DISEASES OF PLANTS. 369 



copper sulphate. There was some difference noted where 2 applications were given, 

 the most adhesive being the Bordeaux mixture containing resin, but where 3 appli- 

 cations were given the vines the relative efficiency of all was the same. The effect 

 of copper and cadmium upon the growth of })lants is discussed at some length, 

 quotations being given from a nundter of authors regarding the effects of these 

 fungicides. In a limited experiment to test the nund:)er of organisms developed on 

 the leaves when treated with copper and cadmium, the average results obtained were 

 the same. 



The influence of the gray rot of grapes on the yield and quality of wine, 

 A. MuNTZ {Ann. Agron., 28 {1902), No. 4, pp. 177-208).— T\ie season of 1900, accord- 

 ing to the author, was abnormal in many ways. The summer was unusually hot 

 and the grape ci'op extraordinarily abundant in every grajje district of France. The 

 period of ripening of the grapes was considerably delayed by fogs and rain, and at 

 the time of harvesting in some regions the gray rot {Botrytis clnerea) was so bad that 

 nearly the whole crop was destroyed. In other regions where the grapes were used 

 in making wine the quality was said to be very inferior. The author studied the 

 effect of this fungus as shown in the wine of a certain region, and gives the results 

 of his investigations, which were quite extensively pursued. The attack of the fun- 

 gus was found to reduce the amount of grapes gathered, and also lowered the amount 

 of wine produced from a given amount of grapes. There was a marked reduction of 

 the alcohol and tartaric acid, due to the same cause. The color of the wine was 

 likewise affected, the clear vinous color of the wine from sound grapes 1 jeing changed 

 to a brownish color, and finally to a peculiar yellowish liquid having little resem- 

 blance to wine, the degree of the alteration being due to the stage of the disease. 

 The tannin content of wine was greatly reduced by the presence of the fungus, and 

 the actual loss due to this cause is estimated at 30 per cent of the wine production. 

 Among the practical suggestions of the author to be followed upon the recurrence of 

 similar conditions, it is recommended that upon the appearance of disease the grapes 

 should be immediately cut, as delay only tends to increase the loss. Where the 

 disease is present it will l)e found advantageous to collect only the sound grapes or, 

 where it is possible, to make white rather than red wine. Other suggestions are 

 given for the handling and final disposition of the wine. 



Development of black rot, A. PRrNET(/o«r. Agr. Prat., n. ser., S {1902), No. 21, 

 pp. 674-'j7iJ) . — As a ifsult ( if 5 years' investigations on the development of the black rot 

 fungus {<iiugnar<li(i or LnKtudia hkhuellli), the author states that the fungus does not 

 winter on the host plant but is carried over in the sclerotia which form in great 

 abundance on the diseased grapes. The sclerotia germinating in the spring have 

 their spores transferred to the green jjarts of the vine, forming the first or, as the 

 author calls it, the primary attack of the black rot. The attacks which arise from 

 the development of the fungus on the grape leaves are called secondary. The time 

 of appearance of the different invasions has been investigated, and the first seems 

 to occur between April 20 and 25. The secondary attacks occur at different intervals 

 during the growing season. The length of the period of incubation depends largely 

 upon the temperature. In general, it is from 16 to 22 days in April and May, 14 to 

 16 days in June, and 10 to 14 in July and August. Drought or low temperature 

 retards the formation of the pycnidia and, so far as the author's observations go, fogs 

 are not beneficial to the development of black rot, although favoring that of the 

 mildew. For the black rot, rain appears to be necessary and the period of develop- 

 ment depends somewhat on the al:)undance of the rain and on its continuance. 



The fire disease of narcissus, J. Ritzema Bos {TijdacJir. Pluntenziekten, 7 {1901), 

 No. 1, pp. 12-24)- — A description is given of a disease of narcissus caused by Jfeteros- 

 porium gracile, a fungus not hitherto recorded as attacking this host. Differences in 

 susceptibility of varieties are shown, some being not attacked by the disease, while 

 others seem especially subject to it. The disease causes the death of the leaves, 



