DISEASES OF PLANTS. 259 



and means for prevention are iliscuHsed at. eonsiderable len<,'t]i. The lunuljer of 

 ppeeies recognized by tlie autlior are as foUoAvn: CystoiniH, 18; I'hytoplitliora, 4; 

 Basidiopliora, 1; Plasniopora, 18; Sclercspora, 4. 



Concerning a grape disease in the Caucasus region, L. Montemartini and R. 

 Fakxeti { All i Inst. Hot. Vnic. Paiia, 2. .src, 7 {^1900), pjt. 7,7; aJti^. in Bnl. Ccntbl.,S5 

 {1901), No. 12, pp. 204, '205). — The autliors have made a stud}- of the fungus causing 

 a disease of grapes in tl>e Caucasus, tiie general api)earance of wliicli is similar to 

 that of the black rot. It differs, however, from the l)lack-rot fungus, Phi/mJospora 

 [LfT.siacZttf] bldtirUil, and also from that more recently described as fiaignardla reni- 

 formis. The name given the; organism causing the disease is f'liyxahspora woroninii, 

 a description of wiiich is given. 



Grape rots in Ohio, A. 1). SEUiv {Oliio Stu. Ilid. 12S, pp. 85-94, Jigs. 3). — A brief 

 account is given of the different diseases to whi(;h the grapes are subject, particular 

 attention being paid the black rot and the white or ripe rot. The influence of soil 

 and variety upon the amount of disease is shown, and suggestions given for the 

 prevention of these diseases by the use of fungicides. 



Experiments in the prevention of grape rot, A. D. Selbv and J. F. Hicks ( Oldo 

 Sta. Bid. 123, pp. 94-102). — A report is given of a series of experiments conducted in 

 an Ohio vineyard in w' hich the vines were given 7 or 8 sprayings of Bordeaux mix- 

 ture, formalin solution, salicylic acid and lime, and salicylate of soda. The applications 

 were begun April 18 and continued at intervals of about 2 weeks until the middle of 

 August. The black rot appeared at about the usual time and destroyed nearly all 

 the crops in the unsprayed rows, and. the rows sprayed with salicylate of soda and 

 the salicylic acid-lime solution were severely injured. The cost of spraying with 4 

 applications of Bordeaux mixture, followed by 3 of ammoniacal copper carbonate 

 solution, is given at $11.39 per acre. On the misjirayed portion there were prac- 

 tically no marketable crops. The most favorable results were oljtained where 5 

 applications of Bordeaux mixture were followed by 3 of ammoniacal copper carbon- 

 ate. The effect of omitting some of the applications was tested and it was found 

 that the omission of spraying the young shoots just before blossoming showed as a 

 . result a loss of 90 per cent from black rot. Earlier or later omissions of spraying 

 showed no decided loss. The total beneficial result on the vineyard experimented 

 upon, which contained Concord grapes, was a saving of about 50 per cent of the 

 marketable crop. Upon more favorable soils better results have been obtained. 

 The standard strength of Bordeaux mixture (4 lbs. of copper sulphate, 4 lbs. of 

 lime, and 50 gal. of water) j^roved equally as efficient as greater strengths, and shorter 

 intervals than 2 weeks between sprayings are recommended after June 20. 



Hexenbesen on cacao trees, J. Ritzema-Bos ( Orgaan Ver. Oudleer. Rijls. Land- 

 hoiucscJiooI, 12 [1900), No. 149, pp. 220-224, figs. 3). — The author examined branches 

 of cacao trees affected with a disease resembling the well-known hexenbesen of the 

 cherry. The growths are thicker than the twigs upon which they are borne. They 

 are upright, twisted, and bear small curled leaves, on one of which were formed 

 spores of a species of Exoascus. The disease is attributed to a new species called 

 provisionally Exoascus throhrorinv. The remedy suggested is persistently cutting out 

 the abnormal growths and l)urning tliem. — ii. M. pieters. 



The dwarf mistletoe in Michigan, C. F. Wheeler [Michigan Sta. Bid. ISO, j)p. 

 27, 28, pis. 4)- — A brief account is given of the occurrence of the dwarf mistletoe 

 [Arceuthohiu7u jmsUlurn) . This mistletoe was observed on l)lack spruce in tamarack 

 swamps a short distance from the station. It was noticed in a nund,>er of other places 

 and seems to be widely distributed in the upper peninsula, having been observed in 

 nearly every tamarack swamp to a distance of a hundred miles. In some of the 

 swamps nearly every tree had been killed. The parasite stinuilates the branches of 

 the tree to extra growth, forming witches' brooms of considerable size, and when a 

 number of branches are affected the tree dies as a result of the attack. A fungus 



