752 EXPEEIMENT STATION KECORD. [VoL 36 



susceptible plants, aud, in tlie author's opiuiou, there is reason to believe that 

 it is an ultramicroscopic parasite of some kind. 



Mosaic disease of tobacco and tomatoes (Gard. Chron., S. ser., 59 {1916), 

 No. 1526, pp. 112, i?.?).— This is a discussion of the report of Clinton regarding 

 calico tlisoaso of solanaceous plants (E. S. K., 34, p. 52). 



Armillaria mellea killing- fruit trees {Agr. Gaz. N. S. Walts, 27 {1916), No. 

 1, p. 16). — It is stated that a disease killing apple, peach, nectarine, plum, and 

 other fruit trees has been found by E. Mackinnon to be caused by the honey 

 fungus, A. mcllca, previously noted (E. S. R., 33, p. 149) in connection with 

 citrus trees. 



If the parasite is found on the roots in the form of brown strands, all dead 

 portions should be removed and the diseased areas scraped and treated with 

 strong Bordeaux paste, made up of copper sulphate 1.5 lbs., quick lime 1 lb., 

 and water 2 gal., and applied with a brush. Wounds should be dressed with 

 Stockholm tar and the lower trunk and adjacent roots left exposed to the air 

 from three to four weeks. 



Spraying experiments and apple diseases in 1915, W. J. Mobse {Maine Sta. 

 Bui. 252 {1916), pp. 167-192, pis. 2). — This bulletin gives an acct»unt of apple 

 spraying experiments carried on for the prevention of apple scab, describes 

 winter injury to trees set in dynamited holes, and discusses two apple-leaf 

 troubles, chlorosis and silver leaf, which are said to be new in Maine, and the 

 overwintering of the apple-scab fungus on apple twigs. 



The work on spraying is in continuation of a series of experiments which 

 have been in progress for a number of years, and a summary of the results 

 has already been given (E. S. R.. 35, p. 549). In 1915, the scab developed to 

 such a slight extent on the experimental plats even where no spray was applied 

 that the results are considered less conclusive than in previous years. The 

 application of Bordeaux mixture in connection with arsenate of lead resulted 

 in considerable russeting of the fi-uit. The highest percentages of perfect 

 apples were obtained from those trees which received a blossom bud application 

 of a rather strong lime-sulphur solution to which lead arsenate was added, 

 followed by two applications of lead arsenate, and from trees which were 

 treated with lead arsenate alone. The application of dormant strength lime- 

 sulphur after the leaf buds had begun to open, but at a time when the flower 

 buds were still thoroughly protected, increased the amount of fruit russeting 

 in a way that does not seem to be readily explained. The author, as a result 

 of his investigations, does not consider the applying of dormant sprays later 

 than usually recommended for use against scale and similar insects as of advan- 

 tage from the standpoint of scab prevention. 



An account is given of winter injury to Baldwin apple trees set in dynamited 

 holes, comparison being made with those planted in dug holes. The trees were 

 planted in 1913 in a soil having a hardpan subsoil, and in 1915, out of 126 

 trees set in holes previously dynamited, 49 were either winterkilled or badly 

 Injured, while of 52 trees set in shovel-dug holes, only 4 suffered in a like 

 manner. No attempt is made to draw general conclusions from these figures, 

 but it is believed that the method of setting trees in dynamited holes is not 

 adapted to soil conditions at the Maine Station. 



Two apple-leaf troubles new to Maine are described, a chlorosis in which 

 the leaves are variously spotted or mottled with irregular splotches of yellow, 

 and a silver leaf which had been previously reported in Europe but had not 

 been observed in Maine. The cause of the chlorosis has not been definitely 

 determined, nor has the author been able to confirm the connection between 

 silver leaf and the occurrence of Stereum purpureum. This fungus was not 



