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Postharvest storage of southernpeas is crucial in the production process. Governed by consumer demands, farmers strive for a product that is high in quality and freshness, and has an appropriate texture and appealing color. Improper storage of southernpeas results in their premature deterioration, lack of acceptance, and possible loss of profit. Therefore, an appropriate storage facility and temperature should be devised that will benefit both farmer and consumer. In an effort to prevent potential losses of southernpeas, a study was conducted to determine the best environmental condition at which to store and to potentially extend shelf life. In 2004, two experiments were conducted on the University of Arkansas Agriculture Research and Extension Center, Fayetteville, Ark., to determine the best genotype and storage environmental condition to maintain a quality marketable prod-uct. In the first experiment, a screening of 23 southernpea genotypes was conducted from single plots to determine which genotypes could maintain their appearance the longest in a refrigerated environment. In the second experiment, two separate plantings were made of five southernpea genotypes in a randomized block design in two separate fields. Upon maturity, 12 mature green pods of each genotype were subjected to a sweated and unsweated treatment. After shelling, seeds were subjected to one of three different environmental conditions: cool regime, room temperature, and ambient air, evaluating each on the basis of changes in physical appearance; a hot water dip treatment was also examined. A refrigerated environment at or near 37 to 41 °F was the best environment to store southernpeas for nearly 2 weeks. The sweated treatment also aided in the shelling process and appeared to maintain the appearance of each genotype longer.

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Postharvest storage of southernpeas, Vigna unguiculata (L.) Walp., is a crucial point of the production process. Governed by consumer demands, farmers strive for a product that is high in quality and freshness, and has an appropriate texture and appealing color. Improper storage of southernpeas will result in their eventual deterioration, unacceptance, and possible loss of profit. Because of this, an appropriate storage facility and temperature should be devised that will benefit both farmer and consumer. In an effort to prevent potential losses of southernpeas, a study was conducted to determine the best environmental condition at which to store them to potentially extend their shelf-life. In 2004, five southernpea varieties—`Early Acre,' `Early Scarlet,' `Excel Select,' `Coronet,' and `Arkansas Blackeye #1'—were planted in a randomized block design on the University of Arkansas horticulture farm. Upon maturity, 12 green pods of each variety were subjected to a sweated and unsweated treatment and then shelled. After shelling, the seeds were subjected to four different environmental conditions evaluating each on the basis of changes in physical appearance. Further objectives of the study were to determine the best variety, environmental condition, and treatment to maintain product quality in a manner that would relate to growers on a commercial basis. Results showed that a refrigerated environment at or near 3 to 5 °C is a good environment to store this particular crop for nearly 2 weeks. It also appeared that the sweated treatment assisted with the shelling process and maintained the appearance of each variety longer. From the results, temperature and percent relative humidity are arguably two important components of postharvest storage that have the potential of negatively affecting the crop.

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There are four southernpea breeding programs left in the United States: USDA-South Carolina, Louisiana, Texas and the largest at University of Arkansas. Selected breeding lines from these programs are grown in the Southernpea Cooperative Trial along with industry standards as checks. The yield trial is conducted in Alabama, Arkansas, Louisiana, Oklahoma, South Carolina, and Texas. Each location collects yield data; at the University of Arkansas-Fayetteville samples are also canned at the Department of Food Science Pilot Plant Facility. The process we use for canning southernpeas is similar to that used in the industry. Dry weights are recorded then soaked overnight in water. Imbibed weights are recorded after the peas are drained, blanched, and cooled. A weighed amount of peas are placed in each can; prepared brine (water, salt, and preservatives) is poured to the top of the can. The cans are sealed then cooked in a retort. The cans set a month before the tasting evaluation. For the tasting evaluation we use a minimum of 10 individuals for a consumer panel. Panelists rate pea color, liquor color, wholeness, texture, flavor, and the general appearance on a scale of 1–10, 10 being best. The industry standards are included, these are used as checks. This allows breeders to see how their lines look and taste as a canned product.

