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Open access

Shinyoung Kim, Stephen L. Meyers, Juan L. Silva, M. Wesley Schilling, and Lurdes Siberio Wood

A traditional dairy-based frozen dessert (ice cream) was developed with three levels of sweetpotato (Ipomoea batatas) puree [20%, 30%, and 40% (by weight)] to determine the impact of sweetpotato content on product functionality, nutritional content, and sensory characteristics. Increased sweetpotato puree resulted in increased orange color, flavor intensity, and sweetpotato flavor, but 40% puree proved difficult to incorporate into the mixture. Additionally, nondairy frozen desserts containing 30% sweetpotato puree were compared with a milk-based control in which all ingredients were the same except that milk was replaced with soy (Glycine max) and almond (Prunus dulcis) milk. Consumer acceptability tests were conducted with panelists at Mississippi State University (n = 101) and in Pontotoc, MS (n = 43). Panelists in Pontotoc rated the overall acceptability of all three frozen desserts the same, but they preferred the appearance of the milk-based frozen dessert over that of soy- and almond-based milk alternatives. According to the panelists at Mississippi State, the milk-based frozen dessert had greater overall acceptability and aroma than the almond-based dessert and a preferential texture and appearance compared with the soy- and almond-based desserts. Milk-, soy-, and almond-based frozen desserts were rated as “slightly liked” or better by 92%, 80%, and 69% of the panelists, respectively.

Open access

Trent M. Tate, Stacy A. Bonos, and William A. Meyer

Fine fescues (Festuca sp.) are a group of species that require fewer inputs, such as fertilizer, than other cool-season species managed for turf. They are adapted to infertile, acidic soils; shade; and drought. One area that poses additional challenges is the lack of weed control options for fine fescues during establishment from seed. Mesotrione is a herbicide that provides preemergence control of many broadleaf and grassy weeds, such as annual bluegrass (Poa annua), but is currently not labeled for use in fine fescues at seeding. The objectives of this research were 1) to use a recurrent selection technique to develop mesotrione-tolerant chewings fescue (Festuca rubra ssp. commutata), hard fescue (Festuca brevipila), and strong creeping red fescue (F. rubra spp. rubra); and 2) to conduct field trials to compare the new selections to commercially available cultivars and experimental lines not selected for tolerance to mesotrione. Progress was made after each of the three generations of recurrent selection. The top statistical grouping of entries for injury following application of mesotrione at the 8-oz/acre rate included all the third-generation (G3) hard fescues, all the G3 chewings fescues, and the G3 strong creeping red fescue STB1 Composite. After three generations, selections of hard, chewings, and strong creeping red fescues had equivalent or better tolerance to mesotrione than tall fescue (Festuca arundinacea) and kentucky bluegrass (Poa pratensis) cultivars, which are on the label for safe use at seeding. These new selections would provide turf managers an option to control weeds using mesotrione during seedling establishment of fine fescues.

Open access

Jianlu Zhang and Trevor Ranford

The methodology of r contour mapping was used in this study of ‘Sirora’ pistachio (Pistacia vera) to establish whether there are any significant relationships between fruit quality characteristics in commercial pistachio production and air temperature in the year before the harvest of the crop as measured at a nearby meteorological station. The work was done near Mildura in Australia. Blank nut percentages were found to be reduced by lower minimum temperatures in mid to late August (southern hemisphere). The percentage of narrow-split nuts was decreased by higher maximum temperatures across almost the whole growing season. Damaged-shell nuts were reduced by higher average daily minimum temperatures between 26 Nov. and 3 Feb. The technique of r contour mapping is shown to have potential as a way to provide early warning of possible quality problems before harvest and as a means of generating hypotheses for future physiological studies

Open access

Stephanie E. Burnett, Bryan J. Peterson, and Marjorie Peronto

The novel propagation system submist, which applies water to the bases of cuttings rather than overhead, is a promising alternative. We developed and tested a commercial-scale submist system to make this propagation system more accessible to commercial propagators. Five species, including blue star flower (Amsonia tabernaemontana), faassen nepeta (Nepeta ×faassenii ‘Six Hills Giant’), panicle hydrangea (Hydrangea paniculata ‘Grandiflora’), sweetgale (Myrica gale), and sweetfern (Comptonia peregrina), were propagated from cuttings in commercial-scale submist and overhead mist systems. Blue star flower and faassen nepeta cuttings had greater root length, root rating, and root number with the submist system. Panicle hydrangea cuttings had more roots in submist, but longer roots in overhead mist. There were no differences in rooting between the systems for sweetgale and sweetfern cuttings. The comparable or superior rooting of these five species in a submist system compared with traditional overhead mist systems is evidence that submist is a viable alternative propagation system. Water use in submist systems was 98% less than that for overhead mist systems.

