and Magazine of the Ceylon Agricultural Society.— December, 1911. 567 



cacao soil like that of Peradeniya is a waste 

 of money, under the conditions of this 

 experiment. Disappointing as the manurial re- 

 sults may appear at first sight, they are by no 

 means devoid of interest when considered in 

 the light of general agricultural principles. 

 Apart from the question of actual fertilizers, 

 several important facts have come to light 

 bearing on the general cultivation of cacao. As 

 to the effect of treatment other than manurial, 

 Dr. Lock says it is not impossible that judi- 

 cious pruning might lead to a somewhat bet- 

 ter result, but upon this point the experi- 

 ments under discussion afford no evidence. 

 The practice of forking the soil during dry 

 weather is decidedly harmful, even when only 

 carried out to the small extent involved in 

 burying artificial manure of little bulk. Two 

 factors probably contribute to cause the dam- 

 age herein involved : (1) the actual physi- 

 cal injury to the surface-feeding roots of the 

 cacao tree, and (2) the increased evaporation 

 from the soil caused by the removal of the 

 surface mulch of leaves which is always pre- 

 sent on good cocoa land. This in turn doubt- 

 less leads to further damage to the exposed 

 roots. There seems to be no doubt, therefore, 

 that forking as an annually recurrent practice 

 must be condemned. In the cultivation of 

 cacao in Ceylon nothing is more important 

 than the proper treatment of shade. If the 

 shade is too heavy, the attacks of canker during 

 wet weather are facilitated ; whilst absence of 

 shade encourages the visitations of Relopeltis 

 during the drier months. The shade t r ee par 

 excellence for cacao in Ceylon is the dadap, 

 and any excess of leafy branches affords an 

 invaluable mulch. Finally, Dr. Lock says, the 

 result of the experiments at Peradeniya warns 

 us to excercise the greatest possible caution 

 in drawing deductions from the results of ex- 

 periments in the manuring of permanent crops 

 in the tropics. The greater part of Dr. 

 Lock's report had been completed when the 

 new edition of the late Mr J H Hart's book on 

 cacao came into his hands for review, and it is 

 stated that Mr Hart's experience of cacao culti- 

 vation in the West Indies agrees closely with 

 the deductions drawn from actual experiments 

 at Peradeniya. Hart considers that the appli- 

 cation of strong manures to trees in good 

 health and in average bearing would tend to 

 encourage rank and sappy growth, which would 

 be non-productive, and loss of crop would re- 

 sult, and also that to dig deeply about the roots 

 of a surface-feeding plant for the purpose of 

 applying manure would be absolutely absurd. 

 In conclusion, we quote in full the following 

 practical recommendations by Dr. Lock : — 

 Peactical Recommendations. 

 A. — For Further Experiments at Peradeniya. 



1. The application of the present series of 

 manures should be brought to an end without 

 exception. A differential result as between the 

 different plots is then more likely to assert itself 

 than if the manures are continued. The sepa- 

 rate gathering of crop from the different plots 

 should therefore still be carefully carried on. 



2. Experiments in pruning should be begun. 

 This may best be effected by dividing existing 



plots into two. and pruning one-half whilst the 

 other remains unpruned. 



3. Forking and the burying of leaves in 

 trenches should be discontinued, and the sur- 

 face mulch should be encouraged as much as 

 possible. This does not apply to the burial of 

 husks, which must be continued for sanitary 

 reasons. 



B. — For the Improvement of Estates in Poor 

 Condition. 



1. The most important step is to get a high 

 shade of dadaps in sound condition. If there is 

 difficulty in getting dadaps to grow, artificial 

 manures can probably be applied to them with 

 greater advantage than to the cacao itself. A 

 small quantity of basic slag and sulphate of 

 potash, in the proportion of two of the former 

 to one of the latter, applied about three feet 

 from the base of the young dadap, should afford 

 considerable encouragement to its growth. If 

 shade is too heavy, on the other hand, ic should 

 be thinned out the operation being performed 

 at the end, and not at the beginning, of the dry 

 weather. About thirty well-grown dadap trees 

 per acre is generally sufficient, and even these 

 should have some branches lopped at the begin- 

 ning of the south-west monsoon in districts 

 which get heavy rain at this season. The old 

 dadaps should be cut out periodically, and their 

 places taken by newly-grown cuttings ; seven 

 years is probably quite long enough for any 

 dadap to stand, 



2. Removal of excessive shade is the first step 

 in the treatment of canker — the greatest scourge 

 of cacao in Ceylon. Other important measures 

 are collection, if possible weekly during the 

 season of heavy crop, of all diseased pods, which 

 should be deeply buried, and the excision of 

 diseased bark. In this connection it may be 

 pointed out that it is generally better to remove 

 the whole of a cankered branch than to peel off 

 the bark from three-quarters of its surface, as is 

 often done. Spraying may also be resorted to. 



3. IE cattle manure is available it may ba 

 applied freely as a surface mulch. In the dry 

 weather especially some form of surface mulch 

 is very desirable. And since, if the cacao is 

 in poor condition, its own leaves will not be 

 sufficient for this purpose, they should bo sup- 

 plemented by any cut grass, jungle leaves, and 

 "cheddy" that can be collected. 



4. If artificials are to be applied, the best 

 appear to be bone or fish manure, in com- 

 bination with a potash salt if the soil is deficient 

 in that constituent. These should not be dug in 

 deeply, but applied on the surface, and the soil 

 just scraped over them with as little disturbance 

 of the cacao roots as possible. Dadaps, as pre- 

 viously stated, may be fed up with phosphatic 

 and potassic manure in small quantities and their 

 leaves applied as a mulch. 



5. In places where the growth of cacao is 

 poor no pruning is likely to be required beyond 

 the removal of weak and cankered branches. The 

 need for pruning is indicated by over-luxuriance 

 in the growth of the trees which run to leaf in- 

 stead of producing crop. It is difficult to lay 

 down any definite rules for pruning, since this is 

 a matter for practical study and experience, the 



