884 EXPERIMENT STATION RECORD. 



Report on charlock spraying, W. Bruce {Edinburgh and East of Scotland Col. 

 Agr. Bui. •>', 1904, i>i>- 10, figs. .'). — A repori is given <>f experiments carried on in 

 1902 and L903 for the eradication of charlock among cereals. The investigations 

 were conducted on L'4 farms in different parts of Scotland, 6 acres or more being 



treated at each center, and in some cases as much as 20 acres being sprayed. The 

 treatment recommended is spraying while the plants are young with a ."> per cent 

 solution of copper sulphate at the rate of - r )() gal. per acre. In many cases a single 

 application is all that will he needed, but if the plants have attained considerable 

 size a second may be required. In order to realize the full advantage of the spray- 

 ing, other methods, such as cultural methods, etc., should be diligently practiced. 



Concerning the change of hosts of dodders, F. Nobhe and J. Simon (Landw. 

 Vers. SUit.,61 (1904), No. l-4,pp. 313-317). — The authors describe experiments made 

 to determine the host plants of a number of species of dodder. 



In the first series reported small plats of flax and red, white, and alsike clover were 

 sown, together with seed of a species of dodder known to infest each particular host 

 plant, and also seed of as many of the other species of dodder as were available. In 

 August the plats showed that the flax was strongly attacked by the common Max 

 dodder; the red clover was either wholly free from dodder or only a few plants were 

 to be found, although 8 species of dodder seed had been used; the white clover was 

 strongly attacked by dodder from red clover, from alsike clover, ami by Cuscuta 

 racemosa; and the alsike clover was attacked by the red clover dodder and by its own 

 common parasite, but not by < '. racemosa or other species. 



In another series of experiments red, white, alsike, and Egyptian clovers were 

 grown as seedlings in pots, and after the plants had attained some growth the 

 authors transferred from filter paper to the pots a number of dodder seedlings, 

 placing them in contact with the clover plants. The red clover became infested to a 

 greater or less extent with C. chiliana, < '. racemosa, < '. epilinum, and C. trifolii, while 

 ('. africana and dodder from alsike clover failed to become established. C. trifolii 

 became estahlished on white clover, while ( '. racemosa failed. Alsike clover was 

 attacked only by C. trifolii, and upon the Egyptian clover C. africana failed to grow, 

 although the dodder seed had been separated from the Egyptian clover seed. 



The germinative ability of dodder seed grown upon host plants other than their 

 usual ones was tested and found to range from 0.66 per cent for ('. trifolii grown on 

 alsike clover to 100 per cent for < '. epilinum on the different hosts. 



DISEASES OF PLANTS. 



Report of the section for plant protection, Hohenheim, 1903, O. Kirchner 

 (Ber. Tiit. K. Anst. Pflanzenschutz, Hohenheim, 1903, pp. 19). — Brief summaries are 

 given of the various diseases of plants observed during the year covered by the report, 

 and brief accounts of the investigations carried on for their control. The diseases 

 are grouped under their appropriate host plants, as cereals, potatoes, forage plants, 

 garden plants, fruit trees, grapes, etc. 



The smuts of cereals and means for combating them, 0. Rose ( Tnaug. Diss., 

 Univ. Rostock, 1903, pp. 59, pis. 2). — A review is given of the present status of knowl- 

 edge relating to the smuts of cereals, and the author describes the various factors 

 favoring or retarding the development of the fungi causing these diseases. The 

 susceptibility of different varieties of cereals to smuts is pointed out, after which the 

 influence of time of seeding, the effect of soil temperatures, fertilizers, etc., are dis- 

 cussed, and the results of experiments for combating smuts are given. 



The naked barleys, whether early or late sown, are especially subject to smut, the 

 two-rowed varieties of barley are less subject to disease, while the many-rowed 

 varieties with closely adherent glumes are least subject to smut. No variety of spelt 



