88 



NEW ENGLAND FARMER. 



August 25, ISSe. 



NEW ENGLAND FARMER. 



BOSTON, FRIDAY, AUGUST 25, 1826. 



PREMATURE DECAY OF PEAR TREES. 

 When we were favoured with a communication 

 from his Excellency Gov. Li.ncol,-v, on "a disease 

 ■which has recently appeared in pear-trees " (pub- 

 lished in the first page of our current volume,) we 

 did not hesitate to attribute the disorder to the 

 pernicious agency of an insect, Scolj/tus Pyri. In 

 a matter of such moment, however, we did not 

 think it advisable to rely on our own opinion, form- 

 ed without experimental knowledge of the subject. 

 We therefore consulted several scientific friends 

 in this city, and called on the Hon. Mr. Lowell, 

 at his residence in Ro.xbury, in order to obtain as 

 much information as possible, on a topic so inter- 

 esting. The result of our application to Mr Low- 

 ell was, as we had reason to anticipate, prompt at- 

 tention, scientific investigation, and a frank com- 

 munication of his sentiments relative to the object 

 of inquiry. 



Further investigation of the causes and conse- 

 quences of the m.'lady in pear-trees, which has ex- 

 cited so much alarm in horticulturists, together 

 with the light thrown on the subject by our. cor- 

 respondents, has led us to doubt the correctness 

 ofour first rormed opinion. We now doubt wheth- I 

 or the Scolytus Pyri can be the perpetrator of all 

 the mischief which we were at first disposed to 

 attribute to its agency. We can hardly believe 

 that an insect, which, according to Professor 

 Peck's account oi" its operations, had " eaten the 

 inner layer of wood, a part of the medulla or pith, 

 and about half of the second layer of wood" of the 

 branches of the pear tree, leaving "the alburnum 

 or sap-wood untouched, except at its exit," could 

 cause the sudden, and in some instances entire de- 

 struction, referred to by Gov. Lincoln. The disor- 

 der, caused by the Scolytus Pyri we now think is 

 a different complaint from that which Gov. Lincoln 

 has described. That insect leaves (or did, in the 

 instance cited, leave) the alburnum untouched. — 

 The alburnum, or sap-wood is the only part of the 

 wood, which is necessary for the life and growth 

 of tlie tree. The pith and heart-wood of trees, 

 (like the horns, hoofs, nails and claws of animals,) 

 serve for strength and security, but are not seats 

 of vitality. Hollow trees often remain vigorous, 

 fruitful and thrifty for years after the heart-wood 

 lias decayed, and even disappeared. If then the 

 Scolytus Pyri confines its depredations to the pith 

 and heart-wood of the branches, (and we have not 

 heard of its being found, or leaving traces of its 

 habitation in any otiier part) it attacks the trees 

 where they are bast vulnerable, and can hardly 

 effect their entire destruction. 



By the foregoing, among other reasons, we are 

 induced to believe that this comi laint in pear-trees 

 is not a mere local, or topical disorder ; but one 

 which affects the whole vegetable, as much as gout 

 or scurvy affects the whole animal system. In 

 persons attacked with gout or scurvy, local com- 

 plaints often first indicate the general affection 

 and, perhaps a few withered or discoloured leaves 

 on a single limb may be indicative and symptomat- 

 ic of a disorder, which has attacked, or is about 

 to sei?e on a whole tree. 



In the second volume of the New Enaland Farm- 

 er, page .'?24, we republished an article from the 

 American Farmer vol. ii. page ?A7, with the sig- 

 nature " Silvanus," dated Elmwood, Jan. 1, 1821. 



This writer mentions a disease in pear trees,which 

 consists " in a withering of the interior bark, es- 

 pecially of the limbs, appearing in spots and bars, 

 and more extended affections of the same kind, 

 spreading to the destruction of the individual limbs" 

 &c. This disease he calls " Kibes," and says 

 " hard winters with long cold springs give us 

 good pears and leave us sound trees,whilst a warm 

 winter and especially a warm Febriiriiy,followed by 

 a cold March destroys our trees.'" Mr Jackson, al- 

 so says, [see New England Farmer, page 10, cur- 

 rent vol.] " it will be recollected tliat tiie spring 

 of 1825 was early, the weather in February uncom- 

 monly warm, so'much so as to put in circulation 

 the sap of the early fruit trees, and was followed 

 by severe cold the last of March." Warm weath- 

 er early in the season and cold weather late in the 

 season, by Mr Jackson and by Silvanus are sup- 

 posed to cause disease in pear trees. Another 

 coincidence of opinions we will advert to. Duha- 

 mel, Silvanus, and a very judicious writer for the 

 New England Farmer, with the signature " Culti- 



well as all other fruit trees tliere can be no doubt;i 

 and the consequence will be " Kibes," or soma 

 other disease of repletion. But we do not bpliev( 

 in the doctrine which inculcates the propriety oj 

 " suffering grass, shrubs or suckers to grow neat 

 the roots in order to restrain" or " divert abuo 

 dant juices" as recommended by Silvanus. This 

 would seem to us like feeding an epicure too 

 highly for his health, and at the same time at- 

 tempting to counteract the effects of a too luxuri- 

 ant diet by bleeding and leeches. The better wayi 

 would be that prescribed by Duhamel, accord in, 

 to Cultivator, (see page 2ij) to remove the oW 

 earth from the roots and substitute fresh soil of 

 poorer quality. This should be a light loam, nat- 

 urally good, but not enriched by manure. 



