Abelia ×grandiflora is a drought-tolerant, pest-resistant, flowering shrub that has long been used as a foundation plant. Interspecific hybridization has produced seedlings with an assortment of morphological traits, allowing for development of new cultivars with unique or improved qualities. `Raspberry Profusion' and `Lavender Mist', developed at the University of Georgia, are seedling selections of `Edward Goucher' × Abelia chinensis. `Raspberry Profusion' is a very heavy and very early bloomer. Panicles are large and showy with fragrant pink flowers and raspberry-colored sepals. Flowering begins in early May and becomes very heavy by early June. The bright-colored sepals remain on the plant throughout the summer. Summer foliage is a medium to dark green color. In a pot, `Raspberry Profusion' blooms early and heavily. `Lavender Mist' is a heavy bloomer, with clusters of fragrant lavender flowers beginning in mid-June, and continuing into autumn. Sepals are a straw-green color at the base, becoming rose at the tips. Summer foliage is gray-green. `Lavender Mist' performs well in a pot, forming a gray-green mound contrasting with the lavender blossoms scattered around the plant. Leaves on both cultivars are glossy, particularly from mid-summer through autumn. Both plants tend to be mostly deciduous in the winter. Laboratory evaluations of cold hardiness in Griffin, Ga., during Winter 2003–04 revealed a mid-winter hardiness of –18 °C to –21 °C for `Raspberry Profusion' and –15 °C to –17 °C for `Lavender Mist'. These plants develop into dense compact shrubs following pruning and establishment in the landscape.
Carol D. Robacker and Sloane M. Scheiber
Paul E. Read*, William J. Waltman, and Stephen Gamet
Terroir embodies a defined place, integrating soils, geology, climate, the cultivar, and the role of cultivation, culture, and history in producing wine (Wilson, 1999; White, 2003).The understated topographic changes, thick loess soils, diffuse climatic boundaries (humid to arid), and brief viticultural history contribute to a misconception that “terroir” may not be applicable or that niche microclimates for vineyards may not exist in Nebraska. With many new cultivars and selections now available that are adapted to growing environments once considered marginal vineyard settings and the wealth of geospatial resource databases (soils, climate, and topography) available, we have begun to combine traditional field cultivar evaluation studies with the geophysical data to determine appropriate site/cultivar suitability. Our data have shown that cultivars that were previously considered unlikely to be successful may be suited to viticulture in specific locations, e.g., Riesling, Lemberger, Cynthiana/Norton, Vignoles, and Chambourcin in southeast Nebraska (our “vinifera triangle”). Mean hardiness ratings (scale 1 to 9, where 1 = dead and 9 = no injury) have been obtained for more than 50 cultivars and selections, ranging from 1.86 for Viognier to 8.66 for Frontenac and 8.71 for Saint Croix, for example. Data for most of the cultivars under test will be presented and matched with “terroirs”, providing growers with a vineyard decision support system that can help match genotypes to their specific vineyard sites and help avoid poor cultivar selection.
Mario R. Morales and James E. Simon
`African Beauty', a new ornamental camphor basil cultivar, was developed through three cycles of selfing and selection from USDA accession PI 500942, originally collected in Zambia, Africa. `African Beauty' was field-evaluated and compared with PI 500942 (the original population), PI 500954 (another accession from Zambia), a camphor cultivar from Companion Plants, and three other related lines in 1997 and 1998. Most commercial camphor basils are tall (50 to 60 cm), late-flowering, and unattractive. Our goal was to develop a new cultivar that had a short stature (≈40 cm), an early flowering, and an attractive appearance. The outcome was `African Beauty', which has the following characteristics: plant height: 30 to 35 cm, plant spread: 50 to 55 cm, leaf length: 6.3 to 6.7 cm, days to flower: 76 days, inflorescence length: 25 cm, essential oil yield: 3 mL/100 g dw. The essential oil of `African Beauty' is also highly aromatic, with 72% camphor, 12% camphene, and 9% limonene. The plant is a fast-growing, semicompact aromatic plant that produces small leaves and large quantities of long and slender inflorescences that, when fully developed, curve at the tip like the tail of a cat. Blooming usually lasts from 20 to 25 days, when the plant looks most beautiful. `African Beauty' is an attractive ornamental that would be excellent as a garden border plant, or as an indoor potted plant.
