1038 inSICASKS OF VARIOUS CROPS 



On a small pk;t under white clover {Trifolinm repcns) destroyed by 

 this parasite, it was found that from the many sclerotia remaining flush 

 with the ground, owing to break-up of the neck and stalks of clover, 

 innumerable apothecia began to grow towards the end of October, and 

 continiied to appear in the first fortnight of November. 



On placing a few ripe apothecia in Petri dishes the spores are found to 

 be scattered in small heaps a few hours later. Kach of these heaps is made 

 up of the 8 spores contained in each ascus. As soon as disseminated the 

 ascospores are read}^ to germinate, both in distilled water and in ordinary 

 nutrient media. Scl. trifoliorum is psychrophile. At a relatively low tempe- 

 rature (80 to 10" C.) it rapidly penetrates the entire mass of medium, and 

 in a short time gives rise to man}' sclerotia. The fragments of mycelium 

 serve perfectly well for transplantation of the fungus in the pure state. 



In spreading fragments of mycelium from pure gelatine cultures on 

 potted earth sown with common forage pulses (clover, lucerne, fenugreek), 

 the young plants are rapidly destroyed in proportion as they grow. Scl. 

 trifoliorum forms a sort of inconspicuous network or spider's web, which 

 spreads on the surface of the soil, surrounds the base of the young stalk 

 and causes its disintegration. The young plants lodge, and in a few days' 

 time the differentiation of the conidiophores is seen to take place on them. 

 The young plants are liable to infection during the entire germinating phase. 

 As soon as the first leaves have formed, the receptivity appears to cease. 



This fungus may also attack the bean, causing a disease with the same 

 characteristics as that attributed to Scl. lihertiana. The author conclu- 

 des from the results of experimental infections that the injuries attributed 

 to the latter are also sometimes caused by Scl. trifoliorum. 



Trial was made of several means of causing the germination of the sporidia 

 springing from the mycelium, but in this as in previous experiments the 

 results were negative. 



During years taking a regular course and in which grass crops are at 

 rest before frosts supervene, the " sclerotium disease of clover" does not 

 occur On the other hand, when vegetation is still active at the onset of frosts, 

 the latter soften or injure the tissues and thus facilitate penetration by and 

 growth of the Scl. trifoliorum, the apothecia and ascospores of which elTect 

 their differentiation even towards the end of autumn, the fungus being 

 markedly ps3'chrophile. 



812 - Ustulina zonata on Hevea brasiliensis in the Federated Malay States (1). 



— Sharples a., in The Agricultitral Bulletin of fhe Federated Malay States, \'o\. IV, No. 4, 

 pp. 98-105. Singapore, Janu^rx' 1916. 



Ustulina zonata (Lev.) Sacc. caused extensive damage in 1915. It spread 

 more and more in Hevea hrasiliensis plantations in the Federated Malay 

 States. 



It has been noted that the attacks of boring insects are almost always 

 accompanied by the presence of fungi. The latter, b}' weakening the wood, 

 facilitate the boring of the tunnels both by the larvae and the adults. The 



(1) Sec B. Sept. iQi.-i, No. 981. {Ed). 



