I'm in the Rogue Valley in Southern Oregon where Fireflight has been a huge problem for culinary pears (comice and bosc mostly) for many decades. I'm growing perry pears and dealing with fireflight. We've had 10 year old trees go from looking healthy to completely dying in a week before I got my practices more vigilant. It's a devastating bacterial disease that is borne from tree to tree, mostly spread by insects who find the sweet, dark discharge from infected trees irresistible. I'll let you know what I've been recommended to do by the local extension researchers.
I don't know of any magic bullets. OHxF 87 seems to be the best rootstock for resistance. None of the trees I planted are immune. Barnet seems to be the most susceptible to fireblight and Romanian seems to be the most resistant. Green horse, Oldfield, Martin Sec, and Gelbmostler seem to be better than Barland, Thorn, Butt, and the Huffcaps.
In addition to dormant copper sprays, the best spraying regime that we've been recommended to use is antibiotic during flowering. Does Captian Jack have an antibacterial agent? When the temperatures are mild, above 60 degrees F, the bacterial loads inside the nectaries of the blooming trees spike dramatically, and it is during flowering that trees seem the most susceptible. Getting antibiotic into the nectaries when bees are active seems to help a lot. The sprays are only effective on open flowers. We've been recommended to use Agri-Mycin and Mycoshield cocktail with horticultural oil to help it stick. I spray every 3 days during flowering. A gas powered backback sprayer on a blower platform helps get a mist up high enough to get into flowers.
After flowering, I walk the orchard every couple days in the spring and summer, looking for any sign of infected twings. Black twig tips with the classic shepherd's crook are a telltale sign. Getting them cut off, bagged up and out of the orchard immediately helps. Once you see multiple branches dying back and black discolored bark on the trunk the tree is lost. Disinfecting tools with alcohol is good, but being aggressive and cutting out any infected twig, branch or tree immediately seems to be most important.
Good luck, and I'd be interested to hear any other folks' experience controlling fireblight.
Jeremy, Blossom Barn Cidery