DISEASES OF PLANTS. 1085 



It i- said that probably no remedial measures will be found effective in the i 

 palms already seriously attacked, but to prevenl tin- further spread of tin- dis< >ase all 

 affected palms should be cut down and burned or buried with lime Experiments 

 in Jamaica have shown that Bpraying with Bordeaux mixture on tin- first indication 

 of the disease is somewhat effectual. A- the disease is "t' a virulent character, ener- 

 getic efforts arc recommended to stamp it out. 



A green-skinned variety of cocoanul in Jamaica is said t<> be less liable to bud rol 

 than the yellowish and reddish varieties commonly grown, ami it' this should be 

 confirmed it may he possible to establish a race of cocoanuts resistant to disease. 



Cacao disease in Ceylon ( Trop. Agr. and Mag. Ceylon Agr. Soc, ?5 I 1905 I, No. ., 

 /i/ ). 898-296 ). — The cacao trees in Ceylon are Bubject to a Berious disease, which finds 

 favorable conditions for its spread in dense shade and abundance of moisture com- 

 monly found <»n cacao plantations. 



The disease, which is of fungus origin, attacks both fruit and stems. The puds 

 become dark brown or black, and unless controlled the disease spreads rapidly. 

 The disease can be restrained by collecting and destroying the diseased pod- at fre- 

 quent intervals, or by spraying with Bordeaux mixture. In addition the shade 

 should be removed to some extent and the diseased tissues of the stems collected 

 and burned. 



In "h>02, 96 per cent of the trees and 14 to Hi' per cent of the pods of a plantation 

 were attacked by the fungus. The preventive measures described above were begun 

 in 1902 and within 6 months an improvement was noted. In 1904 Less than 4 per 

 cent of the fruit was attacked and the yield increased from 0.83 cwt. peracre in L902 

 to over 2 cwt. in 1904. 



Canker of rubber, T. Petch t Trop. Agr. and Mag. Ceylon Agr. Soc, 25 i 1905), No. 

 .', j>. 298). — In a report on the canker of Hi r,,i brasiliensis mention is made of the fact 

 that a large portion of the fruit did not ripen and split in the normal way, but 

 remained on the tree and blackened or fell off without splitting. 



An examination showed that this condition is due to a parasitic fungus similar to, 

 if not identical with, that which causes the decay of cacao pods, which is generally 

 attributed to Phytophtkora omnivora and Colletotrichum hir<trn<it<i,n, the first of which 

 is the more destructive. The Hevea fruits examined were all attacked by a species 

 of Phytophthora which permeates the soft outer tissues of the fruits, causing the 

 seeds to dry up. All diseased fruit should be collected and burned as a precautionary 

 measure. 



A disease of Hevea seedlings, T. Pbtcb ('J'r<>/>. Agr. "//</ Mag. Ceylon Agr. Soc, 

 24(190.',), No. 12, />. 188). — A report is given of leaves of Eevea seedlings being 

 attacked by a species of Helminthosporium. 



The leaves were studded with circular, semi-transparent spot.~. each surrounded by 

 a brown layer. It is thought probable that the spots art- due to insect punctures and 

 that the fungus gains access to the tissues through these injuries. A.S a consequence 

 of this discovery a number <»f nurseries of this species of rubber were examined with- 

 out discovering much disease, hut there were found commonly present injuries that 

 seemed to be due to fungi, the most common of which was Periconia pyenospora. It 

 is believed that the fungi were present as a result of mechanical injury, which in 

 many instances is attributed to the burning of the leaves by light shining through 



globules of water collected on the foliage. 



The destruction of Siberian firs in Adlisberg, II. C. Schellenbkbg [Mitt. 

 Schweiz. Cerdralamt. ForaU. Versuchaw., 8 1 1905 i, No. 8, pp. 969-286, pi. t).—Jn L901 

 the author examined a plantation of Siberian firs that was about 30 years old and 

 found many of the trees Buffering from the attacks of some fungus. Qpon closer 

 investigation the hark was found thickly studded with the small orange-yellow fruit- 

 ing bodies of Dasyscypha calyciformw, and where these bodies were abundant the 



