lyiO] FIELD CROPS. 735 



state and cultural experiments made at Fargo are described. The results 

 of the variety tests are held to indicate that Irish Cobbler potatoes might 

 well be grown to a greater extent, while Burbank is deemed unsuited to 

 North Dakota conditions. 



Experiments with different sized seed pieces indicated that the best average 

 results are secured from 1.5 oz. seed pieces. The selection of seed potatoes 

 from the bin is regarded as much less satisfactory than hill selection. Little 

 difference was observed in the comparative value of buds from various parts 

 of the tuber, or between seed pieces having 1, 2. or 4 eyes. In a comparison 

 of different methods of cutting seed potatoes, the maximum yield, 275.7 bu. 

 per acre, was secured from hand cutting with the cuts made just above the 

 bud and slanting toward the stem end of the tuber. The rapidity of emer- 

 gence of shoots showed little difference for seed pieces of different sizes, 

 for pieces from various parts of the tuber, for pieces with 1, 2, or 4 eyes or for 

 seed cut in different ways, except that tubers quartered lengthwise were much 

 slower than the others. 



In 1918 the highest yield, 259.1 bu. per acre, was secured from the earliest 

 planting (May 4). In spacing experiments made during 1918 the net yield 

 decreasetl as the area per plant increased. The total yields ranged from 195.7 

 bu. per acre for a planting distance of 2.5 ft. between rows with 24 in. between 

 plants to 373.4 bu. for a distance of 2 ft. between rows and 6. in. between plants. 

 Seed treatment and spraying with Bordeaux mixture resulted in increased 

 yields on both manui'ed and unmanured plats, this being more marked on the 

 former than on the latter. Hilling potatoes reduced the yield as compared 

 with level cultivation. 



In a study of the time and rate of tuber growth in Green Mountain potatoes 

 during 1917, the total yield secured August 10 was 121.6 bu. per acre as 

 compared with 220 bu. on September 11 when the vines were killed by frost. 

 The daily increase during the first 10-day interval was found to be 2.34 bu. 

 per acre, and during the last 3-day interval 5.27 bu. 



The prickly pear in Australia, W. B. Alexander {Aust. Inst. Sci. and Indus. 

 Bui. 12 (1919), pp. Jf8, pi- 1, figs. 16). — This comprises a somewhat detailed ac- 

 count of the introduction and spread of the prickly pear, particularly the so- 

 called pest pear (Opuntia inermis) in Queensland and New South Wales, 

 together with a discussion of its utilization and of methods of eradication. 

 The use of arsenicals either as a spray or as a gas is said to have given the 

 most promising results. 



Probable material for the study of the experimental evolution of Oryza 

 sativa, var. plena, R. K. Bhide (Agr. Join: India, llf (1919), No. 3, pp. 494- 

 499, pis. 2). — Variations in different varieties of rice grown at Alibag (India) 

 tending toward the so-called double grain rice or O. sativa, var. plena are 

 described. The possibility of developing the double grain type from an ordi- 

 nary variety without crossing is indicated. 



Propagating- sorghum by cuttings, A. Piedaixu (Btil. Soc. Natl. Acclim. 

 France. 66 (1919), No. 1, pp. 15-17). — The author states that sorghum can be 

 readily propagated by means of cuttings of the stem and that desirable varieties 

 can thus be maintained in a pure state. 



The effect of soy bean germination upon the growth of its nodule-forming 

 bacteria, A. K. C. Haas and E. B. Fred (Soil Sci., 7 (1919), No. 3, pp. 237-243, 

 pl- 1). — In this paper, a contribution from the Wisconsin Experiment Station, 

 the authors describe investigations in which a study was made of the toxic 

 effect of the germination of soy bean seeds upon the growth of nodule bacteria 

 inoculated upon the seed coat. The studies also involved observations on 

 various methods of sterilizing soy bean seeds. 



