DISEASES OF PLANTS. 449 



For the eradication and control of tlie fungus, attention should be given to 

 nurseries, and all diseased pines destroyed, so far as possible. At the same 

 time it' will be necessary to eradicate the Comandra plants in the vicinity of 

 the nursery beds. Spraying these plants with poison substances, it is thought, 

 might prove efficient so far as nursery control is concerned, but under forest 

 conditions this would probably be too expensive. It is recommended that in 

 badly infected areas all diseased trees should be cut out and destroyed wher- 

 ever possible, and in lumbering, trees showing cankers of the fungus should not 

 be left for seed trees. 



A bibliography of literature referred to is given. 



A fungus disease of Hevea in the plantations of Bakusu, Vermoesen 

 {Bui. Agr. Congo Beige, 5 {1914), ^o. 2, pp. 312-321). — Notes are given of a 

 number of diseases observed in a preliminary survey of the Para rubber planta- 

 tions at Bakusu. 



Root diseases due to Fomes semitostus and similar parasites were found to be 

 causing considerable loss. A trunk canker or die-back due apparently to 

 Diplodia cacaoicola was also troublesome. A number of other parasitic or 

 saprophytic fungi were noted, among them au undetermined fungus near 

 Hyiiocrella and a species of Cephaleuros occurring on the leaves. A species of 

 Glceosporium was also found present on branches. 



Suggestions are given for the control of the different diseases. 



Disease of Para rubber trees in the gardens, W. R. Rutter (Ann. Rpt. Bot., 

 Forestry and Sci. Dept. Uganda, 1914, P- 4)- — The occurrence of fungus diseases 

 due to Fomes semitostus and Hymenochcete moxia on Para rubber trees in the 

 botanical gardens is reported. The fungi were traced to old tree stumps and 

 decaying timber left on the land not properly cleared of forest trees. 



From experiments noted in a previous report (B. S. R. 30, p. 850), trench- 

 ing about the trees and the use of lime has been foimd efficient in keeping the 

 fungus from si^reading. 



Root disease of Para rubber caused by Sphserostilbe repens, F. T. Brooks 

 {Agr. Bui. Fed. Malay States, 3 {1914), No. 2, pp. 4M3).— The author states 

 that during 1914 several rubber trees were found to have been attacked by the 

 fungus 8. repens. The trees usually show thin foliage and the branches grad- 

 ually die back. If the roots are examined the disease may be readily distin- 

 guished from those caused by Fomes semitostus and Hymenochcete noxia by the 

 absence of external mycelium and by the presence of characteristic mycelial 

 strands or rhizomorphs between the bark and the wood. It is sometimes 

 claimed that this fungus is saprophytic, but the author states that he has traced 

 it into living tissues where it is undoubtedly acting as a parasite. 



Planters are advised to cut out and bum all trees affected by this fungus. 

 While there is said to be no evidence that the fungus spreads by means of sub- 

 terranean strands to neighboring trees, it is recommended that trenches should 

 be dug about the affected trees to prevent any possibility of underground in- 

 fection. 



Study of Bordeaux mixture, L. Sicaed {Prog. Agr. et Vit. {Ed. VEst-Centre), 

 35 {1914), Nos. 33, pp. 211-211; 34, pp. 235-241; 35, pp. 263-266; 36, pp. 289- 

 291; 37, pp. 304-309; 3S, pp. 323-327).— A report on a study of the preparation 

 and use of Bordeaux mixtui-e, the reactions and qualities corresponding to 

 given compositions and to changes therein, and the practical preparation and 

 employment of this fungicide under conditions obtaining in the vineyard. 



Adherent fungicides, V. Vermorel and E. Dantony (Prog. Agr. et Vit. {Ed. 

 VEst-Centre), 35 {1914), No. 18, pp. 561, 562).— The authors describe two ad- 

 herent fungicides, one composed of copper acetate to which gelatin is added, and 

 the other of Bordeaux mixture containing casein. 



