FIELD CROPS. 135 



square, in which 20 varieties^ were so arranged as to repeat each 5 times, is 



I ± d. 0.845 



explained and illustrated. The use of the formula ~,- ^ .- i—j is explained 



■yJn{n—\).-yJn^ 



in calculating the probable experimental error for these 20 plats. In this 



formula 2= the sum of the yield of the repeated plats; (Z= the difference in 



yield from the mean; n= the number of plats, and 0.845 is a constant. By the 



use of this formula the author states that the probable error for each plat 



may be determined and so increase the accuracy and usefulness of the result 



of a test. 



The influence of different veg-etative factors on yield and counteracting 

 relations of artificial factors added to the soil, E. A. Mitscherlicii and 

 IJ. Floess {Landw. Juhrb., J,3 {1913), Ao. 7,, pp. 6.',9-66S, figs. 3).— In this article 

 the authors discuss the law of minimum yield, the vegetative factors of light, 

 soil temperature, and water, and the opposing influences of artificial vegetative 

 factors in the way of fertilizers. It was noted that responsive energy was 

 at its optimum in sunlight; that active energy in the roots was the result of 

 soil temperature and favored increased yields; that loss of energy through 

 increased root labor was a factor in decreasing yields; that the plant yield 

 correlated with soil water subject to the law of minimum ; and that yields were 

 limited by the small quantity of soil water, but favored when this water was 

 in the upper soil layer and when the plant food was such as to be soluble in 

 the water during the entire vegetative period, so that the roots were relieved 

 of heavy work. 



Cereal investigations at the Nephi [Utah] substation, P. V. Cakdon {U. 8. 

 Dcpt. Agr. Bui. 30, pp. 50, figs. 0). — This bulletin contains a report of the 

 work of the substation, previously mentioned (E. S. R., 23, p. 434), and includes 

 a description of the substation and of the soil and climatic conditions that 

 surround it. Tables give some meteorological data for the years 1S9S to 1912, 

 inclusive. The experimental work reported consists mainly of varietal and 

 improvement tests of 68 varieties and strains of winter wheat, 1 of winter oats, 

 3 of winter barley, 2 of winter emmer, 10 of spring wheat, 7 of spring oats, 

 and 14 of spring barley. Tables present data concerning yields, stand, dates 

 of ripening, height, ratio of weight of grain to straw, and average weight per 

 bushel of wheats and barleys, and the results of testing large, medium, small, 

 and unseparated seeds of wheat planted at different distances in the row. 



The results obtained show that " the winter varieties of all cereals have 

 given better results than have the spring varieties. Of the winter wheat varie- 

 ties, the hard red group has given the best yields. The soft white group, com- 

 monly grown in the Intermountain States, is comparatively low in yield. There 

 seems to have been no definite correlation between stand and yield. The aver- 

 age date of heading and also the average date of ripening were about the same 

 for all varieties. The average height of the winter wheats at Nephi during 

 1908 to 1912, inclusive, was 27 in. Approximately 1 lb. of grain was produced 

 with every pound of straw. 



"The average bushel weight for all varieties of winter wheat for the 5-year 

 period was 61.4 lbs., or 1.4 lbs. above the standard weight. The average acre 

 yield of spring wheats since 1908 is only 7.5 bu. for durum varieties and 8.9 bu. 

 for common varieties, which is unprofitable in comparison with the acre yield 

 of 17 to 23 bu. from winter wheats. Boswell winter oats have yielded very 

 well in some seasons. In other seasons the yield has been low, thus reducing 

 the average acre yield to 17.2 bu. for 1909 to 1912. However, the variety gives 

 great promise as a winter oat for the intermountain region. The Black Ameri- 

 can, Giant Yellow, and Swedish Select varieties of spring oats have acre yields 



