226 phytophthora sp. on hevea brasiliensis 



not only on fruits and the tapping area of the stem but also on young tender 

 leaflets, leaves in the buds, stalk of leaflets, main stalk of the leaf and on young 

 branches. In Burma the parasite has been found to attack only fruits and 

 the tapping surface. McRae and Sundararaman rej)Oit that a second leaf- 

 fall occurs in Travancore and Cochin in July and August, and they are of opinion 

 that though their experiments do not prove that Ph. Fuhe.ri is the cause of the 

 second leaf-fall, the presence of this fungus on the leaves is suggestive. 

 According to Petch^ the fungus from the fruits passes on to the green shoots 

 and kills them back or it attacks the stalks and causes extensive defoliation 

 and in a recent Report^ of the Department of Agriculture, Ceylon, he says that 

 the leaf -fall which often follows the fruit disease and is characterized by the 

 appearance of a dark brown ring on the leaf stalk is caused by Ph. Faheri. A 

 similar leaf-fall also occurs at Twante in Burma but the writer could not trace 

 the fall to any pathogenic fungus. The falling leaf stalks were found to be 

 healthy as far as any parasitic organism was concerned and the leaf stalk did 

 not show any dark brown ring. The falling leaves did not become curled or 

 flaccid. The writer was inclined to attribute the fall to the excessive 

 humidity prevalent in July. 



In Cochin and Travancore the Phytophthora which attacks fruits of Hevea 

 producing symptoms similar to those found on diseased fruits in Bui ma also 

 causes the darkening of the renewing bark a little above the tapping cut ; it 

 seems, therefore, that in all probability this Phytojjhthora, wliich McRae^ 

 does not now consider to be the same as Ph. Faheri, is identical with the 

 one causing " Black Thread " in Burma, in spite of the differences enumerated 

 above. The tendency of the South India Phtjtophthom to attack various 

 parts of Hevea is probably to be attributed to local climatic conditions. 



Rutgers* distinguishes two acute forms of Hevea canker in Java, Sumatra 

 and Borneo which he considers to be due to the same fungus Ph. Faheri. One 

 form is form A or " Streepjeskanker " and the other is form B or " Vlekkanker." 

 His illustration and description of the former, " Streepjeskanker," clearly show 



1 Fetch T. The Fungus-diseases of Hevea brasiliensis. Internationaal Riibber-Congres 

 met Tentoonstellinpr, Batavia, 1914, p. 12. 



2 Fetch, T. Rep. Dept. Agr. Ceylon, July 1912 to Dec. 1913. Pub. in 1014, p. c7. 



8 McRae, W. Administration Report of the Government Mycologist for 1915-1916, Rep. 

 Dept. Agr., Madras, 1915-1916, Fub. 1916, p. 53. 



♦ Rutgers, A. A. L. and Dammcrman, K. W. Zickten en Beschadigingen van Hevea 

 Brasiliensis op Java. Dcp. Landbouw Nijvcrheid en Handel. Mcded. Labor, voor Plantcnzeik- 

 ten. No. 10, 1914, pp. 27—30, and 



Rutgers, A. A. L. and Arena, P. ho. cit. 1914, pp. 27—30. 



