DISEASES OF PLANTS. 848 



mallties, the author states that along with the well known " mole " character- 

 istic of their Invasion by Hypomyces pemiciosus there exist also in both these 

 and wild mushrooms other characteristic deformities or ruptures. Some of 

 these are due to parasitism, as evidenced by a characteristic odor and other 

 indications of the organic nature of the trouble, which has been noted in con- 

 nection with the presence of certain plant mites. 



Plus and minus strains in the genus Glomerella, C. W. Edgebton (Amer. 

 Jour. Bot., 1 (1914), No. 5, pp. 2U-254, pis. 2, fig. i).— The substance of this 

 contribution has already been noted from another source (E. S. R., 30, p. 745). 



A study of the physiological relations of Sclerotinia cinerea, J. S. Cooley 

 {Ann. Missouri Bot. Gard., 1 (1914), No. 3, pp. 291-326).— A report is given of an 

 experimental study on the physiological activities of the brown rot fungus of 

 stone fruits, in which the conditions influencing the penetration and infection 

 of green and ripe fruits by the fungus were studied as well as the action of 

 the parasite on the host cells and the secretion of enzyms which act upon the 

 cellulose and pectic substances of the host. 



It was found that the brown rot organism infects immature fruit provided 

 the skin is punctured, while on the other hand ripe or nearly ripe fruits may be 

 readily Inoculated through the unpunctured surface. The fungus was found to 

 penetrate with equal ease any part of the host tissue, showing no preference 

 for the middle lamella. No evidence was found that the fungus secreted a 

 toxic substance in advance of penetration. An aqueous solution of pectin 

 isolated from plums was coagulated by the fungus, indicating the secretion 

 of pectinase. The changing acidity of the host as the fruit reaches maturity 

 was not considered sufficient to explain the fact that ripe fruit is more sus- 

 ceptible to the disease than green fruit. 



A bibliography is appended. 



Protection against Spheerotheca mors-uvae, D. Hegyi (Rev. Phytopath. 

 AppL, 1 U914), -A^o. 22-23, pp. 30, 31).— The author reports that in experiments 

 since 1909 looking toward control of gooseberiy mildew it was found that treat- 

 ment with liver of sulphur caused fall of both fruit and leaves, also that iron 

 sulphate had little effect on the disease. Bordeaux mixture, however, ai^plled 

 once or twice during the winter at 5 per cent and in early spring at 1 per cent 

 strength, or lime sulphur employed according to plans outlined, is an efficient 

 means of defense against this fungus. 



The status of investigational work on pear and apple blight, D. B. Swingle 

 {Montana Sta. Circ. 39 {1914), PP- 13-16). — The author gives a summary of 

 work that has been carried on by this Department and various experiment 

 stations on the cause and methods of control of pear and apple blight due to 

 Bacillus amylovorus. ' 



Black spot of the mandarin {Agr. Oaz. N. S. Wales, 25 {1914), No. 8, p. 

 684)- — The prevalence of black spot in mandarin orchards in New South Wales 

 is reported. Pending experiments for combating the disease, it is recommended 

 that Infected trees be severely pruned, and after pruning the trees and ground 

 beneath should be sprayed with Bordeaux mixture or lime sulphur, three appli- 

 cations during the season being considered sufficient. 



Spraying experiments with the peach and grape in 1912, E. Pantanelli 

 {8tas. Sper. Agr. Ital., 46 {1913), No. 5, pp. 329-346) .—Reporting on later 

 experiments (E. S. R., 27, p. 855), the author states that polysulphids of cal- 

 cium and barium, kept in sealed receptacles and diluted at the time of appli- 

 cation, were found to be efficacious in controlling Exoascus defornKins on the 

 peach, but not Plasmopara viticola on the grape. Bordeaux mixture gave good 

 results against P. viticola. Self-boiled lime sulphur proved helpful against E. 

 deformans on peach, also against Monilia dkerea. 



