620 SUMMARY OF CURRENT RESEARCHES RELATING TO 



year, about the middle of June, and is most severe in wet seasons. The 

 first symptoms are the withering of the leaves and the stunted appearance 

 of the plants, and at the base of the stem the formation of inky-black 

 spots. The disease passes along the rhizomes and enters the tubers. 

 Advice is given as to the control and cure of this disease. 



Lucien Daniel * suggests means of combating the oak Oidium. The 

 usual method on farms has been to cut back the oak every seven years, 

 and to remove the crown. The result is that numerous short branches 

 are formed. A second method is to decapitate the tree. In that 

 instance the normal balance of growth is upset and the tissues become 

 surcharged with water, which favours the Oidium. Daniel recommends 

 the retaining of the crown and branches at the top of the trees as ensur- 

 ing more free transpiration. 



R. 0. Cromwell j describes a disease of soy-bean due to the attack of 

 Fusarium tracheiphilum, the fungus that causes " cowpea-wilt." Infec- 

 tion probably occurs through the root ; the largest percentage of diseased 

 plants appeared in coarse sandy soil. 



P. VoglinoJ has investigated the fungi that causes root-rot of the 

 mulberry in Piedmont, Italy. The trees are stripped of their leaves, 

 every year, and thus weakened and rendered liable to attack. Two 

 fungi are mainly responsible for the rot : — Armillaria mellea, which 

 causes the roots to rot and frequently kills the trees, and Rosellinia 

 necatrix, the latter, usually found on young planted-out trees. The 

 first symptoms of disease are the yellowing of the leaves. In the case 

 of such rotting of the roots it is advisable not to plant mulberry-trees on 

 the same ground for at least two years. 



Melanconiuni Sacchari has been diagnosed by J. R. Johnston § as 

 the cause of " rind-disease " of sugar-cane which has been reported 

 from many countries. It is a wound parasite which causes eruptions on 

 the rind, with a consequent drying-up of the leaves. Various remedial 

 measures are suggested. 



P. Voglino and V. Bongini |] describe a disease of chestnuts which 

 appears while they are in storage. It is due to the fungus Phoma 

 endogeiia, which forms a white-felted mycelium on the cotyledons 

 beneath the pericarp. The latter becomes detached owing to the shrink- 

 age of the seed. The pycnidia of the fungus are formed in abundance 

 on the white mycelium on the surface of the cotyledons ; they rarely 

 develop on the seed-coat. 



* Comptes Rendus, clxiv. (1917) pp. 957-9. 



t Journ. Agric. Research, Washington, viii. (1917) pp. 421-40 (1 pi. and 1 fig.). 

 See also Bull. Agric. Intell. Rome, viii. (1917) pp. 1059-60. 



X Inform. Seriche, Rome, iv. pp. 97-104. See also Bull. Agric. Intell. Rome, 

 viii. (1917) pp. 1060-1. 



$ Journ. Agric. Porto Rico, i. (1917) pp. 17-47. See also Bull. Agric. Intell. 

 Rome, viii. (1917) p. 1060. 



II Ann. Accad. Agric. Turin, Ix. (1917) 12 pp. (8 pi. and 3 figs.). See alsoBuU. 

 Agric. Intell. Rome, viii. (1917) pp. 1062-3. 



