464 



THE TROPICAL AGRICULTURIST. 



[December i, 1882. 



timulate it to the reproduction of the lost foliage, an 

 effort the strain of which is easily estimated, and in 

 fact is well-kuuwn. (Ju the other hand, the mildest 

 attack of the peronospora inflicts a mortal blow. 



He who " propounded tlie internal ulcer theory" was 

 no " quack" (Olj'-rroer Oot. 14th), but the late lamented 

 Dr. Tliwuitcs,* who, if he ever entirely renounced his 

 first formed opinion as to the internal character of the 

 attack of heiiiileia, did so only when the fact of its 

 true nature had been established by the exhaustive 

 demonstrations of Mr. Ward. If I am not mistaken, 

 Mr. Alibay also held the opinion that hemileia car- 

 ried on its operations in the litals of the tree, and 

 I believe this was assumed to be the case by scien- 

 tific men at the time the fungus received its name of 

 \ast:itrix. Tlie terrible ravages of the potato blight 

 we:e uppermost in the minds of experts at home. (So 

 long as the new invad<.'i- of our coffee plantitions 

 was supposed to be of the same nature as the pero- 

 nospora the alarm it excited was reasonable, and in 

 fact unavoidable, but the old opinions have bnen 

 utterly exploded by the more recently discovered 

 facts, and there is no longer the same ground for 

 the terror first inspired. The past history of the 

 coffee fungus proves how very unreliable 

 are opinionn, even of the highest authorities in such 

 matters; and also how unsafe it is to draw conclu- 

 sions exc.-pt on fads well ascertained and established. 

 Hence the evidence advanced throughout this series 

 ol letters has been adduced entirely from the facts 

 of our ixperience; and the aid the writer has sought 

 from fellow-planters was from euch facts, corrobora- 

 tive or o herwise, as their experience might supply. 

 To revi-rt once more to the action of hemileia, 

 occasioual allusions occur in correspondence on this 

 subject, v.hicli are evidently based on a supposition 

 that tome hidden mischief is done to the permanent 

 structures of our coffee trees by the action of the 

 fungus on the leaves, as though some poisouous in- 

 fluence were disseminated by means of circulation. 

 Indeed, planters frequently speak about circulation as 

 if it were an acknowledged fact of vegetable physio- 

 logy. It may not be altogether supeifluous, therefore, 

 to state that such is not -the case. There is, of course, 

 a floio of sap from the roots upwards, and so long as 

 the idea was entertained that hemileia entered the 

 plant through its roots, and permeated its internal 

 structures in the manner of perenospora, (as some 

 planters even j'et believe) the flow of sap gave a sort 

 of sanction to the expression. It is altogether incor- 

 rect, however, and therefore any inferences which 

 imply th" existence of circulation in the coffee tree are 

 inadinisoiblc 



The conditions of fertility in fruit-bearing trees are 

 very obscure. The imagination could ecircely invent 

 theories more curious, fanciful, and apparently 

 inconsistent thau the facts of our experience in 

 regard to fruit trees. We see trees which once bore 

 abundantly cea?e, or nearly cease to bear at all, for 

 considerable periods, without any assignable cause. And 

 tve see thcii- fertility restored and perpetuated by the 

 most impi-obablfl means. For instance, a pear tree of 

 rem>irkiihly luxuriant ki'O""^) ^'^'^ renowned in its 

 ueighliourhood for its luscious fruit, beciine utterly 

 sterile for several years, in ^pite of various remedial 

 measures, and so continued until the desperate expedient 

 of sawing off its largest root was adopted. It then 

 fruited Ireely for some yeais. Walnut trees are said 

 to require thrashing to make them yield their fruit. 

