190 DISEASES OF TROPICAL PLANTS CH . 



or stump serves as a source of contagion from which 

 the fungus spreads to the surrounding trees. 



The only satisfactory remedies known are to clean 

 the land thoroughly of debris of all kinds which will in 

 any way afford suitable food material for the organisms. 

 Dig out and burn the diseased trees and treat the soil 

 in that place with lime, mixing thoroughly, and 

 stirring from time to time. Dig trenches from 18 to 

 24 inches deep around the healthy trees, and put in 

 lime or a mixture of lime and sulphur. 



Hymenochaete noxia, Berk. , is an organism which is 

 reported as killing the cacao in many places, and also 

 the rubber trees in Apia. It has been reported from 

 Samoa on cacao, castilloa, bread fruits, and other trees. 



Epiphytes are very abundant on the cacao and other 

 trees. Their injuries are due to the clogging or 

 blocking of the lenticles, and thus preventing the 

 proper physiological activities of the trees. They also 

 interfere with the formation of the buds, flowers, and 

 pods. They should be removed by hand. Washing 

 the trees with a 6 per cent copper sulphate solution 

 or rosin compound is also advantageous, especially for 

 the removal and prevention of lichens. Species of 

 mistletoe and dodder are also the source of some 

 trouble, and should be removed in order to prevent 

 their spreading and becoming more troublesome. 



There are other fungus pests of more or less 

 importance, among which may be mentioned Clono- 

 stachys theobromae, Del, on the fruits in Colombia ; 

 Acrostalagnus vulmorinii, a fruit mould which follows 

 the attacks of beetles ; Phytophthora Faberi, Maubl., 

 of tropical America ; Exoascus bussei, Von Faber ; 

 Colletotrichum Cradwickii, Bancroft, from Jamaica ; 

 C. theobromae, Appel and Strunp, from America ; C. 

 brachytrichum, Del. , from Trinidad ; C. theobromae, 

 Del., from the West Indies ; C. incarnatum, Zimm. ; 

 Pestalozzia sp. A Capnodium has also been reported 

 as troublesome in St. Lucia and Grenada. This pest, 

 like others of this genus, is not parasitic on the plant, 



