May 3, 1924 
Relative Merits of Sweet Com Varieties for Canning 409 
throughout the flowering period each plot was carefully searched for all speci¬ 
mens showing the first appearance of silks, and tags bearing the respective dates 
were attached thereto. To facilitate the later gathering of sample ears of a 
given date tags of different colors were used on different days. This detail 
proved of great assistance in the rapid collection of samples. Careful records 
were kept of each day's tags so that the rate of silking and the length of the 
silking period of each variety were known, and data were at hand to tell when 
sufficient material was available for the various tests. 
Samples were taken for canning tests at the ages of 15, 20, 25, and 30 days, and 
samples for chemical analysis were taken at the ages of 5,10,15,20,25, and 30 days. 
Since the behavior of varieties and the chemical composition of samples is 
affected by climatic factors data upon temperature and rainfall are given in 
the accompanying chart which shows the conditions under which the corns were 
grown. Complete temperature records covering the test period were not obtain¬ 
able at the Arlington experiment farm as only maximum and minimum daily 
temperatures were recorded. The figures given are those obtained from the 
United States Weather Bureau at Washington whose station is situated but a 
short distance across the river from the Arlington farm. Careful comparison of 
the records from the two sources have shown that differences in temperature in 
the two places were too small to be of significance. In most cases the temper¬ 
atures were practically identical, and the data given, therefore, may be consid¬ 
ered as fairly representing the actual temperature conditions under which the 
corn was grown. The data upon rainfall were obtained at the Arlington farm. 
Examination of the chart shows that the mean daily temperature for the 
growing and maturing period of the corns under study was somewhat above the 
49-year average during May and June, but fairly close to it during July. August 
was somewhat below the average. 
Taken as a whole, the season was rather wet, there being an excess of 3f inches 
of rainfall for the months May to August, inclusive. The excessively heavy 
downpour of September 2, while occurring before all the samples were harvested, 
had little if any effect upon those remaining to be handled since they were well 
along toward maturity at this time. It will be noted that the rainfall was well 
distributed throughout the test period. While several rather heavy rains 
occurred, in no case was there a drowning of the corn as the underground drain¬ 
age system rapidly removed all excess of moisture. 
It is regretted that data upon soil temperatures and moisture content of the 
test plots are not available for presentation in this connection. 
EXPERIMENTAL RESULTS 
THE SILKING PERIOD 
The significance of the silking period of corn as a practical aid in determining 
when and how rapidly a field of corn would come to canning maturity seems never 
to have been appreciated, but the fact that the quality of the canned product is 
intimately associated with the stage of ripeness of the corn when it goes into the 
can makes the consideration of this matter of importance. Burrill and McCluer 
(12, 13) in studies upon a considerable number of varieties noted the date of the 
first bloom, the date of the full bloom and that when the corn was first fit for use. 
Butz and Baldwin {16) recorded the date of tassel and the dates of the first and 
last ears upon a number of varieties including Crosby, Mammoth Sugar, and 
Stowell’s Evergreen. Munson and Gould (43) observed the dates of the first 
appearance of tassels, the appearance of silks and of edible maturity upon 15 
varieties of sweet corn, and Gould (26, 27) gave like data for the two succeeding 
years upon 25 varieties. Butz (16) recorded the date of tassel and the date of 
the first and of the last ears. Kiesselbach (34) in investigations upon field corn 
gave attention to the length of the period of pollination, the life of the pollen 
and the life of the silk; and in the tabulation of results of his experiments has 
shown the dates of tasselling along with the dates when the corns were ripe. 
