January r, 1883.] 



THE TROPICAL AGRICULTURIST. 



587 



by year. " It our trees were diseased the surest sign 

 woujd bo the sickliness of their leaves," says '* "W"." But 

 surely an unusual amount of bad beans is quite as good 

 a proof of a " constitutional disturbance " of the 

 tree. 



The rootlets are admitted, both by Mr. Ward and Mr. 

 Morris, to be covered more or le.ss with the mycelia of 

 the fungus. Certainly they do not enter or feed on or 

 destroy the rootlets, but their presence there is not a 

 forced one. Their advanced st.ige of development in the 

 leaf i.s no proof that they are harmless in other stages 

 of development or existence, when besetting the fruit, 

 bark, or rootlets. It is not affirmed by any scientist that 

 their contiguity to these organs of the tree is not pre- 

 judicial. "The black bug fungus lives upon (or rather 

 exists on) the leaf without entering in, and feeds on the 

 honey-dew of the aphis." In the case of this last fungus, 

 though the leaves do not drop before their natural time, 

 yet it prevents them from performing their office pro- 

 perly, probably by depriving tliem of the benefit of the 

 atmosphere. Profuse flushes of new foliage do not invari- 

 ably manifest vigour of growth. The flickering and dying 

 flame of an expiring light often fitfully increases its former 

 brightness. Observation has besides shown that repeated 

 attacks of the fungus have resulted in the tree growing 

 spindly thin branches, having a bark of a dry leathery 

 appearance, in lieu of a soft one with a free epidermis, 

 if I may so use the term. These sickly branches in form- 

 ation grow out seemingly, and prboably for the time being, 

 healthy leaves. A profuse flush of leaves is not, however, 

 what seems sufiicient. The leaves must not only attain 

 their growth, but must remain in a healthy condition ex- 

 erting i heir power when the blossom opens and sets, and 

 after the fruit is formed till it m.atures and ripens. It 

 is when the fruit is just opening that the leaves begin 

 to faile and yellow and prepare to drop, showing that their 

 aid is no longer required. These leaves .are those near 

 and where the fruit appears, that is to say, at the lower 

 end of a bearing branch. Those leaves at the upper end 

 of the same branch, where there are no fruit, remain 

 green, and are in a preparatory condition to support the 

 next blossom that will appear amongst them. After the 

 ripe berries or fruits drop, it is then that the old leaves, 

 which have been their companions, fall. The sound leaf 

 has really, according to the climate, a natural existence 

 of 12 to 13 months after its first appearance. //. Vastati'ix 

 makes it drop too soon, which is one bad perceptible eff^ect, 

 apart from others unseen, which it cau.ses to the leaf and 

 tree. The dropping of the leaf a couple of months too 

 soon may in some instances not affect the yield of cher- 

 ries, but it is enough to affect the quality and weight 

 of the beans in them. Earlier attacks affect the yield by 

 preventing development of the fruit, causing them to 

 shrivel and drop, while a very early attack prevents, if 

 not the forming, the setting of the blossom. 



Strip a branch of its leaves just before the blossom 

 sets. It will generally set unusually well, but an unusually 

 large proportion of the tiny berries that succeed will 

 begin to drop at all stages of growth, and at crop time 

 there will be very few berries with sound beans left. The 

 fact of trees bearing a hea^'y crop of coffee and then dying 

 is often attributed to the disproportion in the quantity of 

 leaves to fruit. Such a crop contains invariably a large 

 proportion of imperfect and light cherries. All these 

 results are noticed apart from the effects of leaf 

 disease. 



" W." also thinks it strange that while the loss of foliage 

 by leaf disease is detrimental to the fruit-bearing capacity 

 or condition of the coffee tree, that a tremendous sacri- 

 fice of leaf by handling and pruning is usually resorted 

 to for the express purpose of promoting blossom and crop. 

 It must however be remembered that the branches that 

 are intended to yield are not deprived of a single leaf, 

 and in handling and pruning, with the foliage removed, 

 go the brandies on which such leaves adhered and grew ! 

