1917] DISEASES OF PLANTS. 347 



China's forest laws, W. F. Shebfesee {Forestry Quart., 14 (1916), No. 4, pp. 

 650-661).— This comprises a free translation of the forest laws or mandates 

 issued since tlie inauguration of tlie Ctiinese republic, together with the trans- 

 lation of certain documents dealing with the organization of the present Chinese 

 national forest service. 



DISEASES OF PLANTS. 



[Serious plant diseases in 1914], D. Reddick {West. N. Y. Hort. Soc. Proc, 

 60 {1915), pp. 78-81).— The author states that Venturia inwquaUs, the cause of 

 apple scab, was destructive throughout the State of New York, the damage 

 done being at least as great as in 1910. Fire blight, due to Bacillus amylovorus, 

 was preeminently an apple disease during 1914. No suitable method of con- 

 trolling the fire blight in old trees has been found, but for young trees, care- 

 ful pruning and use of corrosive sublimate (1:1000) are the remedies recom- 

 mended. 



Peach leaf curl, due to Exoascus delormans, was generally prevalent through- 

 out the State. The many cases noted of successful control are thought to in- 

 dicate that failures are due to bad method or wrong time of spraying. Peach 

 mildew, due to Podosphwra oxyacaiithce, was not reported in 1914, owing, pre- 

 sumably, to the absence of fruit. 



The raspberry bushes did not show injury from cold until relatively late in 

 the season. Anthracnose {Glwospurium venetum) was further studied. 



Downy mildew {Plasmopara riticola) became destructive in the Keuka Lake 

 region. This is easily controlled with Bordeaux mixture. Powdery mildew 

 {Uncinula necator) was abundant in the Chautauqua grape belt. The use of 

 Bordeaux mixture about August 1 is recommended. Dead-arm disease has al- 

 ready been reported (E. S. R., 32, p. 52). 



Keport of the plant pathologist, E. W. Bkandes {Porto Rico Sia. Rpt. 1915, 

 pp. 34, 35). — A brief account is given of some experiments for the control of 

 the banana disease described on page 352. In addition, the author has investi- 

 gated the practicability of controlling diseases of coffee, vanilla, and man- 

 gosteen. 



[Report on plant pathology], C. H. Knowles {Fiji Dcpt. Apr. Ann. Rpt. 

 1915, pp. 26-31). — This is the report for the division of plant pathology on 

 diseases of economic plants, some ornamentals, and several weeds. 



Coconut is attacked by a disease very similar to that caused by Pestalozzia 

 palmarum, but this fungus has larger spores. The same leaflets (usually old 

 or unhealthy ones) are sometimes attacked by a fungus identified as Graphiola 

 cocoina. The remedy, as also in case of Pestalozzia, is i-estoration of vigor 

 in ti'ees. Coffee at the Nasinu station showed a leaf disease due to Hemileia 

 vastatrix. 



Cacao brown rot, due to Thyridaria tarda, was found at Lami. This fungus 

 also causes a dieback of the younger branches. Pink disease {Corticium lilaco- 

 fuscum) was noted in one locality. Its chief objectionable feature is the split- 

 ting of the bark, allowing other fungi to enter. Black rot, attacking mostly 

 young pods, may prove to be due to PhytopMJiora faberi. A bro\\Ti root disease 

 destroying cacao plants may be the same as that {Hymenochwte noxia) causing 

 a similar disease in para rubber, which also shows leaf diseases probably due 

 to Pestalozzia palmarum and P. guepini. 



A spot disease of banana leaves showed spores of Cercospora inusce and other 

 fungi. A nematode, probably Tylenchus similis, also causes damage to banana 

 by attacking the roots. 



