22, BULLETIN 353, U. S. DEPARTMENT OF AGRICULTURE. 
lower than the field weights, even when the sorghum had been curing 
through seven weeks of good drying weather after harvest. The dif- 
ferences in field-cured and computed air-dry weights for different 
varieties and different dates of planting varied from minus 3.7 per 
cent to plus 31.3 per cent. It would seem, therefore, that maturity 
at harvest, size of shock, and succulence of the variety are factors 
affecting the moisture content of field-cured sorghum almost as much 
as different lengths of drying periods. At Amarillo, Tex., the differ- 
ence in the percentage of moisture in field-cured material of Red 
Amber sorghum and air-dry samples of the same varied from 12 to 
33 per cent, while the total moisture in the samples varied from 35.8 
to 55.7 per cent, as determined by oven drying. Such differences are 
enough in many instances to change the conclusions of the value of 
different methods of treatment or different dates of planting. 
Sudan grass.—At Hays, Kans., after Sudan grass had been cured 
three days, the field weights were 25 to 40 per cent greater than the 
computed air-dry weights based on samples, and there was 21 to 40 
per cent difference after a similar period of curing at Chillicothe, Tex. 
Many of the phenomenal yields of Sudan grass and sorghum that are 
reported by newspapers can be explained in part by this excessive 
moisture content. 
Alfalfa—The computed air-dry weights of alfalfa at Chico, Cal., 
were 10 to 15 per cent less than the field-cured weights, while at Hays, 
Kans., in good curing weather, there was a difference of only 2 per cent. 
Different methods of culture affect the moisture content quite 
decidedly, as shown with alfalfa at Chico, where in the May 15 cutting 
the hay from drilled plats showed only 10.9 per cent loss in air drying, 
while in the 35-inch rows the loss was 24.3 per cent. Cuttings of 
alfalfa made at different stages of maturity can not be compared 
accurately unless they are checked by the sample method. The 
difference in moisture content of the field-cured material has been 
found in a number of instances to be as great as 30 per cent. 
Millet —Of all the crops tested, millet showed the least difference 
between the air-dried and the field-cured material. The loss at 
Hays, Kans., averaged about 9.3 per cent. 
RELATION OF THE STAGE OF GROWTH OF FORAGE PLANTS TO THEIR 
MOISTURE CONTENT. 
It has long been known that plants when young contain a larger 
percentage of water than they do when mature, but no great amount 
of data on this point, even for our principal crop plants, is to be 
found. A compilation’! of all the data available on this subject 
indicates the average percentage of moisture in alfalfa to be as follows: 
1 Vinall, H. N.,and McKee, Roland. A digest of literature relating to the moisture content and shrink- 
age of{forage. In Jour. Amer. Soc. Agron., v. 8, no. 2, 1916. 
