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M. Jalaluddin and Md. Shahidul Islam*

Foods from plants can provide enough energy and essential nutrients for maintaining human health as well as for prevention of many serious diseases. Many exotic vegetables are known for their special nutritional and medicinal properties. Bitter Melon (Momordica charantia L.), an annual vegetable of Cucurbitaceae family, is found to be one of the important vegetables of special nutritional and medicinal qualities. Germplasm lines and land races of Bitter Melon were evaluated in 2000 and 2001 for their adaptability in Southeast Arkansas. Seven adaptable lines/varieties were tested in replicated field trials for productivity at the Univ. of Arkansas at Pine Bluff Agricultural Research Center in 2002 and 2003. Melons were harvested at their marketable stages beginning in June and ending in September for yield estimation. Nutritional qualities of Bitter Melons were examined by chemical analyses conducted at the Univ. of Arkansas, Fayetteville (UAF) Food Science Laboratory. Analyses for antioxidants and other compounds as well as cooking qualities are currently underway. Several recipes have been tasted for consumer acceptance. The popular belief of bitter melon to improve glucose tolerance in Type II diabetes and lower blood cholesterol are being investigated. It is still to be determined if the chemical constituents such as certain alkaloids and polypeptides found in bitter melons are effective individually or in combination.

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P. N. Maynard, G. W. Elmstrom, L. Wessel-Beaver and T. G. McCollum

Calabaza is a pumpkin-like fruit that is grown throughout the tropics and subtropics. In the Caribbean “calabaza” is used in soups and other traditional dishes. In Puerto Rico, the 1987-88 calabaza crop was worth $8 million and the value of the crop in Florida is estimated to exceed $5 million. Mainland production of tropical calabaza types of C. moschata is limited largely to Florida where it is used mostly by those of Cuban descent. Despite the popularity and commercial significance of calabaza, little effort has been directed toward the study of cultural practices or varietal improvement. Only two improved varieties, `Borinquen' introduced by the Puerto Rico Agricultural Experiment Station in the 1940s and `La Primera' introduced by the Florida Agricultural Experiment Station in 1979 are available. Approaches to calabaza improvement including development of plants with shorter vines, incorporation of powdery mildew resistance, and production of uniform, symmetrical, hard-shelled, medium-sized fruit with enhanced nutritional quality in relationship to management systems are discussed.

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Christopher Gunter, David Francis and Alba Clivati McIntyre

Yellow shoulder disorder (YSD) is a physiological disorder of processing tomato that affects both the appearance and nutritional quality of the fruit. This disorder reduces the suitability of fruit intended for the whole-peeled and diced product markets. The YSD involves an interaction between plant genotype and the environment. A number of soil factors have been related to the incidence of YSD, including organic matter, phosphorous, K/Mg ratios, and soil K. Varieties of tomatoes differ in their susceptibility to color disorders, thus variety selection offers growers one strategy to manage this color disorder. The use of supplemental K application at a time when plants are blooming and actively growing offers a second strategy for management of YSD. To this end, a field study was conducted at the Southwest Purdue Agricultural Program in southwestern Indiana to study the effects of different sources of K on the color and quality of tomato fruit. Potassium chloride, potassium nitrate, and potassium sulfate were applied at first flowering in a solid, broadcast application. Appropriate controls were used to balance the nutrients supplied in addition to K. Supplemental K, regardless of source, improved fruit hue, though the trend was not always statistically significant between treatments. Variety specific effects were observed. This is a complex disorder and its management will entail minimizing risk of incidence through careful selection of variety and field location.

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Young-Sang Lee, Yong-Ho Kim and Sung-Bae Kim

To study the effects of chitosan on the productivity and nutritional quality of soybean (Glycine max L.) sprouts, soybean seeds were soaked in solutions containing 1,000 ppm chitosan of low (<10 kDa), medium (50 to 100 kDa), or high (>1,000 kDa) molecular weight, and the respiration, growth, and vitamin C content of the sprouts were subsequently evaluated. Sprouts treated with high molecular weight chitosan exhibited a significant increase in respiration, 5%, within 1 day of treatment. Chitosan effectively increased the growth of the sprouts: sprouts treated with high molecular weight chitosan showed increases of 3%, 1%, 3%, 1%, and 12% in the total length, hypocotyl length, root length, hypocotyl thickness, and fresh weight, respectively, as compared to a control. The growth-improving effects of chitosan were proportional to the molecular weight of the molecule used in the treatment. Chitosan treatment did not result in any significant reduction in vitamin C content or postharvest chlorophyll formation, traits that determine the nutritional and marketing values of soybean sprouts. All these results suggest that soaking soybean seeds in a solution of chitosan, especially of high molecular weight, may effectively enhance the productivity of soybean sprouts without adverse effects on the nutritional and postharvest characteristics.

