236 EXPERIMENT STATION RECORD. 



whitisli sunken spots appear. Yery badly diseased plants usually have 

 tbeir leaves more yellowish-green than normal, more transi^arent, and 

 usually smaller. 



The disease has been under investigation since 1887-'88, but it was 

 determined to be of bacterial origin in 1889, when Mr. Bolley carried 

 on extensive investigations on the biology of the organism. The 

 methods of isolation and cultivation of the germ are given in detail as 

 well as its morphological characteristics. It is said to be an aerobic 

 germ, while in another place we read ''in hydrogen under pressure the 

 growth was to all appearance normal, but with very faint coloration." 



Inoculation experiments were conducted with varying -success, prob- 

 ably due to the almost universal presence of the disease in the plants or 

 lack of purity of the cultures. In January, 1890, three seedlings were 

 inoculated and "the disease became manifest in 6 days," seeming to 

 indicate successful inoculations, but the later statement that scarcely 

 a plant could be found in doors or out that did not show the disease 

 would suggest the possible infection of the plants before inoculation. 



It is said that no variety of carnations is wholly immune from attacks 

 of this organism, although they vary considerably in their suscepti- 

 bility, and that it may be conveyed to other pinks through inocula- 

 tions. The disease is considered as common throughout eastern [N^orth 

 America, occurring wherever carnations are extensively grown. 



For the jjreveution of the disease the plants should be kept as dry 

 as possible, watering to be done between the rows, so as not to wet the 

 foliage. An occasional spraying on bright days with water containing 

 a small quantity of ammouiacal carbonate of copper will also be found 

 advantageous. 



Report on black rot in Armagnac during 1895, G. Lavergne 

 {Bui. Min. Agr. France, 15 {1896), No. 2, pp. 285-291).— A report is given 

 of held experiments in southwestern France for the repression of black 

 rot of grapes. During 1894 the disease was very destructive, and a 

 special commission was appointed to conduct experiments for its pre- 

 vention. The meteorological conditions Avere very unfavorable during 

 the experiments on account of heavy rains atid numerous fogs. Seven- 

 teen plats were used in this work, applications being made of lysol, 

 verdigris, Bordeaux mixture, Bordeaux sucrate, tannin copper mixture, 

 Burgundy mixture with and without molasses, Bordeaux mixture alter- 

 nating with sulphur, copper sulphosteatite, and sulphur and sulphate 

 of copper applied in the form of a powder, from 2 to 5 api5lications being 

 given at various times. 



The results obtained expressed in percentages of loss due to black 

 rot at the end of July and at the time of harvest are tabulated. The 

 most successful treatment was 5 applications of 3 per cent Bordeaux 

 mixture, the first spraying being given the vines May 2, the last July 17. 

 This treatment prevented any apjiearance of disease at the end of July 

 and a loss of but 3 to 5 per cent of the fruit at harvest. When but 2 



