234 
THE TROPICAL AGRICULTURIST. [Oct. 1, 1899. 
from furthei' action; but, unfortnnately, some of it 
tiBually breaks away, exposing fresh surface to tbe 
injurious action, and also proving au annoyance by 
passing through the hose and clogging the nozsle. 
For these reasons it is best not to use these sul- 
phur mixtures in knapsack pumps.' 
III. tiimpliciti/.— All the parts of the pump should 
be readily accessible and removeable, so that, should 
aaything go wrong, they may be taken to pieces and 
cleaned, or damaged parts renewed. The want of 
these facilities is a serious fait in many machines, 
the slightest injury necessitating the sending of the 
whole apparatus to the repairers. 
IV. The Production of a Uniform and Effective 
Spray. — Ihe continuity and force of the flow is de- 
pendent upon an air chamber in the pump, this 
feature constituting a 'force-pump.' On this account 
all hand syringes are almost useless. The nature 
of the spray is regulated by the form of nozzle em- 
ployed. The chief object is to break up the liquid 
into such a fine spray that it will penetrate the 
thickest foliage in the form of a dense mist and 
come in contract with every part. For this purpose 
one of the 'cyclone nozzles' is most admirably 
adapted, but where it i.3 necessary to throw 
the liquid to a considerable distance, as, iu spraying 
large trees, a nozzle throwing a coarser spray must 
be used. It is advisable to have several interchange- 
able nozzles to suit the different kinds of work. 
There should always be a detachable cap to the 
nozzle, so that any obstruction may be quickly and 
easily removed. Many nozzles are provided with a 
fine point, held back by a spring, but which, when 
pushed forward, clears tbe aperture. 
A few further remarks may be quoted from Mr. 
Lounsbury's report, in which he gives some recom- 
mendations for the care of spray pumps. ' Before a 
spray pump of any kind is put away after use, it 
should be throughly washed and clear water pumped 
through it ; hot water answers much better than cold 
if stickly or soapy washes have been used. The 
working parts should be occasionally oiled, and it 
the paint on the iron parts becomes worn away it 
should be renewed. Attention to these details wUl 
preserve the pump for a long period, while, if they 
are neglected, the pump may never save its initial 
cost.' 
(To be contimied.) 
■ «> 
CACAO POD DISEASE. 
In December, 1898, my attention was specially called 
to the fact of the presence of a disease of Cacao 
pods on several large estates. Examination proved 
them to be attacked by a prasitic fungus, the full 
characters of which have not yet been worked out. 
From literature recently received from professor 
Harrisop, it is seen that he reported the existence 
of a disease in Grenada in April, 1895, and also 
described the conditions in such a way as to leave 
little doubt that it was idential with that now re- 
cognised as affecting the Trinidad trees. Professor 
Harrison also alludes to the presence of the same 
disease iu Surinam, and refers to my report on 
specimens sent by him, in the following words: — 
"J. Hinckley Hart, Esq., F. L. S., the Government 
Botanist of Trinidad, to whom I cuhmitted some of the 
diseased pods from Surinam has informed me that a 
similar disease oecasionn/li/ occurs on cacoa in Trinidad, 
hut is not there loohed upon as being in an;/ way serious, 
and is generally aacrihed to an excess of moisture." 
Professor Harrison's conclusions have been recently 
confirmed by the receipt of infected pods from Grenda, 
•which show identical characters with the infected 
pods from Trinidad estates. From these pods I was 
able to reproduce the disease in healthy pods, as 
in the first in.';tance, and also to make pure culture 
for the study of the various forma of the fungus, 
and it has now been grown through its entire cycle 
of esiatence in several separate experiments. 
Remarks upon the forms assumed during the 
growth of the fungus are however withheld, until 
they have been confirmed by the expert to whom 
they haTB been submitted, and it will be suf&cient 
to note that the life history of the fungus promises 
to be of an interesting character. This, disease, 
therefore, has long been recognised in Trinidad in 
Surinam and in Grenada, but its infectious character 
was first proved by reproducing the disease by in- 
oculation again and again at the Royal Botanic 
Gardens by the writer, in December, 1898. Professor 
Harrison observed in 1895, that where an affected 
pod touched a healthy one the disease was com- 
municated, but it does not appear that special in- 
oculations were made. Mr. Whitfield Smith, now of 
the imperial Department of Agriculture for the 
West Indies also noted the disease in Grenada while 
trayelling with Professor Harrison. Mr. Massee of 
Kew rn^ikes the following interim Report, pending 
thj receipt of full material for further investigation: — 
Interm Report on Cacao Pod Disease. 
1. The fungus appears to beloug to the Peronos- 
pore£B, but cannot as yet be determined with cer- 
tainty, as the sporen in sprit will not of course ger- 
minate. 
2. The pods sent are completely covered with a 
dense felt of variously coloured hyphae and have 
coraletely lost all trace of the fungus causing the 
disease which can only be seen in the spirit material 
sent. 
3. If the Superintendent could send a couple of 
Hensen's fi isks with germinating spores, perhaps 
something might be done to determine the nature 
of the fungr.s. 
4. Preventive Measures. — Spring with potassium 
sulphide solution (jounce to one gallon of water) would 
destroy zoospores and germinating conidia; Bordeaux 
mixture might answer, but a very dilute mixture 
should be used at first, as it appears to frequently 
injure foliage in a worm climate. 
5. All infected pods should be removed and burned. 
The disease can hardly exist on the pods only and 
search should be made to find its source. The conidia 
are frequently distributed by insects and if the trees 
are infested with winged insect? an insecticide should 
be used. 
On receipt of this Report I immediately applied 
to several planters for further material, and was 
met by the statements that on account of the dry 
weather, no diseased pods were to be found. 
As, however, pods were obtainable in Grenada, 
there is evidence that the disease is not restricted 
to any certain time of the year, but is more pre- 
valent under conditions which prevail during the 
wet season. 
The work of investigation is being continued, and 
when complete a Report will be published giving 
full details. The remedial measures to be adopted 
are those laid down in my Report to the Govern- 
ment, viz. : — 
1st. To gather and destroy all diseased pods. 
2nd. Ihe early removal and destruction of tlie 
empty pods, after the beans are removed for curing. 
3rd. The dressing of all badly infected trees with 
sulphate of copper solution. 
A strict attention to these primary recommenda- 
tions will probably result in confinding the disease 
to small areas, but more summary measures must 
be taken if it is seen to make way. As however, 
it is fairly evident from the Reports of experienced 
planters, from the Report of Professor Harrison, and 
from my own observation, that the disease is no 
new thing; there is every reason to think ths^t with 
due care on the part of planters, the disease will 
not increase. On the contrary, there is every reason 
to hope that when the full-life history of the or- 
ganism is known, it may be possible practically to 
eradicate it. This hope is further justified by a 
Report from one of the most careful of our planters, 
who has adapted the tentative course laid down for 
treatment, as he states that the number of pods 
afiected is rapidly diminishing on the estate he 
manages, — Trinidad Bnlletin. 
