FIELD CROPS. 731 



varieties of introiluced cotton and their liybriils grown in various parts of tlie 

 Bombaj' Presidency since 1905, witli brief notes regarding tlie performances 

 of some of tlie selections and hybrids. 



Flax culture, R. Kuhnekt (Dcr Flachshau. Berlin: Dcut. Landw. OcscU., 

 1915, S. ed., pp. XV-\-34). — A revised and enlarged third edition of a book 

 previously noted (E. S. R., 14, p. 960). 



Experiments on the development of oats under the influence of irrigation 

 and root pruning, B. Schulze {Landic. Vers. Stat., 86 {1915), Ko. 1-2, pp. 

 63-74). — Oats grown in a series of six concrete pots and receiving during the 

 growing period, aside from the seasonal precipitation, no water and 1.3, 1.G9, 

 1.91, 2.11, and 2.34 times as much water as the seasonal precipitation, produced, 

 respectively, 132.5, 160.7, 176.1, 191, 178.7, and 187.4 gm. of grain per pot. For 

 each 100 liters of water the amount of dry matter produced per pot was 621, 

 580, 504, 472, 421, and 377 gm. The ratios of grain to straw were for each pot 

 1 : 1.9, 1 : 1.91, 1 : 1.99, 1 : 1.91, 1 : 2.08, and 1 : 1.91 ; and the ratios of tops to 

 roots, 100:14.8, 100:12.4, 100:11.9, 100:9.8, 100:11.7, and 100:12.9, respec- 

 tively. 



For the study of root pruning, oats were grown in concrete pots that per- 

 mitted of the introduction of an iron plate so as to cut horizontally the contents 

 of the pot at a required depth. Oats planted on March 20 were pruned on 

 May 2 at a depth of 30 cm., and on May 16 and 30, June 15, and July 1 at 40 

 cm., respectively. The harvest of grain from each of these pots in August was 

 148, 117.5, 85.9, 67.3, and 158.4 gm., respectively, and 161.9 gm. from the pot 

 not pruned. The ratios by weights of the tops to the roots were 100 : 10.4, 

 100:10.1, 100:11.1, 100:10.7, 100:6.8, and 100:9.9. 



It is noted that a shortening of the roots during the period of shooting and 

 blossoming of the plant was the most injurious, and that this injury seemed 

 to lie in a reduction of the food supply rather than a cutting off of the water 

 supply. 



Oats for North. Carolina, C. B. Williams {North Carolina Sta. Circ. 30 

 {1915), pp. 8, figs. 2). — This circular gives cultural suggestions for the oat crop 

 when grown alone and in combination with crimson clover, vetch, and rape. 

 Rotations, including oats, for the various sections are suggested. 



Experiments with potatoes, P. R. Fedorov {Besenchuk. Selsk. Klioz. Opytn. 

 Stants'ita, No. 59 {1914), PP- 9). — ^This report shows that deep plowing, 5i 

 verchoks (9.62 in.), gave better results than shallow depths, and large seed 

 tubers planted whole better results than small, medium, or cut pieces. In a 

 spacing test 12 verchoks (21 in.) square gave the best results. In manurial 

 tests Thomas slag alone gave higher yields than barnyard manure, either alone 

 or with Thomas slag. The potatoes from the unfertilized soil gave the highest 

 percentage of starch, 17.6 per cent, but the lowest yield. 



Soy bean growing' in North Carolina, C. B. Williams {North Carolina Sta. 

 Circ. 31 {1915), pp. 8, figs. 3). — This circular gives instructions for the pi'oduc- 

 tion of the soy bean crop in North Carolina. Brief notes discuss the crop as 

 grown for hay, seed, soil improvement, soiling, and pasture. 



Experiments with fertilizers and manure on tobacco grown continuously 

 and in rotation with wheat and clover, C. E. Thorne {Ohio Sta. Bid. 285 

 {1915), pp. 210-221, figs. 2). — This reports the continuation of work begun in 

 1903 and previously noted (E. S. R., 22, p. 23). Data show the yield and in- 

 crease of tobacco grown continuously and of that grown in rotation with wheat 

 and clover, with various fertilizer treatments of the soil, covering 6, 5, and 4 

 year periods. In the rotations the fertilizer applications were made to the 

 tobacco crop only. 



