246 Report of the Department op Botany of the 



furrows and soil inequalities. Spraying was commenced when the 

 plants were six to eight inches high and repeated at intervals of two 

 weeks until frost, which occurred on September 14. At this time 

 the rows in the early-planted fields had received six sprayings and 

 those in the later-planted fields five sprayings. All spraying was 

 done very thoroughly by means of a knapsack sprayer. The first 

 two applications were made with bordeaux mixture containing four 

 pounds of copper sulphate (and sufficient lime to neutralize it, as 

 shown by the potassium ferrocyanide test) to each fifty gallons. 

 Paris green was added at the rate of one pound to fifty gallons. 

 Subsequent applications were made with bordeaux mixture, alone, 

 in which the quantity of copper sulphate was six pounds to fifty gal- 

 lons The supply of bordeaux for each day's work was carried in 

 a barrel fastened on the rear of a one-horse buggy which was driven 

 from field to field as needed. In 47 of the fields containing experi- 

 ments the owner used no bordeaux, but applied only such treatment 

 as he considered necessary for the control of bugs. In the remaining 

 19 fields more or less bordeaux was applied by the owner, the 

 number of applications in different cases varying from one to eight 

 (see Table II) and there were no unsprayed rows; that is to say, in 

 these fields the spraying done by the Station was in addition to that 

 done by the owner. If the owner sprayed three times and the 

 Station six times the plants on the Station row received a total of 

 nine sprayings. 



The season was a very dry one and there was no late blight 

 (Phytophthora infestans) in any of the fields, not even on unsprayed 

 plants. Neither was there early blight (Alternaria solani) of any 

 consequence, nor serious damage done by flea beetles. But in nearly 

 all fields there was more or less tip-burn which, in some cases, was 

 quite severe. " Bugs " were moderately plentiful. In a few fields they 

 were not fully controlled by the treatment employed by the owner. 



A killing frost occurred on the night of September 14. At this 

 time the plants in most of the fields were in nearly full foliage. As 

 51 of the fields had been planted after June 1, and many of 

 them between June 10 and 17, this untimely frost cut off from two 

 to four weeks of growth and thereby lowered the yield considerably. 



At digging time the row sprayed by the Station and an adjacent 

 row of equal length were dug by hand and the product sorted and 

 weighed. This work was all done by Mr. Keyes. The yields are 

 shown in Tables I and II. 



