NEWENGL AND FARMER 



Published by Juan B. Rcssf.i.;. ;U t, • lornor of Coiigrosg nnd LiiidiiU Slryots. — Thomas G. Fessemjkn, Editor. 



VOL. V. 



BOS'rON, FRIDAY, AUGUST 18. l.S2(). 



NO. 4. 



OR IGINA L PAPERS. 



DISEASE IN PEAR TREES. 

 ■' Mr Fessendkn — If the following article be not 



long and tedious and you think it woith alten- 

 ■' jn, you cr.n publish it at your leisure or when 



ithing uioro important is offered to the public. 

 As my pear trees have surtercd much from the 

 evailing malady, both this season and last, I have 



en led to look for the cause. Mr Lowell's 

 )mnuinication in answer to Governor Lincoln, 



your paper of the 28th ult. I have read with in- 

 rest, as I am well aware of the importance, 

 hich I ought to attach to any article coming 

 am that source. But I am sorry that I cannot 

 free with that gentleman in his views of the sub- 

 ct, because, if he is right, I think the evil could 

 on be remedied. 



1 shall make no apology for offering my opinions 

 I tliis subject in opposition to Mr Lowell, as I 

 ould consider it a poor compliment to his can- 



)ur as well as his good sense, to suppose him ca- 

 ible of feeling hurt at a fair discussion of any 

 ct, which is interesting to the public, merely be- 

 luse he had pronounced an opinion founded on 

 hat he conceived irrefragable proof of the fact. 

 Mr Lowell says, speaking of the sudden death 

 "the branches of the pear trees — " The effect in 

 short is precisely the same as if you had sawed 

 off the limb and thrown it on the wood pile ; and 

 so it ought to be, for in effect it has been sawed 

 off by the teeth, or rather instruments, of a mi- 

 noto insect." 



I shall not here dispute the fact, that there may 

 e found insects, which are denominated Wood 

 .'aters, in the buds, or under the shoulder of buds, 

 roceeding from branches of pear trees that are dis- 

 ased ; — and for the sake of shortening discus- 

 •ons, I shall admit the fact of the injiiry done by 

 lem, to the full e.Ktent to which Mr Lowell and 

 'rofessor Peck have stated it. 

 Mr Peck says — " for several years past the ends 

 of the branches of pear trees have been observ- 

 ed to perish suddenly insomuch that it has been 

 attributed to lightning.^Mr Lowell believed 

 it was caused by insects and on examining the 

 ■ dead part of the branch proved the correctness 

 ' of his judrrinent. He piesented me one of the 

 'insects with a part of the branch which contain- 

 ' ed it in its perfect state." Mr Peck then goes 

 )n to describe the manner of its laying its egg 

 inder the bud — and then adds — " the piece of 

 the branch which I had, was three years old ; it 

 'had, therefore, one layer of sap and two of 

 wood. — The grub had eaten the inner layer of 

 wood, a part of the medulla or pith, and about 

 half of the second layer of wood, in a circuh^r 

 direction, leaving the alburnum or sap wood vr,- 

 « touched, except at its exit." — " the insect is 

 J_|>_ gf an inch in length, and ^i- of an inch in 

 breadth." This is all that I need quote from Mr 

 Peck's description of the injury done by the in- 



" luul, behind which tlie egg was probably dcpos- 

 " itiui.lollow ing the course of the eye ot'the bud irito 

 " tlie pith wiiicli ho had coiisumeri,to'votlior with all 

 ■♦the heart wood, — he had thtin gone into the 

 " chrysalis state, in the scene of his depredations, 

 " and was in a perfect state when I found him." 

 " The hole or space eaten," says Mr Lowelf., 

 " will be found <tt the root of some bud, and in the 

 "centre of the twig." 



Mr Lowell then adds — " there are tliosc who 

 " are incredulous as to tiiis minute insect's beitig 

 " the cause of this evil. 1 can only say, that on all 

 " subjects of this sort I never seek for two solu- 

 " tions, when one is sufRcient." 



I have given these long quotations from Mr Low- 

 ell and Mr Peck, that the reader may have the 

 whole subject before him,and I believe I have cop- 

 ied all that is necessary for this purpose. 



I have no pretensions either to the scientific or 

 practical knowledge in horticulture which Mr 

 Lowell possesseSj and for which he is so justly 

 celebrated ; yet I have some knowledge and sonii 

 practice in the art, and of course have an interest 

 in getting at the fact in question if possible. 



