New YorkK AGRICULTURAL EXPERIMENT STATION.. 287 
pounds of fertilizer to the acre gave a net gain of $27.58; but 
the use of 2,000 gave a gain of only $20.46, or a loss, as compared 
with the use of 1,000 pounds, of $7.12. 
Similar tests°® were carried out in four localities on Long Island 
during the years 1897 to 1900 with results which strengthen the 
conclusion that it is bad practice to use, on the ordinary Long 
Island soils, more than 1,000 pounds to the acre of any good com- 
plete fertilizer. In these tests two different brands were compared 
and the quantities of each used varied by quarter-tons from one- 
quarter to a full ton. The results were quite consistent year by 
year, farm by farm and plat by plat; and the averages show un- 
disputably that the use of more than 1,000 pounds to the acre 
decreases rather than increases the net profit from the crop. The 
formulas tested were two: One in common use on the island, con- 
taining 4 per ct. nitrogen, 8 per ct. phosphoric acid and Io per ct. 
potash; and another based more nearly on the chemical com- 
position of the potato crop. This “ potato” formula contains more 
nitrogen, less phosphoric acid and the same amount of potash. 
Notwithstanding its apparently more rational composition, the 
“potato”? formula gave poorer results on each farm, each year, 
and, with but one exception in one year, with each quantity used. 
Cultivation. Few tests of cultural methods with the potato have 
been made, and these’ give no definite results except in disproving 
some “ freak” beliefs. Pinching off the terminal shoots of the 
potato tops proved detrimental to the crop as did mowing off the 
tops or rolling them down in July. Burying the plants when four 
weeks old by a furrow turned upon the row, and intensifying this 
treatment by plowing up a second furrow ten days later, were both 
harmful. 
Varieties —Variety tests have, of course, been carried on in 
one form or another, and during several seasons in both garden 
and field, but the varieties of potatoes prove acceptable in only 
restricted localities, vary so much on different soils, and deteriorate 
so fast, that tests of them are even less valuable than those with 
grains and fruits. Merely as a reminder of some that may have 
* Buls. 137, 154 and 187; same, Rpts. 16:596-616 (1807); 17:417-429 
(1898) and 19:213-230 (1900). 
Rpts. 4:238, 239 (1885); 5:55 (1886) ; 9:386-388 (1800). 
Rpts. 1:62 (1882); 2:211-218 (1883); 3:203-305 (1884); 4:230-232 
(1885) ; 5:140-147 (1886); 6:76-81 (1887); 7:158-162 (1888); 8:321-325 
(1889). 
