Oct. 2 3> 1916 Daily Transpiration during Normal Growth Period 
193 
it is recorded for all crops and is to be attributed largely to the errors in 
measuring transpiration during a period of rainy weather. 
The transpiration coefficient of Swedish Select oat, which began to 
head on June 28, did not reach its maximum until July 13, after which it 
declined rather rapidly to about 25 per cent of the maximum at harvest 
time. Burt oat began to head much earlier, but showed the same 
gradual increase to the maximum. The value at harvest time was very 
high, amounting to 50 per cent of the maximum. Hannchen barley and 
Burt oat showed very little difference in the march of the' transpiration 
coefficient. 
Rye was beginning to head when the measurements were started. The 
transpiration coefficient was unusually uniform throughout the season. 
At harvest it was 65 per cent of the maximum and did not differ mate¬ 
rially from that at the period of heading. 
The graph for cowpea is almost symmetrical, beginning and ending at 
about 20 per cent of the maximum, which occurred just after the flower¬ 
ing period. 
Lupine blossomed earlier than cowpea and showed no marked maxi¬ 
mum period, the rate remaining about the same from the 10th of July to 
the 1st of August. 
Kursk and Siberian millet showed no significant differences. The 
graphs include practically the whole growth period. The increase was 
rapid and uniform and the maximum was reached at the period of head¬ 
ing. The transpiration coefficient was about 40 per cent of the maximum 
at the time of harvest. 
The two varieties of Amber sorghum showed no marked differences. 
Dakota Amber headed a little earlier than Minnesota Amber. The maxi¬ 
mum transpiration coefficient of both crops occurred about 10 days after 
the plants began to head. The decline was gradual, the value at harvest 
being over 40 per cent of the maximum, notwithstanding the fact that 
the seeds were ripe at that time. 
Sudan grass was grown in the screened inclosure and also in the open. 
The transpiration coefficient of the plants in the inclosure increased some¬ 
what more rapidly at first than in the open, although the maximum was 
reached at the same time. The second crop was much smaller than the 
first and the transpiration coefficient reached only about one-fourth the 
value attained during the first crop. 
Algeria com reached its maximum much later than Northwestern Dent 
and showed no marked decrease in its transpiration coefficient, the value 
at harvest being 40 per cent of the maximum. Algeria corn did not 
ripen at Akron, which accounts for the high transpiration coefficient 
when the crop was harvested. 
The graph for Amaranthus shows no marked change in the transpira¬ 
tion coefficient during the first crop. In other words, the young large- 
