AbstractObjectives in breeding are to obtain erect-growing, productive, disease-resistant cultivars which will crop consistently with the minimum of pruning when grown as hedgerows for machine harvesting, and with improved fruit qualities acceptable for processing. Nearly all the characters required occur in existing cultivars, black currant species or selected hybrids, but it has proved difficult to combine an erect habit with strong, stout branches and high productivity; late flowering with high productivity and a shorter maturation period; and, additionally, resistance to late spring frosts and freedom from 'running-off'.
Material being studied includes progenies of Westra (a fastigiate, X-ray induced mutant of Westwick Choice), Ben Nevis, Ben Lomond, Green's Black, hybrids between Goliath x Íjebyn, Seabrook's Black x Amos Black and derivatives of Ribes dikuscha, R. bracteosum and R. hudsonianum.
An R. nigrum x R. dikuscha x R. hudsonianum hybrid - N43/6 - is described which has been used as a parent to reduce losses from 'running-off' and to improve consistency of cropping.
Data from 179 selected clones assayed for juice yield (m1/100 g fruit), juice colour, ascorbic acid and specific gravity gave interesting correlations.