FIELD CROPS. 635 



riy and the w.inii wcatliiM- and tiiiioly rains in SeptenilxT fav«)re<l tlu> (sirly 

 seeding, while cool weather in October and November chtH-ked the growth of 

 the later seeding. 



Wheat culture tests of the Silesian wheat growers' association, 1906-1908, 

 Opitz {Ztschr. Landic. Kammcr Schlesien, 13 (1909), No. 35. pp. lO.'fO-lO.'fS).— 

 The results of this cooperative experiment indicated the superiority of Leute- 

 witz squarehead and Strube Schlanstedt sqnarehead wheats, the average yields 

 of these varieties being 2,!)87 and 2.S45.5 kg. per hectare ( 2.<;oS and 2,531 lbs. 

 per acre), respectively. These sorts also prodnced the stiffest straw. The 

 resnlts for all varieties of each individnal test are given in tables. 



Grain yields of the world in 1907 (Die Gctreideeriitc drr Welt im Jahre 

 J907. BiKhipest: Govt.. J908, 2. ed., pp. .',5). — The production of different grains 

 in all the principal grain-prodncing countries of the world is briefly noted. 



Production of the principal grains in 1908 (Ernteergebnis der Wichtigsten 

 h'onterfriichte iniJoliie li)l)S. Vienna, I90S, pp. 12, dgina. 5). — Statistics on the 

 production of wheat, rye, barley, oats, and maize in the Austrian Empire are 

 presented. 



Weeds; their eradication and control. (}. E. Adams (Rlnidc Island t^ta. Bui. 

 133, pp. 51-61, pis. 2). — A classification of weeds is given in this bulletin, gen- 

 eral methods of control are pointed out. and the results of experiments with 

 iron sulphate in eradicating certain weeds are briefly reported. 



It was found that solutions of this substance can be used to control the daisy 

 in hay fields, mustard in cereal fields, and dandelions on lawns. Charlock 

 (Rapltanus raplianistrmn) proved resistant to the iron suli)iiate spray. The 

 most satisfactory results were obtained from the use of a 20 per cent solution, 

 applying about 1(X> to 150 lbs. of iron sulphate per acre. It is stated that suc- 

 cess depends upon the ap])lication of the solution in a fine spray and in a forci- 

 ble manner at the proper stage of growth. 



The eradication of bindweed, or wild morning-glory, II. K. Cox ( U. 8. 

 Dept. Agr., Farmers' Bui. 3(i8, pp. 19, figs. 6). — This bulletin contains a descrip- 

 tion of the different plants known as bindweed and presents methods of their 

 eradication. 



The most ti'oublesome species are hedge bindweed (Convolvulus sepium) and 

 field bindweed (C. arvensis), while C. sepium repens and C. californieus are of 

 secondary importance. It is pointed out that hedge bindweed is propagated by 

 rootstocks and field bindweed by roots, and that the top growth of the plants 

 nnist be kept down to starve out the roots and rootstocks as one of the principal 

 steps in their eradication. Clean cultivation, especially with implements that 

 will keep down the top growth is advised. It is also stated that the bindweed 

 may be greatly reduced or entirely destroyed by seeding the land to alfalfa and 

 then following this plant with a cultivated crop. The use of chemicals as a 

 method of eradicating bindweed has not been found very successful. 



The cultivation of Passiflora fcetida and Mikania scandens to keep down 

 other weeds, M. K. Bamber (Vires, and Agr. Jour. 7>'o//. Bot. Card. Cei/lon, 

 .'/ (1909). \o. 16. pp. 1.'il-l.'i5, pi. /). — The value of these two plants in subduing 

 other undesirable tropical growth is iiointed out and mechanical and chemical 

 analyses of the two species are rejwrted. 



P. fcetida loses on an average about 70 per cent of moisture on sun drying, 

 and produces about T.SOO lbs. of air-dried material per acre, which contains jis 

 shown by the analyses 169 lbs. of nitrogen and .500 lbs. of ash. the latter includ- 

 ing ].").(') llts. of lime, 85 lbs. of potash, and 20.3 lbs. of phosphoric acid. M. 

 scandens lost over 85 per cent of moisture on air drying. This species differs 

 largely from the foregoing in containing only abonl one-J'ourtli as niucli lime 

 and two and one-half times as much [totash. 



