DTSEASES OF PLANTS. 845 



C'iUTiod on for a consiclerable ])erio(l. tlio autlior has determined that the stem 

 canla>r and the drop of cahhajres are manifestations of tlie same disease, hotli 

 bein,u caused liy the funfxus I'Iioiiki (ilcidccd. A techincal description is given 

 of file l'nn.!,'ns, and the effect wliicli it prochices upon tlie host plant is descrilied. 



Tlie practice of leaving cabbage stallcs standing in the field is conden)ned, as 

 the fungus is carried over the winter in them. Investigations seem to indicate 

 that the fungus can not attack sound roots, lait nuist find entrance through 

 wounds and insect injuries. In the latter class especial attention is called to 

 the ca])bage maggot { Aiiflioiiinin hrax.sica'), which should be rigonmsly attacked 

 in order to ])revent injuries which may he followed by the fungus. , 



A spot disease of stone fruits, 1'. Vocjlino {Italia Af/r., 1!)07, pi). iJ, 13, jil. 1; 

 abs. ill li'ir. I'atnl. ]'('</., ,i {Ifliil), No. 7. pp. JO), U).'>). — A disease of cherries, 

 peaches, and almonds, in which the leaves, twigs, ;md maturing fruits are 

 attacked by the fmigus Vla.stcrospuiiuiii cariiopliilum, is described. The fungus 

 produces discolored s])ots on the foliage and soon the tissues in these areas dry 

 and fall out, the leaves presenting a ragged api)earance. Sometimes a copicms 

 exudation of gum accompanies the disease, but the author was unable to (>stab- 

 lish any I'elation iietween the fungus and the formation of gum. It is believed 

 that the gum is due to the arrested development of the cambium. 



S] (raying trees at frequent intervals with a 5 per cent solution of eoijper and 

 iron sulphate and lime has given good results. The application of a solution 

 of 10 per cent iron sulphate and 5 pel' cent lime to the trees during winter is 

 reconmiended as an additional precaution. 



Pear canker and means for its control, G. Paparozzi (Roihc: Offlc. PoU- 

 (jrafica Ital., 1006, pp. 29, figs. 7; ahs. in, Riv. Patol. Vey., 2 (1907), No. 7, pp. 

 103, lO.'i). — An experimental study was carried on to determine the etiology of 

 pear canker, the relative resistance or predisposition of different varieties to 

 the disease, and the efticiency of various methods of control. 



The cause of the canker was found to be the fungus Nectria dltissima follow- 

 ing frost injuries. If protected from the action of cold no canker was found 

 en pear trees. Wide variations were found in predisposition to the disease, and 

 in making plantings in exposed regions susceptible varieties should be omitted. 

 When cankered areas are observed on trees they should be cut out, and the 

 wound treated with carbolic acid or corrosive sublimate, after which it may be 

 covered with a mixture of resin, alcohol, and coal dust. 



Experience in combating grape downy mildew in 1906, IIensleb {Pral;t. 

 lil. r/loiizrnbaii u. Hchutz, ii. ser., .'> {1907), \o. 2, pp. 18-23). — An account of a 

 series of experiments with P.ordeaux mixture for the prevention of downy mil- 

 dew of grapes due to Peronospora viticola. 



Various strengths of the fungicide were used, and although the season was 

 a very rainy one, the results obtained were so encouraging that the author feels 

 warranted in recommending the treatments for 1907. He suggests that the 

 vines be thoroughly sprayed with not less than a 2 per cent solution of Bor- 

 deaux nuxture. The first api)lication should be given in ;\Iay when the young 

 shoots have attained a length of "20 to 25 cm. The second spraying should be 

 made just before the opening of the flowers, followed by a third inmi^diately 

 iTfter the flowering period is over. Two or more additional applications should 

 be given at intervals during the season, depending on the state of the weather 

 and the development of the fruit. There is said to be no economy in the use 

 of v<>ry dilute solutions, and thoroughness of application to all parts of the 

 vine is a jirime requisite for the success of the treatment. 



Localized stem blight in Ohio vineyards, A. D. Sklby and J. M. Van Hook 

 (Ohio Sta. Ciir: (].',. pp. 6, figs. 2).— In .Vugust. 1906, the authors' attention was 

 called to an extensive dying of grapevines in Ashtabula County, Ohio. The 



