746 EXPERIMENT STATION RECORD. 



from ; avoidance of suspected seed, or treatment thereof as directed ; destruction 

 of weeds on embanliments ; spacing from 10 to 14 in. apart ; and rotation of crops 

 or of varieties wliere possible. 



[Report of the assistant in plant pathology], J. H. IMuncie (Michigan Sta. 

 Rpt. 1915, p. 211). — Tlie author's investigations have been confined to a study 

 of bean diseases, particularly in connection with measures for control of an- 

 thracnose and blight. It is believed that by growing early-maturing varieties 

 of beans to a large extent the losses hitherto reported might be eliminated. 

 Some experiments are being carrieil o\it to determine whether or not the bean 

 disease organisms may winter over in the soil and attack the next year's crop. 



Pseudomonas phaseoli in beans, W. Giltneb, C. W. PJkown, and S. T. Sapiko 

 {ilkhif/an ^ta. L'pt. 1015, p. 20S). — On account of the possibility of seed bean 

 infection, the authors. have made an examination of the presence of bacteria 

 causing bacteriosis of beans. 



It was found that seed from diseased pods may or may not contain the causal 

 organism, and that healthy-looking, clean beans from diseased pods may contain, 

 a few weeks after ripening, from 100,000 to S.OOO.aM) l)a(teria per bean, while 

 discolored ones may contain from 1.000.000 to 100.0(X).(X)0 bacteria. Only 4 

 out of 27 discolored beans which liad been kept for a year in a dry room showed 

 the presence of living bacteria. As P. phaseoli was found to make fair growth 

 on nutrient agar containing 2 per cent copper sulphate, the treatment of beans 

 with copper sulphate is not considered of much value in the control of bean 

 Ijacteriosis. 



Phytophthora disease of gingseng, .1. Uosk.nravm {Xcw York Conull Sta. 

 Bui. .%'.? {1!U5), pp. G.i-jnG. fiiiH. /?).— The n-sults are given of a study carrinl 

 on in cooperation with this I)t'i)artment of the Thytophthora disease of ginseng, 

 which was first reported in the Unit»Ml States by Van Hook (E. S. R., 18, p. 342) 

 and which was studied by Hori in Japan (K. S. R., 19, p. 752). The symptoms 

 of the disease, its cause, patliogenicity of the organism (P. cactorum), the life 

 history, and the morphology' of the fungus are descrlbeil at length, after which 

 results of experiments in control are given. Si»raying with fungicides, removal 

 of diseased tops or roots of plants, dtvp planting, crop rotation, sterilization 

 of tht' soil, and adequate draij\age are suggesteil. 



Spraying of peanuts for leaf rust, W. Nowell {.\(jr. Ncirs [Barbado.<<]. 14 

 (/.'»/.'>), Xo. iM}2, p. S50). — Information taken from a report by W. Robson regard- 

 ing spraying for the control of pi'anut rust (Urcdo aja<hi*liJi) indicates that 

 the fungus is effectively controlled by spraying with Bordeaux mixture, the 

 yield being increased about 28 per cent in one instance. 



The degree of infestation by this fungus depends largely upon conditions of 

 soil and climate. Under favoral)le conditions oidy those leaves which are ap- 

 proaching senility are attacked, but luifavorable circumstances result some- 

 times in the death of the whole plant. This fact leads to varying results from 

 spraying at dilTerent times and places. 



Studies of health in potatoes, C. L. Fitch (Colorado Sta. Bui. 216 (1915), 

 pp. 3-31, figs. 17). — On accoinit of the serious losses experiencetl by potato 

 growers in parts of Colora<lo, the author made an investigation of some of the 

 factors which influence the health of the potato plant. Field and lal)orat<^ry 

 studies were made of soil temperature, moisture, irrigation, and the roots and 

 leaves of the potato plant. 



The conclusion was reached that high soil temperatures, which cKCur in years 

 of more than average sunshine, and soakage of soil causing a lack of aer.-ition 

 are among the most im]iortant factors contributing to the loss. The presence 

 of hyplia? of Fusarluiu was noted in unheidlliy plants, but it is thought that (he 

 occurrence of the Fusarluni is secondary to (he effects proiluced by \uifavor:ible 



