648 EXPERIMENT STATION EECORD. 



(6) the mycelium iuside the tubers is sterilized when subjected to a dry heat 

 of from 48 to 50° for 4 hours without injury to the vitality of the potatoes. 



The leaf roll disease of the potato in moor lands, W. Bejisch {Ztschr. 

 MoorkultuK u. Torfvcrwcrt., 8 {1910). No. 2, pp. 90-96, figs. 2).— Attention is 

 called to the gradual spread of this disease to potatoes cultivated on both high 

 aftd low moor lands. In some instances the disease appeared on land which 

 for the first time had been planted in potatoes, thus excluding the possibility 

 of the infection coming from the soil. A record is given of 3 varieties of pota- 

 toes which for 4 years have proved highly resistant to the disease, as evi- 

 denced by a practically undiminished yield during that time. 



The author gives the characteristics of this disease during its progressive 

 development, from the first year, which usually shows only discolored fibro- 

 vascular bundles, to the third year of dwarfed plants, curled leaves, and 

 small greenish tubers, which often lie on or near the surface of the soil. By 

 this time the disease has usually reached its maximum of intensity in any 

 given locality and for any siieclal variety of potatoes. 



Our present knowledg'e of the leaf roll disease of the potato, G. Kock 

 (Monatsh. Landw., 2 {1909), p. 379; abs. in CentU. Bakt. [etc.], 2. AM., 26 

 {1910), No. 25, pp. 697, 69S).— After briefly reviewing the theories held by 

 various investigators as to the cause of this disease, the author states that so 

 far inoculation experiments with Fusarium solani, F. schachtii, F. oxysporiim, 

 and Yerticillium on healthy potato plants have given only negative results. 

 Nevertheless it seems certain that the disease, at least during its earlier stages, is 

 due to a fungus parasite which is transmitted through the seed tubers and 

 tmder certain conditions by means of infected soil. 



Investig'ations on the cause of the heart or dry rot of the sugar beet, 

 W. RuHLAND and K. Albrecht {Mitt. K. Biol. Anst. Land u. Forstw., 1910, No. 

 10, p. 16). — In a brief discussion of the claim that heart or dry rot of beets 

 is caused by the fungus Phoma brtw it is stated that neither by experiments 

 nor by the direct exiiniination of the diseased beets has it lieen possible to show 

 that P. hctir is the primary cause of the disease. 



Cultural experiments on the control of the heart or dry rot of the beet, 

 W. RuHLAND and K. Albrecht {Mitt. K. Biol. Anst. Land ti. Forstw., 1910, 

 No. 10, p. 17). — Several varieties of sugar beets were tested for their resistance 

 to this disease. Experiments were also conducted on the use of ammonia 

 nitrogen in place of nitrate nitrogen, but no essentially new results were 

 obtained. 



Some sugar cane diseases, C. W. Edgerton {Louisiana Bias. Bill. 120, pp. 

 3-28. fiffs. 12). — On account of the difficulty in obtaining good stands of cane 

 during the past season, investigations as to the cause were made. The trouble 

 was found to be due primarily to several fungus diseases which have been much 

 more severe this year than usual, partly on account of the very dry spring, this 

 reducing the vitality of the cane and thus making it more susceptible to the 

 diseases. 



Red rot {Colletotrichuni falcatum), rind disease {Melancnniuni sacchari), 

 and root rot {Marasinius plica t us), are widely distributed over the State, while 

 the pineai)ple disease {TJiiclariopsjs etltaceticus) is known in only one parish. 



The distribution in the State, chnracteristics of each fungus, damage to the 

 cane, and methods of treatment are given. 



The root diseases of the sugar cane in Barbados {West Indian BuL, 10 {1910), 

 No. If, pp. 3.>i7-3.it9) . — In response to a letter of inquiry concerning the prevalence 

 and hosts of the root disease of sugar cane {Marasmiux sacchari). it is stated 

 that the disease is very prevalent- in Barbados and is increasing in extent and 



