DISEASES OF PLANTS. 1049 



A second form of (li\v rot wliirli is not uiicoiiunon is duo to a siiccies of 

 Fiisnriiini. A third form, noticed for the first time the i)ast season, is due to 

 a sterile fuufrns. The inftn-tion in tliis case, with few exceptions, talces place 

 at the ti]) of the ear and the myceliinn soon develops a deep jiink color. The 

 effect on the corn is nuich the same as that produced by the later infections of 

 Diplodia. Other forms of rot have been found due to other sjjecies of Fusariuni, 

 and one or two forms to si)ecies of bacteria. 



The physiology of the sore shin disease of cotton and means for its con- 

 trol, W. L. Balls {Ynirbndk Khcdlr. Ayr. .s'or. Cuiii,, lUiHi. pji. D.i-lll, pis. J,, 

 ill/Ill. /). — The sore shin of cotton, due to a sterile funsius, is said to have 

 assumed jii'Pi^t economic imi)ortance in Egy|»t since the itreliminary note by the 

 author (K. S. It.. IS, p. rt~i'2). The disease ap])ears to occur locally and at times 

 (luite destructively, and soil conditions seem to be resjionsible to a great degree 

 f(»r the occurrence and distribution of the fungus. There appear to be two dis- 

 tinct periods of attack. The first, which occurs almost immediately after the 

 germination of the seed, causes the greatest amount of loss. At this time the 

 jiriniary root is attacked and many plants fail to appear above the ground. The 

 secondary attack comes later, is made on the hypocotyl, and is less destructive. 



Bare fallow and good tilth of soil tend to reduce the percentage of loss. As 

 the disease appears to be closely associated with the germination of the cotton 

 seed, exjjeriments were conducted in treating the seed, from which it was found 

 that the disease could be checked by di'essing the seed with naphthalin, using 

 from 1h to 3 per cent, according to soil texture. As a means for causing the 

 naphthalin to adhere to the seed, gypsum was found satisfactory. The cost of 

 the treatment need not exceed 2.5 cts. per acre, which can be more than saved 

 by the reduction in the amount of seed required. This treatment is said to pro- 

 tect the plants for about 20 days after the first irrigation, and most of the 

 damage is done during this period. As the rough condition of the soil seems to 

 favor the di.sease, the author states that cotton should not be grown after late 

 berseeuL When it does follow this crop, the latter should be plowed up soon 

 enough to ]»ermit of thorough cultivation. 



Notes on the hop mildew, E. S. Salmon (Jour. Agr. ScL, 2 (1907), No. 3, 

 pp. 327-332, figs. 6). — A study is reported of the dehiscence of the perithecinm 

 of the hoi) mildew {t^pharothcca Jtumuli), in which it is shown that it differs 

 very materially from the dehiscence of the grass mildew (FJrijsiplic gr(tniinis). 



A number of inoculation experiments were conducted in which conidia were 

 transferred to hops from a number of host plants which bear a morphologically 

 similar si)ecies, and vice versa. The evidence obtained indicates that the 

 morjthological species occurring on the hop will not infest a number of rosa- 

 ceous species, all of which are hosts for a species which can not be distinguished 

 by any morphological characters from the mildew occurring on the hop. 



Diseases of potatoes, G. Gandara (Bol. Sec. Fomento [Mexico], 2. srr., 7 

 (J 907), \o. Jj, I, pp. 197-203, pi. 1, fig. 1). — The author enumerates and briefly 

 describes a number of organisms which cause diseases of potatoes, and gives 

 directions for the formaldehyde and corrosive sublimate treatments of seed 

 potatoes for the prevention of the different kinds of jiotato scab. 



The heart rot of sug^ar beets, C Merlk (fiucr. Indig. ct Colon., 71 {1908), 

 No. .'i, pp. 91-97). — An account is given of experiments for the control of the 

 heart rot of sugar beets, due to the fungus Phomn hcttv. 



This disease is said to make its appearance usually during the dry seasons, 

 generally during August and the first part of September. It is especially trou- 

 blesome on tertiary clay soils. i)articularly those containing considerable quan- 

 tities of silica, t'naerated subsoils and soils lacking in humidity during the 



