70 REPORT OF THE BOTANICAL DEPARTMENT OF THE 
turn brown around the margin. Its nature was not definitely 
determined, but we incline to the opinion that it was due chiefly 
to excessive heat and dry weather. The early blight fungus, 
Alternaria solant, was responsible for only a small part of the 
trouble. Whatever the cause, the sprayed rows suffered less 
than the unsprayed ones. 
At Riverhead.—In the experiment at Riverhead the principal 
enemies were late blight“ and flea beetles, there being a moderate 
attack of both. Early blight was not sufficiently abundant at 
any time to cause material injury. 
On July 20 the sprayed series (I and II) presented a some- 
what better appearance than the unsprayed series (III), but there 
was not a marked contrast. The greatest difference probably 
occurred about August 1 when the condition of the sprayed 
series was decidedly superior to that of the unsprayed. 
AS SHOWN BY THE YIELD, 
At Geneva.— The potatoes were dug by hand October 8. The 
product of each row was earefully sorted into two grades — 
marketable tubers and culls—and weighed. According to our 
usual method all sound tubers larger than a hen’s egg were 
graded as marketable. 
TABLE [X.—YIELDS IN THE EXPERIMENT AT GENEVA IN 1906. 






| YIELD PER ROW.! YIELD PER ACRE, 
Section. | Row. | TREATMENT. ae 
| Market- | Culls. | Marketable. Culls. 
ee en ee feo eee ee, eS) Se ee ee eS 
| lbs. lbs. Bu. lbs. | Bu. lbs. 
Ae In| oOprayed lo) times seen | 275 23 | 229 10 | 19 10 
2.) Sprayed) times. e .) 4. | 304 174253 20 | 14 10 
| S eUris prayed ase nitions | 224 29 | 186 40 | 24 10 
1.4, Ae Ra. | 4 | Sprayed 3 times....... | 2554 22 | 212 55 | 18 20 
Hil\Sprayed Srtimes a: . | 281 16 | 234 lO vids 20 
6 | Unsprayed.. ot Sau 2374 184} 197 55: FEBS 25 
Cay 7 | Sprayed 3 timess cc. | 2774 lege ey! 15 | 14 10 
| S |) Sprayed oitimesi say... 324 134| 270 — / 11 Ley 
Ot Unsprayed guy setae | 244 17 | 203 20a T+ 10 
Dae sats 10 | Sprayed 3 times....... | 292 124| 243 20>} 10 25 
11 | Sprayed 5 times....... | 326 UT Med 40 | 14 10 
12 | Unsprayed.. ber ae 2384 15 | 198 45°} 2 30 
Beis ot | 13 | Sprayed 3 times...... ‘| 2644 194} 220 25 | 16 15 
14 | Sprayed 5 times....... / 317 19 | 264 10 | 15 50 
1 6ci UnsOrayed sadpea mie | 230 19 | 191 40 | 15 50 | 


1 Rows 290.4 feet long by three feet wide making the area of each row exactly one-fiftieth 
acre. Concerning the loss from rot see page 77. 
Comments on the table— (1) In every section the five-sprayed 
row outyielded the three-sprayed row. 

