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THE TROPICAL AGRICULTURIST. [November i, 1884. 



country during a residence of 22 years in Matale. 

 The experience throughout that time has only em- 

 phasized the opinions we have expressed in this re- 

 port, that the so-called blight is due mainly to local 

 influences and local circumstances, want of shelter 

 being the chief cause of the suffering of cacao. 



The report was then read by the Secretary as 

 follows : — 



Report of the Sub-Oommittee of the Planters' Associ- 

 ation of Oeylon appointed at a General Meeting held on 

 the 28th June 1884, to take evidence and to report upon 

 the cacao blight. 



1. Your Sub-Committee have visited sevural estates in 

 different districts with the hope of finding out the cause of 

 the injury to our cacao trees in certain places recently. 

 It has not been possible for us with the short time at 

 our disposal to visit all the cacao estates or patches that 

 have suffered, but we have seen enough to enable us 

 to arrive at certain definite conclusions. We are convinced 

 that upon careful examination the injury done may be 

 referred to one or more of the causes we uame. 



2. Over well-defined areas in several districts we have 

 found injury done to the cacao trees : the young shoots die 

 and, in some instances, almost every new flush of young 

 leaves is destroyed, and where this process is continued the 

 older branches die back leaving in time only the stump ; this 

 retains vitality, and under favorable circumstances will grow 

 numerous suckers from which a new tree can be formed. 

 AVe have heard of considerable areas being killed out en- 

 tirely, but in our extensive observation we have seen 

 comparatively few dead trees. That the injuries described 

 are due to insects seems certain ; but whether to one or 

 more, or what insect or insects, we are not in possession 

 of sufficient evidence to say with certainty. This point, 

 however, we consider of minor importance, as our belief 

 is that under certain conditions the insects would not be 

 numerous nor do any serious mischief. As certain meteoro- 

 logical conditions have a great influence on the in- 

 crease of insect life, we are of opinion that the very 

 abnormal season we are passing through has been 

 unusually prolific in this respect and that the altered con- 

 dition of the sap has rendered the trees more liable to the 

 attacks of insects than they would be in normal seasons. 



3. That the prolonged drought this season in most of 

 the cacao districts amounting to an almost total failure of 

 the south-west monsoon has had much to do with the 

 damage is, we think, beyond dispute ; and we would even 

 venture to say that but for this many of the estates that 

 have suffered would have escaped almost entirely. This 

 is borne out by the rapidity with which trees in fail- 

 soil have recovered after a few heavy showers of rain i trees 

 that in May were a " ghastly sight " recovered so 

 buickly that early in July two cacao plauters went so far as 

 to say the " blight" could never have bten there ; this 

 improvement has steadily progressed, and there have been 

 no fresh attacks of insects or anything else. Another case 

 in illustration. A small swamp, the soil of which is white 

 quartz gravel with a little black mould, has about 20 trees 

 four years old growing upon it ; deep drains were cut in it 

 last year to drain off excess of moisture ; the trees have 

 all withstood the drought, have lost none of their old 

 leaves (their heads are so dense that they afford complete 

 shelter to stems and the ground retarding evaporatiou), 

 have had no insect attacks and have now a very good 

 crop on them. On the other hand, those adjoining, in pretty 

 much the same description of soil, suffered severely. The 

 inference, we think, is plain : in one case, the trees had 

 moisture and abundant nutriment which enabled 

 them to resist both drought and insects, while, in the 

 other, they suffered from starvation. 



4. Speaking generally, we found that where the cacao 

 trees were suffering severely they were without shelter they 

 and the soil being exposed to the full force of the 

 sun's fervid rays and to any wind that blew. We saw 

 evidence in many instances of the plants having been 

 at some period of their growth injured either at time 

 of planting by clubbing of the roots or want of staking 

 when growing or fallen trees and branches or Sowing of 

 the subsoil by checking of evaporatiou caused by excessive 

 drought and consequent baking of the surface soil. In this 

 connection we may mention that the late Dr. Thwaites 

 was a strenuous advocate for mulching the soil, but as this 



cauuot be done owing to risk from fire, the next best thing 

 is to protect it by moderate shade overhead. 



