786 
THE TROPICAL 
AGRICULTURIST. 
[May i, 1890. 
for some time." The Veyangoda correspondent writing 
of this opinion of Dr. Trimen makes the following 
statement :— "To support the theory of innutrition there 
is the fact that the severely affected plants are invari- 
ably the weakly ones : per contra all the weakly plants 
are not affected." The former statement ia an 
important one, and the conclusions to be drawn from 
it are in no way affected by the latter. I hold, and 
I trust I shall make it clear further on, that it is 
the fact of a tree being insufficiently nourished that 
brings it under the influence of those agents, the effect 
of whose work is seen in coconut leaf-disease. 
In an article on "salt in coconut cultivation" pub- 
lished in the "Examiner" of February 21st, 1889, 
the theory put forward by the writer "B" is that 
trees are possibly suffering from the absence in the 
Boil of salt, or from its presence in too small quant- 
ities. This I considered very improbable in an island 
of the extent of Ceylon, which moreover comes under 
the influence of monsoon winds. Again there is the 
fact that a good many trees were affected and badly 
affected by " coconut leaf-disease " on the sea-borde. 
Quite lately the same writer made the statement that 
the application of salt to badly attacked trees re- 
sulted in no beneficial effeot, in faot that it aggravated 
the attack. 
In the " Examiner " of the 22nd February 1889, 
the Veyangoda correspondent gives the opinion of 
" perhaps the most intelligent and practical planter 
engaged in the cultivation of coconuts " to the effect 
that trees are suffering from an insect attack, that 
the juices of the trees are weakened and diseased by 
want of nutrition, and that innutrition is due to the 
hard and impervious nature of the soil at Veyangoda 
(where the attack is prevalent in its worst form). 
This opinion is, in the "Examiner" of March 5th, 
1889, said to be that of Mr. William Jardine of Golua 
Pokuna estate, Kadirana. 
Of the salt theory propounded by "B." Dr. Trimen 
says: — " I scarcely think that the mal-nutrition of your 
trees — to which I attribute the dead spots in the 
leaves — is due to want of salt in the soil ; unless 
indeed the land where they grow is quite abnormally 
wanting in this almost invariable constituent . . . 
I should rather look to the physical properties of 
the soil, and especially the drainage. That the mor- 
tified spots may be set going in the first instance 
by the punctures of a minute bug is by no means 
improbable. So far as I have seen, I am not disposed 
to consider these spots a very alarming phenomenon. 
They are pretty frequently to be seen on all palms 
if not in quite a healthy condition, and I quite expect 
that under a more liberal treatment they will cease 
to appear. 
" W. J." recommendel the following treatment to 
raise the condition of the trees so as to cope with 
the disease :—" Stiff and clay lands should be broken 
and turned over in clods to a depth of fully eighteen 
inches by means of slrotig steel-bladed pick", afterwards 
treated with 30 or 40 bushels of freshly slaked coral 
lime to the acre scattered broad-cast and allowed to 
be washed in by the rains. The clods would permit 
of free aeration, and all the rain would be absorbed 
and percolate through the soil, iusteadof as at present, 
more than one-half being lost owing to the impervious 
condition of the soil." I oannot pass over this re- 
commendation withuc a word of support. The 
niggardly treatment whioh coconut land generally 
gets, as to the working up of the soil, cannot but 
tell disadvantageous^ on the crop. No amount of 
"trenching" as I have seen it done on some estates 
will compensate for this neglect. This thorough 
workiug up of the soil while it has all the advantages 
of draining, at the same time facilitates the pre- 
paration of plant food. The soil will then be able to 
draw its moisture both from above and below. The 
suitability of thorough drainage for coconut cultivation 
has been questioned.* It is against the principles 
* In he "Examiner" of Sept. 10th. 1889, the Veyangt da 
correspondent eays that having occasion to drain 
deeply a bit of rich clayey laud on which coconuts 
did not make the growth that one can reasonably expect 
of agricultural chemistry that a tree whose roots rest 
on a water-logged strata should thrive for long. The 
sickly appearance of trees growing under such con- 
ditions is quite a common and familiar sight. It is 
absurd to point to a solitary apparent exoeption to 
this rule and, clinging to it, lose sight of facts founded 
on laborious scientific research. This mode of 
argument, characteristic of a warped judgment, ia 
most unsatisfactory to meet. Water may be present 
to the roots to any extent, but the necessary condition 
is that it should not be stationary. On the sea-shore 
we see the roots of the coconut palms continually 
bathed with water, but the texture of the soil is 
such as admits of its ready percolation. Thorough 
draining not only relieves a soil of excess of water, 
but, paradoxical as it may at first appear, it greatly mi- 
tigates the effects of dry weather; when soil is drenched 
with water, and dried by evaporation, it becomes hard, 
especially if it be of a clayey nature. L*nd that is 
dried by drainage is absorptive and retentive of mois- 
ture dropped by dews and acquired from the atmos- 
phere ; while the soil deepened by drainage or deep 
cultivation permits the crop to put forth stronger and 
healthier roots, and thus becomes secured against 
drought. The most successful estates I have looked 
over bave reoeived the treatment which secures such 
results. I observe that within the last year the 
thorough working up of the soil is being adopted 
more generally, but the benefits to the tree to be ex- 
pected in this case will have to be waited for. This 
mode of treatment must be considered a matter of 
routine at such intervals as may be thought advisable. 
It is no argument to say that Oecaute the necessity 
for such cultivation has apparantly not been recog- 
nised hitherto therefore it cannot be recognised now. 
In America once on a time, corn grew and gave 
large yields year after year with little 
attention and care, but the time came 
when this manner of cultivation was no longer 
admissible, for whatever the crops cultivated, it is 
plain that oontinued croping without proper cultivation 
and the use of manures must ultimately bring us to 
a time when the crops grown will no longer pay 
the cost of cultivation. 
As I mentioned in my first repoit, there is some 
considerable difficulty in getting at the history of the 
various plantations, affected and unaffected, but dm ing 
the time that has elapsed since I wrote, 1 have been 
able to gather a good deal of information of this niture, 
in most cases from those who had a personal know- 
ledge of the facts. I do not intend to mention the 
names of any estates or even indirectly indicate their 
situation, for I do not oonsider it fair (being con- 
vinced of the predisposing causes of the disease) to 
make disclosures regarding the history of any private 
property in a public report. I am thoroughly satisfied 
in my own miud that where I have seen the disease 
in its worst form there was always an antecedent of 
bad treatment, whether from sheer neglect, from 
motives of economy, from the use of bad seed-cuts 
and careless planting; or on the other hand there 
were natural disadvantages. For while a s^il can be 
made fertile by much mechanical labour and the 
addition of such substances as it ii deficient in, if 
this cannot be done except at a cost as great as, 
or greater than, that for whioh fertile soils can be 
prooured, the soil may be regarded as practically 
worthless. I have during my observations, seen soils 
that illustrate all these conditions either singly or 
in combination. 
The circumstance that the mechanical condition of 
the soil where the trees show the attack, is favour- 
able, is not sufficient for healthy growth. It may 
occur that though the mechanical condition is not of 
the best, there may be preseat in the soil a suffi- 
ciency of soluble plant food for a certain period ; 
but on the other hand though the mechanical 
of them, more especially as that particular patch had 
received very generous treatment, he was surprised 
to find very little root growth, a marked absence of 
feeding-roots, and most of the rootsrotted. This was 
an opportune bit of experience. 
