Oct. 1, 1900.1 THE TEOPICAL AGRICULTURIST. 
233 
BASIC SLAG TO INSURE BEST, 
QUICK, AND PROFITABLE RETURNS. 
( Extract from an Essaij by Professor Dr. P. Wag- 
ner, P.O. Director of the Government Research 
Station, Darmstadt. ) 
I have said ah'eady that to a soil distinctly poor 
in Phosphoric acid more of this ingredient should 
he restored than is being removed by the crop. 
This application of a Phosphoric acid manure 
should be continued until the Phosphoric acid 
has become laid up as a store, for use in the soil 
ensuring quick and profitable returns. Only then 
will it suffice to return to the soil the same amount 
of Phosphoric acid by means of cattle manure or 
artificial Phosphoric acid fertilizers as is removed 
by the crop. 
As the most suitable Phosphate to increase the 
fertility of the soil, I have recommended BASIC 
SIjAG. and I would draw attention to a previous 
contribution of mine in which I proved the superi- 
ority of Basic slag over Superphosphate. I would 
point out that quick and satisfactory effects can 
only be looked for from the appilication of Basic slag 
rich in Phosphoric acid readily available to the plant, 
i.e.. Phosphoric acid soluble in Citric acid. Below 
I give results obtained by the application of liasic 
slag with a low percentage of Phosphoric acid 
soluble in Citric acid and Slag, most of the Phos- 
phoric acid of which was soluble in Citric acixT. 
It will be perceived that the efficacy of the Basic 
slag increases in proportion to the solubility in 
Citric acid of the Phosphoric acid in the Slag. 
The trials were made in three rows side by side : — 
Increase in 
Phospho- Amount yield over 
ric acid. of yield unnianur- 
ed plot. 
0'5 gr. Superphosphate 
641-2 gr. 397'2gr. 
Basic slag No. 1. 503-1 ,, 359T ,, 
0 5 „ \ 89% soluble in 
Citric acid. 
/Basic slag No. 2. 464-7 ,, 320-7,, 
^ ' " \ 82% soluble. 
r..^ /Basic slag No. 3. 4167 ,, 272-7,, 
" ° " \65% soluble. 
)Basic slag No. 4, 306 9 „ 1G2-9 ,, 
" " '(39% soluble. 
0-5 „ 
1-0 
fBasic slag No. 5. 281 ■! ,, 137-1 
\36% soluble. 
No manure 
Phosjihate meal 159'0 
prep. 2% soluble 
144-0 
150 
The prepared Phosphate meal hardly had an cfiect 
Upon the yield worth mentioning. Basic slag No. 
1, 89% of the Phosphoric acid of which were soluble 
in Citric, acid very nearly equalled in effect the 
increase in yield derived from the application of 
Superphosphate. But Basic slag No. 5, of which 
only 36% of the Phosphoric acid was soluble in 
Citric acid, had only one-third of the effect of Super- 
phosphate. As the quality of Basic slag offered by 
the trade varies to a great extent, it is not to ba 
wondered at that the results obtained by the applica- 
tion of Basic slag have often differed. It is most 
satisfactory that the difference, in quality and ths 
value of the various Slar/s as to their inamtrial 
effects is noiu becoming more and more loidely 
known. It isalsoamatterof satisfaction that almost 
all Thomas's Phosphate Works now use Quartzose 
for dissolving the hot fluid of the Slag, a7id that 
farmers are now beginning to lay stress upon 
a fair percentage of the Phosphoric acid in 
Basic slagbeinggitaranteed as soluble in Citric 
acid. 
PLANTING IN TOBAGO. 
(Continued from page 155.) 
.9. Mulch around the trees, iiit do not disturb the 
roots bij forhinfj. Scratch the surface gently viith a 
hoc or rake previous to laying on the mulching. 
To "■laidch," is to place upon the ground, near 
to the trees, vegetable matter which will gradually 
afford food to the roots and check the evaporation of 
water from the ground. Dried or wet grass, leaves 
&c. usually called trash," should be laid six to 
nine inches deep about each tree, leaving a space 
of six inches clear just around the stem. A few 
heavy stones may be placed on the mulching, if 
necessary, to keep it in place, but this is seldom 
required except in windy districts, and there, cacao 
should not be planted. The trash or mulch will 
keep the ground perfectly moist through the dry 
weather, and enable the cacao plant to pass success- 
fully through the dry season. Mulching should there- 
fore be done previous to the dry weather setting in, 
but if any quantity is left undecomposed when moist 
weather again prevails, ic should be raked into 
wind rows and allowed to rot, and then evenly spread 
over the whole surface. 
10. Alivays keep the ground clean and free from weeds. 
The ground should be kept clean and free fr(5m 
weeds, or they they will overgrow the young cacao 
plants and rob them of their nutriment. Frequent 
hoeinga should be made, but the greatest care shuold 
be exercised not to cut too deep with the hoe, or 
the roots may be injured. It is best to weed by 
hand immediately around the stem of the trees. 
Pruning — Lst the cacao tree grow freely during' 
its young state, and allow the young branches to 
spread until neighbouring trees meet ; but keep them 
in form and well balanced, by pinching out the 
points of the shoots, from time to time, as found 
desirable. Allow the tree to form its head, but remove 
all weak branches with a sharp knife, and never 
allow any part of the tree to get too thick, or the 
free circulation of the air will be prevented' All 
branches which are decayed or diseased in any way 
should be at once removed. No attempt should be 
made to limit the trees to a certain height. The larger 
the tree, the more fruit it can bear. Shoots called 
'■rohhers" or "thieues" when occurring out of place, 
should be removed ; but when they ai*ise where a 
branch is required, they may be used with the greatest 
safety and economy, as for example to rejuvenate 
stunted trees, and to replace diseased or broken 
branches, which have had to be removed. 
In pruning, use a sharp knife. No special directions 
can be laid down how to use it. A good pruuer ia 
"made not born," and the best written instructions 
are but a poor substitute for practical teaching. The 
general principles which should guide everyone who 
is cultivating cacao are : — Prune little and prune 
often. Never cut large branches away at one time. 
Cnt close and clean, so that no water may lodge 
in the wounds. Never leave stumps or spurs to rolj 
out. Cover all large wounds with tar or paint. 
PICKING CACAO. 
The first point to settle is, when the pod is ripe. 
It should be ripe but not over-ripe. The colour 
should be fully attained, whether red or yellow. If the 
beans shake easily about, the pod is probably over- 
ripe. When picking Cacao always cut the pod with 
sharp knife, 
