Ferbttary, 1909.]/ 



i 45 



Eddble ProOucts, 



plot has given a very large return. These 

 facts go to prove that nitrogen and phos- 

 phate are the constituents most required, 

 while the effect of potash is doubtful. 



The best returns of all are obtained 

 from the use of pen manure which 

 contains nitrogen, phosphate, and po- 

 tash, and in addition large quantities of 

 organic matter. This latter substance 

 greatly improves the texture of the soil 

 and so adds very materially to its 

 fertility. Dried blood has also given 

 good results. This manure contains 

 nitrogen, phosphate and potash with 

 organic matter. The general results 

 with compost plot 9, have not been 

 satisfactory ; either the compost has 

 not been sufficient, or it is unexpectedly 

 slow in its action. 



(1) Very vigorous, with fin^ 



healthy foliage and 

 robust trees, 



(2) Good, with healthy foli 



age and robust trees. 



(3) Fair 



(4) Lacking vigorous 



growth, foliage poor. 



Judged by the appearance of the trees, 

 we get a great deal of light thrown on 

 the effect of manures. The best results, 

 taking both the vigour of the trees and 

 the yield of cacao into account, have 

 been given by the use of pen manure. 

 The yield is the highest of all the plots 

 and the trees are the most vigorous. 

 Next to this we must place the bone 

 meal and the dried blood plots. Both 

 these manures convey to the soil nitrogen 

 and phosphate. Following these come 

 plot 10, ammonia ; and plot 5, ammonia 

 and potash ; and then plot 4, with 

 ammonia and phosphate ; and plot 11, 

 with ammonia, phosphate, and potash. 



After these, we come to a group where 

 the trees obviously lack vigour, and 

 where we may soon look for a derided 

 falling off. The striking feature in this 

 group is that none of the plots have 

 received any nitrogenous manure. It is 

 to be noted that this group includes plot 

 2, phosphate ; plot 3, potash ; and plot 6, 

 phosphate and potash, all of which 

 have given good numbers of pods, and 

 which, judged from the crop returns 

 alone, would be regarded as satisfactory. 

 They cannot be regarded as satis- 

 factory, however, and a falling off in 

 crop is anticipated. The group includes 

 plot 9, compost ; and plot 12, no-manure. 

 17 



Estimating the effect of manures on 

 young cacao trees by taking account 

 only of the yield of cacao is likely to 

 be fallacious for more than one reason. 

 In the early stages there is likely to be 

 irregularity in the manner in which 

 youug trees come into bearing;, while 

 some manures may tend to force the 

 trees into early bearing and lead to 

 early exhaustion. It is therefore neces- 

 sary to add to the statement of the yield 

 of cacao, observations as to the general 

 condition of the trees. When this is 

 done in connexion with these experi- 

 ments we ai rive at very interesting re- 

 sults. 



The plots may be roughly grouped 

 according to ;the health and vigorous 

 appearance of the trees :— 



1 



Plot 



Pen manure 



}Plot 8. Dried blood. 

 Plot 1, Bone meal. 

 Plot 10. Ammonia. 

 Plot 5. Ammonia and potash. 

 \ Plot 4. Ammonia and phosphate 

 j Plot 11. Ammonia, phosphate, 



and potash. 

 ) Plot 9. Compost 

 I Plot 2. Phosphate 

 [-Plot 3. Potash 

 | Plot 0. Phosphate and potash 

 J Plot 12. No manure. 



The lessons from these experiments 

 already begin to be valuable and may 

 be summarized thus : — 



Manures are useful in establishing 

 cacao fields. Pen manure, when obtain- 

 able, is likely to give the best results. 



Efforts should be made to increase 

 the humus in the soil as much as 

 possible. Manures supplying oiganic 

 matter are desirable as they tend to 

 maintain the supply of humus. Nitro- 

 genous manures are essential ; without 

 nitrogen the trees lack vigour. Phos- 

 phatic manures increase the crops, but 

 should not be used without nitrogen. 

 It would probably be good policy to use 

 nitrogenous and phosphatic manures 

 together. The effect of potash is not 

 very clear. It is probably not at present 

 urgently required as a manure. 



It is recognized that some of the plots 

 are not likely to improve under the 

 mauurial treatmeut tbey are receiving, 

 but their retrograde movement, should 

 it occur, will throw valuable light on 

 important points bearing on the manur- 

 ing of cacao. This will entail some loss 

 upon owners, but it is hoped this pros- 

 pective loas may be faced for the sake 

 of the valuable information likely to be 

 obtained. 