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Floyd M. Woods, William A. Dozier, Robert C. Ebel, Raymond Thomas, Monte Nesbitt, Bryan S. Wilkins and David G. Himelrick

Changes in fruit quality attributes and antioxidative properties from six cultivars of thornless blackberries (Rubus sp.) (`Apache', `Arapaho', `Chester', `Loch Ness', `Navaho', and `Triple Crown') during four different ripening stages (red, mottled, shiny-black, and dull-black) were determined under Alabama growing conditions. Berry fruit samples were evaluated for pH, titratable acidity, total soluble solids, TSS/TA ratio, soluble sugars, vitamin C (reduced, oxidized and total), and antioxidant capacity (measured as trolox equivalent antioxidant capacity, TEAC). Significant variation among cultivars were noted in fruit quality attributes and antioxidative properties, which were influenced by maturity at harvest. An increase in fruit pH concomitant with a decline in titratable acidity (TA) was observed during ripening for all cultivars. Total soluble solids (TSS) values increased from 5.7% to 11.6%, with associated TSS/TA ratio values ranging from 11.92 to 63.56 in ripening fruit. Highest reducing and total sugar content were contained in dull-black fruit. Vitamin C content either declined or remained unchanged with ripening, and the pattern was dependent on cultivar, maturity at harvest and form determined. In general, antioxidant activity declined between red and dull-black ripening stages. The results suggest that the TSS/TA ratio may provide the best maturity index in determining optimal eating quality and antioxidant capacity in terms of TEAC value the best indicator of optimal nutritional quality as influenced by maturity at harvest.

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Christopher C. Gunter and David Francis

Physiological disorders affect both the appearance and nutritional quality of processing tomatoes intended for whole-peel and diced products. The cause of color disorders, such as yellow shoulder disorder (YSD), involves an interaction between plant genotype and the environment. Soil factors that correlate with the incidence of YSD are soil K, K:Mg ratios, organic matter, and phosphorus. Fields with an organic matter above 3.5% have a lower incidence of YSD. Progress in developing an integrated crop management system that growers and processors can use to profitably improve quality and nutritional value while reducing color disorders of tomato has been made. Decision tools for managing color disorders have been developed. Varieties of tomato differ in their susceptibility to color disorders; thus, variety use may offer growers a strategy to manage fields with low potassium, phosphorus, or low organic matter. Soil K application through drip irrigation was effective when applied at full bloom when the plants were most actively growing. Trials conducted in Indiana and Ohio during the 2003 and 2004 growing seasons demonstrated that weekly K application as a batch injection or solid application improved fruit color and reduced internal whitening. The effect of K addition is toward improved hue and L (lower values), but that trend is not always statistically significant and variety-specific responses are observed. Environmental factors for this response are explored. Managing this complex color disorder will entail minimizing risk of incidence, rather than preventative or curative applications.

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K. Francis Salifu, Douglass F. Jacobs, Guillermo Pardillo and Mary Schott

We examined growth and nitrogen (N), phosphorus (P), potassium (K), and microelement nutrition of grafted black walnut (Juglans nigra L.) seedlings exposed to increasing nutrient supply and grown in the greenhouse for 18 week. Plants were potted and grafted within the first 4 week, then fertigated once each week for a 7-week period with a varying nutrient solution of 20N–4.4P–16.6K that delivered 0, 1160, 2320, and 4620 mg N/plant. Plants were harvested at week 18. There was a positive mean growth response to increased fertilization, although trends were statistically similar across treatments. Leaf nutrient concentration ranged from 22 to 31 g · kg–1 N, 5 to 14 g · kg–1 P, and 19 to 25 g · kg–1 K. The 2320 mg N/plant treatment increased leaf nutrient content 18% to 86% for N, 33% to 303% for P, and 23% to 58% for K compared with the control. Nitrogen efficiency decreased with increased N supply. Increased nutrient retention in the growing medium at higher fertility suggests root plugs could serve as immediate critical nutrient sources for grafted black walnut seedlings after outplanting. Study results suggests nursery fertilization can be used to improve the nutritional quality of grafted black walnut as well as store nutrients in root plugs for later utilization to benefit early establishment success.

