FIELD CROPS. 133 



on these types of soils. Such crops invariably outyieUled others, even when 

 highly bred on the uplands. 



A text-book of grasses, with especial reference to the economic species of 

 the United States, A. S. Hitchcock (Xcw York, JOL't, pp. XVI I +.276, fujs. 6^).— 

 Primarily a text-book of 25 chapters, this contains some reference matter, 

 and although the chief emphasis is placed on systematic agrostology, this 

 comprising part 2, a brief outline of economic agrostology is presented in 

 part 1, 



Alfalfa experiments, L. Carrier, E. R. Hodgson, R. P. Cocke, and B. G. 

 Anderson (Viryinia Sta. Bui. 207 {1914), pp. 3-20, figs. 5). — This bulletin gives 

 cultural methods and results of exi)eriments, in cooperation with the State 

 Department of Agriculture, which are summarized as folUows : 



"August seeding is preferable to spring seeding. Liming is usually neces- 

 sary, even on limestone soils. Experiments at Appomattox and Williamsburg 

 showed very marked benefit from liming. At Staunton little benefit was 

 observed. 



"Acid phosphate and basic slag have given the most marked results on alfalfa 

 of any commercial fertilizer, especially when used in connection with a liberal 

 application of stable manure. At Williamsburg, in Tidewater, a plat seeded 

 in September, 1912, and fertilized with 10 tons of manure and 400 lbs. acid 

 phosphate per acre yielded at the rate of G tons per acre in 1913' [as against 

 2 tons 356 lbs. without fertilizers]. At Staunton, in the Shenandoah Valley, 

 alfalfa fertilized with 15 tons of stable manure alone yielded 6 tons per acre 

 in 1913 and 2i tons the first cutting in 1914. The use of inoculating soil is 

 strongly reconmiended over any other method. Pure cultures are a less desir- 

 able, but practicable substitute. The experiments on rates of seeding, using 

 from 10 to 30 lbs. per acre, gave very little diiference between light and heavy 

 seedings. On a good seed bed 15 lbs. should be sufficient. A comparison of 

 alfalfa seeded alone with alfalfa seeded with other grasses or clovers indicates 

 that it is the best to seed it alone." 



The cultivation of Turkestan alfalfa, J. Gy areas (MonatsJi. Lanclw., 7 

 {19U),^No. 8, pp. 192, 193). — This discusses results obtained in Hungary at 26 

 different centers that show the inferiority of Turkestan alfalfa as compared 

 with the native varieties. 



A more accurate method of comparing first-generation maize hybrids with 

 their parents, G. N. Collins {U. 8. Dept. Agr., Jour. Agr. Research, 3 (1914), 

 No. 1, pp. 85-91). — The author states that "the development of satisfactory 

 methods of comparing the yield of first-generation hybrids with that of their 

 parents has been retarded by (1) a failure to fully appreciate the importance of 

 individual diversity in hybrids, (2) the abnormal behavior of self -pollinated 

 maize plants, and (3) the difficulty of securing for comparison hybrids and 

 parents with identical ancestry. 



" To compare the behavior of two varieties, which may be called A and B, 

 with that of a hybrid between them, two plants were selected in each variety, 

 Al and A2 in the one variety, and Bl and B2 in the other variety. The follow- 

 ing hand pollinations were made: A1XA2, A2XB1, B1XB2, and B2XA1. 

 The result is two hj'brid ears and one cross-pollinated ear of each variety. 

 It is believed that the mean yield produced by seed from the two hybrid ears 

 compared with the mean yield produced by seed from the two pure seed ears 

 gives a fair measure of the effects of hybridization. By making two hybrids 

 involving all the plants used in producing the pure seed ears individual differ- 

 ences that affect the yielding power of the pure seed ears are similarly repre- 

 sented in the hybrids. Thus in both the parents and the hybrids the average 

 yield represents the mean yielding power of the four parent plants, the only 



