144 Report of the Botanist of the 



formula and the water used in its preparation was obtained from a 

 well about 20 rods distant. 



Traces of blig"ht appeared in all parts of the field about September 

 2. Thereafter it made steady progress among both the sprayed 

 and unsprayed plants, being most destructive to the latter. After 

 about September 15 the unsprayed row was noticeably inferior to 

 the rest of the field and could be readily located even at a considerable 

 distance, but the contrast was never as striking as in either of the 

 Salisbury experiments. This may have been because there was but 

 a single unsprayed row, and the plants on the sprayed rows being 

 large somewhat obscured it. Although the spraying did not by any 

 means wholly prevent the blight it held it in check to such an extent 

 that the life of the plants was prolonged far beyond that of plants 

 in unsprayed fields. Over the central portion of the field the plants 

 still had one-third to one-half their foliage on October 3. 



The increase in yield was determined in the same manner as in 

 the Salisbury Experiment No. i ; that is, the yield of the unsprayed 

 row was compared with one-half the combined yield of two sprayed 

 rows, the second row on either side of the luisprayed row. This 

 will be better understood by an examination of the accompanying 

 diagram. 



DIAGRAM SHOWING METHOD OF DETERMINING THE INCREASE IN 

 YIELD IN WELCH EXPERIMENT. 

 Row I Yield 1028 lbs. Culls 86 lbs. ^ 



Sprayed. 



Unsprayed. 



Sprayed. 