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M. Rangappa, McArthur Floyd, Val Sapra, Jagmohan Joshi, Thomas Carter and M. R. Reddy

A USDA/OICD sponsored agricultural research team visited the Republic of China (Taiwan) and the People's Republic of China (PRC) in 1990 to gather information regarding soybean utilization and to increase genetic diversity of the soybean crop through new germplasm collections. A total of 25 new soybean accessions were collected and brought to the Virginia State University, Petersburg, VA, one of the OICD sponsored team participants. In accordance with the U.S. policy on the New Germplasm Collection, part of the seed of each accession was sent in original packs to USDA Soybean Germplasm Collections, University of Illinois, Urbana, Ill. Limited seed increase was done in the greenhouse and one 10m long observational row of each accession was grown at VSU Research Station in 1991. Seed traits, plant agronomic characteristics, insect pest, and disease pathogen reactions were observed and documented. Chemical analysis for nutritional quality, antinutritional factors, and biochemical components of green seeds and pods at R-7 stage and mature seeds of each accession are underway and those values will be compared with existing commercial cultivars, advanced breeding lines, and plant introductions.

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San-Gwang Hwang, Yi-Ying Li and Huey-Ling Lin

The king oyster mushroom [Pleurotus eryngii (DC.:Fr.) Quél.] is gaining popularity across the world due to its excellent taste, high nutritional quality, medicinal value, and long shelf life. Conventional substrates for king oyster mushroom cultivation consist of sawdust derived from various tree species. Sawdust demand is increasing worldwide, creating a need for alternative materials that can at least partially replace sawdust as substrate for king oyster mushroom. In Taiwan, as in other countries that grow fruit trees, pruned fruit tree branches are an expensive agricultural waste, particularly if they are not recycled or reused. In the present study, we evaluated substrates containing sawdust and different proportions of material ground from pruned wax apple or Indian jujube branches for cultivation of king oyster mushroom. Our results suggested that among all five substrate mixes tested, the best substitute for conventional sawdust (100% sawdust) was a substrate that contained 75% sawdust mixed with 25% materials ground from trimmed wax apple branches (Wax apple 25%). Furthermore, determination of mineral element content, pH, and electrical conductivity (EC) levels of the substrates both before spawn inoculation and after harvesting revealed no significant changes in mineral content, a slight reduction in pH value, and a minor increase in EC levels after cultivation. Taken together, results from this study suggest that agricultural wastes from pruned fruit tree branches can partially replace sawdust as the cultivation substrate for king oyster mushroom.

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Joshua D. Williamson, Cameron P. Peace, Frederick A. Bliss, David T. Garner and Carlos H. Crisosto

The Y locus of peach [Prunus persica (L.) Batsch] controls whether a tree will produce fruit with white or yellow flesh. Flesh color has implications for consumer acceptance and nutritional quality, and improved cultivars of both flesh types are actively sought. This paper focuses on evidence that the flesh color locus also controls senescent leaf color (easily observed in the fall) and hypanthium color. In two progeny populations totaling 115 progeny plus their parents, the three traits co-segregated completely. Trees carrying the dominant allele for white flesh had yellow senescent leaves and yellow hypanthia, while homozygous recessive yellow-fleshed types exhibited orange senescent leaves and orange hypanthia. Senescent leaf color was also measured quantitatively, with major colorimetric differences observed between white-fleshed and yellow-fleshed progeny. Senescent leaf hue angle and reflected light wavelengths of 500 to 560 nm were the parameters most affected by the flesh color locus. Results were verified with 10 white-fleshed and 10 yellow-fleshed cultivars. The findings show that the Y locus in peach controls the type and concentration of carotenoids in multiple organs, including fruit, leaves, and flowers. The ability to discriminate between white and yellow flesh color using a simple visual method, applicable in plants not yet at reproductive maturity, is valuable to breeders wanting to save time, growing space, and money.