76 
THE GEAPE ROOT-WORM. 
of these operations was recognized at the outset of the experiment and 
arrangements were made to give the vines thorough cultivation and 
liberal fertilizing in addition to thorough spraying with a poison and 
a fungicide; in fact, to treat the vineyard according to the most 
approved methods of vineyard management. 
That spring when the vineyard was pruned many of the badly 
weakened vines were cut back to the ground and others to the lower 
wire of the trellis. Even on the most vigorous vines, not more than 
one to three fruit-bearing canes were left, it being thought desirable 
to concentrate the remaining energies of the weakened vines and 
force the vegetative growth rather than attempt to produce fruit of 
an inferior quality such as was borne by the vines during the season 
of 1906. In order that some light might be thrown on the effect of 
different kinds and amounts of fertilizer used in restoring these 
injured vines it was decided to divide the vineyard into seven plats 
of one acre each and the following kinds and amounts of fertilizer 
were applied : 
Plat I. Barnyard manure, 7 wagon loads. 
Plat II. Complete high grade commercial fertilizer, 1,000 pounds. 
Plat III. Complete high grade commercial fertilizer, 1,000 pounds plus 100 pounds 
sodium nitrate. 
Plat IV. Sodium nitrate, 400 pounds. 
Plat V. High grade commercial fertilizer, 1,000 pounds. 
Plat VI. High grade commercial fertilizer, 500 pounds. 
Plat VII. No fertilizer; no spraying. 
The brand of fertilizer used in 1907-8 analyzed available phos- 
phoric acid, 11.28 per cent; potash, 5.89 per cent; nitrogen, 3.41 
per cent. In 1909 a brand of fertilizer was used analyzing phos- 
phoric acid, 8 per cent; potash, 8 per cent; nitrogen, 5 per cent. 
The plats commenced on the west side of the vineyard and ran east- 
ward. Plats I, V, VI, and VII included seven rows measuring 
approximately one acre in area. Plats II, III, and IV contained 14 
rows each, but all the data here given are reduced to a 7-row or 1-acre 
basis for convenience in comparison. The ground on which this 
vineyard is planted is quite level and is of a stony loam on the west 
side grading to an almost stoneless clay on the east side where it 
has been somewhat enriched by wash from a slight elevation lying 
immediately south, which doubtless is responsible for the greater 
productivity of plats 5, 6, and 7, at the beginning of the experiment. 
The barnyard manure was spread broadcast over the rows of Plat 
I during the month of April. The commercial fertilizer was dis- 
tributed on the other plats in two equal applications, the first being 
made May 21, when active growth of the vines commenced. The 
second application was made June 18, about one month later. 
All of the fertilizer was applied with a broadcast fertilizer dis- 
tributor and immediately followed by a spring-tooth cultivator. 
