Cold Hardiness Zones Research Articles

Analyzing the distribution patterns and dynamic niche of Magnolia grandiflora L. in the United States and China in response to climate change.

Magnolia grandiflora L. (southern magnolia) is native to the southeastern coastal areas of the United States, from North Carolina to eastern Texas (USDA Cold Hardiness Zone 8). It is currently widely cultivated in Zones 5-10 in the U.S. and in southern Yangtze River regions in China. Limited studies have examined the effects of climate change and human activities on the geographical distribution and adaptability of M. grandiflora during its introduction to China. We selected 127 occurrence points in the U.S. and 87 occurrence points in China, along with 43 environmental variables, to predict suitable habitat areas for M. grandiflora using present climate data (1970-2000) and projected future climate data (2050-2070) based on a complete niche ensemble model (EM) using the Biomod2 package. We also predicted the niche change of M. grandiflora in both countries using the 'ecospat' package in R. The ensemble models demonstrated high reliability, with an AUC of 0.993 and TSS of 0.932. Solar radiation in July, human impact index, and precipitation of the wettest month were identified as the most critical variables influencing M. grandiflora distribution. The species shows a similar trend of distribution expansion under climate change scenarios in both countries, with predicted expansions towards the northwest and northeast, and contractions in southern regions. Our study emphasizes a practical framework for predicting suitable habitats and migration of Magnoliaceae species under climate change scenarios. These findings provide valuable insights. for species conservation, introduction, management strategies, and sustainable utilization of M. grandiflora.

Mitigating grapevine winter damage in cold climate areas

Growing grapes in cool climate areas is the same front type challenging due to the high risk of winter injury. Passive and active methods can be used to reduce or prevent cold damage and protect the vineyards. Passive protection methods are generally cultural practices and performed before cold damage events, such as cultivar and rootstock selection. The proper scion-rootstock combination would ideally help the vines acclimate earlier in the fall, allowing them to withstand colder weather in the fall and winter and de-acclimate later in the spring to minimise the late spring frost damage. The introduction of new North American hybrid cultivars accompanied with other cultural practices has increased the hope for developing viticulture in areas with lower cold hardiness zones. Furthermore, active protection methods are usually performed at the time of cold damage events to protect the vineyard by preventing or reducing the loss of thermal energy from vine tissues. The objective of this manuscript is to review the viticulture challenges in cold climates and mitigate the risks with Ontario, Canada as an example of a cold climate area.

An integrated approach to conservation of rare fern species using the example of Polystichum craspedosorum (Dryopteridaceae) in Amur Region, Far East оf Russia

Currently changes in the earth's vegetative cover have reached a planetary scale. The danger of extinction of species and ecosystems has become increasingly significant. Active measures must be undertaken to restore particular plant species and populations in order to minimise an ongoing loss of species. Polystichum craspedosorum is a cliff-dwelling fern, an East-Asian relict species whose northern range includes the Russian Far East. The northernmost population of this species, located in the Amur Region, is at risk of flooding by the Lower Bureya Dam. A series of measures were developed and implemented to conserve this plant. Plant individuals were translocated from the flood zone to other suitable habitats on the territory of the Amur Region. Monitoring has indicated that, after three years, the translocated plants have their usual seasonal rhythm, sporulation and the formation of gemmae. The survival rate at new places ranged from 60% to 88%. However, the final conclusions about the research efficiency can be made only after long-term monitoring for more than ten years. Cultivation of this species is being done in outdoor conditions at the Amur Branch of the Far Eastern Botanical Garden-Institute of RAS. The seasonal rhythm of cultivated plants was similar to the natural one in both spore production and gemma formation. The species can be assigned to cold hardiness zone 3 and it is promising for cultivation in the Amur Region. The possibility of cryopreservation of P. craspedosorum spores has been studied along with in vitro culture. After ultra-low temperatures, spores did not lose their viability and, thus, they can be stored in cryobanks for a long time. An integrated approach provides the maximum opportunity for the species conservation in nature and in culture. This integrated approach to conservation of a rare fern species is unique for Russia.

