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Raul I. Cabrera*

Rooted liners of the crape myrtle cultivars `Pink Lace', `Natchez' and `Basham's Party Pink' (`BPP') were grown in 20-L containers filled with a 2 peat: 1 pine bark: 1 sand (v/v) medium and irrigated for 15 weeks with irrigation water containing 0, 3, 6, 12, and 24 mm NaCl. Cultivar selection and salinity significantly affected plant growth and quality. Regardless of salinity level, `Natchez' plants had higher leaf area, total and shoot (top) dry weights and growth indices, whereas `Pink Lace' had the lowest. `BPP' had the highest average root dry weights across salt treatments. The vigorous shoot (top) growth of `Natchez' was also evident with an average shoot to root ratio of 4.1, compared to 2.7 and 2.4 for `BPP' and Pink Lace', respectively. Salinity significantly decreased plant growth and quality in the three cultivars, but the rate at which these parameters were reduced with increases in salinity differed among the cultivars. The rate of reduction in plant growth parameters was lower in `Pink Lace' plants compared to `Natchez' and `BPP'. However, foliage burn symptoms due to salt stress increased at significantly higher rate for `Pink Lace' plants compared to the other two cultivars. `BPP' plants had in general the lowest salt burn ratings at each salinity level. Leaf concentrations of Na and Cl increased with salt stress in all cultivars, but significantly lower concentrations were found in `BPP' plants. `Pink Lace' plants had better correlations with the recorded salt burn symptoms as compared to the other two cultivars.

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Lorraine Berkett, Terry Schettini, Dan Cooley, Dean Polk, and David Rosenberg

Developing sustainable production systems based on the disease resistant apple cultivars (DRACs) and IPM techniques is a key objective of this multidisciplinary project involving 19 principle investigators across 5 cooperating institutions. Cultivar selection is a crucial decision for an apple grower which will impact the farm's competitiveness and profitability for many years. Factors that growers consider when deciding what cultivars to plant include consumer acceptance and marketability; winter hardiness; yield potential; fruit storage qualities, color, taste, and size; and potential pest management problems. These factors are being researched in this project. Disease resistant orchards will undoubtedly present new economic considerations to growers, wholesalers, and processors. A further objective is to provide economic analyses of alternative techniques and to forecast the impact of changes in production systems on the Northeast apple industry. Apple growers must have access to research-generated information that addresses the critical issues facing them Rapid information dissemination is a high priority of this project. The Northeast Sustainable Apple Production Newsletter has over 1200 active subscribers across the United States and in 7 foreign countries. The Management Guide for Low-Input Sustainable Apple production has been well received and continues to be requested world-wide.

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Arthur Villordon*, Simon Gichuki, Heneriko Kulembeka, Simon C. Jeremiah, and Don LaBonte

Africa represents a unique secondary site of genetic diversity for the sweetpotato [Ipomoea batatas (L.) Lam.]. Despite the genetic resources available for sweetpotato breeding and cultivar selection, regional conflicts and adverse weather in the last two decades have accelerated the risk of germplasm loss, particularly in East and Central Africa. A cooperative research project is currently underway to assess genetic diversity as well as help conserve sweetpotato germplasm in East Africa. One of the tools that are currently being used is a web-accessible GIS database that enables access to spatial and temporal data by project investigators and other stakeholders. Although proprietary methods are available for delivering GIS data through web interfaces, these methods often require expensive licensing agreements. The use of ALOV Map, a freely available Java® application for publishing vector and raster maps, along with basemaps and other thematic maps downloaded from publicly accessible web sites, helped provide the framework for a web-accessible GIS database. DIVA-GIS, a free desktop based GIS software was used to generate shapefiles as well as preview files prior to uploading. This demonstrates that the availability of publicly available software requiring minimal or flexible licensing costs provide a cost-effective alternative to institutions that are considering access to GIS databases via a web-accessible interface. We describe procedures, software, and other applications that we used to develop a publicly accessible web interface to a GIS database of sweetpotato germplasm collections in Kenya and Tanzania.

