December i, 1889.] Supplement to the "Tropical Agriculturist." 
443 
the crop, strengthen it to withstand the attack, or 
" rush " it past the critical stage when it is most open 
to insect ravages. 
Again in some instances such mechanical operations 
as ploughing, harrowing, and rotting at particular 
periods, and chemical means such as application of 
slaked lime, gas-lime, soot, &c, are of inestimable benefit 
where intelligently adopted. 
Draining of wet places is very necessary, as excess of 
moisture helps insects to thrive while the crops are kept 
in low condition. All weeds, stubble, and unnecessary 
growth of shrubs should be cleared off the land and 
from fences and ditches, and the cleanings burnt, as 
pests generally find shelter in such places. Manure 
heaps and collections of vegetable refuse are commonly 
frequented by insects as convenient places for laying 
their eggs, so that it would be a safe precaution to 
throw quick or gas lime over such heaps. Sometimes 
it is necessary as in the case of the wireworm attack 
in England to adopt a rotation, and bring in a crop 
which is no favourite of the pest, thus olearing the 
land of them periodically. 
Very often cultivators reekldssly resort to costly 
methods of ridding their crops of pest, when convenient 
and inexpensive means suffice. Iu some cases it is 
necessary to resort to insecticide-sprays, and in this 
connection the inventiou of Mr. Strawson patented as 
"The Strawaoniser " is worthy of meution as the 
most p?rfect machine of its kind for the distribution 
of insecticides. 
What we want before all, howover, is reliable informa- 
tion with regard to the insects themselves. Easy means 
of identification, and a better knowledge of their 
feeding and breeding peculiaritie. From the attention 
the subject is receiving in more than one quarter, there is 
no doubt that before long we shall be able to have this 
information as regards not only coffee and tea-pests, but 
those of cotton and piddy and all the crops of large 
and small cultivators, in a collected form, convenient 
both for circulation and reference. 
COTTON. V. 
By Aba. 
About a week after planting the cotton seeds ger- 
minate and expand their basal leaves. After two weeks 
the vacancies where the seeds have failed to grow 
should be replanted. When the plants are from three 
to four weeks old, the land should be cleaned by re- 
moving especially the weeds growing rouud the young 
plants by the hand. If the weeds are allowed to re- 
main the growth of the cotton is very much retarded) 
therefore the operation of weeding should not be put 
off. An important fact to be kept in mind with re- 
gard to weeding is to do it before the weeds have 
flowered and seeded, otherwise they will make a rapid 
growth again by means of the seed shed iu the soi' 
Auother evil is that weeds harbour, aud act as breed 
ing grounds for insects, which are injurious to the 
growing crop. 
When the plants are about a month or six weeks 
old, the soil should be loosened by digging with a 
mamoty or some other suitable implement. There 
are a great many advantages to be derived by thi s 
operation. For example, it facilitates the growth and 
distribution of roots, removes on excess of moisture 
when present, and increases the absorptive properties of 
the soil. It adds to the store of plant food, and im- 
proves the material in the soil by exposure to 
the sun and the atmospheric agencies. Another material 
benefit to be derived by digging the soil is the destruc- 
tion of weeds. 
When the cotton plants are nearly four months 
old and are ready to flower, the soil should be again 
loosened and the earth drawn up to the roots of the 
plants. Not only are the roots strengthened by this 
process, but a good deal of nutritive matter is brought 
within the reach of the plants, thereby helping to 
increase the numbers of flowers, and hence the pro- 
duce too. 
When a perennial cotton, such as the Kidney, is 
cultivated, after each plucking all the green wood 
should be removed, when the plants put forth new 
branohes and bear very much better during the next 
season. 
(To be continued,) 
PADDY CULTIVATION AND THAN SPLANTING . 
V. 
Bv W. A. De Silva. 
(Continued.) 
Irrigation. — In my last I dwelt on the subject of 
irrigation without taking into account its actions re. 
garding the increase of fertility in soils. The quantity 
of water necessary for the proper growth of a crop 
was discussed at length, and the minimum, that is 
a supply of 7 weeks was found necessary in the case 
of transplanted paddy. This quantity is quite suffi- 
cient to act mechanically, and as will be seen here- 
after, it is more than enough regarding the increase 
of fertility in a soil. It cannot be said that the more 
water we have, the advantages too will be more. All 
the advantages may be brought about by a certain 
limited supply, and more than that supply would 
either be powerless to be of any additional service or 
might act injuriously. 
Water used in paddy cultivation acts beneficially in 
four ways, besides being mechanically useful. First, 
it brings along with it earthy particles or matter in 
suspension, and enriches the soil by depositing them. 
Secondly, it brings substances held in solution. Thirdly, 
it aids in the solution of plant food in the soil. 
Fourthly, it enters into the composition of plants, and 
improves the temperature of soils and distributes 
manure. Under the first condition, the addition of 
silt, the fields depend more or less for an addition of 
such matter, on the nature of the water used in irriga- 
tion In Ceylon, fields are irrigated from water ob- 
tained from different sources, rain water which flows 
