10 H. H. Love and C. E. Leighty 



MATERIAL AND METHODS 



Owing to the fact that the commercial varieties of grains are composed 

 of a mixture of several tjqDes, and that as they are grown from year to- 

 year there may be a tendency toward a selective elimination of certain 

 tjT^es, it was thought advisable to make this first study on a pure line. 

 For this reason a pure line of Sixty Day oats was grown for the 

 purpose. 



The first year (1908) this pure line was grown in a drill row. It was 

 consequently impossible to harvest the crop plant by plant. The entire 

 row was harvested, and the studies were made on the individual culms. 



In the years 1909, 1910, 1911, and 1912 the planting was done in 

 a different manner. The soil was prepared and marked off in rows one 

 foot apart, then the seeds were dropped about two inches apart in the 

 rows. By this method it w^as possible to harvest the plants as individuals, 

 so that the notes could be taken on each plant. The crops were all grown 

 on the same t}^e of soil with the exception of that of 1910, when it was 

 necessary to use a different soil type. This was unfortunate, but unavoid- 

 able. 



The crop of 1911 was so injured by storms that it was impossible 

 to gather any statistical data for it. 



The climatic conditions of 1910 were Dot so favorable as those of the 

 other years. The month of June was very drj^, followed by a dry July 

 with high temperature. The table on the following page gives the 

 amount of rainfall, hours of sunshine, and temperature for the seasons 

 considered. From this table it is apparent that the average rainfall for 

 the months of March, April, ]May, June, and July was much lower in 

 1910 than in any other of the years considered. This is important, as 

 will be shoN\m later by the behavior of the correlation constants. 



At the time of harvesting, the individual plants were bound, and were 

 thus preserved ^ith all their culms intact. After being pulled they were 

 well dried, and thereafter were handled carefulh^ so that there would be 

 as Uttle shattering as possible. 



The data for the years 1909, 1910, and 1912 used in this publication 

 are: (1) Average height of plant, in centimeters, obtained by measuring 

 separately each cuhn of a plant from the base of the culm to the base 

 of the apical spikelet, and dividing the smn of these measurements by 

 the number of cuhns making up the plant. (2) Total yield of plant, 



