108 Report oF ‘THE BOTANICAL DEPARTMENT OF THE 
The potatoes were of two varieties mixed—Carman No. 3 and 
Sir Walter Raleigh. [Eleven acres were planted May 25 to 28 
and the remaining fifteen acres June 6 to 11. The soil was a 
gravelly loam. Five rows 1,032 feet long were left unsprayed. 
These rows were in the later-planted portion of the field and a 
public highway ran by them at the north end. They were kept 
free from bugs by three applications of arsenite of soda in lime 
water, on July 22, 30 and August 17. 
On August 17 the field was examined by one of the writers. 
The sprayed rows were in perfect foliage with no signs of blight, 
but on the unsprayed rows traces of late blight, Phytophthora 
infestans, were found. There was no evidence of injury from 
bugs on either the sprayed or unsprayed vines. The sprayed 
plants appeared somewhat larger than the unsprayed. 
During this visit we had the opportunity, through the kind- 
ness of Mr. Brainerd, of examining a large number of potato 
fields in the vicinity of Gainesville. Several of these fields had 
been sprayed and were in good condition; but in every un- 
sprayed field examined more or less blight was found. In the 
majority of cases no damage was done as yet, but in a few 
fields the disease was already well advanced and one field of 
five acres on low ground was entirely dead and the tubers 
rotting. 
On August 23 Brainerd & Beaumont reported that the five 
unsprayed rows were quite badly blighted toward the north end 
next the road. The sprayed plants in the same part of the field 
were perfect. However, the contrast was not yet sufficiently 
marked to be noticed by one passing along the road. All 
unsprayed fields were becoming badly blighted. 
On September 1 we personally examined the field a second 
time. Next the road the contrast in appearance between sprayed 
and unsprayed rows was now very marked. For a distance of 
about ten rods back from the road the unsprayed rows had lost 
from one-half to two-thirds of their foliage while the sprayed 
plants on both sides were nearly perfect with only an occasional 
leaf affected. Throughout the remainder of the unsprayed rows 
there was some blighted foliage all along but not enough to mate- 
rially affect the growth of the plants. The unsprayed rows had 
not been in the least injured by bugs. 
