 

 spraying are cumulative. 



The increase in quantity of fruit on the McFarlin plot was 

 accompanied by a much more light-colored and sickly appear- 

 ance to the foliage than was shown l)y the vines of the check 

 plot. The contrast between the sprayed and unsprayed vines in 

 this respect was noticeable by the 1st of September, and very 

 marked after the crop was picked, being plainly evident to the 

 eye from a long distance. A redder and more sickly color was 

 also distinctly evident on the two Early Black plots as compared 

 with the surrounding unsprayed vines, but the contrast was not 

 nearly so great as with the McFarlin plot. No such difference 

 was apparent on the Howe vines, possibly because it was hidden 

 by the naturally very dark color of their foliage. The McFarlin 

 and Early Black vines seemed to show that there was not suffi- 

 cient available plant food present to maintain a strong vine 

 condition and at the same time develop the extra amount of 

 fruit which the reduction of fungous diseases by the spraying 

 had made possible. Possibly the effects of fungus spraying are 

 often limited by such a lack, and combination experiments with 

 fungus spraying and fertilizers have been planned to determine 

 this point. 



When the fruit was gathered no distinct difference in color 

 between the berries from the sprayed plots and their checks 