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Southernpea varieties have shown the ability to yield differently when planting dates are altered. Identification of yield potential based on planting date would allow producers to select varieties based on time of planting. Ten varieties of peas with three different maturities were selected. The ten varieties were planted on five dates over a 2-year period. Results indicate that relative days to maturity can be shortened or lengthened by time of planting. Varieties planted in early June or early August took longer to mature than when they were planted in late June or early July. Southernpeas planted between 15 June and 15 July will normally produce the highest yields. Some long-season, upright varieties can be planted as early as 1 June with no loss in yield. Indeterminate and short-season varieties in this experiment showed the ability to produce high yields when planted as late as 1 Aug. These results suggest that some southernpea varieties will respond dramatically to different environmental conditions created by altered planting dates.

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Spinach (Spinacia oleracea L.) is a highly nutritious leafy green vegetable that contains high levels of vitamins A, C, E and folate as well as minerals such as iron and calcium. Spinach is high in carotenoids, specifically lutein and β-carotene. Spinach has also been shown to have high ORAC (oxygen radical absorbency capacity) values and to have a high total flavonoids content (100 mg·kg-1). Leaves were collected from 11 commercial cultivars and 15 advanced breeding lines which were grown at the Univ. of Arkansas vegetable substation near Kibler, Arkansas. Samples were placed in polyethylene bags in ice chests and transported to the Univ. of Arkansas within 2 hours and samples were stored at -20 °C until analysis were performed. Both growing season and genotype had an effect on both ORAC and total phenolics. Over-winter spinach, which is planted in the fall and harvested in the spring, had higher total phenolics as well as higher ORAC than fall-planted fall-harvested spinach. Univ. of Arkansas breeding lines had higher average levels of total phenolics and ORAC than commercial cultivars. These data indicate that it should be possible to breed for higher antioxidant capacity in spinach. In a separate study involving the same cultivars wide variation in lutein content was observed with the cultivars F380 and Fallgreen having the highest levels. Data indicate wide variation in lutein and that breeding for increased lutein content is possible.

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Temperate zone fruit crops undergo bud dormancy which can be described as a mechanism for avoiding the exposure of tender flowers and leaves to low winter temperatures. In Kenya, apple growing is mostly hampered by inadequate chilling that causes the plants to have prolonged dormancy leading to poor flowering and consequently low yield. Although the chilling requirements are obligatory, under subtropical and especially tropical conditions avoidance is possible. To achieve this, it is necessary to select cultivars with low chilling requirements. This has proven effective in Zimbabwe with cultivar Matsu which is grown without a need for artificial breaking of dormancy. In Kenya like Zimbabwe, low chilling requiring cultivars such as Anna have been grown successfully. However, for cultivars with high chilling requirements, there is need to apply artificial techniques/methods to enhance bud break. Some of the cultural techniques used are: defoliation after harvesting and bending of the shoots holizontally. Defoliation after harvesting has particularly been used successfully in the island of Java in Indonesia and it enables two crops to be grown per year. Root chilling of rootstock has also been found to enhance bud break of the shoot. In addition, chemicals like KNO3, mineral oil and thiourea (TU) have been found to be effective in breaking bud dormancy in Kenya. This paper is reviewing the challenges encountered in growing apples in the tropics and Kenya in particular and the progress that has made in addressing them.

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Cowpea, or southernpea, is an important food legume that provides a source of high-quality protein, especially in the mature seeds. In the United States, industries exist to supply dry and processed seeds. Our aim is to develop a regeneration system for cowpea as a prerequisite for genetic engineering. Our objective was to examine the in vitro responses of shoot tips to growth regulators. Shoot tips isolated from in vitro-germinated seedlings (`Coronet') were cultured on MS medium containing 2,4-D at 0, 0.01, 0.1, or 1 mg·liter–1 and kinetin at 2.5, 5, 10, or 20 mg·liter–1. Cultures were maintained at 12-hour photoperiods and 24C. Callus, shoots, and roots or combinations thereof developed depending on the treatment. Callus formed on 1 mg 2,4-D/liter, regardless of the kinetin level, but at 0.1 mg 2,4-D/liter and 5 or 10 mg kinetin/liter, shoots also grew. Callus, shoots, and roots developed on 2,4-D lower than 0.1 mg·liter–1. Callus induced on 5 mg kinetin/liter and 0.01 mg 2,4-D/liter regenerated shoots on transfer to 5 mg kinetin/liter and 0.1 mg NAA/liter. This work may assist in the development of a micropropagation system for cowpea.

