152 



MAINE AGRICULTURAL EXPERIMENT STATION. 



between the starch content of potatoes whose vines were sprayed 

 with Bordeaux mixture and those unsprayed. Theoretically, 

 anything- which prolongs the growing season ought to increase 

 the amount of starch which will be stored up in the potato; 

 hence, if vines sprayed with Bordeaux mixture live longer than 

 those not treated, not only should the yield of potatoes be larger, 

 but the percentage of starch should be higher. 



PERCENTAGES OF STARCH IS' SPRAYED AND UNSPRAYED POTATOES. 





Sprayed. 



Unsprated. 



Variety of potatoes. 



s 



CO 



5 



03 



z 



o 



M 



s 





f303S 

 3039 



<3045 

 3046 



13050 



% 



19.96 

 20.38 

 19.31 

 18.81 

 18.14 

 19.32 

 19.20 

 18.63 

 18.92 

 18.03 

 19.06 





% 









White Elephant 



3044 

 3047 

 3051 



3041 

 3053 



3055 



15.96 





18.12 

 18.62 

 17.52 





i 3040 

 ( 3052 



18.63 





16.26 

 17.45 



Carmen No. 1 



3054 



17.07 



17.43 









In the case of the Hebron potatoes, the unsprayed had a 

 larger starch content than the sprayed. From the description of 

 the samples, it will be noted that the field from which the 

 sprayed potatoes were taken had been planted to this crop for 

 three years, while the unsprayed was on sod, and that the grow- 

 ing time of the plants was not prolonged by the spraying. In 

 the other instances, spraying seemed to increase the percentage 

 of starch in the tubers. The four samples of White Elephant 

 potatoes which had been sprayed, contained 19.3 per cent of 

 starch, while the three samples of the same variety unsprayed 

 had on the average only 17.5 per cent. The two samples of 

 sprayed Delawares had 18.9 per cent and the unsprayed 17.4 

 per cent of starch, and the one sample of sprayed Carmen had 

 18.0 per cent against 17.1 per cent for the unsprayed. So far 



