FIELD CEOPS. 431 



International catalogue of scientific literature. M — Botany {Internat. Cat. 

 Sci, Lit., 7 {1910), pp. r///+.9S6).— This is a list of titles of botanical articles 

 most of wliich appeared in the literature of 1907. It is somewhat surprising 

 to find that only about 50 titles are given of American contributions to plant 

 pathology and not a single title relating to the control of plant diseases. 



FIELD CROPS. 



Limitations in field experiments, M. A. Cakleton (Proc. 8oc. Prom. Agr. 

 ScL, 30 (1909), pp. 55-61). — The author discusses the difficulties of securing 

 comparable results from different plats in the same field experiment. 



The most common difficulty arises from variations in the soil of different 

 plats. It is pointed out that in variety tests at the Ohio Station, in case every 

 third^plat is a check and the soil proves progressively more productive from one 

 portion of the field to another, the yields of some varieties are " corrected by 

 adding or subtracting such a fraction of the difference in yields between these 

 checks as is indicated by their position with reference to the checks." A 

 similar method is used at the Pennsylvania Station. 



The Office of Grain Investigations of this Department has adopted the follow- 

 ing method : "An average of the yield of all the checks is taken. Then for each 

 variety there is added to or subtracted from its absolute yield the difference 

 between the nearest check yield and average check yield — this difference being 

 added if the yield of the nearest check is below the average check yield and 

 subtracted if the reverse." If a given variety stands between 2 checks, both 

 their yields must be considered as well as the average yield of all the checks. 



If the soil is abruptly variable, but uniform within small areas, very small 

 plats may be preferable. If the variation extends in one direction it may be 

 overcome by lengthening the plats in that direction. 



Field crops, J. M. Scott (Florida Sta. Rpt. 1909, pp. XVIII-XXIV, figs. 2).— 

 Analyses from various sources are presented in pai-allel columns for the pur- 

 pose of comparing the composition of various Florida forage crops. 



Guinea grass planted April 9 and 10 by means of roots placed 2 ft. apart in 

 rows 4 ft. apart produced a yield of oj tons of field-cured hay per acre by 

 October 14 of the same year. Ninety days after planting, Natal grass was 

 ready to cut for hay. Two cuttings of hay aggregating 5,250 lbs. per acre in 

 addition to 2 crops of hand-gathered seed were secured the first season. It is 

 estimated that under favorable soil and moisture conditions a yield of from 

 3 to 4 tons per acre may be expected. 



Among 9 varieties of corn, Rawls and Evans produced the highest yields, 

 19.19 and 19.01 bu. per acre, respectively. Japanese sugar cane, planted Janu- 

 ary 18 and harvested November 19, yielded 24.5 tons per acre of green material, 

 or 16 tons of sun-cured hay. It is thought that no other forage crop will 

 produce so large a yield of carbohydrates in Florida. 



The white and common velvet beans produced 26.9 bu. and 23.3 bu. of shelled 

 beans per acre respectively, while an acre under continuous planting produced 

 14.77 bu. The Lyon bean produced 32.5 bu. per acre. The stock ate these 

 beans with greater relish than they did cotton-seed hulls. The fertilizing 

 values of velvet bean hulls and Lyon bean hulls are estimated at $7.75 and 

 $8.25 per ton respectively and the additional feeding value at at least half 

 their fertilizing value. 



The kudzu vine (Pueraria thunhergiana) is a perennial legume with large 

 tuberous roots native to Japan and China. After the first season the vines 

 often make a growth of 40 to 60 ft. It may be propagated by division or by 

 seeds, but is usually grown from cuttings or layers of the vines. Should it 



