DISEASES OF PLANTS. 145 



periments foi* the control of the disease of grapes due to Pseiidopeziza trach- 

 eiphila. 



On plats which received a heavy application of stable manure the disease 

 made less progress than on the check iilats. The effects of the application of 

 manure were evident throughout the season and on all parts of the vine. The 

 soil in the region reported upon is a very light sandy one, and the addition of 

 manure increased the water holding capacity. This is thought to have made 

 the plants more resistant to the attack of the fungus. Spraying with Bordeaux 

 mixture had no effect in reducing the disease, although 4 or 5 applications of 

 the fungicide were given the vines at suitable dates. 



A variety of Cladosporium herbarum on Citrus aurantium in Florida, 

 H. S. Fawcett and O. F. Burger (Phytopathology, 1 {1911), No. 5, pp. 164- 

 166). — Upon investigating the scaly bark of citrus trees in Florida the authors 

 found a fungus similar to but differing somewhat from C. herharum as gener- 

 ally recognized. 



Parallel cultures were made between the organism as found in Florida and 

 pure cultures of C. herbarum received from Europe, and certain differences are 

 noted which are considered important but not sufficient to warrant the descrip- 

 tion of a new species. On account of the differences the authors have described 

 the form occurring in the scaly bark disease as C. herharum citricolum n. vai\ 



A more detailed description of the fungus and its relation to the disease is to 

 appear in a bulletin of the Florida Station. 



Report of mycologist for year ending' March 31, 1911, II, J. B. Rorer {Bel. 

 Ayr. Trinklacl and Tobago Circ. 4, 1011, pp. 10, pis. 13). — This report deals 

 chiefly with experiments in cacao spraying and the diseases of the coconut 

 palm. 



Preliminary experiments showed that Bordeaux mixture and lime-sulphur 

 solutions strong enough to be active fungicides were slightly injurious to cacao 

 flowers and very young tissues but in no way harmful to the young fruits. It 

 was found that when trees were well sprayed twice the young fruit was pro- 

 tected from fungus attack, giving a net profit of from $20 to $40 per thousand 

 trees. This profit, it is thought, should be greater in a few years, as the 

 sprayed trees are free from moss and less liable to the canker infection. For 

 the present it is recommended that trees be sprayed once just after the larger 

 setting of the fruit and again a month or 6 weeks later. 



The author, in discussing some other cacao troubles, states that the cacao 

 witches' broom as it occurs in Surinam (E. S. R., 23, p. 455) is not found in 

 Trinidad. In disposing of the empty cacao shells, composting them is recom- 

 mended as the best method, and attention is called to the fact that spraying 

 them with Bordeaux mixture is inefficient and expensive as generally applied. 



The second portion of the report deals with diseases of the coconut palm, 

 particular attention being given to the bud rot (E. S. R., 25, p. 552). The 

 author claims to have isolated the causative bacterium, grown it in pure cul- 

 tures, and produced successful inoculations both by wounding the tree and by 

 pouring water containing cultures over the crown of the tree. The most suc- 

 cessful means for the control of this disease seemed to be the cutting out and 

 destroying those trees which showed the presence of the bud rot and thorough 

 spraying with Bordeaux mixture. 



A root disease is described the trees affected by which are said to resemble 

 those attacked by the bud rot, but the author does not agree with others that 

 the diseases are identical. He believes that the root disease is due to a 

 physiological trouble resulting from unfavorable soil conditions. 



Notes are given on a stem disease due to the fungus Thielaviopsis paradoxa 

 and on leaf diseases caused by Pestalozzia palmamm. 



