DANGEROUS INTERNATIONAL FOREST TREE DISEASES 5 



by four kinds of needle rust very severely and also by Armillaria root 

 rot. Nursery stocks of P. radiala are very heavily attacked by Di- 

 plodia pineae. P. radiata, P. canariensis, P. nigra, P. luchuensis, P. 

 strobus are very susceptible to the leaf blight caused by Cercospora 

 densiflorae Hori & Nambu. 



Among many exotic pines, Pinus strobus is one of the most promis- 

 ing in Japan and is now planted everywhere in this country. The 

 plantation area will be increased year by year. In this situation of 

 plantation planting with this exotic, the forest pathologists must ex- 

 ercise utmost precaution against the occurrence of blister rust. Need- 

 less to say, we must establish whatever effective counter-measures are 

 necessary to prevent the introduction of this disease from abroad and 

 as quickly as possible. 



While this work is still going on, it is considered very necessary to 

 make a thorough survey in order to ascertain whether the fungus 

 Cronartium ribicola is present or not on native Ribes spp. in Japan, 

 although we have not been aware of the occurrence of the blister rust 

 on Japanese native five-leaved pines. 



Pathologists of the Government Forest Experiment Station, Hok- 

 kaido University, and Tokyo University searched for C. ribicola on 

 wild and cultivated Ribes spp. throughout Hokkaido in 1959. Dur- 

 ing this cooperative survey they collected some Cronartium growing 

 on some Ribes from several parts of Hokkaido. It is uncertain whether 

 the collected Cronartium is exactly the same as the true C. ribicola al- 

 though the fungus seems very similar to the latter morphologically. 

 This important question remains to be solved quickly. 



This is my report covering the past 3 years. I will take this 

 opportunity to express our sincere gratitude to Prof. N. Takahashi 

 who did so much to establish the foundation of our Working Group. 

 He retired from the representative position of the Group in Japan and 

 recommended me in place of him in June last year. 



I shall make every effort to accomplish the significant objective of 

 this international cooperative investigation on the forest disease prob- 

 lem, keeping close contact with the forest pathologists in Korea and 

 China with whom I, to my regret, have not yet been able to get an 

 opportunity to talk over the activity of the Working Group. 



India 



B. K. Bakshi 



Head, Division of Forest Protection, Forest Research Institute. 

 New Forest (Dehra Dun), India 



Reports for India have been prepared on the parasitic fungi on 

 Finn*. Populus, and Quercus and on the exotic forest trees that have 

 been successfully established in India. Requests were sent to the fol- 

 lowing countries for information on the diseases of Pinus, Populus, 

 and Quercus: Burma, Cambodia, Ceylon, Indonesia, Laos, Malaya, 

 Pakistan, Philippines, Singapore, Thailand, and Vietnam. 



Pakistan responded with a list of the parasitic fungi on Finns and 

 Quercus; Burma with a list of the species of Pinus occurring naturally 

 in that country, with the notation that no information is available on 

 diseases; and the Philippines with a brief report on the diseases of the 

 two species of Pinus in that country. The remaining countries replied 