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R.J. Henny, T.A. Mellich, and D.J. Norman

Thirty-one spathiphyllum (Spathiphyllum Schott.) cultivars were evaluated for flowering response following treatment with gibberellic acid (GA3). Greenhouse-grown plants were treated once with 250 mg·L-1 (ppm) GA3 applied as a foliar spray. Within 16 weeks after treatment all GA3-treated plants had flowered but none of the untreated controls produced flowers. `Vickilynn' (14.1 flowers/plant after 16 weeks), `Piccolino' (12.8), `Mascha' (12.6), `Chris' (11.7), `Alpha' (11.7), and `Daniel' (11.0) produced significantly more flowers than other cultivars. The cultivars producing the fewest flowers per plant after 16 weeks were `Sierra' (2.5), `S1008' (3.2), `Rica' (3.4), `Sonya' (4.3), `Vanessa' (5.1), `S18' (5.5) and `S4002' (5.6). `Alpha,' `Textura,' `Daniel,' `Mascha,' `S1007', and `Showpiece' had significantly better flower quality. `S1008,' `Codys Color', and `Petite' had poor flower quality. `Mascha' was the earliest cultivar to bloom producing maximum flower counts during weeks 9 to 10 after treatment while `Vanessa' was the latest to flower with peak bloom occurring 15 to 16 weeks after treatment. Most cultivars reached peak bloom at 11 to 13 weeks after treatment. Results indicate sufficient genetic variability in spathiphyllum flowering response to GA3 treatment exists to permit cultivar selections based on differences in flowering time, number of flowers and flower quality.

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Paul W. Wilson, Gloria B. McClure, and Julian C. Miller Hall

The demand for hot sauce products continues to expand in the U.S. In the case of jalapeno pepper sauce, there are many cultivars available for sauce production but those best suited for processing have not been adequately determined. Six cultivars (four replications) of jalapeno peppers (`Coyame', `Grande', `Jalapeno-M', `Mitla', `Tula' and `Veracruz') were evaluated for mash fermentation. The attributes studied during mash aging were color spectra, capsaicin content and fermentable sugars. Fructose and glucose were the predominant sugars in jalapeno peppers and these sugars were utilized gradually with time indicating slow fermentation by microorganisms in the 15% salt mash. Capsaicin and dihydrocapsaicin were the predominant capsaicinoids in the jalapeno peppers with `Tula' containing the greatest concentration and `Veracruz' the least. All mashes displayed an apparent and unexpected rise in measurable capsaicinoids up to 6 months with a decline at 12 months. Color changes in the pepper mash were rapid initially but slowed after the first month of fermentation. Percent reflectance in fresh ground peppers was strongest in the range of 550–560 nm but, after salting, reflectance shifted to 580–590 nm and remained throughout the fermentation. Based on the characteristics tested, any of these cultivars would make a suitable mash for sauce. The heat content of the final product could be controlled by cultivar selection or through blending.

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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.

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J.S. Ebdon, R.A. Gagne, and R.C. Manley

Turf loss from freezing injury results in costly reestablishment, especially with turfgrasses such as perennial ryegrass (Lolium perenne L.) having poor low-temperature tolerance. However, no studies have been conducted to investigate the relative importance of low-temperature tolerance and its contribution to turfgrass quality (performance) in northern climates. The objective of this research was to compare critical freezing thresholds (LT50) of 10 perennial ryegrass cultivars representing contrasting turf-quality types (five high- and five low-performance cultivars). Cultivar selection was based on turfgrass quality ranking (top and bottom five) from the 1997 National Turfgrass Evaluation Program (NTEP) trial conducted at the Maine (Orono) location. Ten freeze-stress temperatures (-3 to -21 °C) and a nonfrozen control (5 °C) were applied to 5-month-old plants. Acclimated (AC) plant material maintained in an unheated polyhouse during the fall and winter in Massachusetts was compared to nonacclimated (NA) plant material (grown at 18 °C minimum in a greenhouse). Low-temperature tolerance was assessed using whole-plant survival and electrolyte leakage (EL). Estimates of LT50 were derived from fitted EL and survival curves using nonlinear regression. High-performance cultivars were able to tolerate significantly lower freeze-stress temperatures indicated by less EL and greater survival compared to low-performance cultivars. The EL method had good predictive capability for low-temperature survival. Acclimated tissues and high-performance cultivars had significantly flatter EL curves and lower mortality rates. These results underscore the importance of selecting cold-tolerant perennial ryegrass genotypes for adaptation to northern climates.

