2 5 ° 
Journal of Agricultural Research 
Vol. XXVI, No. 6 
Table V .—Comparative cryoscopic readings in IQ22 —Continued 
De- 
De- 
pres- 
Date. 
Weather and remarks. 
Variety and portion of the plant. pres- 
sion in 
sion. 
atm os- 
pheres. 
Aug. 15 I Very hot and sultry but hazy; very 
I little tip burn. 
Sept. 1 Bright and fairly warm with the 
ground full of moisture; plants 
watered regularly. 
Plants grown in tiles under a cloth 
shelter. 
Green Mountain: 
Young leaves.i o. 663 
Old leaves. . 789 
Stems.789 
New tubers. . 485 
Dibble’s Russet: 
Young leaves.752 
Old leaves.700 
Stems. . 708 
New tubers.4S0 
Green Mountain: 
Young leaves. . 856 
Old leaves.i . 794 
Stems. .746 
New tubers. .530 
Young leaves.; .672 
Old leaves. . 796 
Stems.! .791 
New tubers.i .568 
9 - 50 
9 - 50 
5 * $4 
9. 06 
8- 43 
8- 53 
5 - 78 
10. 31 
9. 60 
8 . 99 
6-39 
8. 09 
9 - 59 
9 - 5 3 
6. 84 
SUMMER OF 1919 
The cryoscopic readings taken in the summer of 1919 were not as 
numerous as those made in 1918 and were all on one variety, Green 
Mountain. Unfortunately, no readings were made in early July, and 
by the time the first juices were frozen the plants were already coming 
into blossom. It will be noted that on July 13, and again on July 21, the 
juice content of the stem was higher than that of any other part of the 
plant. Moreover, on August 13, which was a hot dry day, giving the 
leaf juice a greater depression, the leaves were in a state of incipient wilt. 
The juices from various portions of the tuber tip, as compared with 
those of the butt, or those of the inside compared with those of the out¬ 
side, do not seem to vary much in their cryoscopic readings, as can be 
seen from the reading on August 13. 
The greater depression of the juice from the aerial portions of plants 
grown in shade, is to be noted on August 7, while mosaic plants gave 
greater depressions from the foliage portions on August 18 and on 
August 28. The mosaic stems, however, showed a reverse condition. 
One of the most interesting sets of observations is that made on pota¬ 
toes from Randolph, Vt. The field from which these plants were ob¬ 
tained is in one of the best potato regions in the northern United States, 
and the plants themselves were in splendid condition, without a trace 
of tip bum and still actively growing. It will be noticed that the juice 
from the young leaves has a markedly large depression, a fact that 
in the 1918 observations was associated with continued or renewed growth. 