Evaluation of Native and Nonnative Ornamentals as Pollinator Plants in Florida: I. Floral Abundance and Insect Visitation

Diverse floral resources impart immense value for pollinating insects of all types. With increasing popularity and demand for modern ornamental hybrids, cultivation by breeders has led to selection for a suite of traits such as extended bloom periods and novel colors and forms deemed attractive to the human eye. Largely understudied is pollinator preference for these new cultivars, as compared with their native congeners. To address this gap in understanding, 10 species of popular herbaceous flowering plants, commonly labeled as pollinator-friendly, were evaluated at two sites in Florida [U.S. Department of Agriculture (USDA) cold hardiness zones 8b and 9a] and across three seasons for their floral abundance and overall attractiveness to different groups of pollinating insects. Each genus, apart from pentas, encompassed a native and nonnative species. Native species included blanket flower (Gaillardia pulchella), lanceleaf coreopsis (Coreopsis lanceolata), pineland lantana (Lantana depressa), and scarlet sage (Salvia coccinea). Nonnative species included Barbican™ yellow-red ring blanket flower (G. aristata ‘Gaiz005’), Bloomify™ rose lantana (L. camara ‘UF-1011-2’), mysty salvia (S. longispicata ×farinacea ‘Balsalmysty’), Lucky Star® dark red pentas (Pentas lanceolata ‘PAS1231189’), ruby glow pentas (P. lanceolata ‘Ruby glow’) and Uptick™ Gold & Bronze coreopsis (Coreopsis × ‘Baluptgonz’). Flower-visiting insects were recorded during five-minute intervals in the morning and categorized into the following morpho-groups: honey bees, large-bodied bees (bumble and carpenter bees), other bees (small to medium-bodied native bees), butterflies/moths, and wasps. Floral abundance and pollinator visitation varied widely by season, location, and species. Of the plant species evaluated, nonnative plants produced nearly twice as many flowers as native plants. About 22,000 floral visitations were observed. The majority of visits were by native, small to medium-bodied bees (55.28%), followed by butterflies and moths (15.4%), large-bodied native bees (11.8%), wasps (10.0%), and honey bees (7.6%). Among plant genera, both native and nonnative coreopsis and blanket flower were most attractive to native, small to medium-bodied bees (e.g., sweat bees, leafcutter bees) with the greatest number of visitations occurring during the early and midmonths of the study (May–August). Across the study, butterflies and moths visited lantana more frequently than all other ornamentals evaluated, whereas pentas were most attractive to wasps. Large-bodied bees visited plants most frequently in May and June, primarily foraging from both native and nonnative salvia. While results from this study showed nominal differences between native and nonnative species in their ability to attract the studied pollinator groups, care should be taken to making similar assessments of other modern plant types.

Identification and Regionalization of Cold Resistance of Wine Grape Germplasms (V. vinifera)

With the extreme changes of the global climate, winter freezing injury has become an important limiting factor for the development of the global grape industry. Therefore, there is a significant need for the screening of cold-resistant wine grape germplasms and cold regionalization for cold-resistant breeding and the development of grapevine cultivation in cold regions. In this study, the low-temperature half-lethal temperature (LT50) values were determined for the annual dormant branches of 124 wine grape germplasms (V. vinifera) to evaluate their cold resistance. The LT50 values of the 124 tested germplasms ranged from −22.01 °C to −13.18 °C, with six cold-resistant germplasms below −20 °C. Based on the LT50 values, the 124 germplasms were clustered into four types, with cold resistance from strong to weak in the order of type Ⅱ > type Ⅰ > type Ⅳ > type Ⅲ, corresponding to the four cold hardiness zones. Zones 1, 2, 3, and 4 included 6, 22, 68, and 28 germplasms, respectively, with decreasing cold resistance. The number of germplasms in different hardiness zones followed a normal distribution, with the most in zone 3. In Type Ⅱ, the fruit skin color of germplasms was positively correlated with cold hardiness, while the temperature of origin was negatively correlated with cold hardiness. The average LT50 of germplasms in different origin regions ranged from −17.44 °C to −16.26 °C, with differences among some regions. The cold regionalization analysis resulted in the distribution of 124 germplasms in four temperature regions in China with six germplasms in region A (−22 °C ≤ LT50 ≤ −20 °C), 30 germplasms in region B (−20°C ≤ LT50 ≤ −18°C), 71 germplasms in region C (−18 °C ≤ LT50 ≤ −15 °C), and 17 germplasms in region D (−15 °C ≤ LT50 ≤ −13 °C). Strong cold-resistant wine grape germplasms (V. vinifera) were identified, and these could be used as parental material for cold-resistant breeding. In some areas in China, soil-burial over-wintering strategies are used, but our results suggest that some wine grapes could be cultivated without requiring winter burial during overwintering. The results of this study should provide guidance for the selection of promising strains for cold-resistant breeding for expanded cultivation of improved varieties for wine grape production in China.