 Loquats and several other trees, on refusing to bear 

 fruit, may oft.u be induced to bear by a massacre 

 of their largest branches, or " barbarous hacldng of 

 *Tn^ Thwaites propounded what Hooker described as an 

 imscientific theory ; but it was not he but an unmitigated 

 quack who wrote of " internal ulcers " developing into 

 u^iiiiUia. — Ed. 



their trunks. Vines often remain unproductive till 

 their roots are bared, and the plants receive a check 

 of growth, or an artificial winter, as it is called. — 

 If it wore safe to generalize on such data as these, 

 it would seem as if luxuriance of growth, or growth 

 unchecked, were adverse to fruit- brearing. Even in 

 sug.arcane, coutiuuous growth in a forcing climate 

 seems to hinder the elaboration of sugar. Two planters 

 from Mauritius exclaimed, on seeing the magnificent 

 canes at INlattagodn, that "thisivcis the country for 

 siri/ar." But when they saw the liquor in the lolling 

 house, and howthe saccharometer stood, they speedily 

 changed their note ! We often had to consume the 

 whole of our megass, and sometimes required fire- 

 wood besides, to get the sugar ! We managed to 

 make all ends meet as long as we could obtain retail 

 price lor our sugar, locally, but were unable to compete 

 m the markets of the world with the pioduce of other 

 countries. Eventually, the estate was S'ld to a 

 Frenchman, who would not be convinced that such 

 luxuriant growth of cane could be so unproductive 

 ot suyar. His confident opinion outweighed the 

 facts of our experience, and he spent £12,000 iu 

 undeceiving himself. Pardon this digression. It may 

 possibly save some victim from following our worthy 

 Governor's recent recommendation to try sugar-grow- 

 ing again. 



Xurning again to the subject of continuous or un- 

 checked growth as a condition adverse, in some cases at 

 least, to fruit-bearing, the fact that many of the fruit 

 trees of temperate climates grow profusely in the tropics 

 and yet refuse to bear fruit there has led to the general 

 belief that the check of their wintering in their own 

 countries is what constitutes the difference. And this 

 idea receives some confirmation from tlie success of 

 sucii treatment as exposure of roots, and those other 

 means above specified for checking growth. Moreover, 

 our owu coffee trees offer some evidence in support of 

 the idea ; for we kuow that the hot, parching weather 

 we u.^ually h.ave iu the months of January and Febru- 

 arj', and the pruning of the trees which usually pre- 

 cedes or accompanies it, have a decided tendency to 

 check growth, and they are also the conditions most 

 favourable to our ciop prospects. On the other hand, 

 when tliese months are wet and forcing, and when 

 growth is uuohecked, the formation of blossom is dis- 

 couragfd, aud in planters' parlance the blossom "turns 

 to leaf." 



The facts of our observation and the results of our 

 experience show that teiuporary sterility in fruit trees 

 is no rare phenomenon, and though science has not 

 yet probed deep enough into the mystery, we have 

 /actetoaid our fea-ioning and research, without lesort- 

 ing to assumptions and theories opposed at once to 

 ecience and logic. 



Other tropical countries have been subject in years 

 gone by to waves of agricultural depression, similar to 

 that through which we are now unhappily passing, 

 aud of even longer duration. Some, indeed, have shared 

 with us the ill-fortune of this past decade, aud their 

 experience, past and present, might serve to enlighten, 

 and possibly to help us. The ebbs and flows of 

 agricultural tides in other countries offer a promising 

 lield for inquiry iu our present difficulties. Ths Board 

 of Agriculture of the 0. 8. of America, in their annual 

 report for, I think 1S79, refer to the persistent failure 

 of the fruit crops of the States for so many years that 

 those crops had cease*! to attract attention. And they 

 conclude by a mpiJosition that the "art of fruit 

 culture had been lost." The truth is, not that they 

 had loit, but that they had neivr punfiesned a knowledge 

 of the essential con lilions of fertility iu their fruit 

 trees! The fruit hiil come forth ahundautly, they 

 knew not why ; and it had ceased for reasons they 

 therefore could not divine ! If they had had a scape- 

 goat_fungus liandy, they would prob.ibly Invc been 



