FIELD CROPS. 531 



sized meshes would seem to indicate that in some cases red clover is self-ferti- 

 lized or else fertilized by small insects, while the work with the finer meshes 

 would seem to indicate that it is seldom, if ever, self-fertilized. It is possible 

 that wind rustling is a necessary element in this work and that the screens 

 with the finer meshes largely prevented this." A later and more complete re- 

 port on this work will be made. 



Distance between hills for corn in the Illinois corn belt, A. N. Hume, O. D. 

 Center, and L. Hegnauer {Illinois 8ta. Bui. 126, pp. 3.57-37'/). — Distance ex- 

 I)eriments with corn were conducted by the Illinois Experiment Station in dif- 

 ferent sections and on different soils in Illinois from 1903 to 1907, for the pur- 

 pose of determining the distance at which check rows of corn returned the 

 highest and most profitable yields and whether planting 2 kernels per hill at 

 closer distances is better than 3 kernels at greater distances. The thickness 

 it planting was varied by increasing or decreasing the distance between rows in 

 both directions. The bills were checked on different plats at distances ranging 

 from 33 to 44 in., the intermediate distances being 39.6 and 36 in. The differ- 

 ent series were repeated as many times as practicable according to the size of 

 the fields, and variations in stand were eliminated to make results comparable. 



In northern Illinois on the 2-kernel plats the average yield for the 4 years 

 rangetl from 44.1 bu. per acre for the 44 by 44 in., or widest planting, to 54.3 

 bu. for the second thickest, or 33 by 36 in. planting. Where 3 kernels were 

 planted per hill the widest planting produced on an average 54.1 bu., which in- 

 creased as the distance was narrowed down to 61 bu. per acre for the closest, 

 or 33 by 33 in., planting. 



In central Illinois the plats planted with 2 kernels per hill increased in avei*- 

 age yield from the widest planting to the second thickest, the yields ranging 

 from 47.7 to 55 bu. per acre. The plats with 3 kernels in the hill ranged in 

 average yield per acre from 46.S bu. for the closest planting to 52.3 bu. for the 

 39.6 by 39.6 and the 36 by 44 in. distances. The plats planted 36 by 36 in. with 

 2 kernels per hill yieled 2.2 bu. per acre more than the plats planted 39.6 by 

 39.6 in. with 3 kernels per hill. In the northern part of the State the best yields 

 were taken from the plats with 3 kernels i)er hill and also from those in which 

 the hills were not more than 36 in. apart each way, and in the central part of 

 the State the highest average yield from land producing over 50 bu. per acre was 

 secured by planting 2 kernels at a distance of 33 by 36 in., but almost the same 

 yield was obtained when the hills were planted 39.6 in. apart each way with 3 

 kernels per hill. On land yielding less than 50 bu. per acre pi'actically the 

 higest average j-ield was secured where 2 kernels were planted per hill in rows 

 36 in. apart in each direction. 



It is advised that on all ordinary corn belt land in northern Illinois the hills 

 be planted not more than 36 in. apart with at least 3 kernels per hill, and that 

 in central Illinois on the common brown silt loam prairie lands usually produc- 

 ing over 50 bu. per acre corn be checked 39.6 in. apart and 3 kernels planted per 

 hill, while on the common prairie land not generally producing 50 bu. per acre 

 the hills should be 36 in. ai)art and onls^ 2 kernels planted per hill. 



Ten generations of corn breeding, L. H. Smith { Illinois Sta. Bui. J. 28, pp. 

 -'i 07 -57 -J, figs. 2). — This bulletin discusses the importance of corn improvement, 

 outlines the fundamental principles upon which this work at the station is 

 based, reviews some of the earlier results, describes the general plan of the 

 experiments, and summarizes the results secured during 10 years of investiga- 

 tion. Much of this subject matter is condensed from Bulletins 55, 82, 87, and 

 lOT) of ilie station previously noted (E. S. E., 11, p. 033; 14, p. 855; 15, p. 352; 

 17, p. 26). 



