123 



well in hand. As was only to be expected the disease is doing most 

 damage among the older trees in neglected fields aud in the small 

 holdings, where little if any care seems to be taken of the trees The 

 disease has probably existed in Grenada for many years and there is 

 no evidence to show whether it has increased or not during recent 

 years. At the present time, it is of sufficient importance for the adop- 

 tion of the remedial measures indicated, which will not only keep this 

 disease in check locally, but, by preventing infection, will largely ren- 

 der any one planter independent of the attitude adopted by his neigh- 

 bour. 



"Root" Disease. 



General Character. — In three instances cacao trees were met with 

 which had dried off in small patches from no apparent cause. They 

 had been growing in good well drained soil and were surrounded by 

 healthy vigorous trees in good bearing. No indications of disease were 

 found in the stems or branches of these trees, but on examining the 

 root system, it was found that the roots were decayed and filled with 

 fungus, especially between the wood and the bark where the matted 

 "roots" of the fungus can be seen with the naked eye as a white felt- 

 like substance surrounding the wood. The characters of these " roots" 

 showeu them to belong to the highest group of the fungi which in- 

 cludes several forms which cause " root diseases" very much like the 

 one in question. A similar if not identical fungus in all probability 

 causes a root disease of the nutmeg in Grenada and also attacks many 

 of the cultivated trees in the West Indies. Thus Mr. C. A. Barber in 

 his report on the failure of the Dominica cacao crop in 18;i2-93 (Sup- 

 plement to the Leeward Islands Gazette April 27th 1893) describes a 

 root disease of the cacao in that Island which also attacked mangoes, 

 oranges, coffee and breadfruit and which seems to be identical witn 

 the oue under discussion. He also noted a similar disease in Jamaica, 

 locally called " salt-petre," in the cacao and coffee cultivation. Last 

 year cacao trees affected with this disease were forwarded from Domi- 

 nica to the Imperial Department of Agriculture for examination It is 

 highly probable that the root disease of the Grenada cacao is caused by 

 the fungus found in the diseased roots and that it spreads from tree to 

 tree underground by means of a diseased root of an attacked tree com- 

 ing in contact with a living root of a neighbouring tree. 



Remedial Measures. — The only practical remedy in diseases of this 

 nature is to isolate the diseased tree from the rest of the plantation by 

 means of a trench three or four feet deep dug midway between the 

 affected tree and its neighbours and thus prevent the spread of the 

 disease to the rest of the plantation The healthy trees surrounding 

 the trench should be kept under observation for some time in order io 

 determine whether the isolatiou has been done in time, i'he roots of 

 the diseased trees should be dug up and burnt and tae soil limed before 

 planting a fresh tree. This treatment has already been successfully 

 adopted by one of the leading planters in Grenada in the case of the 

 nutmeg root disease and there is no reason to suppose that it would 

 not be equally successful in the case of cacao. 



Summary of Conclusions. 



In reviewing the general situation in Grenada, the conclusion I have 

 arrived at is that most of the damage alleged to be due to " thrips" i» 



