350 



THE AORICULTURAL NEWS. 



October 28, 1911. 



FUNGUS NOTES. 



WOUNDS IN PLANTS AND THEIR 



TREATMENT. 



PART II. 



In the last number of the Agi-icultural Nen's some 

 account was given of wounds on plants. In the present 

 article, some kinds of accidental wounds will lie di.scussed, 

 with iheir treatment, and a few points will be considered 

 which ari.=e in connexion with the whole subject. 



ACCIDENTAL wouND.s. In temperate and cold climates, 

 several natural agencies, such as frost, hail and wind, are 

 responsible for wounds on trees, but in the tropics wind is the 

 only harmful factor in this class that is of any importance. 

 Very strong winds often lireak off large branches, or cause 

 .splitting of the trunk at a fork where a large branch is given 

 otf. Less serious winds damage young foliage and soft green 

 twigs, and give rise to the appearance known as die-back or 

 stag head. When a large limb is torn out of a tree by wind in 

 such a way that there is no danger of the torn surface hold- 

 ing water, the exposed wood should be smoothed down and 

 covered with one of the preparations described in Part I of 

 this article. If a hollow is left in which water will collect, 

 and there is no means of preventing this by cutting a drain- 

 ing channel, or by smoothing away the side of the hollow, 

 then the hole must be filled uj) with cement, and the surface 

 of the cement must be smoothed off at such an angle as will 

 enable water to run away. 



Splits in the trunks of trees, which arise where two 

 large branches fork, may be closed up in the following 

 manner. An iron bolt should be driven through either branch 

 at some distance above the fork. A tarred wad may be pu.shed 

 through at the same time by the bolt to protect the tissues 

 exi.osed by the augur in drilling the hole for the bolts. The 

 ends of the bolts on the outer side of each branch should 

 carry a thread; on these a flat plate may be held in po.si- 

 tion by means of a nut.' The inside ends of the bolts should be 

 connected by a strong chain. By screwing up the nuts the 

 two branches are forced together and the .split is closed. It 

 is advisable to ajjply a thick coat of tar to each of the exposed 

 .surfaces before closing the split. 



In the case of cacao or lime trees severely damaged by 

 wind, the question often arises whether it is advisable to 

 treat the damaged trees, or whether it is preferable to allow 

 them to be replaced by a sucker or a new tree. This is 

 a question which each planter must settle for himself, under 

 the conditions with which he finds himself confronted. 

 Larger trees grown for ornamental purposes are often dithcult 

 to replace and may be successfully treated in the manner 

 described above. 



Abrasions are often caused by the rubbing of one branch 

 against another. In this case one of the branches should be 

 cut otr and tlic damaged surface of the other should be treated 

 ivith some protective covering, as also .should tlie cut end of 

 the branch removed, '^oung twigs killed by wind should be 

 removed by pruning. 



Among the injuries inflicted by animals mention may be 

 made of tho.se duo to the gnawing of rats and agoutis. 

 (Such wounds should be treated in a manner similar to that 

 <'mj)loyed for cankered areas. 



Hmall sucking insects injure the .surfaces of leaves 

 and green twigs and encourage the entrance of parasitic 

 organisnas, but the remedy against them lies rather in the 

 destruction of the insects than in the treatment of the minute 

 imnctures which they inflict. 



Again, wounds may be caused by other plant organ- 

 isms, parasiticffungi and bacteria. The treatment for these 

 involves pruning and excision, and has been considered 

 already in the previous part of this article. 



GENERAL .:coNsiDERATloxs. In dealing with the ques- 

 tion of wound treatment in general, it must be borne in mind 

 that the trees in a permanent cultivation represent capital, 

 and as such, are worthy of the exercise of all reasonable pre- 

 cautions for their protection. Careless workmen, particularly 

 rubber tapper.s, cacao pickers and men engaged in cutlassing 

 and forking, may well cause very serious diminution in that 

 capital. Every encouragement should, therefore, be given to 

 such workmen to attain jiroficiency in their work, while at 

 the .same time very strict supervision should be exercised 

 over them, especially when they are engaged in tapping 

 ruVjber or picking cacao. 



On large estates, much can be done to maintain the 

 general health of the trees, by training very carefully 

 a special gang of pruners, chosen for their neatness and care 

 as workmen. There is always enough work on a large estate 

 to employ fully at least one such gang of three or four men 

 throughout the whole year, and even if this class of work 

 should call for high wages, the money spent would be amply 

 repaid by the benefit to the trees; while it should be looked 

 upon only as a reasonable insurance against any heavy loss 

 of capital. The members of the gang should be trained not 

 merely to carry out the pruning operations necessary in all 

 permanent cultivations, but also to treat adequately all forms 

 of wounds to which trees are liable. The employment of 

 such a gang is very strongly advocated by Petch, in Ceylon, 

 and is actually adopted on some of the larger rubber estates 

 in the East, as well as on certain cacao estates in Grenada. 



One other point worthy of consideration is the extra- 

 ordinary amount of wilful damage inflicted on trees by 

 human beings, particularly in the West Indies. This is appa- 

 rently an evil which must be tolerated, since there does not 

 seem to be any remedy likely to have any immediate pre- 

 ventive effect upon it. Something may be done in course of 

 time by dint of carefully instilling the idea of the value of 

 plant life into children, and in this Arbor Day may play 

 a useful part, but this course must of necessity be slow 

 in its action. One form of damage to trees growing in 

 public places might, however, be prevented: namely that 

 caused by nailing advertisements upon them. This could be 

 checked by stringent legislation. 



BUD ROT OF THE COCOA-NUT PaLM 

 IN CUBA. 



An interesting note on the extent of the damage inflicted 

 on cocoa-nuts in Cuba by the bud rot diseate is given in the 

 ChIm Rcineu' ioT September 1911, p. "29. It appears that 

 I'rofessor F. O. .Earle has been appointed as one of the com- 

 missioners to investigate this disease and has submitted, 

 among oiher matters, the following information in a prelimin- 

 ary report (in the words of the Cnlia Rerirw): 'The exports 

 of cocoa-nuts f rom Baracoa have dropped from 18,000,000 to 

 (>,000,000, that more than half of the trees are dead and that 

 many more are affected. The factory for making oil from 

 unshipped nuts that formerly operated day and night, now 

 operates only two days a week. 



' The disease has been virulent live years. Aflected 

 trees are found on all kinds of soils and all altitudes. Whole 

 plantations have been completely destroyed. It is a serious 

 calamity to the district, aa cocoa-nut groves are the prime- 

 source of revenue.' 



