DISEASES OF PLANTS. 249 



Severe pruning and spraying as directed, it is said, will completely restore the 

 life of a tree in a single season. 



A description is also given of the witches' brooms of cherrj', due to E. cerasi. 



Becent studies of the olive-tubercle organism, E. F. Smith (U. 'S. Dept, 

 Ayr., Bur. Plant Indus. Bui. 131, pp. 2')-'i.i). — On account of apparent confusion 

 as to the true cause of the disease of olives known as tuberculosis, olive knot, 

 tumor, etc., the author lias reviewed the work of a number of investigators and 

 has made studies of material secured from California, Italy, and other coun- 

 tries. He has found that apparently mixed cultures have been used by a num- 

 ber of former experimenters and that the true cause of the olive tuberculosis 

 is a white, nonliquefying bacterium, which is found in the olive tubercle and 

 develops in many culture media as a short rod with rounded ends, occurring 

 singly or in pairs. The yellow organism and others that have been described 

 from time to time as causing the disease are believed to be present sapro- 

 phytically. 



A description is given of the organism, which for nomeuclatorial reasons the 

 author calls Bacterium surastanoi, together with an account of studies made 

 with it in different media. 



The disease is known to OQCur in Italy, France, Spam, Algeria, Tunis, and Cal- 

 ifornia, injuring the olive trees and sometimes destroying them. The organism 

 enters the plants, so far as known, exclusively through wounds. Some varieties 

 of olives seem more subject to the disease than others, and these should be dis- 

 carded. Skillful pruning, particularly if accompanied by sterilization, will help 

 hold the disease in check, and it is thought probable that the application of some 

 of the better fungicides would aid in its control. 



Investigations and trials relating to the appearance of the gooseberry 

 mildew, and measures for its eradication, J. Lind and F. K. Ravn (Separate 

 from Gart. Tid., 1908, ;\'o. 1, pp. 15). — Spraying with Bordeaux mixture and 

 potassium sulphid solution and dusting with sulphur was found to decrease, but 

 not to prevent entirely, attacks of the fungus disease. The winter treatment 

 recommended consists in (1) pruning the bushes and burning all cut branches 

 and berries, (2) raking together fallen leaves, berries, twigs, etc., and burying 

 them in the ground, and (3) disinfecting the bushes by spraying with acid Bor- 

 deaux solution (100 parts water, S 1I)S. co])per sulphate, and 1 lb. quicklime or 

 li lbs. slaked lime). This treatment should be followed by spraying with potas- 

 sium sulphid solution, common Bordeaux mixture, or sulphur every 8 to 10 days 

 from the beginning of May to the beginning of July. The cutting and removal 

 of all diseased branches and berries should be continued throughout the season. 



Notes on the treatment of mildew, L. Degrully (Prog. Agr. ct Vit. (Ed. 

 VEst-Centrc), 29 (1908), No. 1',, pp. J, 19-427, pi. 1, fig. i ) .—Attention is called 

 to the necessity of preventive treatments in combating the downy mildew of the 

 grape, and a discussion is given of the quantity of fungicide required in sijray- 

 ing and the relative adhesiveness of different mixtures. Formulas are given 

 for the prepai-ation of about one dozen fungicides. 



The black rot of the grape, and its control, D. Eeddick and C. S. Wilson 

 (Neic York Cornell Sta. Bui. 253, pp. 367-388, figs. 11).— An account is given of 

 the fungus {Gutgnardia hidwellii) that causes the black rot of grapes, the dif- 

 ferent stages of the fungus being described in considerable detail. 



A report is given of experiments conducted during 1900 and 1907 for the con- 

 trol of the black rot, in which Bordeaux mixture of different strengths, supple- 

 mented by treatments with other fungicides, was tested. The experiments in 

 1907 were undertaken on a considerable scale in a commercial vineyard, and as 