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Callus, induced in the dark from leaf tissue of spinach (Spinacia oleracea L. cv. Fall Green) on Murashige and Skoog (MS) medium supplemented with (in mg·liter -1) 2 kinetin and 0.5 2,4-D regenerated shoots upon transfer to a medium containing 2 kinetin, 0.01 2,4-D, and 1 GA3. Complete plants were established by stimulating rooting of the shoots with 1 mg IBA/liter and transferring them to potting soil; survival was 60%. Chemical names used: N-(2-furanylmethyl)-1H-purin-6-amine (kinetin); 2;4-dichlorophenoxy acetic acid (2,4-D); gibberellic acid (GA3); 1H-indole-3-butanoic acid (IBA).

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Genotype by environment (G × E) effects in Regional Cooperative Southernpea trials for the southeastern United States were investigated to characterize the extent, pattern, and potential impact of G × E on seed yield of southernpea [Vigna unguiculata (L.) Walp] genotypes. The structure of G × E effects was investigated using the Additive Main Effect and Multiplicative Interaction (AMMI) method. AMMI analyses revealed a highly significant genotype × environment interaction, most of which was partitioned into a genotype × location component of variance. AMMI first principal component axis scores stratified environments into two groups that minimized variation within groups. Biological interpretation of groupings and visual assessment of the AMMI biplot, revealed high-yielding genotypes interacting positively with one group of environments and conversely, low-yielding genotypes interacting positively with the other group. There were some significant rank changes of genotypes as yield potential varied across environments. Some environments showed similar main effects and interaction patterns indicating that most of the G × E effects could be captured with fewer testing sites, and consequently redundancy of some testing environments over years.

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Three taxa, Colletotrichum orbiculare, the unconfirmed teleomorph of C. orbiculare (Glomerella cingulata var. orbiculare), and C. magna, have been reported to cause anthracnose of cucurbits. In a previous study, virulence, vegetative compatibility, and mtDNA RFLPs have been used to examine these taxa. The three taxa can be distinguished based on mtDNA RFLPs. Under controlled greenhouse inoculation tests, only isolates of C. orbiculare (CO) from cucurbit hosts were highly virulent on cucurbit foliage; isolates of G. cingulata (GC) and C. magna (CM), and CO from cocklebur hosts were weakly virulent or avirulent. The majority of CM and GC isolates were recovered from fruit, whereas most CO isolates were recovered from foliage. A study was conducted to evaluate the pathogenicity and virulence of anthracnose isolates on cucurbit fruit. Twenty-seven isolates of the three taxa were selected based on the host and geographic origin, mtDNA RFLP haplotype, vegetative compatibility group, and race. Mature fruit from cucumber cultivars Marketer (susceptible) and H19 (resistant) and watermelon cultivars Black Diamond (susceptible) and Charleston Gray (resistant) were used. Fruit were inoculated by placing Torula yeast agar inoculum plugs (8mm in diameter) into wounds. Following inoculation, the wounds were covered with Parafilm and incubated for 8 days at 25C at 100% RH. On the third day the Parafilm was removed from the wound. Disease symptoms were evaluated by measuring lesion diameter and depth and evaluating the presence or absence of sporulation. All three anthracnose taxa are capable of infecting cucurbit fruit. CM and GC isolates were more virulent than CO isolates on cucumber. In contrast, on `Black Diamond', CO isolates were more virulent than CM and GC isolates. No significant differences in virulence were observed on `Charleston Gray'. There were no significant differences in virulence between the races of CO except on `Charleston Gray', where race 2 isolates were significantly more virulent than race 1. CO isolates from cocklebur were only weakly virulent on cucurbit fruit.

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