We will suppose then that the " Scolytus" has 

 Ciiten into the twig or branch, and destroyed the 

 pith and inner wood of the twig,for a considerable 

 distance, (although both Mr Lowell and Mr 

 Peck confine his depredations to the neighbor- 

 hood ot the bud, and my own observations satisfy 

 me that i-.e does not go far from it.) Still, I do 

 not 'inderstand how the lower part of the branch, 

 and the' body of the tree, is to be affected much 

 beyond the seat of the injury or part destroyed. — 

 If we saw off a branch ; or break it ; or iu any 

 way cut off the communication of the sap from the 

 trunk, and great branches, to the smaller ones, 

 tiie injury is confined to the branch which is sup- 

 pressed, or to the inmiediate neighborhood of the 

 wound. If the wound be made where there is no 

 lateral shoot or branch, the most that will happen 

 is, that the wood will decay down to the first lat- 

 eral below it ; and that will require some time. — 

 Hut in the present case the disease extends itself 

 with a rapidity unparalleled, destroying all the 

 laterals, as well as the mother branch, even to the 

 trunk and roots of the tree, however large it may 

 be ; although as Professor Peck says, and as I 

 have myself observed, it begins to show itself at 

 the " e«rfji" of the branches, and often at the ex- 

 tremity of a small shoot fifteen or twenty feet 

 from the trunk of the trees. This, if not taken off 

 down to that part of the branch which is entirely 

 free from disease, will soon affect the whole body, 

 destroying leaves, buds, fruit, bark and wood, in 

 a few hours, as effectually as if a fire had been 

 flaced immediately under them. The discolora- 

 lion of the inner bark, and the alburnum may be 

 traced far below where the outer bark appears 

 to be injured, and the saw or knife should be 

 applied a good distance within this internal dis- 

 ease. 



sect. Mr Lowell says — he spent a great deal of That the insect does not extend its operations 

 time in searching, before he found the insect — far, may be seen by cutting the shoot or branch, 

 yet when discovered the injury was quite suffi- transversely ,a few inches below or immediately a/ 

 " cient to produce all the effect." "He had I the point between the injured and the uninjured 

 ">aten," saK^ Mr Lowell " frtm the root of the ) exterior bark ; — or to. facj a few inches from the 



extremity of tiie brancii where the injury begartt 

 or" anywhere else, so far as I have been able to 

 te.st it. Yet the disease will continue to run 

 downwards, if not checked, until it reach the 

 roots through the body of the tree. This seems 

 to'bo admitted by Mr Lowell, who says that the 

 insect had eaten into the pith of the wood, following 

 the e;/c of the bud, and had tlien gone into the 

 chrysalis state : so that the " scene of his depre- 

 dations" could not have been many inches, if it 

 were even one beyond the spot where the egg was 

 deposited. If then the extensive evil complained 

 of is caused by this little insect, it must be by iu- 

 jecting a virus into the circulating juices of the 

 tree, more subtle and corroding than the venom of 

 any other animal within our knowledge. But this 

 is not pretended to be the case either by Mr Low- 

 ell or Mr Peck. — They both agree that the ex- 

 tent of the wound made by the " Scolytus" is in 

 the destruction of the pith and innerwoods of the 

 shoot, near to the bud where the egg was deposit- 

 ed, leaving the alburnum entire, except where he 

 made his exit. 



But allowing- that all the wood within the albur 

 num was removed, would that alone destroy the 

 branch ? if there was strength enough left in it to 

 keep it together, I conceive that vegetation and 

 the circulation of the sap \*ould go on, the same 

 as though the interior wood was left. The irmer 

 wood gives strength to the branch, and to the 

 tree, but I believe is no otherwise necessary to 

 the maintenance of its growth or even to its fe- 

 cundity. I c un'it tlierefore think that the rapid 

 decay, and unhealthy state of the juices of the 

 tree, arise from the injury laid down by Mr Low- 

 ell and Professor Peck. Is it a sufficient solu- 

 tion of the question then to know that a small in- 

 sect,one tenth of an inch long, and four hundredths 

 of an inch broad ; of the tribe of wood eaters, has 

 descended into the centre of a twig, and eaten away 

 a very small portion of its inner substance at the 

 end, or at the side of a shoot ; which shoot is per- 

 haps at the e.xtremity of a large full bearing tree, 

 and itself not a quarter of an inch in diameter ! 



That tlie destruction of the inner wood of a 

 twig, by an insect ai the extremity of a large tree 

 should destroy its whole body, is to me inconciev- 

 ablc, when you may destroy the same shoot or 

 branch by any means which man possesses, eveti 

 by fire, without injuring the wood below its imme- 

 diate influence. 



In answer to the piece signed "Veritas," in 

 your paper of the 5th instant I shall only observe 

 that the disease is not of recent date. I have a 

 description of it published eighty years ago. It ia 

 also a mistake to suppose that the evil arises from 

 exhaustion, or want of nutriment, as that writer 

 supposes. He recommends regular manuring and 

 free pruning, as a remedy. The best answer I cart 

 give to this opinion is the fact, that all the trees 

 that have been affected by the disease in my 

 grotinds, are those that grow in my vegetable 

 garden which is regularly and well qaanured ; and 

 among those, the most vigorous and thrifty h&vs 

 suffered most. And all tliose that grow in my 

 grass land, where they are seldom or never ma- 

 nured, are entirely free from the disease. 



Mr Jack&om's theory I confess I do uot undet- 



