734 EXPERIMENT STATION EECOED. 



entirely to the presence or absence of any one compound, but are more or less 

 dependent upon the total constituents of the tobacco." 



Tobacco growing in Minnesota, C. P. Btjll (Minnesota Sta. Bill. 150 {1915), 

 pp. l-Jil, figs. 26) . — This gives a survey of the progress of the tobacco industry 

 for the period from 1909 to 1914, inclusive, together with cultural, harvesting, 

 and curing directions for Minnesota growers. Cost accounts show the total 

 cost to range from $25 to $45 per acre and the yields from 755 to 2,100 lbs. per 

 acre. 



Hairy vetcli, V, M. Shoesmith (Michigan Sta. Circ. 27 (1915), pp. 3-8, 

 figs. 2). — This deals with cultural methods and the uses of vetch as a green 

 manure, forage, or seed crop, and in rotation with wheat. 



Spacing and depth of planting for spring wheat, A. D. Bochkova (Zhur. 

 Opytn. Agron. (Russ. Jour. Expt. Landw.), U (1913), No. 2, pp. 43-63). — In 

 experiments in spacing wheat so as to allow 25, 50, 75, 100, 125, 150, 187, 225, 

 300, and 400 sq. cm. per plant, it was found that the total yield per plant in- 

 creased with the increase of area per plant. The closer the spacing the better 

 was the quality of the grain, the greater the weight of 1,000 kernels, and the 

 higher the yield per unit of area. 



In tests of depth of planting a difference between 6 and 7 days was observed 

 in the appearance of the seedling when planted at depths of 2, 4, 5, 8, and 10 cm. 

 The germinative ability was noted to decrease with the increase in depth of 

 planting. Tillering and shooting occurred at the same tirne for all depths, but 

 the degree of tillering decreased with the depth of the seed. After the shooting 

 the higher temperature seemed to hasten the development of the plants from 

 the deep-planted seeds so that the spike matured two or three days earlier than 

 those from the shallow-planted seeds. The length of spike and number of 

 kernels per spike increased with the depth of planting, while the weight of 

 the kernels diminished. The total yield and yield of grain increased with the 

 depth of seed, while the proportion of straw decreased. 



Some quantitative data from laboratory investigations of seeds of rye and 

 oats, N. Leontevskii (Abs. in Zhur. Opytn. Agron. (Russ. Jour. Expt. Landic), 

 15 (1914), No. 2, pp. 184, 185). — This gives results of seed examinations and 

 chemical analyses of rye and oats grown in various parts of the Government of 

 Vologda. 



Weediness of fields and influence thereon of various methods of husbandry, 

 P. I. Leshchenko (Trudy Poltav. Selsk. Khoz. Opytn. StantsU, No. 25 (1914), 

 pp. VIII +79, figs. 8). — ^At the Poltava Experiment Station the following ob- 

 servations were made : 



For each cultivated plant there were one, two, or more weeds, and for each 

 unit of the green weight of grain from one to two units of weeds. Both in 

 winter and spring cereals annual weeds were in greater number than the 

 perennials. The winter cereals had a larger quantity of weeds than the spring, 

 and also, according to the weight of grain, more annual and biennial weeds, 

 while in the spring cereals there were more perennial weeds. 



The predominant annuals and biennials in winter cereals were Viola tricolor, 

 Sclerantus annuus, Capsclla bursa pastoris, and Tlaspi, which are typical for 

 a 3-course crop rotation with later fertilization. All these developed completely 

 and produced seed. For spring cereals with a 3-course crop rotation the 

 typical weeds were Setaria glauca, Stachys, Polygonum aviculare, several species 

 of Vicia, and P. convolvulus. 



Experiments covering a period of 19 years showed that in a 3-course crop 

 rotation of late fertilization caused Avena fatua and Centaurea cyamis to dis- 

 appear entirely, while Matricaria and Triticum repens occurred very seldom. 

 "Where early fertilization had been practiced, annual and biennial weeds char- 