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D.S. NeSmith, G. Hoogenboom, and D.W. Groff

Staminate and pistillate flower production in summer squash (Cucurbita pepo L.) fluctuates readily in response to the various crop production environments throughout the southeastern United States. `Dixie', `Senator `, `Lemondrop', `Meigs', and `Elite' squash were planted at various times over 2 years in Griffin, Ga., to determine the effect of planting date on staminate and pistillate flower counts for the first 2 weeks of flowering. Staminate and pistillate flower counts varied considerably depending on cultivar and time of planting, but no consistent pattern emerged. The production of staminate flowers was generally more variable than that of pistillate flowers. The distillate: staminate flower ratio was generally stable for `Senator' and `Elite', but not for the other cultivars, particularly `Dixie'. `Dixie' produced more distillate than staminate flowers 50% of the time, whereas `Senator' always produced more staminate flowers. Pistillate flower production for `Senator' and `Elite' was restricted during hot weather. These data indicate that staminate and pistillate flower counts of squash fluctuate under varying environmental conditions and that maintaining production over a range of planting dates will depend on careful cultivar selection.

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R.J. Campbell and C. de B. Campbell

Mango (Mangifera indica L.) currently ranks fifth, along with apple, among fresh fruit imported by the United States, with more than 142,000 MT imported in 1995. Imports have doubled in the past 5 years and are projected to increase by 20% to 30% by the year 2000. Mexico supplied >80% of the imported volume in 1995, with the remaining 20% supplied by Brazil, Ecuador, Guatemala, Haiti, Nicaragua, Peru, and Venezuela. Individual production areas (countries) have traditionally controlled a market, defined by time of year, resulting in a near 12-month supply of mangos in the United States in the past few years. However, market share among producing countries is rapidly changing as individual producers and production regions extend their season through the use of different available microclimates, bloom manipulation, and new cultivars. With this extension of production season in each region, there is now significant market overlap and traditional regional windows have been shortened or eliminated. Producers in all regions must now make timely management decisions to assure their future profitability. A holistic management scheme involving attention to fruit quality, cultivar selection, volume consistency, and marketing is presented. Such a management plan is key to an individual region's success in establishing and holding a given market window.

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Anita Solar and Franci Štampar

Three cultivars and three selections from Oregon State University's (OSU) hazelnut (Corylus avellana) breeding program were investigated in a yield trial during the period 1997 to 2007 in northeastern Slovenia with the Italian ‘Tonda Gentile delle Langhe’ as the standard. All OSU genotypes had higher cumulative yield and yield efficiency than the standard, all exceeded the kernel percentage of 45%, and all had at least 76% good kernels. OSU 228.084 is promising due to good vegetative growth and the highest yields and yield efficiency. It set many catkins and had the highest percentage of marketable kernels. Its disadvantage could be early flowering and large yield reduction due to low temperatures in early spring. Cultivars/selections that were late flowering (‘Lewis’ and OSU 244.001) had longer durations of pistillate flower receptivity (‘Willamette’ and OSU 238.125) and had lower sensitivity to unfavorable weather conditions in early spring (‘Clark’) expressed the best climatic adaptation. Unmarketable nuts were mainly blanks and poorly filled nuts. ‘Clark’ is precocious early maturing, and well-suited to the kernel market. Due to its upright growth habit, ‘Clark’ could be planted more densely than others. ‘Lewis’ yielded well and had medium yield efficiency, and is suitable for in-shell and kernel markets. Excellent pellicle removal was observed in OSU 244.001 and OSU 238.125. All OSU cultivars and selections showed relatively low susceptibility to hazelnut weevil (Balaninus nucum).