Impact of training system on ‘Blanc Du Bois’ vegetative growth, yield components and fruit composition

‘Blanc Du Bois’ (Vitisspp.) is the most widely grown Pierce’s disease tolerant white grapevine cultivar in Texas. As an interspecific hybrid, its growth habit is seimi-drooping, and 'Blanc Du Bois' is characterized as vigorous. This study evaluated the impact of training system (Mid-Wire Cordon with VSP, Mid-Wire Cane with VSP and Smart-Dyson, High-Wire Quadralateral, and Watson) on 'Blanc Du Bois' growth, yield components, and fruit composition at two locations in Texas. The first site was located in the Rio Grande Valley where the mean extreme minimum winter temperature is -1.1 to 1.7° C (USDA Cold Hardiness Zone 10a). As a result of climate and site conditions, vine size, determined by dormant pruning weight, was very large averaging from 3.71 to 5.56 kg per vine across training systems over a three-year period. At this site, the horizontally divided systems, High-Wire Quadrilateral and Watson were the highest yielding averaging 10.66 and 7.49 kg per vine, respectively, as a result of more shoots per vine, and higher fruitfulness. The Mid-Wire Cordon and Mid-Wire Cane Pruned Training Systems had lower yields in two out of three years, but fruit maturity indices soluble solids and pH reflected more advanced maturity at harvest. At the second site, located in the Central Gulf Coast of Texas (USDA Cold Hardiness Zone 8b), vines were less vigorous with pruning weights averaging 1.66 to 1.83 kg per vine across training systems over three years. Consistent differences in yield components, vine size, and fruit composition were not observed, and all the three training systems under study had acceptable growth and fruiting characteristics. The results of this research suggest that 'Blanc Du Bois’ vigor potential and growth habit makes it well-suited for horizontally divided canopy training systems, particularly on vigorous sites.

Projected changes in cold hardiness zones and suitable overwinter ranges of perennial crops over the United States

Average annual absolute minimum temperatures (TNn) provide a means of delineating agriculturally relevant climate zones and are used to define cold hardiness zones (CHZ) by the United States Department of Agriculture. Projected changes in TNn, mean winter minimum temperatures, and CHZs over the conterminous United States (CONUS) were assessed using an ensemble of statistically downscaled daily climate model output through the mid 21st century (2041–2070). Warming of TNn is on average ∼40% greater than that of mean winter minimum temperatures across CONUS with an average climate velocity of 21.4 km decade−1 resulting in widespread shifts in CHZs. These changes enable a geographic expansion of thermally suitable areas for the cultivation of cold-intolerant perennial agriculture including almond, kiwi, and orange crops. Beyond these crops, warming of TNn has broad implications for food security and biotic interactions.

