Nov. 1, 1898.] 
THE TROPICAL AGRICULTUEIST. 
35i 
THE CACAO FUNGUS AND MK. 
CAKRUTHERS' REPORT. 
(From an Aqricaltural Authorifi/.) 
This Report, (see page 359) is undoubtedly an able 
document showinp; as it does a great deal of work 
beiiind it, and proving the author, to Judge from his 
deductions, a most careful observer. At the out- 
set we find a very important and welcome state- 
ment, viz.; — "In my opinion the result of the in- 
vestigation has been to show that though no 
doubt the presence of the canker will mean an 
extra expense in cultivation (though not a serious 
one) it in no waj threatens the profitable culti- 
vation of cacao." Mr. Carruthers refers to some 
estates wliich have not been attacked at all, 
and these have no doubt proved valuable object 
lessons of the methods of cultivation and envi- 
ronments which are calculated to keep off the 
fungus. A damp condition is pointed out as one 
of the factors which favour the pest and for 
that reason Mr, Carruthers preaches against dense 
shade for cacao. " There is no doubt," he says, 
"that the cacao is much safer from canker when 
grown absolutely in the open" .... "A 
light flickering shade is in most cases enough 
to keep away Hclopeltis in great quantity, and 
such a shade at some distance above the cacao 
trees does not keep the undergrowth at all 
damp." 
We should also have expected that attention 
would have been called to tiie need for looking 
to the better draining of cacao lands — which are 
as a rule of a dense and heavy character — 
80 as to minimise the dampness against which 
Mr. Carruthers complains; while, to the same and 
Other ends and to the benefit of the tree, might 
have been recommended the benefits of liming 
heavy lands. 
As regards suckers, Mr. Carruthers says : — "My 
observation leads me to doubt the advisability of 
the hard and fast rule to remove suckers from 
the tree without regard to the respective require- 
ments of each plant, and in cases of estates 
where they were left, the health and cropping of 
the trees seem to be better." 
It is further pointed out that there is very 
little tendency on the ~ part of suckers to be 
attacked by the fungus. The practice of 
leaving suckers alone, unless under exceptional 
cases of over-crowding, has been strongly 
advocated by a small section of cacao-planters 
who now have the satisfaction of learning that 
the practice is one calculated to minimise the 
ravages of the fungus. It will be remembered 
how some time ago, when the cacao disease was 
attibuted to the boring beetle Toviicus perforans, 
the question of "suckering" was warmly dis- 
cussed in the press ; and one writer referred to 
the process as "a method of rejuvenating itself 
and guarding against dissolution, that the tree 
lias provided for it." How true has it proved 
that the methods adopted in the agriculture 
of one country, though with reference to the same 
crop, may not answer in another part of tiic 
world 1 The removal of suckers, whicii is the 
common practice in the West Indies, has cer- 
tainly prov«d an undesirable one for Ceylon. 
It is certainly surprising, however, to find Mr. 
.Carruthers overthrowing what may be called an 
axiom by stating that it is misleading to sup- 
pose that an unhealthy tree is more liable to 
disease than one full of vigour, and further 
(hat as regards cacao canker " the evidence points 
13 
more to the infection of healthy trees that un- 
healthy ones," though he admits that the 
former are in a better position to fight the 
disease than the latter. " No special disposition 
of the tree is necessary for the attack of the 
fungus," but may not tiie conditions of exces- 
sive atmosplieric and soil moisture due to shad- 
ing overhead and dampness of land beneath in- 
duce a '•softening" effect— not apparent, per- 
haps, externally — which makes the cacao tree 
under such conditions a suitable host for the 
parasite ? 
Again, as regards varieties, Mr. Caruthers 
says " both experiments and observations jioint 
to the fact that the Forastero is much less at- 
tacked by the canker than the CrioUo. Ih fact, 
the Forastero seems more robust in resisting all 
the enemies of cacao." The hardiness of the 
Forastero will of course, be admitted by all ; but 
there is the objection to growing this variety in 
the fact that the produce is of a lesser market 
value than that of the Criollo. Mr. Carruthers, 
however, only refers to the typical Forastero, 
which he describes as that witii tlie white or 
green pod, and makes no mention of what is 
spoken of some times as the pink Forastero or 
hybrid variety, which appears to combine the 
hardiness of the typical Forastero with the supe- 
riority of seed of the Criollo. It would be inter- 
esting to hear something of his experience with 
regard to this particular form as distinct from 
the white and green-podded tree on the one 
hand and the distinctly red-podded tree on the 
other. Hybridisation has been of much service 
to agriculture, as is witnessed by its results in 
vine culture and wheat-growing, and may yet 
prove to be an important consideration in rela- 
tion to the cacao disease. Mr, Carruthers men- 
tions the occurrence of cacao canker on the com- 
mon shade used on plantations which he refers 
to as Erijthrina umhrosa. As it is important that 
the tree should be identified, and since at least 
four species of JScyiAcmft are used for cacao shade, 
it would be well to know that the shade tree 
refers to is really E. umbrosa. The commonest 
tree thus used is, however, E. Indica (Sin. 
Erabadu), which is a thorny species. 
On the whole, Mr. Carruthers' Report is very 
reassuring; and, as he himself puts it, it is to be 
hoped that the cacao scare " will lead to an 
improvement in methods, and a consequent in- 
crease of yield." 
We rejoice to hear that he has deferred 
his departure from the Island, and trust that 
this will give a tardy Government an oppor- 
tunity to decide as to the retention of the ser- 
vices of a really useful Scientist. 
^ 
THE AGRICULTURAL MAGAZINE. 
The following are the contents of the October 
number of this monthly :— 1. Season reports 
for August ; 2 Rainfall taken at the School of 
Agriculture during August ; 3 Kekuna oil ; 4 
Occassional notes ; 5 The plantain tree and its 
products ; 6 Citronella oil ; 7 The cultivation 
of chillies ; 8 The analysis of soil as a'guido to 
its fertility ; 9 The uses of wood. 10. A di- 
sease of the plantain tree; 11 How India has 
saved her forests ; 12 Cattle and their manage- 
ment in the interior. 
We note that there are enquiries from abroad 
for the oil from the kekuna tree (Alcaritcs triloba) 
to be distinguished from another kekuna (Cnna- 
rium Z'njlankuiii), and trust that it \viU lead to th« 
