FIELD CROPS. 227 



Oil the leaves and involucral bracts of cotton to determiue whetlier they can be 

 used as diagnostic characters for the chissitication of species of Gossypium. 



Symbiosis in fern prothallia, D. H. Campbell (Amer. Xat., ^2 (1908), No. 

 495. pp. 154-165, pgx. 3). — Attention is called to the fact that the anthor reported 

 in 1895 the presence of an endophytic fungus in the prothallium of Botnjcliiiim 

 rirgiiiiamiin. Studies have since been made of a number of other species of 

 ferns that sht)w conclusively that an endophytic fungus is normally present in 

 the green prothallia of several additional species, and it is highly probable that 

 further research will show similar fungus endophytes in other ferns. 



FIELD CROPS. 



Dry farming- in Idaho, E. Nelson ihlaho Sta. Bui. 62, pp. 3-Ji2, figs. 2, 

 mnp 1). — Experiments were carried on near Caldwell by tlie station in coopera- 

 tion with this Ottice to determine the best methods of cultivation for different 

 dry-laud crops. These experiments were begun in October, 1906, and as the 

 work in 1907 was largely preliminary only few references to results obtained 

 are made. The bulletin treats of dry farming in a general way, giving its 

 history, discussing climatic and soil conditions in regions where dry farming 

 is practiced or is feasible, and describing the advantages of different methods 

 followed in producing crops under dry-land conditions. The monthly precipi- 

 tation at 46 different points in the State for recent years is given in a table. 

 At Caldwell the yearly precipitation is 10.32 in. 



It is stated that the surface soil in the Snake River plains will hold per 

 cubic foot I8.6.5 lbs. of moisture in the form of capillary water, or 22.46 per 

 cent of the dry weight of the soil. The author observed that a certain deep 

 clay loam had become moist to the depth of only 18 in. during winter. When 

 tested in April it contained 4.85 in. of water in the first 3 ft. of soil, but in the 

 latter iiart of August it contained only 2.32 in., and this entirely hygroscopic 

 iiKiisture. The rainfall during the period had been 4.53 in., thus making a total 

 of 7.06 in. evai)orated in 3 months. The tests were made on unbroken ground. 

 Ou summer fallow plats at Caldwell, wliich had been disked and harrowed early, 

 the moisture content in June after plowing and establishing a dry mulch was 7.03 

 in. in 3 ft. of soil, while late in September it was still 6.55 in., showing a loss 

 (if only 0.48 in. The moisture content on new land plowed in spring and cropped 

 ill 1907 was 16.63 per cent, 19.20 per cent, and 17.04 per cent for the first, second, 

 and third foot, respectively, at planting time, and 5.98 per cent, 10.88 per cent, 

 and 13.17 per cent for the first, second, and third foot, respectively, at harvest 

 time. 



The different varieties enumerated as adapted to southern Idaho dry-laud 

 conditions are as follows: Winter wheat, Turkey Red, Forty-fold, Gold Coin, 

 Lofthouse, Jones Fife, Odessa, and Canada Hybrid ; spring wheat, Kubanka, 

 P.luestem, Little Club, Red Chaff, Jenkins, Early Wilbur, and Sonora ; oat.s, 

 Si.xty Day, Kherson, Big Four, and P>lack American ; barley. Beardless and 

 Smooth PInlless: potatoes, Early Ohio, Early Acme, Six Week.s, and Early 

 Eureka. Rye, enimer, Polisli wlieat, alfalfa, field peas. Dwarf milo maize, 

 white durra, flint corn, and bronie grass are also successfully grown. 



On the plains about 15 bu. of wheat per acre niay.be grown by dry-farming 

 methods. It is estimated that the cost of producing wheat in Idaho, not includ- 

 ing thrashing and marketing, is $3 per acre when the work is performed by the 

 farmer, and .$5..30 per acre when the work is contracted. 



Dry-land farming- in the Great Plains area, E. C. Chilcott iV. ^. Dcpt. 

 Agr. Ycdrhool: l!l07. iip. //.■;/- '/6'8. flf/x. 2). — This article discusses the Great 

 Plains area as a field for investigation, considers the climate of the region and 