래빗아이 블루베리 품종별 꽃눈의 내동성과 재배안전지역

Floral Bud Cold Hardiness and Cultural Safety Zone in Rabbiteye Blueberry Cultivars Hong-Lim Kim, Yong-Bum Kwack, Jeom-Hwa Han, Pill-Kyung Oh, Won-Byoung Chae, Seong-Cheol Kim, Mok-Jong Kim and Jin-Gook Kim, (Namhae Sub‐Station, NIHHS, RDA, Namhae 668‐812, Korea, Fruit Research Division, NIHHS, RDA, Suwon 440-706, Korea, Vegetable Research Division, NIHHS, RDA, Suwon 440‐706, Korea, Department of Horticulture, Gyeongsang National University, Jinju 660‐701, Korea)

Mexican Sycamore (Platanus mexicana)

Mexican sycamore (Platanus Mexicana) is a fast growing, drought tolerant tree boasting smooth white and tan bark and large, maple-like leaves with velvety, silver undersides. Native to northeastern and central Mexico, this tree’s cold hardiness is not well defined. However, Mexican sycamore grows well as far north as USDA Cold Hardiness Zone 8b in Texas and Florida. This 2-page fact sheet was written by Gary W. Knox and published by the UF Department of Environmental Horticulture, June 2014. ENH1241/EP502: Rzedowski’s Sycamore (Platanus rzedowskii), a Smaller Alternative to American Sycamore (ufl.edu)

Smooth-bark Mexican Pine (Pinus pseudostrobus)

This beautiful pine is distinguished by long, pendulous needles that form a graceful, open evergreen conifer. The slender needles are up to 12 inches long in groups (fascicles) of five. In its native environment, smooth-bark Mexican pine is considered fast growing, and can reach more than 120 feet tall and about 60 feet wide. In southern Georgia, trees have reached heights of 32 feet and widths of 25 feet in 10 years. Trees have a pyramidal form when young, becoming flat-topped with age. In its native range, smooth-bark Mexican pine grows in temperate to warm temperate areas with predominately summer rainfall. Florida’s similar climatic conditions suggest that smooth-bark Mexican pine will adapt well throughout the state. Cold hardiness is not well-defined, but this species has grown well in southern Georgia (USDA Cold Hardiness Zone 8b). This 2-page fact sheet was written by Gary W. Knox and published by the UF Department of Environmental Horticulture, June 2014. ENH1239/EP500: Smooth-Bark Mexican Pine (Pinus pseudostrobus) (ufl.edu)

Roystonea regia: Royal Palm

The royal palm is a large majestic palm that is native to south Florida and Cuba. It is considered cold hardy to about 28°F or USDA Cold Hardiness Zone 10A. This species quickly grows to heights of 50–70 ft., with a spread of 20–25 ft., and has a smooth light gray trunk up to 2 ft. in diameter. It is ideal for landscaping streets, parks, and commercial properties, but becomes too large for typical residential landscapes. This revised 4-page fact sheet was written by T.K. Broschat and published by the UF Department of Environmental Horticulture, February 2014.
 ENH-732/ST574: Roystonea regia: Royal Palm (ufl.edu)

Apalachee Crapemyrtle—Lagerstroemia indica × fauriei ‘Apalachee’

‘Apalachee’ crapemyrtle is a small deciduous tree with lavender flowers, dark green leaves, and cinnamon-orange bark. Lagerstroemia indica x fauriei ‘Apalachee’ is one of the hybrids released in 1987 from the breeding program of the U.S. National Arboretum. It grows as an upright to vase-shaped multi-stemmed tree in USDA Cold Hardiness Zones 7a-9b. This 2-page fact sheet was written by Gary W. Knox and published by the UF Department of Environmental Horticulture, December 2013.
 ENH1230/EP491: Apalachee Crapemyrtle—Lagerstroemia indica × fauriei ‘Apalachee’ (ufl.edu)

