138 EXPERIMENT STATION EECOKD. 



The work here reported from 14 stations covers an aggregate of 73 station 

 years, embodies the data from a total of 1,683 plat years, and includes parts 

 of ten States. Data for each station regarding yield and cost of production 

 cover the items of fallow, plowing, disking, listing, subsoiling, green manuring, 

 summer tilling, and previous crop. 



It is shown that "some seasons are so unfavorable as to result in failure 

 of the spring wheat crop without regard to the cultural methods under investi- 

 gation. Extremely unfavorable climatic conditions can not be overcome by 

 cultural methods. It is only in those seasons when the rainfall deficit is so 

 small that it can be overcome by moisture stored in the soil that the cultural 

 methods under investigation have shown important effects upon yields, . . . 



" Reducing the cost of production has in most cases in these investigations 

 proved a more important factor in determining profits than increasing yields 

 by cultural methods. 



"Northern Colorado and Kansas seem from these investigations to be the 

 southern limit of profitable spring wheat production on the Great Plains. This 

 limitation does not apply to winter wheat and other crops under investigation. 



" Disked corn ground has given consistently high yields. This, together with 

 the low cost of preparation, has resulted in its showing the highest average 

 profit or lowest average loss of any of the methods tried at all of the 14 sta- 

 tions except one. These profits are based on the assumption that the corn crop 

 was so utilized as to pay for the cost of its production. Furrowing with a 

 lister and leaving the surface ridged through the winter has resulted in a small 

 increase in yield over plowing at seven of the eight stations where it has been 

 tried. As it is a somewhat cheaper method of preparation than plowing, it 

 has consequently been more profitable. The average difference in the yields of 

 spring wheat following fall plowing and spring plowing are very small. At 

 most stations the advantage of one over the other depends upon the season. 



" Subsoiling has been of doubtful utility as a means of increasing yields. As 

 a means of overcoming drought it is without value. Summer tillage without 

 crop has given the highest average yields of any method under trial at 12 of 

 the 14 stations. However, on account of its high cost, due to extra labor and 

 alternate year cropping, it has not been the most profitable practice. The most 

 expensive method under trial is green manuring. It has produced less profit or 

 greater loss than any other method under investigation." 



Tillering of spring wheat, S. I. Vokobev (Bezenchulc. Selsk. Khoz. Opytn. 

 Stants'im, No. 29 (1912), pp. 3; ahs. in Zhur. Opytn. Agron. (Buss. Jour. Expt. 

 Lanchv.), 14 {1913), No. 4, pp. 405-^07). — This gives the results of experiments 

 conducted in 1912 to study factors influencing the tillering of wheat. 



The author concludes that soil fertility, available light, and moisture, as in- 

 fluenced by the spacing of the plants, are the chief determining factors of tiller- 

 ing in the variety studied (Poltavka). In wide spacing the tillering period 

 continued 13 days, while with close spacing no new shoots were sent up after S 

 days. It was found that the grain produced on the early appearing tillers was 

 superior to those produced on later tillers. The data are given in tabular form. 



Pure seed law, T. P. Cooper {North Dakota 8ta. Rpt. 1914, pt. 1, pp. 14-1-7).— 

 This gives results of the examination of 5,577 samples of seeds for purity and 

 germination. Tables show the approximate purity and the number of samples 

 received of a given grade of germination and of hard seed, and the number 

 which contained prohibited seeds. 



Pure seed law {Cheyenne, Wyo.: State Dairy, Food, and Oil Comr. [1913], 

 pp. 11 ) . — The text of the Wyoming pure seed law is given. 



Weed seeds in farm lands, J. R. Fbyer {Agr. Gaz. Canada., 2 {1915), No. 1, 

 pp. 21-23), — This article gives results of tests to determine the prevalence of 



