FIELD CROPS. 133 



their lesser rainfall during the growing season the medium planted with the 

 broad low ridge cultivation is preferably to either of the others." 



From some results of soy-bean experiments the author concludes that " soy 

 beans can be grown in parts of Maine where corn thrives. Where early coru 

 matures, the early white soy bean will usually mature. Where Sanford corn 

 ears, the early medium soy bean will form pods. . . . 



" It is doubtful if it would be profitable to grow soy beans for seed in Maine. 

 The varieties that will ripen seed in this climate make small vine growth. 

 The crop is best adapted for feeding green or for silage. ... A yield of 8 

 tons of green crop is an average in average seasons on average soil." 



Directions are given for the use of iron sulphate as a spray to destroy wild 

 mustard and related plants in fields of sown cereals. Further. " the experi- 

 ence indicates that witli a field of potatoes badly infested with mustard spray- 

 ing with sulphate of iron solution may be resorted to with a reasonable ex- 

 pectation that the yield of tubers will not be diminished. At present such a 

 treatment can only be recommended as a rather extreme measure." 



Beport of the work done by the agricultural experimental station in St. 

 Croix during' the year [ended June 30, 1912] {Rpt. Agr. Expt. Sta. St. Croix, 

 1911-12, pp. 61, pis. 8, figs. 10). — This is a report of progress on the work of 

 this station which was recently established. Results of variety tests with sugar 

 cane, cotton, maize, and sorghum, and soil analyses are reported, with meteoro- 

 logical observations. 



Field experiments and demonstrations (North of Scot. Col. Agr. Leaflets, 

 1912, pp. VI +166, figs. 2). — This gives results of variety and manurial tests 

 with cereals, turnips, carrots, sugar beets, mangels, potatoes, alfalfa, grass, and 

 weeds during 1912 in 10 county districts of Scotland. 



[Field crop experiments], F. Smith {Ann. Rpt. Chinsurah Agr. Sta. [Itidia], 

 1912, pp. Jf-lO). — This reports manurial and variety tests with rice, hemp, soy 

 beans, sugar cane, flax, wheat, mustard, lentils, etc. 



Alfalfa seed production; pollination studies, C. V. Pipee, M. W. Ev.\ns, R. 

 McKee, aud W. J. Morse ( f. N. Dcpi. Agr. Bui. 15 (1914), pp. 32, fig. J).— 

 Earlier investigations along this line are reviewed. The structure of the 

 alfalfa flower is described and the relation of tripping to the development of 

 the seed. 



The results of these studies of pollination of alfalfa flowers brought out the 

 follow'ing conclusions: "Alfalfa flowers remain fully susceptible to pollination 

 from the time of opening until the petals wither. Pollination is ordinarily 

 effected when the elastic stamiueal column has become ' tripped.' No evidence 

 was found to favor Burkill's theory that tripping effects the rupture of the 

 stigmatic cells and that this is an important factor in fertilization. Flowers 

 tripped in various ways to prevent any stimulation or rupturing of the stigma 

 by contact set pods equally as well as those tripped naturally. 



" Flowers tripped artificially, and therefore self -pollinated, set pods freely. 

 In one series of experiments on 77 plants at 7 different places, 9,074 flowers set 

 2,784 pods when artificially tripped (a percentage of 30.68), while 8,9.39 flowers 

 on the same j)Iants exposed to natural conditions set 1,499 pods (16.76 per cent). 

 The pods from artificially tripped flowers contained an average of 1.72 seeds 

 each, while those from naturally tripped flowers averaged 2.22 seeds each. 



" Pollination from a different flower on the same plant is no more effective 

 than self-pollination, but pollen from another plant increases both the propor- 

 tion of pods set and the number of seeds per pod. It makes but little differ- 

 ence whether the pollen parent be the same or a different variety. . . . 



" There is a wide range of variability in alfalfa plants as regards the readi- 

 ness with which the flowers become tripped, either automatically or by the 