Vernicia fordii ‘Anna Bella’, a New Ornamental Tung Tree

Despite their floral display and tropical foliage, ornamental use for tung trees has been limited by the production of tung nuts, which are large, heavy, and toxic. ‘Anna Bella’ is a semisterile, or nutless, tung tree selection that significantly reduces homeowner concerns about mowing and toxicity to pets and children. Sterility also reduces the possibility of invasiveness. ‘Anna Bella’ is the first and only ornamental tung tree selection available to landscape professionals and homeowners and is recommended for USDA cold hardiness zones 8 to 10. The Thad Cochran Southern Horticultural Laboratory (TCSHL) was formerly the USDA Tung Oil Research Station in the 1940s, 1950s, and 1960s and maintains the most extensive Vernicia fordii (Hemsl.) Airey Shaw (syn. Aleurites fordii Hemsl.) germplasm collection in the United States that includes historic breeding lines and cultivars used in commercial tung oil production. This collection includes trees that are late-flowering and were used as parents in a USDA-ARS tung tree breeding program to delay flowering and prevent freeze damage to commercial tung oil orchards. Tung germplasm has been conserved by the USDA Agricultural Research Service in Poplarville, MS, for the last 50 years although the mission of the research station transitioned to small fruits in 1971. The germplasm collection was screened for ornamental use and ‘Anna Bella’ was selected for evaluation. Although they have not been shown to displace native flora, tung trees persist in fence rows and along roadsides and are classified as mildly invasive in parts of Florida (Langeland and Craddock Burks, 2008). Some specimens have been retained or planted in landscapes as ornamental trees because they flower profusely in early spring. Tung nuts are large, 8.0 cm in diameter, heavy, and toxic making them a nuisance for homeowners. ‘Anna Bella’ is a semisterile, or nutless, tung tree selection that significantly reduces concerns about mowing and yard maintenance, toxicity to pets and children, and the possibility of invasiveness. In four years of observations, peak flowering for ‘Anna Bella’ occurs 4 weeks later when compared with popular tung tree cultivars for tung oil production such as ‘Folsom’ and ‘Isabel’. ‘Anna Bella’ is the first ornamental tung tree selection released by the USDAARS Southern Horticultural Research Unit.

신 기후변화시나리오에 따른 한반도 내 겨울보리 재배적지 이동

The RCP 8.5 scenario based temperature outlook (12.5 km resolution) was combined with high-definition gridded temperature maps (30 m grid spacing) across the Korean Peninsula in order to reclassify the cold hardiness zone for winter barley, a promising grain crop in the future under warmer winter conditions. Reference maps for the January minimum and mean temperature were prepared by applying the watershed-specific geospatial climate prediction schemes to the synoptic observations from 1981 to 2010 across North and South Korea. Decadal changes in the January minimum and mean temperatures projected by a regional version of RCP8.5 climate change scenario were prepared for the 2011-2100 period at 12.5 km grid spacing and were subsequently added to the reference maps, producing the 30 m resolution temperature surfaces for 9 decades from 2011 to 2100. A criterion for threshold temperature to grow winter barley safely in Korea was applied to the future temperature surfaces and the resulting maps were used to predict the production potential of 3 cultivar groups for the 9 future decades under the projected temperature conditions. By 2020s, hulled barley cultivars could be grown safely at the southern part of North Korea as well as the mountainous Gangwon province. Furthermore, most of South Korean rice paddies will be safe for growing naked barley after harvesting rice. Also, dual cropping systems such as `winter-barley after rice` could be possible at most of the North Korean rice paddies by 2040s. Additional grain production in North Korea could increase up to 4 million tons per year if dual cropping systems can be fully operated, i.e., winter barley after rice at all lowlands and winter barley after maize or potato at all uplands.