It may be asked, if the disease is caused by cold 

 succeeding warm weather, after the sap has be^ 

 gun to ascend in the spring, why do we not pet- 

 ceive symptoms of decay or distemper, in trees aC 

 fected, before about mid-summer. To this Silva- 

 nus says, " It is sometimes the middle of summei 



to I 



vator," all suppose that the disorder in question before tlie whole damage is developed, and some 

 does not take place in soil which is not too moist : imperfect fruit forming has led those, who merely) 

 or too highly manured : the trees must in some take a peep at the tree to conclude it to be dona 

 way, be supplied with more nourishment then they at this time." 



can digest. Silvanus says "I know of only two sets 

 of healthy pear trees ; they have in five or seven 

 years changed owners. In the time of the former 

 owners, mnch attention was paid to them and the 

 disease was constant. The present owners neith- 

 er manure nor dig about them. In one of these 

 I knew that the grass had surrounded them un- 

 broken for years, and they are not only perfect 

 but bear fruit, when all others fail — they are Ber- 

 gamot. In the other set alluded to, more attention 

 is paid, the grass is cleared away in early summer, 

 but the shoots are permitted to grow forty feet 

 around them in such quantity as to defy any re- 

 moval but with a scythe, and tliese remain till next 

 grass time — no manure is applied, and the ground 

 naturally poor, riven the unhealthy trees have 

 shot out new and healthy branches,since they have 

 remained undisturbed, these facts arc too plain to 

 be misunderstood, they point out the remedy as well 

 as the manner of the remedy's acting. The abun- 

 dant juices are restrained in the first case, which 



\Vi! 



iJli 



Again it may be objected thot wc assign tto» j. 

 causes for the same effect, which is not according ,, 

 to the rules of philosophizing. One of our causd 

 is the alternation of heat and cold, the other i 

 wet and rich soil. But the latter may be the pre 

 disposing, and the former the efficient cause 

 Thus a plethoric habit may be a pre-disposingj j, 

 cause of apoplexy, but the immediate cause majj 

 be some act of intemperance, &c. 



That the disorder is produced by an excess oi 

 sap would also seem probable from the circuuM ,| 

 stances related by Dr Fiske, (page 20 of our cuo 

 rent volume.) That experienced and discriniinat 

 ing cultivator speaks of " an occuraukition of viti 

 ated sap," which " had become perceptibly sou 

 from stagnation." The fact stated by Cultivatoi t,j. 

 page 25 points to the same cause. That gentle 

 man, (whose scientific skill aided by pracUci 

 knowledge entitles him to confidence) says, 

 the trees that have been affected by the diseasM], 

 in my grounds, are those that grow in mv vegeta 



is preferable, and in the latter they are partly re- ble garden which is regularly and well manured 

 strained and partly diverted into young scions. and among those, the most vigorous and thrifl 



" I will mention two other facts, though not so [ have suffered most. And all those that grow i 

 plain, yet they confirm the above. I moved to a j my grass land, where they are seldom or neve 

 place where there were two very healthy pear ' manured are entirely free from disease." 

 trees. ( Verge'e ise,) one was choaked as I thought If the causes of the disease are as stated abov 

 v.ith grass, the other was so surrounded with scions tl:e remedies are obvious. Cut away the diseas^ 

 as scarcely to admit approach. I removed the parts some distance below any appearance of 



scions, dug and manured the ground in both, and 

 tlie consequence soon ensued; I lost them by Kibes. 



Tiio other case that confirms these opinions and> move a part and substitute a suitable loam. Pruue 



facts, was that of a gardener of my acquaintance, 

 who was actually on the right track to save his 

 trees, but for want of understanding the true cause 

 of the disease he failed,he discovered that the trees 

 which had honey suckles around tiiem, were less 

 liable to disease ; but he supposed it were protec- 

 tion, and therefore manured and dug, and thus 

 ■ lug the grave of his fine trees. 



" Let us therefore suffer our trees, after they 

 have come near the fruit bearing period to vege- 

 tate naturally — they will be a little more tardy in 

 growing up, but tjiey will he hardy, he.altliy and 

 bear well. If yo-.ir grounds are already rieli and 

 \oosc about the trees, part of it may be removed." 



That ground may be too rich for pear trees, as 



fection. If the soil be too moist, drain it or mix I 

 dryer sort of eartli with it, or both. If too rich re- 



but little, taking away only dead branches, such as 

 interfere with and chafe each other, together v.-ith \r 

 the suckers. |. 



The above opinions and statements, however, may |- 

 be erroneous ; and if so wc sliould be happy to ( 

 correct and ready to retract them. 



Since the above was in type, we have received' ' 

 the following communication. ! 



PEAR TREES. |j 



Mr Pessende.".- — I am inclined to think the|j 

 cause of the mortality among pear trees is not yet 

 ;*iscovered, though several oi" your late corres 

 pondents have evinced muci) ingenuity upon t|,i'- 

 subject. 



