24 
Journal of Agricultural Research 
Vol. XXV, No. I 
not compensate the variations of carbohydrates. In these cultures the 
modifying effect of varying temperature has been relatively free from 
disturbance by variations of either solar radiation or atmospheric 
humidity. Under these conditions an increase in polysaccharids has 
attended a decline of temperature value. 
WATER CULTURES 
Water cultures of buckwheat were conducted for a time parallel to 
the progress of the cultures just described. Seeds from the source 
previously used were suspended upon Shive’s best solution for early 
growth of this plant, diluted to one-tenth # the usual concentration. A 
group of seedlings were started in this manner in each chamber on 
March 15. Three seedlings were set up in each of four culture jars at 
the higher temperature on March 22, still employing one-tenth the 
usual concentration of Shive’s solution. Two days later the seedlings 
were large enough at the lower temperature to be similarly transferred. 
At this time all of the nutrient solutions were made up to the usual 
concentration. On April 7, the third leaf was appearing in plants at 
the higher temperature, while the second leaf was just appearing in the 
other case. The leaves were greener and bases of the stems redder in 
the former case. Buds appeared on April 15 at the lower temperature 
and two days later at the higher one. On April 21, the solutions were 
changed to Shive’s best proportions of salts for the last period of growth 
(35). The plants were harvested on April 26. At this time curling of 
the leaves and other indications of abnormal growth were becoming 
conspicuous, especially at the lower temperature. Only seven plants 
appeared reasonably normal in the latter case, and hence the seven 
best plants were selected from each series. The data of yield and com¬ 
position appear in Table VI. 
With the exception of the length of the tops, the physical measure¬ 
ments show little difference in the effect of the two temperature ranges 
upon the development of the plants. The slight difference in poly- 
saccharid content varies in the same direction as with the soil cultures— 
that is, it was greatest at the lower temperature. 
BUCKWHEAT IN SAND CULTURES WITHIN CLIMATIC CHAMBERS 
Buckwheat was grown in sand cultures in the climatic chambers in 
1921. This was for the purpose of avoiding possible modifying effects 
of temperature upon the fertility of soil, through action upon the soil 
organisms and in other ways. With the exception of using sand in 
place of soil and planting about two weeks later in the year, the experi¬ 
ment was conducted in essentially the same manner as the preceding one. 
TabeE VI .—Growth measurements and composition of buckwheat water cultures of 
climatic chambers in IQ20 
Designation of temperature range. 
Maximum 
length of 
tops. 
Maximum 
length of 
roots. 
Weight 
of dry 
matter. 1 
Composition of dry 
matter. 
Ether 
extract. 
Polysac¬ 
charids. 2 
High. 
Cm. 
48.8 
41. 8 
Cm. 
19. 6 
18. s 
Gm. 
O. 72 
.82 
1 
Per cent. 
4-4 
4.6 
1 
Per cent. 
24. 7 
25-4 
Low. 
1 Total weights, including discarded plants, 1.13 gm. at high temperature and 1.19 gm. at low temperature. 
2 By boiling with 4 per cent HC 1 3 hours alter extraction of sugars and dextrins. 
