50 EXPEKIME^STT STATION RECORD. [Vol. 41 



borne on heavily infested seedlings not germinating so well as those produced 

 on plants approaching maturity. A still, humid atmosphere favored the rapid 

 maturity of the spores, and spores detached from the host plant and stored 

 in dry capsules at 13 to 20° showed increasing germination after six or seven 

 days. 



The biologic form of crown rust occurring on oats uses R. cathartica and 

 R. lanceolata as alternate hosts. R. frangula, R. caroliniana, and R. alnifolia, 

 other species occurring within the State, were not found to harbor the alter- 

 nate stage of the strain of crown rust occurring on oats. 



Data concerning the dissemination of wheat rust, F. U. G. Agrelius ( Trans. 

 Kans. Acad. ScL, 28 (1916-17), pp. 115-111). — It is believed that the persist- 

 ence and succession of wheat ruNC (PuccUiia graminis) without the secidial 

 stage in the neighborhood of Oswego, Kans., are due to the presence of many 

 native (and mostly perennial) grasses, in some cases intimately associated 

 with cultivated grains. The grasses retain their green color and are evi- 

 dently infected with the fungus. Panictim virgatum appeared to harbor 

 Puccinia graminis. 



Report of celeiy investigation, R. F. Poole {New Jersey Stas. Rpt. 1911, 

 pp. 586-539). — Field and greenhouse experiments have been carried on for the 

 control of celery diseases, the principal of which were tlie crown rot due to 

 Bacterium sp., damping-off or stem rot (Sclerotinia lihertiana), root knot 

 caused by nematodes, early blight {Cercospora apii), and late blight {Septoria 

 petroselini apii). Damping-off due to Rliizoctonia sp. is reported to have given 

 trouble in one greenhouse during the spring. 



For the control of the crown rot due to Bacteriium sp., a series of experi- 

 ments in sterilization of the soil with various chemicals was carried out, 

 and while the disease was not controlled the results indicate some promise 

 for hydrochloric acid and calcium carbonate. The author believes that plant 

 breeding offers the best solution of the problem of control of crown rot, as 

 some varieties seem to possess considerable immunity. 



For the control of the damping-oL" due to Sclerotinia Uiertiana, an experi- 

 ment was carried out in which beds were divided into sections, one of which 

 was thinned, the diseased plants being removed, and sodium nitrate added to 

 the soil ; the second was not thinned, but sodium nitrate was added to the 

 soil; the third was thinned, the diseased plants being removed, but no sodium 

 nitrate was added; and the fourth, which was given no treatment, was used 

 as a check. Where the diseased plants were removed and the fertilizer added 

 the best growth was made, very few plants dying. Where all diseased plants 

 were removed and no fertilizer added only a few dead plants were observed. 

 In the other plats many plants succumbed. 



For the control of early blight and late blight, both of which did consid- 

 erable damage, spraying with Bordeaux mixture is recommended. 



The angular leaf spot of cotton, R. C. Faulwetter {South Carolina Sta. 

 Bui. 198 {1919), pp. Ifl, figs. 11). — In continuation of pi-evious studies on the 

 physiology of Bacterium, mulvacearum (E. S. R., 36, p. 648) and rain as a factor 

 In disease dissemination (E. S. R., 38, p. 47) the author brings together the 

 data obtained by him in the course of his investigations, which have covered a 

 period of several years. 



The disea.se caused by B. malvacearum, while most noticeable on the foliage 

 of cotton, may also be found on the cotyledons, stalks, petioles, bracts, and bolls. 

 The factors most probably concerned in the hibernation and appearance of the 

 disease are said to be the presence of bacteria in the soil, their survival in de- 

 caying cotton plants and plant parts, contamination of fuzz or short lint on the 

 seed, internal seed infection, hibernation upon or In insects, and susceptibility 



