WATER CONTENT OF BARLEY KERNELS DURING 
GROWTH AND MATURATION 1 
By Harry V. Harlan, Agronomist in Charge of Barley Investigations, and MERRITT N. 
Pope, Agronomist in Barley Investigations, Office of Cereal Investigations, Bureau of 
Plant Industry , United States Department of Agriculture 
INTRODUCTION 
In studies in kernel development during the last few years close 
records have been kept of a number of variables. Several of these 
studies already have been published. 2 Of all of the variables observed 
the behavior of water has been the most consistent. As shown in 1920, 2 
the percentage of water by days from the date of flowering was practically 
identical in two different seasons at Aberdeen, Idaho, and showed almost 
no fluctuation. When plotted, the percentage was essentially a straight 
line starting at about 82 per cent and ending at about 48 per cent. 
Below 48 per cent the curves were not coincident. The uniformity of 
these results indicates a closely vital relation of water content with 
growth and maturation. The results previously reported have been 
based on the averages of a varying number of spikes per day. The wet 
weights of the kernels were secured individually, but the dry weights 
were obtained on the aggregate kernels of each spike. In the studies here 
reported the dry weight of each individual kernel was obtained, so that 
individual dry weights and percentages of water of individual kernels 
are available for the first time. For certain purposes these data have been 
totaled as before. 
MATERIAL AVAILABLE 
Several varieties were studied in detail. The earlier attempts were 
with hulled varieties. These were found to be unfit because it becomes 
impossible to remove the lemma and palet once mechanical drying has 
begun. In these varieties the sampling became impossible later than 
this period and, therefore, the final incidents of maturation were lacking. 
The results with naked varieties only are reported in this paper. The 
growth tables of three growing periods were available for interpretation. 
These include two seasons, 1919 and 1920, with the Baku variety, and 
one season, 1920, with the Jet. The Baku is a white, naked 2-rowed 
_. Accepted for publication May 20,1922. These studies were made on the Aberdeen Substation, Aberdeen, 
Idaho m connection with cereal experiments conducted cooperatively by the Idaho Agricultural Experi¬ 
ment Station and the Office of Cereal Investigations, Bureau of Plant Industry, United States Department 
01 Agriculture. 
* Harlan, Harry V . daily development op kernels op hannchen barley prom flowering to 
maturity at ABERDEEN, Idaho. In Jour. Agr. Research, v. 19, no. 9, p. 393-430, 17 fig., pi. 83-91. Litera¬ 
ture cited, p. 429. 1920. 
' and Anthony, Stephen, development of barley kernels in normal and clipped spikes and 
fig* awnless and hooded varieties. In Jour. Agr. Research, v. 19, no. 9, p. 431-472, 13 
-EFFECT OF TIME OF irrigation on kernel development OF barley. In Jour. Agr. Re¬ 
search, v. 21, no. I, p. 29^-45, 20 fig. 1921. 
and Pope, Merritt N. ash content of the awn, rachis palea, and kernel of barley during 
growth AND maturation. In Jour. Agr. Research, v. 22, no. 8, p. 433-449, 5 fig. 1921. 
Journal of Agricultural Research, 
Washington, D. C. 
ada 
(333) 
Vol. XXIII, No. s 
Feb. 3, 1923 
Key No. G-275 
