Gooseberries and currants belong to the genus Ribes and include many native species and cultivars used for ornamental plantings and fruit production in North America. Breeding programs in North America and Europe have focused on producing Ribes
Todd A. Burnes, Robert A. Blanchette, Jason A. Smith, and James J. Luby
Ryan N. Contreras and Mara W. Friddle
Flowering currant ( Ribes sanguineum Pursh.), also known as winter currant, is native to the West Coast of the United States, primarily west of the Coast Range from southern California north to British Columbia with populations also occurring in
Kim E. Hummer and Danny L. Barney
Eric T. Wolske, Bruce E. Branham, and Kevin J. Wolz
leaf area and decreasing leaf thickness. As the level of shading increased, plant yield decreased, and the authors concluded that shade levels should be no more than 60% for blueberries to remain economically viable. Black currants ( Ribes nigrum ) have
Layla J. Dunlap, Jeremiah R. Pinto, and Anthony S. Davis
produced during nursery culture to ensure successful establishment. Red-flowering currant is a shrub native to the Pacific Northwest and west coast of the United States and is planted frequently on restoration sites ( Hobbs and McGrath, 1998 ; Houghton and
Fumiomi Takeda, Rajeev Arora, Michael E. Wisniewski, Glen A. Davis, and Michele R. Warmund
A seasonal study was conducted to assess the freezing injury of `Boskoop Giant' black currant (Ribes nigrum L.) samples from Oct. 1991 through Mar. 1992. Buds were subjected to either differential thermal analysis (DTA) or one of a series of temperatures (0 to -36C). Freeze injury was then assessed either visually or with TTC. Results indicated that black currant floral buds have multiple low-temperature exotherms (LTE). Freeze injury in intact buds could not be visually quantified because of the lack of visible browning, nor assayed with TTC reduction. Excised floral primordia incubated in TTC, however, developed colored formazan following exposure to nonfreezing and sublethal freezing temperatures, but remained colorless when exposed to lethal temperatures. The percentage of floral primordia that were colored and colorless were tabulated and a modified Spearman-Karber equation was used to calculate the temperature at which 50% of floral primordia were killed (T50 The T50 temperature was correlated with the temperature at which the lowest LTE was detected (R2 = 0.62). TTC reduction assay using excised floral bud primordia was a good indicator of viability in frozen blackcurrant buds. Chemical name used: 2,3,5-triphenyltetrazolium chloride (TTC).
R.S. Hunt and G.D. Jensen
For the white pine blister rust disease (WPBR), reports conflict concerning the time of year the pathogen, Cronartium ribicola J.C. Fisch., infects western white pine (Pinus monticola D. Don) and what needle age increments are most susceptible. To determine timing of infection, western white pine seedling were placed under infected currants (Ribes nigrum L.) for 1-week periods from May to November. Needles became spotted and stems cankered after exposure to diseased currants from early summer until leaf drop in November. To determine what foliage age increment was most susceptible, 5-year-old seedlings were placed in a disease garden, and older trees were inoculated in situ. All age increments of pine foliage were susceptible to infection. For young seedlings, all age increments were about equally susceptible, but on some older seedlings and trees, the current year's foliage appeared more resistant than older foliage.
Kim E. Hummer and Deric D. Picton
Powdery mildew (Sphaerotheca mors-uvae) severely infects young shoots and leaves of black currants (Ribes nigrum) and red currants (R. rubrum) in the Pacific northwestern U.S. Environmentally sound control measures are being sought as alternatives to sulfur or demethylation-inhibiting fungicides. This study examined the effect of mineral oil spray on powdery mildew infection in susceptible black and red currants. Mineral oil at 8 mL·L-1(8000 ppm) was applied to plants until runoff at 0-, 2-, and 4-week intervals from April through June in 1999 and 2000 on eight currant cultivars growing in Corvallis, Ore. Shoot and leaf surfaces were rated for powdery mildew incidence in early July both years. Oil applications significantly reduced mildew severity in vegetative growth as compared with that of the unsprayed control. The disease control from 2-week interval and 4-week interval oil applications was not significantly different.
The search for appropriate white pine blister rust (WPBR) (Cronartium ribicola J.C. Fischer) resistant germplasm to use in black currant (Ribes nigrum L.) breeding programs began in 1935 in Ottawa. Crosses were made in 1938 and 1939 with three different Ribes L. species and two standard black currant cultivars. The resulting seedlings from these crosses were evaluated for rust resistance. Three promising selections resulted from this program and were named `Coronet', `Crusader' and `Consort'.
Black currant (Ribes nigrum L.) plants of eight varieties were grown either through black plastic mulch or in bare soil and with the area between the rows cultivated or sodded with red fescue (Festuca rubra L.). Over 6 years, black plastic mulch increased yields by 26% over no mulch and cultivation between the rows increased yield by 32% compared to sod. The effect of both treatments was additive, cultivation and black plastic increased yield by 68% over grass and no black plastic. Growers are recommended to plant black currants through black plastic and avoid using sod between the rows.