Physocarpus opulifolius (L.) Maxim ‘Donna May’: A New Compact, Purple-leafed Landscape Shrub

‘Donna May’ is a new vegetatively propagated cultivar of Physocarpus opulifolius (L.) Maxim (common names include ninebark, common ninebark, and eastern ninebark). ‘Donna May’ has a compact, well-branched growth habit ( 1 m in height and width), purple foliage, powdery mildew resistance, and light pink flowers in midto late spring. It is adapted to USDA cold hardiness zones 3 to 7 and does well across a wide range of soil types. The compact, dense growth habit of ‘Donna May’ offers new versatility for purple purple-leafed ninebark. ‘Donna May’ can readily be integrated into containers and used in confined landscape beds as a manageable specimen, grouping, and/or hedge. Physocarpus opulifolius (L.) Maxim is a deciduous woody shrub in the family Rosaceace and subfamily Spiraeoideae. The species is diploid (2n = 2x = 18) and exhibits selfincompatibility (Dickson et al., 1992; Sutherland et al., 2008). Plants typically grow up to 3 m in height and are native throughout the majority of the eastern half of the United States and Canada with the notable exception of Texas, Louisiana, and Mississippi. Ninebark grows in diverse habitats, including woodland edges, near streams, upland slopes, and rock outcrops (U.S. Department of Agriculture, Natural Resources Conservation Service, 2012). The species is tolerant of variable soil conditions (including a range of soil moisture levels, pH, and textures) and grows well in partial to full sun (Dirr, 2009). Older stems on maturing plants develop peeling bark that separates in multiple thin layers (inspiring the name ninebark). Leaves are alternately arranged, simple, petiolate, and typically have three to five pronounced, pointed lobes (Dirr, 2009). Five-petaled, typically white flowers last for 3 d each and are produced in corymbs in midto late spring. Individual flowers open concentrically from the outer edge to the center of corymbs over approximately a 3-week period. Eastern ninebark is becoming increasingly popular as a landscape shrub. Greater variation in plant size and leaf color in newer cultivars has especially contributed to its popularity. ‘Monlo’ (Diabolo , frequently incorrectly spelled Diablo ) was the first commercialized purple-leafed cultivar. It was discovered as a unique seedling at the German nursery Kordes Jungpflanzen in 1968. ‘Monlo’ was issued a U.S. Plant Patent in 2000 (U.S. Plant Patent 11,211) and introduced in North America by Monrovia Nursery (Azusa, CA). The rich purple foliage and large plant size of ‘Monlo’ brought eastern ninebark to the forefront as a more densely growing alternative to purple-leafed sand cherry [Prunus 3 cistena (N. E. Hansen) Koehne], a predominantly used large purple-leafed shrub. In addition, golden-leafed forms (i.e., ‘Luteus’ and ‘Dart’s Gold’) and the compact green-leafed ‘Nanus’ have been landscape staples for decades. Several recent cultivars combine different foliage colors (gold and purple foliage on an individual plant) or foliage colors other than green on more compact plants. Helping to spur on the increase in new cultivars is the fact that purple and gold foliage color in ninebark are simply inherited and easily recovered in progeny. Purple and gold foliage are controlled by different single genes (Pur and Aur located on linkage groups I and III, respectively) and by dominant alleles (Sutherland et al., 2008). Additional reasons for the increased popularity of ninebark is that it is a durable, easy-to-grow U.S. native shrub and can be used as an alternative to purple and yellow-leafed barberry in regions where barberry is deemed invasive (Lubell et al., 2011) or in situations in which the spines of barberry are a liability. Ninebark is relatively pest-resistant but can be significantly impacted by powdery mildew (Phyllactinia guttata, Podosphaera aphanis var. physocarpi, and Podosphaera macularis) and feeding damage from the specialist ninebark beetle (Calligrapha spiraeae). Lubell et al. (2011) surveyed several popular purple, gold, and green-leafed cultivars of ninebark for powdery mildew resistance. Great variability was found among the cultivars; ‘Nanus’ was the only cultivar that did not exhibit infection, ‘Nugget’ had the greatest infection, and ‘Monlo’ was intermediate. Podosphaera aphanis var. physocarpi only infects ninebark (the others are generalists), and plants infected with this fungal species often display witches’ brooms covered in mycelium (i.e., thickened, stunted stem and leaf growth at the terminals). Infected tissue typically dies and becomes unslightly. The generalist fungi typically produce infections more uniformly over plants and do not lead to witches’ brooms. The specialist ninebark beetle feeds on the leaves of ninebark. Tenczar and Krischik (2007) compared feeding and reproductive tendencies of the beetle on ‘Monlo’, ‘Dart’s Gold’, and a wild-type ninebark. They found that the beetles preferred ‘Monlo’ the least and those forced to feed on only ‘Monlo’ had the lowest fecundity. They suggest this may be the result of the high anthocyanin content in ‘Monlo’. Anthocyanins are known to deter feeding of some insects and bind with nitrogen resulting in a less nutritious food source (Tenczar and Krischik, 2007).

