BROOM-CORN EXPERIMENTS AT WOODWARD, OKLAHOMA. 27 



ing. Germination was low, and a number of the young plants did 

 not have vigor enough to withstand the heat after they emerged. 

 In 1918 the thin stands were due to the poor quality of the seed 

 used. This seed was slightly frosted before harvest the previous 

 year. Though it showed a fairly high germination in laboratory 

 tests made prior to seeding time, it evidently was losing its vitality 

 will age, as the stand of each successive seeding was thinner than 

 that of the preceding one. For the last three dates in 1918, seed 

 from another source was used, which gave a stand comparable 

 with the stands in the other years. 



The shortest total growing period required by the crop from any 

 one date of seeding was 73 days, which resulted from the seeding 

 made on April 16, 1917. In any one of the first three years, 1914, 

 1915, and 1916, the variation in the duration of the total growing 

 periods of plats sown at different dates amounted to about 15 

 days. In the 3-year period the greatest variation amounted to 24 

 days. In 1917 the time required for the crop to mature was much 

 longer than it was in any other year. In that year the shortest 

 time was 100 days from the June 2 seeding and the longest time 

 137 days from the April 16 seeding. The abnormally long time 

 required by the crop was due to the very unfavorable growing con- 

 ditions which obtained in varying degrees through the months of 

 May, June, July, and September. The moisture in August was 

 enough to promote normal plant growth. The unusually short time 

 required to reach maturity by the crop sown on July 1, 1916, was due 

 to the lack of moisture at and following the time the crop was head- 

 ing. Only 79.3 per cent of the total number of stalks in the crop 

 produced heads. 



Suckering is influenced largely by growing conditions and varies 

 widely in the same variety when grown under different conditions. 

 In 1914 the suckers amounted to less than 1 per cent of the total 

 number of stalks resulting from any one of the dates of seeding, 

 while in 1915 they ranged from 4.8 per cent to 28.1 per cent of 

 the total. The percentage in 1916 varied about the same as it did 

 in 1915, but it shows quite an increase in 1917, reaching 40 per cent 

 in the July 3 seeding. However, a still wider variation occurred 

 in 1918, when the highest was 62.8 per cent and the lowest only 6.5 

 per cent. This is a difference of 56.3 per cent, which was due to 

 differences in stand and other environing conditions. 



The percentage of stalks that head is influenced largely by grow- 

 ing conditions at heading time.' When there is sufficient moisture 

 lo develop normal plant growth throughout that stage the per- 

 centage of heads developed to total stalks will be much larger than 

 will be the case otherwise. There may be as wide a variation in 

 the percentage of heads developed in plants sown at different dates 