 This is doue expressly to concentrate the flow of sap to 

 the branches reserved and thus to increase their vigour 

 and natm'ally of the leaves on them. It not only causes 

 an increase of blossom, but also gives the fruit sustenance 

 to develope and mature and not drop. In handling pruning, 

 the lernovil of an excess of tender immature and diseased 

 " wood " as the phrase goes, is one of the main objects 



and not the deprivation of the tree of leaves only. When 

 the handlijg and pruning is done, for nearly [Hie: query 

 too early, or too severely ? — Ed.] every practical planter 

 knows that lie will have no wood,' meaning seasoned 

 branches to bear fruit the following year ; the foliage that 

 is left by ordinary hand'ing and pruning properly done, 

 is sufiicient to support a blossom and mature a " crop if 

 the leaves are allowed to perform their function to the 

 end without interruption. 



A.s to the destruction of a portion or all leaves by 

 beetles as in an instance cited by " W.", total destruc- 

 tion of leaves is rare, and even in such cases healthy 

 fresh leaves soon appear at the end of the branches and 

 help the further development of the crop, but whether 

 completely is a question. There is no evidence to show 

 that the yield from trees that have had their leaves so 

 destroyed and replaced was not a little less in quantity 

 than usual, or consisted of an usual proportion of light 

 coffee. 



On the authority of Mr. Ward, " W." says that //. 

 I'astatrix is a fungus whose whole work and influence is 

 declared to consist in the destruction of a certain com- 

 paratively small proportion of leaf. Is it an admitted 

 fact? What of the presence of its mycelia on the branches 

 bark, and rootlets ? Are they inert and harmless because 

 they derive no nourishment such as the leaves afl:'ord? 

 What is meant by a comparatively small proportion of 

 the leaf? When the leaf prematurely drops from the 

 effects of IJ. v., not a hundredth part of it appears sound. 

 It is where the leaves are partially attacked and allowed 

 to remain on the tree the natural length of time that 

 some sort of crop is secured. There is evidence of a 

 constitutional disturbance, and why is it illogical to sup- 

 pose that the destruction of a part of the leaf, whereby 

 also its action is partly retarded, will smite a tree with 

 barrenness? Why does the leaf drop long before its proper 

 time for doing so has e.xpu-ed ? The human .skin is de- 

 clared to be a breathing organ performing the functions 

 of a third lung, and yet it is also a depurating agent 

 and carries o& had humours. What is there to show that 

 the coffee tree, deprived of its leaves by //. ?', is pre- 

 vented from casting off what is objectionable through them, 

 besides absorbing what is needed. If a man's whole boily 

 is peppered with snipe-shot at a certain and reasonable 

 distance, he will present a most alarming and distressing 

 spectacle, but in a few months he seems, and is really, 

 none the worse for it. Administer, however, by placing 

 on his tongue as much strychnine, as a few of those shots 

 would weigh, and it is a question, even if he survives 

 whether his constitution is not seriously shattered ? Who 

 can explain the manner in which, or give a reason why 

 the latter substance acts in so subtle a manner. Why is 

 it unreasonable to suppose that by some such subtle pro- 

 cess the II. V. acts in a similar manner on the whole 

 coffee tree ? In both the above examples the human .sys- 

 tem receives a shock. In the one case the result is 

 temporarily bad, in the other it paralyses the whole system 

 and causes a bad effect permanently. In the former times 

 trees with their leaves riddled with holes, the work of 

 beetles and other insects, did not drop prematurely these 

 leaves nor perceptibly ceased to blossom and bear as usual. 

 Here then we have an instance of a considerable portion 

 of each leaf removed bodily, and yet with no bad result 

 such as //. I', produces. This foe does not only deprive 

 the tree of the full action of every leaf by destroying 

 only a part of the leaf. It does more, as observation 

 proves. It positively, while destroying totally a part, para- 

 lyses the whole leaf and renders it totally useless to the 

 tree. 



"AV." refers to the treatment of the grape vine as an 

 instance of the mastering of the cases of infertility. Has 

 " W." ev.T heard of a vine with only grapes and no leaves, 

 and that such a condition is compatible with the full develop- 

 ment of the fruits? The vine is stripped of leaves to 

 induce an unusual blossom to appear and set. but simulta- 

 neously with the blossom, fresh shoots with leaves appear, 

 and but for these new leaves not only would the fruits, 

 drop but the vine would probably die. That after pcrsisfent 

 attacks the coffee tree retains tlie power of producing 

 iiivitridhlii splendid flu.shes is a question; but admitting 

 that it is true, it does not possess the power of retain- 

 ing these leaves for the natural length of time, and that 