Differences in Seed Set and Fill of Cultivars of Miscanthus Grown in USDA Cold Hardiness Zone 5 and Their Potential for Invasiveness

Miscanthus sinensis Andersson has become a very popular ornamental grass used in a variety of horticultural settings, yet in many states it now appears on invasive species lists. Many cultivars have been released with a range of different characteristics that likely increase or decrease their invasive potential in different climates. To determine the fecundity, and by extension, the invasive potential of cultivars currently sold in USDA cold hardiness Zone 5, thirty-one cultivars of M. sinensis (Maiden grass, Chinese silver grass) along with one Miscanthus subspecies cultivar (M. sinensis Andersson subsp. condensatus (Hack.) T. Koyamama ‘Cabaret’), one Miscanthus hybrid (M. × giganteus J.M. Greef & Deuter ex Hodk. Renvoize), and one related species (M. sacchariflorus (Maxim.) Hack.) were transplanted into a common garden at the Chicago Botanic Garden in Cook County, IL, and evaluated for flowering, growth habit, and seed viability. Over the course of the 5-year trial period, 68.1% of all plants survived. Growth in clump size varied greatly among taxa, as did flowering periods. Most cultivars set filled seed, ranging from 14 to 349,327 seeds per plant; only four produced no seed over the course of the trial. Most cultivars of the species represent a high risk for self-seeding in Zone 5. Because Miscanthus sinensis is self-incompatible (8), risk of self-seeding increases when two or more cultivars are grown together. Implications for potential invasiveness are discussed.

Opuntia Forage Production Systems: Status and Prospects for Rangeland Application

This paper reports recent findings in Opuntia genetics, nutrient fertilization, and cultivation with promise to overcome limitations for Opuntia-based forage production systems. The essentially spineless, fast-growing Opuntia ficus-indica (L.) Mill. has been planted on millions of hectares for forage in tropical areas of Brazil and North Africa. The spiny, cold-hardy Opuntia species have been used for forage in Mexico and the southwestern United States, after the cladodes have been chopped or singed to remove the spines. Due to the recent increases in fuel prices, burning of the spines is more costly. Where only spiny varieties exist, some range animals forage on them without manipulation. As a result, spines frequently penetrate and form lesions on mouth and esophageal tissues, leading to serious health issues. Slow growth and low protein (ca. 5%) of the native Opuntia spiny species on nonfertilized rangeland is an impediment to greater use of Opuntia for forage. The only spineless species adaptable to US Department of Agriculture cold hardiness zones , 8 (i.e., Opuntia ellisiana Griffiths) is relatively slow growing. Full sibling crosses indicate spine heritability is probably single-gene controlled. Interspecific hybrids between the frost-sensitive, fast-growing, and spineless O. ficus-indica with cold-hardy, spiny, slower-growing O. lindheimerii Engelm. have produced spineless progeny, with greater cold hardiness than O. ficus-indica, and greater productivity than cold-hardy, spineless O. ellisiana. Nitrogen limitations on water-use efficiency of Opuntia have been overcome for the 120 million ha of semiarid northeastern Brazil with added nitrogen and phosphorus fertilization. With control of competing vegetation and fertilization, this system has 40 t dry matter ? ha 21 of 9.2% crude protein forage with 600 mm rainfall in 16 mo. Opuntia ficus-indica plantations were profitable even though a duplication of fertilizer current prices was considered.

