156 EXPERIMENT STATION RECORD. [Vol, 



I 



Citrus blast, H. S. Fawcett (Cal. Citrogr., 5 {I!>1!)), No. 1, p. 3, fif/s. 3).~ 

 The information now at hand regarding citrus bhist in counties oT northern 

 California is briefly presented. 



Citrus blast is a bacterial disease "apparently confined at present to northern 

 California during the winter and early spring. The organism destroys leaves, 

 kills fruiting twigs, and forms reddish-brown scabs on live twigs and shoots, 

 usually at the base of the leaf petiole, but does' not attack the growing fruit. 

 The effects differ with varieties, navel oranges being most severely injured,- 

 lemons but slightly affected. A relationship appears probable between the 

 severity of the disease and direction of the prevailing wind, distribution of 

 rainfall, weakness of the tree from neglect or age, and time of maturity of 

 the leaves and branches of the year before. Citrus blast may readily be mis- 

 taken for a relatively unimportant disease characterized by a sudden dying 

 back of twigs at the base of whicli the bark has split and the gum oozed out. 

 This, however, occurs in the summer and fall after dry, hot w'eather in any 

 orange growing portion of the State. 



Phytophthora fabei'i, the cause of coconut bud rot in the Philippines, 

 O. A, Reinking (Philippine Jour. Sci., 14 (1919), No. 1, pp. 131-150, pis. 3; abs. 

 in Agr. News [Barbados], 18 (1919), No. JfSl, pp. J^Hl -^flS). — In a report on 

 studies still in progress, the author states that P. faberi is the basically causal 

 organism in relation with coconut biid rot in the Philippines, though other or- 

 ganisms, notably one similar to Bacillus coli, may quickly follow the original 

 attack and may obscure the original causal organism without being able to 

 initiate the disease. 



Enormous losses are caused annually by the disease, which abounds in humid 

 sections and in thickly planted groves. A number of other plants are suscep- 

 tible to attack, among these coconut, cacao, Hevea, and papaya. 



Trees once severely infected do not recover. All parts must be destroyed, 

 as the organism lives saprophytically in dead host trees. Spaces between the 

 trees should be not less than 10 meters (33 feet) each way. 



Walnut bacteriosis, E. M. Doidge (So. African Jour. Sci., 15 (1919), No. 6, 

 pp. ^07-412). — During the past season the identity of the South African walnut 

 blight with the walnut bacteriosis of California was established, and investi- 

 gations were carried out as to the extent of its occurrence, which is indicated. 

 The disease had been present, supposedly, for some years in this region. From 

 the economic point of view the phase of most serious importance is the bac- 

 teriosis on the young nuts, from which the organism has been isolated repeat- 

 edly, as also from the spot on the leaves. A brief discussion is given of the 

 morphology, cultural and other characters, and favoring conditions. 



A preliminary investigation into a disease attacking young Cupressus 

 plants, A. M. Bottomley (So. African Jour. Sci., 15 (1919), No. 8, pp. 613-617, 

 pis. 4)- — A disease manifested in severe outbreaks on Cupressus torulosa and 

 C. arizonica at Belfast, Transvaal, is said to be due to a fungus believed to be 

 identical with the Phoraa described by Hahn, Hartley, and Pierce (E. S. R., 

 38, p. 53). A closely related or identical trouble on C. macrocarpa is ascribed 

 to a fungus also identified as a Phoma, possibly of a different species. An 

 account is given of a study of this trouble. 



A high sensitivity of the spores to copper sulphate leads to the recommen- 

 dation of Bordeaux mixture as a control measure. 



Notes on the morphology and life liistory of Uromyces aloes, V. A. PuT- 

 TERiLL (So. African Jour. Sci., 15 (1919), No. 8, pp. 656-662, pis. 2, figs. 6).— 

 This is an account of studies on V. aloes, the cause of rust in Aloes, which is 

 said to have wide distribution, similar to that of its host. Biological species of 

 the fungus may exist. 