Juan Chen, Nianhe Xia, Xiaoming Wang, Richard C. Beeson Jr., and Jianjun Chen
Ploidy levels and genome sizes have significant implications in plant evolution and crop improvement. Species of Lonicera L. have long been cultivated as medicinal, ornamental crops, or both. However, chromosome numbers, karyotypes, and DNA contents have only been documented in a few species, of which some controversies regarding basic chromosome numbers and karyotypes remain. This study analyzed the chromosome numbers and karyomorphology of 11 cultivars across four species and also the DNA content of 10 cultivars representing six species of Lonicera. Among them, the chromosome numbers of nine cultivars are reported for the first time. Results showed that the basic chromosome number of x = 9 was constant, and chromosome numbers of 2n = 18, 27, 36, or 54 were observed, suggesting that polyploidy exists in the genus. Five cultivars are diploid with 2n = 18; one cultivar is triploid, four are tetraploid, and one is hexaploid. The karyotypes of all studied cultivars are 3B or 3A, except Lonicera sempervirens ‘Crimson Cascade’ that is 2B based on the Stebbins’ asymmetry classification of karyotypes. The asymmetry index (A1) values vary from 0.47 to 0.60. The chromosome lengths range from 0.77 to 4.09 μm. Total karyotype lengths differ from 33.55 to 78.71 μm. The 1C-value of 10 cultivars varies 3-fold, ranging from 1.158 to 3.664 pg. Information gathered from this study could be valuable for improving breeding efficiency in the development of new cultivars of Lonicera with enhanced medicinal, ornamental value, or both.
Kimberly A. Pickens, (Max) Zong-Ming Cheng, and Stephen A. Kania
Poinsettia, Euphorbia pulcherrima, is an important holiday symbol and is the number one flowering potted plant in the United States. The technique of chromosome doubling has been utilized to increase size of flowers, stems, and leaves of many species, and has been used in poinsettia breeding to obtain new cultivars. Application of colchicine or oryzalin to in vitro tissues may be used to enlarge the inflorescences and brackets and reduce the height of `Winter Rose'™ poinsettias, reduce the likelihood of chimeric tetraploids, and provide a rapid means for producing many tetraploid plants. The purpose of this research was to evaluate the effect of colchicine and oryzalin on callus and adventitious shoot formation of `Winter Rose'™ poinsettia with in vitro grown leaf tissues and its potential for tetraploid induction. In vitro grown leaf midvein sections were placed on various media supplemented with either colchicine or oryzalin at various concentrations for 1–4 days. Colchicine was least damaging to leaf tissues at concentrations of 0.25 or 250.4 μm. A large amount of callus, as well as adventitious shoots, were produced. Regenerated shoots were found to be diploid, determined by flow cytometry. On media with oryzalin (28.9–144 μm), leaf tissues produced callus, but not adventitious shoots. Calluses produced on oryzalin-containing media were tested using the flow cytometer and were found to be diploid.
Stan C. Hokanson and Chad E. Finn
Strawberry (Fragaria ×ananassa Duch.) cultivars used by commercial producers in North America often change rapidly due to several factors including modified cultural practices, processing and marketing practices, the desire for new cultivars with larger and higher quality berries, resistant insect and disease pests, loss of traditional chemical control methods, and private sector breeding programs. Within the past decade, the annual plastic-mulched production system has quickly expanded into eastern North America prompting the need for cold-hardy cultivars adapted to that system. The continuing loss of traditional chemical controls for strawberry insects and diseases, including the impending loss of methyl bromide, has prompted the need for increased insect and disease resistance. In addition, consumer demands for a healthier food product with lower chemical residues has heightened this need. Small fruit experts from across North America provided information on the primary strawberry cultivars used in the recent past, the present, and potential cultivars for the future, as well as on current strawberry acreage in their respective states and provinces.
