1917] FIELD CROPS. 829 



A bibliography of 26 articles comprising the literature cited is given at the 

 end of the paper. 



A semiannual cropping system for bean lands, G. W. Hendry (Univ. Cal. 

 Jour. Agr., 4 (1911), No. 6, pp. 181, 182, fig. 1). — Recommendations are made 

 concerning the utilization of bean land duning the winter months for the pro- 

 duction of certain hardy leguminous crops in California. Increases in the 

 market prices for 1916 over those received before the war, amounting to from 

 21 per cent for horse beans to 150 per cent for Large White (Lady Washington) 

 beans, has i-esulted in increased rentals and share leasings, necessitating more 

 intensive cultural conditions. 



A semiannual cropping system such as proposed presupposes a well-drained 

 soil not subject to winter inundations but readily irrigable in October and May, 

 as well as facilities for rapid handling of the crops in the field. The winter 

 crop should be planted during October and harvested not later than May 15. 

 The following crops are suggested and their market value briefly discussed : 

 Horse beans, garbanzos, garden peas, fi^eld peas, and lentils. 



Investigations on the mode of determining the germinating capacity in 

 beet seed, E. Vitek (Ztschr. Zuckerindus. BUhmen., J/O (1916), No. 8, pp. S63- 

 S81 ; abs. in Internat. Inst. Agr. [Rome], Internat. Rev. Sci. and Pract. Agr., 7 

 (1916), No. 8, p. 1106). — Experiments are reported to determine whether blot- 

 ting paper or sand give more accurate results in germination tests. In 1913, 

 26 samples of seed were compared, 77 per cent showing a higher germination on 

 blotting paper than on sand, and 88 per cent giving a larger number of embryos 

 on blotting paper than on sand. Analogous results were obtained in 1914. 



Influence of very low temperatures on the germination capacity of beet 

 seeds, J. Ueban and E. Vitek (Ztschr. Zuckerindus. Bohmen., 40 (1916), No. 7, 

 pp. 29-SOO; abs. in Internat. Inst. Agr. [Rome], Internat. Rev. Sd. and Pract. 

 Agr., 7 (1916), No. 8, pp. 1105, 1106). — The authors report experiments with 

 sugar beet seed to determine the influence of low temperature on germination. 

 Samples of beet seed were exposed for 30 minutes at a temperature of —180° C, 

 produced by the spontaneous evaporation of liquid air, and germinated with 

 unexposed seed at a temperature varying from 20 to 30°. After 15 days 95 per 

 cent of the unfrozen seed and 96 per cent of the frozen seed had germinated, 

 indicating that the heaviest frosts do not impair the germinability of beet seeds 

 having a normal water content. 



To test the behavior of seed harvested in wet weather samples of seed con- 

 taining approximately 20 per cent water were exposed to the same temperatures 

 as above from 2 to 72 houi-s. The results indicated that the germinative capacity 

 of the seed had been impaired by freezing, but that exposure for 72 hours had 

 had no more effect than exposure for a shorter length of time. 



Boiling buffalo clover seed, A. D. McNaib (Science, n. ser., 1^5 (1917), No. 

 1157, pp. 220, 221). — The author reports tests with the seed of buffalo clover 

 (Trifolium reflexum) in attempts to increase their germinability. The process 

 of boiling the seed one minute as practised in the case of spotted bur clover 

 (Medicago arabica) increased germination from 4 to 30 per cent. Experiments 

 with bur cloyer conducted by the Alabama Elxperiment Station (E. S. R., 32, p. 

 829), in which the seed were soaked before boiling, led to similar tests with 

 buffalo clover, with the following results as to percentages of germination: 

 No treatment, ; boiled 5 seconds, 53 ; boiled 30 seconds, 60 ; boiled 60 seconds, 

 60 ; soaked in cold water 12 hours, ; soaked in cold water 12 hours and boiled 

 5 seconds, 47 ; soaked in cold water 12 hours and boiled 80 seconds, 87 ; and 

 soaked in cold water 12 hours and boiled GO seconds, 93. 



