Hardy Varieties of Pears. Suggestions by Henry Wilbur.

Some things never change.  The Heirloom Orchardist had to deal with the same fruit tree diseases that affect orchards today.  And just like today, the best offense was a strong defense.  The Heirloom Orchardist would try to choose varieties that were not susceptible.  In 1884, Henry Wilbur of Hillsdale County, MI, presented some varieties of Pear that are resistant to the dreaded Fire Blight:

     The Cultivator and Country Gentleman
     March 6, 1884, Albany, NY
     Vol.   XLIX, No.   1623

Hardy Varieties of Pears.
     One very essential quality to be observed in selecting pear trees, is to get those that are least subject to blight.  Duchesse d'Angouleme is one nearly, if not quite, free from it, and is a large valuable sort, either for standard or dwarf.  Seckel is another, not large, but of best flavor.  Beurre d'Anjou is one of the best.  Beure' Clairgeau is one of the largest and handsomest pears, but not the highest quality; the tree seldom or ever blights.  Winter Nelis is good and nearly free from blight.  Bartlett, Clapp's Favorite, and Flemish Beauty are the varieties (except, perhaps, the first named in this list) most extensively planted.  While not entirely (none are) free from blight, they are much more so than many others, and so few of them are lost proportionally to the great number planted, that I advise continuing to plant many of them.
     HENRY WILBUR, Hillsdale County, Mich.

Despite the Heirloom Orchardist's desire to choose hardy pear varieties, I have seen some early 19th century references to the use of "Bordeaux Mixture," known as such because it was first used in French vineyards. A spray that is still in use today, the Bordeaux mix contains copper sulfate and hydrated lime in water.  It is often used as a fungicide, but was found to also be affective against the bacterium that causes blight.  The Heirloom Orchardist was not completely immune to using sprays.