DISEASES OF I'LANTS, 757 



iiiiliUiM.v. jis every prcciiiitioii w.is l.ikcii to iircvciit tlic tnmsinissioii of the 

 distase in this way. 



SUidies were eontiimed to delenniiie the proitapition of rust from season to 

 season by volunteer wheat, hvit as yet no definite results have Ixt'n obtained. 



Kxperinients are in progress on the seieetion of rust-resistant varieties, in 

 V. hii'h a susceptible variety of wheat has been chosen and subjected to the con- 

 ditions believed to favor the develoiMiient of rust. While the past year was 

 one favorable to rust, about .'>." plants were secured that showed consider.-djle 

 resistance. 



Peach leaf curl, yellows, rosette, and little peach, E. L. Worsiiam and 

 W. \'. l{i;ia> (da. liil. Ent. Hid. .i(>, /ip. J J. /i;/s. //).—! )escript ions are j;iven of 

 these di.scases of the i>each, with i)articular attention to the i)e;ich leaf curl. 



From the results of a .series of e.xiteriments for the control of the i>eacli leaf 

 curl, in which the trees were s|)rayed with Bordeaux mixture, copper-sul]tliate 

 solution, linie-suliihur washes, Oregon wash, and soda Bordeaux, it appears that 

 Bordeaux mixtni-e, lime-sulphur wash, and Oregon wash, whidi is a modifica- 

 tion of a lime-sulphur compound, were all effective in the control of the disease. 



The other diseases are briefly descriln-d and, where Icnown, suggestions given 

 for their iirevention. 



Experiments for the control of Peronospora, II. ScuKi.i.iCNUEm; (Lnndir. 

 Jitlnh. Svliuciz, ^.i itHOS), \o. 6, pp. 2S.'i-^S()). — The results of exi)eriments in 

 spraying various fungicides on grapes for the control of downy mildew are 

 given. 



In one series of experiments the relative efficiency was testetl of 0.5 and 1 

 per i-ent solutions of Bordeaux mixture and of different strengths of suli)hur 

 .izmin and of Teiiax, which is said to be a mixture of copper sul[)hate, alumin- 

 itnn sulphate, and soda. In these tests 4 and ;"» applications of thi' fungicides 

 were given jit different periods dtuMng the season, and at the time of harvest- 

 ing the .-iverage weight of grapes and the weight per vine were determined. 

 In both instances the average weight of the individual grapes and the total 

 production per vine were the highest where Bordeaux mixture had been used. 



In a second series of experiments 2 per cent Bordeaux mixture, a sulphur- 

 copper preparation, and 2 strengths of soda Bordeaux were comi>are(l. The 

 best results were obtained with soda ISordeaux containing 2 kg. of copper sul- 

 phate Jind (!.!» kg. of soda to 1(M> liters of water. 



The chestnut bark disease, K. A. Stkhm-Nc; (IJiif/iii. AVwr.v. CO ( lUOS). .Vo. /.?, 

 ;'/». .li.i, .i.}.i). — Attention is called to the disease jtopularly known as chestnut 

 blight, whidi is due to the fungus Diiiportlic imnisitiin. The conunercial im- 

 portance of tlie ra|)id spread of tins disease is pointed out as thre.-itening llie 

 existence of the chestnut tree as a factor in .\merican forestry. The author 

 .'Stales that the spread of the chestnut blight and the ultimate destruction of 

 our chestnut forests will iirobjdtly mean an aniin.il loss to the I'uiti'd States of 

 from .'j; j."..( H M ).( M M ) to .$;;(mmmi,(mhi. 



The promi't removjil and destruifion of infecte«l limbs and In^'s and the 

 jiainting of wounds with tar |iaint will probably save individu.il s|K'cin\ens. but 

 there aiip«>ais to be little promi.'^e that the di.scase can 1k> controlled in the «'x- 

 lensive second-growth stands and mercliantable timber throughout the range of 

 the spfcifs. 



The mildew of oaks, L. .M.v.noin (./(hii: .\i/i: I'nit., ii. .srr., II! (1!)0H), \n. 30, 

 pp. lOH-tlO, flfix. 2). — Tlie mildew of <»aks due to Ohliiiiii (inrniinitn is descrii)e<l. 

 The author thinks that the fungus is the couidial jihase of Micinsplnna Hint, 

 lud th.Mt while its atta<'k could be prevented by the use of sulphur or some of 

 the polysnlpbid sprays where only a few trees ar«> to be treated, it will be 

 found iujiiraclicable tu allempt such means in forests or large itlanlations. 



