EXPERIMENTS WITH FUNGICIDES ON POTATOES. 55 



Sept. 4. Field as a whole doing finely and ripening. Rows 

 1 to 16. Blight making no progress. Rows 17 to 32, 33 to 48, 

 49 to 64. Blight making some progress, but probably not enough 

 to seriously interfere with growth and ripening. Rows 65 to 80. 

 Practically no blight. An occasional leaf on an occasional 

 plant shows a small spot. Rows 81 to 96. Blight has made 

 little advance since Aug. 23. Some dead leaves. Rows 97 to 

 224. Blight has made little, if any progress, since August 14. 

 Unsprayed rows at north end of field. Some plants only a little 

 affected with blight. Most of the plants are three-fourths dead 

 with blight. Unsprayed rows at south of field. Except on the 

 north side of the row next to 224 there is not a green leaf. The 

 stalks are for the most part still standing and are green. 



Sept. 7. Plants badly checked and nearly killed by severe 

 frost. The top leaves are all blackened. 



Sept. 29. Because of inequalities in the field it was not prac- 

 ticable to select even twentieth acre pieces in each plot that 

 would be fairly comparable in yield with the different fungi- 

 cides. At harvest there was very little rot found on any of the 

 sprayed plots. There were rather more rotten potatoes on the 

 Boxal and-Blanchard's Bordeaux plots than on the others. But 

 even these had so few rotten potatoes that they could be fairly 

 said to have "practically no rot." The Adler's Bordeaux which 

 differed from the regular Bordeaux only in not being freshly 

 prepared, gave only 5 decayed potatoes in a row 30 rods long 

 which was as well as in the case of the freshly prepared Bor- 

 deaux mixture. 



YIEED FROM UNSPRAYED AND SPRAYED ROWS COMPARED. 



The vines at the south end of the field were not as rank nor 

 the yield as great as at the north end of the field. On rows 1 to 

 16 and 209 to 224 and on the unsprayed rows which joined these 

 plots, twentieth acre strips (apparently similar except that one 

 had been sprayed and the other was not) were measured and the 

 crop harvested, Sept. 29. The yield was as follows : 



