Blackberries are similar to raspberries, but in my experience are generally larger and sufficiently different to warrant a separate topic.
This is the second year of attempting to progate my stock.
Blackberries and Raspberries (Rubus spp.)ISHS Acta Horticulturae 505: VII International Symposium on Rubus and Ribes
PROPAGATION OF BLACKBERRIES (Rubus spp.) BY STEM CUTTINGS USING VARIOUS IBA FORMULATIONS Authors: A. L. Busby, David G. Himelrick
Keywords: Blackberry, propagation, cuttings, hormone, IBA
Abstract:
Four cultivars of blackberry (Rubus spp.) were propagated in July under intermittent mist by rooting two-node softwood stem cuttings treated with indole-3-butyric acid (IBA). IBA was applied in either a talc preparation or as a liquid quick dip at 0.1, 0.3 or 0.8% concentrations, with non-treated cuttings as a control. Differences in root development were evident and were affected by cultivar, IBA concentration, and method of application. Compared to non-treated cuttings, root development increased on 'Navaho' thornless blackberry cuttings treated with 0.3 and 0.8% KIBA quick dip. Cuttings of 'Chester' thornless blackberry treated with 0.1 and 0.8% IBA in talc and 0.3 and 0.8% KIBA quick dip produced better root systems than non-treated cuttings. Treatment of 'Cheyenne' thorny blackberry with 0.3% IBA in talc and 0.8% KIBA quick dip increased rooting compared to non-treated cuttings. Cuttings of 'Olallie' thorny blackberry rooted better than non-treated cuttings with 0.1 and 0.3% IBA in talc and 0.3% KIBA quick dip.
There are entire symposia devoted to rubus species.
In the picture, you will notice the smaller berries look underdeveloped, and indeed they are. The northeast has had infrequent rain during July and August, and what rain there has been came in the form of localized thunderstorms, which poured heavy rains in few locations with quick runoff. During a drought type period, it is necessary to irrigate - with soaking about every 2 or 3 days.
I picked three blackberries this morning (should have taken a picture) that were about the size of the end of my thumb (about 1.5 cm diameter by 2-3 cm long).
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