Fruit from black, red and white currants, and gooseberries (Ribes L.) were grown commercially in North America at the beginning of the 20th Century. However, when white pine blister rust (WPBR) (Cronartium ribicola J. C. Fisch.) was introduced into the new world, their cultivation was discontinued. About 825,000 t (908,000 tons) of Ribes fruit are produced worldwide, almost entirely in Europe. The fruit is high in vitamin C, and is used to produce juice, and many other products. Now a wide range of imported Ribes products is available particularly in Canada, and the pick-your-own (PYO) market is increasing. Two diseases, powdery mildew [Spaerotheca mors-uvae (Schwein.) Berk. & Curt.] and WPBR, are the major problems encountered by growers. Fortunately, many new cultivars are resistant to these two diseases. Commercial acreage of Ribes in North America is located where the growing day degrees above 5 °C (41 °F), and the annual chilling hours are at least 1200. Initially, the Ribes industry will develop as PYO and for farm markets. But for a large industry to develop, juice products will needed. Our costs of production figures indicate that about 850 Canadian dollars ($CDN) per 1.0 t (1.1 tons) of fruit will be required to break even.
R. L. Fery and P. D. Dukes
The Agricultural Research Service of the United States Department of Agriculture announced the release of Carolina Crowder southernpea on 12 October 1990. The new cultivar is well adapted for production throughout the southern U.S., where it can be expected to produce excellent yields of high quality, crowder-type peas. Carolina Crowder is resistant to the cowpea curculio, the major insect pest of the southernpea in southeastern production areas; blackeye cowpea mosaic virus, an important virus pathogen of southernpea in the United States; and root-knot, a severe root disease incited by several species of the root-knot nematode. Canned samples of fresh Carolina Crowder peas scored well in three years of quality evaluation tests. Pod color is a brilliant red at early green-shell maturity and a brilliant red heavily shaded with cranberry colored pigment at optimum green-shell maturity. The attractive pod color should make Carolina Crowder an excellent candidate for fresh market use. Carolina Crowder plants have a greater tendency to produce a second crop than plants of most southernpea cultivars.
Paul R. Fantz and Donglin Zhang
Horticultural Science in the past quarter of a century has been shifting to increased emphasis on ornamental plants due to the growth of the modern green industry. Numerous species are being introduced into the exterior and interior landscapes. For popular species, the cultivar, as defined by the International Code of Nomenclature for Cultivated Plants (ICNCP), has become the basic taxon of cultivated plants. Named ornamental plant cultivars are rising at a rapid rate creating identification and segregation problems in the landscape industry, nurseries, botanic gardens, arboreta, and breeding programs. Government regulations and legal issues are beginning to infringe as solutions to the problems. There is a critical need existing for taxonomic research on ornamental cultivars utilizing classical morphological analysis supplemented with modern biotechnological techniques (e.g., anatomical, chemical, cytological, DNA, Sem analysis). Taxonomic research on existing and newer cultivars can provide quantitative botanical descriptions, keys of segregation, correct identification, determination of correct names and synonymy, improved cultivar documentation, and grouping of similar cultivars in large complexes. The taxonomic research is basic science that has immediate applied application within the horticultural society, and results should be published in the journals of ASHS.
Terri W. Starman and James E. Faust
Our objective was to determine the effect of planting date and pinching on flowering dates and plant size of field-grown garden mums. Experiments were conducted in the field during two consecutive growing seasons in 1997 and 1998. In one experiment, 15 to 20 cultivars were planted on five dates (14 May, 4 June, 25 June, 16 July, and 4 Aug.) and received no pinching, one manual pinch 2 weeks after potting, or two manual pinches 2 and 4 weeks after potting. In another experiment, four cultivars were planted at the five dates. Pinch treatments were control, one manual pinch, two manual pinches, one Florel spray at 500 mg·L–1, or two Florel sprays at the same time as the manual pinches but on separate plants. Data were collected for days to first color, first open flower, 10 open flowers, and full bloom. Height and width were measured at 10 open blooms. Although the 1998 season was warmer and caused heat delay, the flowering data followed the same trends as the 1997 experiments. Pinching delayed flowering for the early plant dates. Pinching did not affect plant height or plant width. Planting date affected days to 10 blooms for most early season varieties but not late-season varieties. Planting early produced larger plants and more uneven flowering and resulted in greater heat delay of heat-sensitive varieties. Florel delayed flowering and increased plant size. We concluded that pinching was not required to produce high-quality garden mums of many new cultivars.