154 EXPERIMENT STATION RECORD. 



The characters of the fungus are described at considerable length, and as 

 a I'esult of the author's studies he determines it as probably identical with 

 Ustilago shiraiana, an amended description of which is given. 



As preventive measures it is recommended that smutted branches be cut off 

 and burned before the spore masses mature and the spores are scattered, 

 and the removal of wild species in regions where the large bamboo is extensively 

 cultivated. It is believed that spraying with Bordeaux mixture at the time 

 the sjjring Inids are develoiting would i)rove beneficial. 



The wilt disease of pigeon pea and pepper, E. J. Butler (Afir. Jour. India, 

 1 {W06), No. 1, pp. 25-36, pis. J). — A description is given of wilt diseases 

 of the pigeon pea (Cajanus indiciis) and of the cultivated black pepper. 



The pigeon pea wilt is found over a wide extent of India and in some )-egions 

 is of serious consequence. The plants are attacked here and there over the 

 field, and when a period of hot dry weather occurs large areas appear suddeidy 

 infected. The practice in growing this crop in India is to ratoon the fields, 

 and in these the fungus spreads so that in some instances all plants are killed. 



An examination of the diseased plants showed the presence of a fungus 

 which the author has determined as a species of Nectria, and inoculation 

 experiments have shown in a considerable proportion of the trials that the 

 disease is due to some of the stages of this organism, 3 of which are described 

 at some length. 



In the account regarding the pepper vine wilt, the author states that the; 

 serious destruction of the plants in some regions threatens the industry. In 

 many instances it was found that the wilted plants were affected by nematodes 

 (Heterodera radlcicola), but the uniformity of the symptoms of the disease 

 seemed to indicate that some other cause than the nematodes must be ascribed 

 to it, and evidence is presented which the author believes warrants the state- 

 ment that it is due to a species of Nectria. The symptoms of the disease are 

 described, and it appears that while the nematodes may contribute to the de- 

 struction, the primary cause is to be attributed to the fungus. 



In conclusion the author enumerates a number of species of plants that are 

 subject to wilt diseases, about 1 dozen cultivated crops being more or less sub- 

 ject to damage from this cause. 



Tree root rot (./our. Bd. Atir. [London], IS (1906). No. 2, pp. lll-ll'f, flg. 

 J). — A root rot of trees, due to Arniillaria incllea or Agaricuft mellcus, is de- 

 scribed, and it is stated that nearly all kinds of orchard and deciduous trees are 

 subject to its attack as well as many coniferous trees. 



Usually the first indication of disease is to be observed in the drooping and 

 yellowing of the foliage, and when these symptoms appear the presence of a 

 thin firm white sheet of mycelium situated between the bark and the wood 

 about the collar of the plant or on the main root branches indicates that this 

 fungus is the cause of the trouble. Later this mycelium extends up the trunk 

 of the tree and changes into Itlack cord-like strands of mycelium, known as 

 rhizoniorphs. 



When trees are found affected a portion of the bark at the collar should be 

 removed and if the mycelium is found to have grown up the trunk the best 

 course to be recommended is to cut down the tree, removing as much as possible 

 of the root, which should be burned. If the mycelium has not ascended the 

 trunk Init is confined to certain branches of the root they should be removed 

 and as much as possible of the root exposed and covered with a mixture of lime 

 and sulphur. When the toadstool forms appear at the base of the trunk they 

 should !)(' collected and Imrncd. 



A canker of the yellow birch, .T. I'.. Pollock (Rpf. Mich. Acad. *Sfc/., 7 (1905), 

 pp. 55, 56). — A brief description is given of a canker observed on branches and 



