252 REPORT OF THE F'ARM SUPERINTENDENT OF THE 
yield between these two forms from the B plats than could have 
been hoped from duplicates. Indeed; the plats to which different 
amounts of each of the nitrogen salts were applied have produced 
remarkably even yields of tubers. This indicates either that the 
smallest amount applied was sufficient for the crop, or that neither 
was potential in producing the increase over the yield of the plat — 
which received no nitrogen. From the F plats there were variable 
results. One only on which nitrogen was applied as ammonium — 
sulphate, at the rate of 400 pounds per acre, produced more crop ~ 
than that to which no nitrogen was given, while one gave practi- 
cally the same, and two less. On the whole there was a gain on 
the ammonium sulphate plats, which may be regarded as due to 
the application on plat 9. 
Another point of interest in this BOUTIN is the influence of 
potash on potato rot. 
The action of potash in preserving the tops from rot on a soil — 
rather poor in potash, has been noted the past season at the 
Kentucky Experiment Station.* We have here to show on a soil 
which may be called rich in potash, an apparently opposite effect 
on the tubers, though this may not be caused by the salts, but by 
moisture without relation to, or in spite of the presence of potash. 
The five F plats, 3 to 7, were dressed with phosphoric acid, in 
bone, black and ammonium sulphate, as given in the table above, 
and four with potash salts, as shown below. The plats F, 8 to 12, 
all received potash as sulphate, as given in the table above. 
Weight of decayed tubers of merchantable size on F plats with: 


—_—— 
| | : 
| Potassium | No Potassium), Sodium | No Ammonium »° 

















| chloride. | potash. | sulphate. | nitrate. | nitrogen. | sulphate. 
bss 2?) Lbs. 4 Lbs. 
PIGS ciles a3 sons | F3 12.69) F5- 2.03 | F4 15.71 F 8 20.46) F 10 32.66) F 9 18.02 
Pinte. seis. eh Ni GP 87-00 ar cece FT 45.71 | Fit 36.21 | os... seve F12 ~ 56.01. 
Average.... 20.3 | 2.03 | 30.7 | 28.34 | 32.66 34.7 



On F plats entirely without fertilizer, planted with same variety — 
of potato, but different form and amount of seed, F 13 yielded 
70.41 pounds decayed tubers, and on plat F 14, lying in the course 
of surface drainage water, the decayed tubers were so far con- 
sumed that no weights of them were taken. 


*Director M. A. Scovell, in proceedings S. P. A. 8., Toronto meeting, 1889, % <! 