5. It cannot be denied that cacao has often been planted 

 in places quite unfitted to grow it and in such cases we 

 need not be surprized at failure. In free soil with good 

 subsoil drainage, a year old cacao plant will have a tap- 

 root of from two and a half to three feet long, and it will 

 grow longer with the growth of the tree. Suppose a plant 

 planted in ground with a foot or a foot and a half of good 

 surface soil but with a hard and impenetrable or tough 

 clay sub-soil, what would naturally result; as soon as tho 

 tap-root reached thissubsoil, it would turn aside seeking some 

 crevice if possible, and, not tindiug it, would cease to grow 

 downwards; itwould have to depend upon this surface soil en- 

 tirely, and perhaps iu normal seasous would not for several 

 years show signs of distress ; but on the occurrence of a 

 drought it would naturally sutler long before the deep tap- 

 rooted plant even felt it. It is a significant circumstance 

 that cacao plants rarely die at the tips or are attacked by the 

 insects that destroy the young shoots till after their second 

 year, indicating that they have received a check which 

 perhaps sickens them for a time. 



6. We have been greatly impressed by the fact, that, 

 wherever cacao has been planted in good soil with shelter 

 and moderate shade and a suitable climate, there the in- 

 jury is practically nil; and we are convinced that um'er 

 such conditions insects' attacks are not serious. Any ordin- 

 ary drought at this season seems only to have the effect 

 of retarding the formation of blossom and causing the 

 shedding of a few of the more matured leaves ; this latter 

 gives on superficial observation an appearance mistaken 

 frequently for insect depredations, but the twigs and branches 

 are after rain speedily reclad in verdure. The conviction 

 forces itself upon us that those who discarded shade totally, 

 ignoring the experiences of over half-a-century of our 

 West India brother cacao planters, are now feeling the 

 effects of their mistake, and the sooner we take a lessou 

 from them on this head the better it will be— we mean 

 of course light checkered shade where the sunlight cau 

 play through the branches and where the crowns do not meet. 



7. There are numerous insects that live on the cacao plant, 

 but few are yet known here that do much harm or whose 

 depredations cannot be arrested. The one best kuown and 

 most dreaded is the Hilopeltis Antonii which causes such 

 serious damage to the pods. Dr. Trimen tells us that he 

 has taken the eggs from a gravid female and has also 

 found them in sttu in the young shoots and has seen the 

 iusect at work sucking the sap from a young shoot: All 

 this proves that they breed in the shoots as well as on 

 the pods, and may fairly be credited with a share of the 

 harm done, but that they alone are responsible for the 

 destruction of all the young flushes has yet to be estab- 

 lished. Several descriptions of bugs and flies all armed 

 with probosces are found on cacao and are capable of doing 

 mischief. Thrips have been very numerous this season iu 

 parts of the cacao districts, and may have contributed 

 towards retarding the recovery of the trees. 



8. The loss sustained by Helopeltis attacking the pods 

 is often very serious, and measures should be adopted to 

 minimize it. We have heard uuslaked lime sprinkled on the 

 young pods suggested, but against this there is the fact 

 th;it the larvaj have lived and thriven uuder a dressing ot 

 uuslaked lime and sulphur. Picking the insects off the 

 pods will do good and keep down their numbers, and gat her- 

 iug periodically aud burying all badly affected pods will 

 destroy large numbers of eggs as it is known that the in- 

 sects breed on the pods. The most effectual remedy, how- 

 ever, is by establishing a colony of the large red ants in each 

 tree, for where they are the pods are always bright and 

 free from spots. 



9. What in Ceylon are known as the " Caracas " and 

 " Forastero " ' Cacaos iu all their varieties are far less 

 delicate than the ordinary red one we usually grow, and 

 are capable of resisting in a marked degree the combined 

 influences of inferior, soil and insects. That these cacaos 

 raised from pure seed have ever been killed out or even 

 seriously damaged we do not believe ; but where they have 

 been hybridized by a cross with the common red, they 

 are liable equally with the red aud uuder similar circum- 

 stances to the attacks of insects. 



10. From what we have stated in the foregoing remarks 

 we deduce -the following as necessary for the successful 

 cultivation of cacao. 



