284 TWENTY-FIFTH ANNIVERSARY REPORT. 
were also compared, and eyes scooped out of the potato, eyes cut 
from potato parings, and potato shoots were all used as seed. In 
no season but the first did the tests*® favor the use of small, single- 
eye pieces; but there was a chain of evidence extending through 
tests of seven years that the crop was likely to increase profitably 
as the size of the seed pieces increased. In some of these tests 
whole tubers were compared with cuttings. While the results are 
not conclusive in favor of the use of the uncut tubers, as against 
cuttings of equal size, those in about half the tests showed a de- 
cided loss from cutting the tubers. Other tests indicated clearly that 
it is advisable to allow the cutting to dry out for ten days or less be- 
fore planting. It seems probable that under certain conditions the 
exposure of the freshly cut surface to the earth works injury to the 
seed. 
As to the manner of cutting the seed, the tests show a slight 
superiority for the middle third of the tuber as seed, but not enough 
to justify rejecting the tip or butt thirds. No advantage was 
found in the use of the butt half or the tip half of the tuber, either 
as affecting yield or promoting early maturity. Seed cut diagonally 
from the tip end of the potato to include as much as possible of the 
“pith rays,” rather than cut toward the tip and across these rays, 
appeared to give slightly better results; but not enough to be of 
practical value. 
Time and manner of planting.— Only one test*® is recorded in 
which the influence of the time of planting is considered, but the 
results in this case were striking. With the variety White Star, 
seed planted April 23 yielded at the rate of 251 bushels to the acre, 
similar seed planted May 24 gave 191 bushels and seed planted June 
23, only 79 bushels. This plainly shows that the potato, unlike corn, 
does best in soils that are not very warm. This was also brought 
out in other tests along very different lines, as in mulching and 
cultivation experiments. The depth of planting was considered in 
a test®° made in 1882. The results are not very striking or conclu- 
sive, but appeared to indicate some advantage for three inches 
rather than six inches. It was evident that this factor would vary 
so much in effect with different soils that further tests were not 
made. Whatever the soil the seed piece must be placed deep enough 
“Rpts. 1:55-66 (1882); 2:117-122 (1883); 4:60-63 (1885); 5:149-152 
(1886) ; 6:86-90 (1887) ; 7:162-165 (1888); 8:225-238 (1889). 
“ Rpt. .2:122 (1883). 
© Rpt. 1:62 (1882). 
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