49S 



A REVIEW OF OPIMONS ON PEAR TREE BLIGHT. 



summer, it had been severely pruned and 

 headed back, which threw it into late 

 growth. The next season, nearlj'^ the 

 whole remaining part of the tree died, with 

 the frozen sap blight.* Instead of endeav- 

 oring to check early vegetation, those vari- 

 eties should rather be selected, " which are 

 of early habit, and ripen their wood fully 

 before autumn." 



Why is it, if " hard winters witli long 

 cold springs give us good pears and leave 

 us sound trees," while a warm winter fol- 

 lowed by a cold spring " destroys our trees," 

 that the disease is not more prevalent in 

 England, where it is comparatively un- 

 known ? The winter there is much mild- 

 er, and vegetation earlier, and cold winds 

 and sharp frosts, succeeded by hot sun- 

 shine, often occur in the spring. The truth 

 is, we believe, that the autumn is not there 

 so warm, nor vegetation so late and vigor- 

 ous, nor the atmosphere subject to such sud- 

 den, severe and frequent changes at that 

 season, as here ; and in consequence the 

 trees escape from the injury originating the 

 disease. 



A slight protection will guard against 

 cold. In England, netting is successfully 

 used to prevent wall fruit from being in- 

 jured by spring frosts. Ropes of straw 

 stretched in front of the trees, two feet 

 apart, and from six inches to two feet from 

 the wall, have been found to answer the 

 same purpose. And we have no doubt that 

 the fire blight may be prevented by either 

 coating the trunk and main limbs with a 

 composition, or by binding matting or straw 



* Note. — Trees which have arrived at the fruit bearing pe- 

 riod are often seriously injured, and sometimes destroyed by 

 being grafted and subsequently pruned injudiciously. Pear 

 trees are the greatest sufferers. We have known very many 

 to be killed by these means. Only a part of tlie tree should 

 be grafted at one season, and the strong watery shoots that 

 sprout from the limbs should not be removed till the succeed- 

 ing year. — [Excellent advice. — Ed.] 



around them, if done at a seasonable period 

 in the fall. 



In Thacher^s Orcliardist, it is stated, un- 

 der the title canker, that Mr. Yates, of Al- 

 bany, says " it seems extraordinary that the 

 fruit treesin thisclimatearc aZ/;/os< invariably 

 aJJ'ected on the souih-tvest side of the trunk or 

 body. There it generally commences ;" 

 the bark first appearing dark, at length 

 rough, wrinkled, cracked and dead. And 

 it is Yates' opinion that it is caused by cold 

 overtaking the circulation of the sap in the 

 spring. " Fruit trees," he remarks, " gen- 

 erally incline to the north-east. The mo- 

 tion of the sap, which ascends in all vernal 

 months in all deciduous trees, is accelerated 

 by the hot rays of the sun at the south-west. 

 It is retarded and stagnated by the cool of 

 the nights, and by alternate thawing and 

 freezing, particularly at that side of the 

 tree, the vegetation is at last destroyed and 

 mortification ensues." Whether the con- 

 clusion arrived at as to the time when the 

 disease is contracted, is questioned, but the 

 circumstance as to the part of the tree more 

 generally injured would strongly indicate 

 its cause ; and the inquiry is well worthy 

 being made whether the incident be true or 

 otherwise. 



Whatever theory has been advocated as 

 to the origin of the disease, the statement 

 of facts relied upon, the truth of which has 

 been well ascertained, leads to a strong pro- 

 bability of the correctness of the views ex- 

 pressed by Downing m his treatise upon 

 Fruits and Fruit Trees* Much weight is 

 added to them by the circumstances related 

 in the extracts there made from an article 

 written by Mr. Beecher. 



* Note. — In Deane''s American Farmer, there is a higlily in- 

 teresting article upon mildew, principally relating to the dis- 

 temper in grain called rouille or rust. The investigations Of 

 several learned and scientific observers are given. It is as- 

 cribed by them to the same or a similar cause to which 

 DovjTNiNG ascribes the fire blight. 