Palms on the Edge: Species and Strategies for Landscape Utilization

An emerging niche in landscape design is the creation of exotic venues in commercial and residential settings using unusual plant materials. For instance, the creation of a tropical looking pool area at a hotel, a southwestern desert look for a Mexican restaurant or an oasis for the consumer at a shopping venue can all be in part achieved by the addition of specific plants. Palms (Arecaceae) can be an important component of this effort, even in temperate landscapes. This article focuses on issues related to the incorporation of palms in temperate landscapes. Although palms are signature plants of tropical regions, a surprising number of species can be grown in U.S. Department of Agriculture cold hardiness zones 8, 7, or colder via a combination of appropriate genotype selection, attention to microclimates in design specifications, and/or special cultural practices to mitigate the impact of cold temperatures. Cold-tolerant palms can be a critical design element, especially when paired with other lush tropical-appearing plants, to achieve the goal of creating the illusion of an exotic tropical locale in temperate-climate landscapes. Genotypic and site specification, careful attention to establishment requirements, and modified maintenance practices are critical determinants for success that will be addressed.

Palms on the Edge: Species and Strategies for Landscape Utilization

An emerging niche in landscape design is the creation of exotic venues in commercial and residential settings using unusual plant materials. For instance, the creation of a tropical looking pool area at a hotel, a southwestern desert look for a Mexican restaurant or an oasis for the consumer at a shopping venue can all be in part achieved by the addition of specific plants. Palms (Arecaceae) can be an important component of this effort, even in temperate landscapes. This article focuses on issues related to the incorporation of palms in temperate landscapes. Although palms are signature plants of tropical regions, a surprising number of species can be grown in U.S. Department of Agriculture cold hardiness zones 8, 7, or colder via a combination of appropriate genotype selection, attention to microclimates in design specifications, and/or special cultural practices to mitigate the impact of cold temperatures. Cold-tolerant palms can be a critical design element, especially when paired with other lush tropical-appearing plants, to achieve the goal of creating the illusion of an exotic tropical locale in temperate-climate landscapes. Genotypic and site specification, careful attention to establishment requirements, and modified maintenance practices are critical determinants for success that will be addressed.

남한의 겨울기온 상승 예측에 따른 포도 "캠벨얼리" 품종의 단기 내동성 변화 전망

Warming trends during winter seasons in East Asian regions are expected to accelerate in the future according to the climate projection by the Inter-governmental Panel on Climate Change (IPCC). Warmer winters may affect short-term cold hardiness of deciduous fruit trees, and yet phenological observations are scant compared to long-term climate records in the regions. Dormancy depth, which can be estimated by daily temperature, is expected to serve as a reasonable proxy for physiological tolerance of flowering buds to low temperature in winter. In order to delineate the geographical pattern of short-term cold hardiness in grapevines, a selected dormancy depth model was parameterized for "Campbell Early", the major cultivar in South Korea. Gridded data sets of daily maximum and minimum temperature with a 270m cell spacing ("High Definition Digital Temperature Map", HDDTM) were prepared for the current climatological normal year (1971-2000) based on observations at the 56 Korea Meteorological Administration (KMA) stations and a geospatial interpolation scheme for correcting land surface effects (e.g., land use, topography, and site elevation). To generate relevant datasets for climatological normal years in the future, we combined a 25km-resolution, 2011-2100 temperature projection dataset covering South Korea (under the auspices of the IPCC-SRES A2 scenario) with the 1971-2000 HD-DTM. The dormancy depth model was run with the gridded datasets to estimate geographical pattern of change in the cold-hardiness period (the number of days between endo- and forced dormancy release) across South Korea for the normal years (1971-2000, 2011-2040, 2041-2070, and 2071-2100). Results showed that the cold-hardiness zone with 60 days or longer cold-tolerant period would diminish from 58% of the total land area of South Korea in 1971-2000 to 40% in 2011-2040, 14% in 2041-2070, and less than 3% in 2071-2100. This method can be applied to other deciduous fruit trees for delineating geographical shift of cold-hardiness zone under the projected climate change in the future, thereby providing valuable information for adaptation strategy in fruit industry.