Vol. X. Xo. 243. 



THE AGRICULTURAL NEWS. 



261 



CACAO, ITS CULTIVATION AND CURING. By 

 .T. Hinchley Hart, F.L.S. London, Dufki''orfh <t Co. 7.s. 6(7. 

 net. 



This work, which has received reference and quotation 

 from the Aarkulttiral News several times, has appeared 

 already, for the greater part, as a series of articles in the 

 West India Coiiunitfee Circular. Before dealing with the 

 merits of the book itself, it will be well to summarize shortly 

 its contents, which may be stated generally as follows: botany 

 and varieties of cacao. Chapters I and II; planting and grow- 

 ing cacao, Chapters III to VIII; diseases and pests, Chapters 

 IX and X; road-making and draining. Chapter XI; picking 

 and preparation, Chapters XII to XA'; special matters in 

 regard to cacao production, Chapters XVI to XX: food value 

 and manufacture, Chapter XXI; transport of cacao plants and 

 seed. Chapter XXII; miscellaneous matters, Chapters XXIIl 

 to XXV, 



It is hardly necessary to state that the treatment of the 

 whole subject is thorough and authoritative, and this is par- 

 ticularly the case in the parts which will appeal more directly 

 to the practical planter, namely those dealing with the gener- 

 al work of planting and growing the trees, and of harvesting 

 and preparing the product. 



The same is true in regard to those portions which have 

 relation to the diseases to which the cacao plant is liable. 

 The special chapter devoted to the subject presents, on the 

 whole, a sound and reliable summary regarding the fungus 

 species known to occur on the cacao plant, particularly 

 in the West Indies, as well as of the position in regard 

 to the knowledge of these at the time of writing the 

 book. It may, however, be pointed out that cacao canker 

 has practically been proved to be caused by Phi/tophfhora 

 Faberi, Maublanc, which is the modern name for the 

 fungus formerly Icnown as P. omnimra, de Bary; while the 

 present tendency is to regard most of the Nectrias and 

 associated and related fungi as purely saprophytic. Recent 

 work by Coleman has shown that P. FaU'ri is almost always 

 parthenogenetic, and that antheridia very rarely occur, at least 

 as the fungus is known in Ceylon. It is not very clear whether 

 this is the case in Trinidad, or not. Recently acquired knowl- 

 edge would have enabled the author, also, to write far more 

 definitely on the subject of the identity of the various forms 

 of Diplodia, Botryodiplodia, Lasiodiplodia and Chaetodiplo- 

 dia, as they are now known to be identical; while Fetch 

 advocates the use of the old name Botryodiplodia theohromiae, 

 Pat., to designate them all, as representing the soundest 

 cla.ssification. They are, however, more usually known as 

 La-nodiplodia iheohromae (Pat.), Grittbn and Maublanc. 



It is somewhat regrettable that the author has dismissed 

 so summarily the question of root di.sea.se of cacao; there is 

 much evidence to show that, at any rate one form, having no 

 connexion with Lasiodij^lodia theohromai', is of common occur- 

 rence, and possesses well marked characters, although the 

 causative fungus is unidentified. Again, sympathy cannot 



be expressed with the author's view as regards the spraying 

 of cacao, as this is put forward on page 89, and reiterated 

 on page 93. The aspect of the question which deals with 

 the protection of young pods, and even of stems, from original 

 infection by means of a coating of Bordeaux mixture, has 

 been entirely overlooked, notwithstanding the recent demon- 

 stration of its usefulness, by Rorer, in Trinidad. Further, 

 much of what is said in Chapter XXIII as regards the diffi- 

 c'llties of spraying is true, but concurrence with the author 

 cannot be expressed as regards the futility of spraying with 

 fungicides as a preventive for pod diseases: adhesive Bordeaux 

 mixture can be made, and the removal of infected pods may 

 easily be practised in conjunction with spraying. Agreement 

 must, however, be expressed with the author's contention that 

 the application of spraying material should be the work of 

 experienced hands. It is agreed, too, that spraying is of no 

 use as a direct remedial measure against internal para.sites; 

 it is, nevertheless, valuable as a preventive, and this aspect 

 is considered in Chapter XXIII. Another matter for remark 

 is that Hypo.rijlon rubi(jinosurit (Pers.), Fr., has been found 

 recently in St. Lucia on a dead cacao branch, and is almost 

 certainty a saprophyte, onl}'. 



For the rest, good as is the summary of cacao diseases, 

 it is slightly disfigured by one or two printers' errors, among 

 which may be mentioned Pellicu/aria Kaleroga for Pellicu- 

 laria Koleroga, }[arasinius equicrinus for Marasmius equi- 

 crini-'i, Corticiuia lilnco-fuscwm for Corticium lilacino-fiiscum; 

 the last, however, originated in the source from which the 

 information on the subject is taken. Another matter is that 

 the zoospores of Phytophthora are given as about one two- 

 hundredth of an inch in diameter; this must be a misprint 

 for one two thousandth. 



The review of the mycological part of the work would 

 not be complete without reference to the large amount of 

 interesting information that is given under the head 

 Diplodia. It would appear, however, that the fungus is not 

 responsible directly for as much damage as is considered to 

 be the case by the author. It is a very rapidly growing 

 organism, almost universally present in the air where cacao 

 is planted, and consequently its appearance on material kept 

 in a damp chamber cannot be definitely regarded as a proof 

 that it is the primary cause of any given trouble, unless most 

 careful steps have been taken to make certain that it is not 

 an infection following other forms, subsequently to the 

 cutting of the material. The matter of nomenclature in 

 relation to Diplodia has been treated above. 



The forms of animal life found in cacao fields are con- 

 sidered under the head Insects and Mammals, and a table 

 presents in a convenient way the useful facts in regard to 

 these. The account of the insect pests and their treatment 

 is very good, but it would seem that more mention might 

 have been made of the purely beneficial insects such as lady- 

 l>irds, lace-wmg flies, the parasitic and predaceous Hymenop- 

 tera, and of the social and solitary wasps; attention should 

 also have been given to the useful work of birds and reptiles, 

 in the same connexion. The chapter entitled Miscellaneous 

 Notes contains sound advice as regards spraying and the 

 natural control of pests, and it is indicated that the value of 

 the latter may vary under differing surrounding conditions. 

 Finally, a few errors appear in the spelling of technical names, 

 but this detracts little from the value of the general treat- 

 ment, which as has been stated, is good. 



It only remains to say that the work is well produced, 

 with good illustrations, and that, notwithstanding the 

 employment of large type — a welcome feature^the book is 

 light in weight and convenient to handle. 



