This section is from the book "The Gardener's Monthly And Horticulturist V24", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
As there is just now so much complaint of "rust" in blackberries, especially the Kittatinny, anything which will aid in avoiding or combatting it will be hailed with great pleasure by all lovers of this delicious and wholesome fruit.
Last summer I had a plantation of Kittatinny badly affected by the "rust;" so much so that I grubbed out all of the plants, plowed and harrowed the ground thoroughly, gathered the roots which were dragged out by the harrow, made cuttings of them, and planted a new plat, and also " heeled in" several thousand near by where also the old crowns or plants that were affected by "rust" were "heeled in." Many of these "heeled in" cuttings and plants were left unmolested. Now the roots left in the old "patch," those planted in the new, and those "heeled in," have thrown up vigorous, clean scions without a sign of rust, with rare exceptions, and these seem to be sprouts from the base of old plants and not from the lateral roots; while scions coming from the old crown " heeled in," are almost without exception covered with "rust." The new plantation made from root cuttings, and the old from roots left in the ground, promise to be in fine bearing condition for next season.
From the above I would infer that the rust fungus germinates and perpetuates itself in or near the dead wood of the old crowns, and suggests that we may convert a diseased plantation into a healthy one, and maintain it so for years From my experience, the method suggests itself, viz.:
As soon as "rust" shows itself in a plantation - usually about the second or third year after cropping begins - cut out all the old crowns thoroughly in the fall, plow, harrow and renovate the soil well of, say one-half the plantation. In the spring thousands of vigorous scions spring up. Plow out two rows of proper width, and plant potatoes or other crops between. Carefully cull out all scions which may show "rust," and keep well cultivated during sum mer. This will be the bearing plantation the next season or two, till " rust" comes again, and the portion left to bear should alternately be treated in a similar manner. Others may have had some similar experience, though I have not seen it in print, and may have pursued it to more definite results, which would be valuable matter for your excellent journal, and would be greedily read by your humble servant.