Open access

Yue Wen, Shu-chai Su, Ting-ting Jia, and Xiang-nan Wang

The periods of flower bud differentiation and fruit growth for Camellia oleifera overlap greatly affect the allocation of photoassimilates to flower buds and fruit, resulting in obvious alternate bearing. To export the cause and mitigate alternate bearing of Camellia oleifera, the allocation of photoassimilates to buds and fruit supplied by leaves at different node positions was studied by the addition of labeled 13CO2 during the slow fruit growth stage. The fate of 13C photoassimilated carbon was followed during four periods: slow fruit growth (4 hours and 10 days after 13C labeling); rapid growth (63 days after 13C labeling); oil conversion (129 days after 13C labeling); and maturation (159 days after 13C labeling). Photosynthetic parameters and leaf areas of the leaves shared a common pattern (fifth > third > first), and the order of photosynthetic parameters of different fruit growth stages was as follows: oil conversion > maturation > rapid growth > slow growth. The most intense competition between flower bud differentiation and fruit growth occurred during the oil conversion stage. Dry matter accumulation in different sinks occurred as follow: fruit > flower bud > leaf bud. Photoassimilates from the labeled first leaf were mainly translocated to the first flower bud, and the upper buds were always differentiated into flower buds. The photoassimilates from the labeled third leaf were distributed disproportionately to the third flower bud and fruit. They distributed more to the third flower bud, and the middle buds formed either flower or leaf buds. However, the photoassimilates from the labeled fifth leaf were primarily allocated to the fruit that bore on the first node of last year’s bearing shoot, and basal buds did not form flower buds. Based on our results, the basal leaves should be retained for a high yield in the current year, and the top leaves should be retained for a high yield in the following year. Our results have important implications for understanding the management of flower and fruit in C. oleifera. The thinning of fruit during the on-crop year can promote flower bud formation and increase the yield of C. oleifera crops in the following year. During the off-year, more fruit should be retained to maintain the fruit yield. The thinning of middle-upper buds could promote more photoassimilates allocate to the fruit.

Open access

Nathan J. Eylands, Michael R. Evans, and Angela M. Shaw

Various saponins have demonstrated allelochemical effects such as bactericidal impacts as well as antimycotic activity against some plant pathogenic fungi, thereby acting to benefit plant growth and development. A commercial saponin solution was evaluated for bactericidal effects against Escherichia coli and growth of lettuce (Lactuca sativa) in a hydroponic system. E. coli (P4, P13, and P68) inoculum at final concentration of 108 colony-forming units (cfu)/mL was added to 130 L of a fertilized solution recirculating in a nutrient film technique (NFT) system used to grow ‘Rex’ lettuce. After 5 weeks in the NFT system, E. coli populations were lowest in the inoculated treatment that did not contain any saponin addition (0.89 log cfu/mL) when compared with all other inoculated treatments (P < 0.001). The treatment containing 100 µg·mL−1 saponin extract had an E. coli population of 4.61 log cfu/mL after 5 weeks that was higher than treatments containing 25 µg·mL−1 or less (P < 0.0001). Thus, higher E. coli populations were observed at higher saponin concentrations. Plant growth was also inhibited by increasing saponin concentrations. Fresh and dry shoot weight were both higher in the inoculated and uninoculated treatments without the saponin addition after 5 weeks in the NFT system (P < 0.0001). Lettuce head diameter was smaller when exposed to saponin treatments with concentrations of 50 and 100 µg·mL−1 (P < 0.0001). Lettuce leaves were also tested for the potential of E. coli to travel systemically to the edible portions of the plant. No E. coli was found to travel in this manner. It was concluded that steroidal saponins extracted from mojave yucca (Yucca schidigera) are not an acceptable compound for use in mitigation of E. coli in hydroponic fertilizer solution due to its ineffectiveness as a bactericide and its negative impact on lettuce growth.

Open access

Maxym Reva, Custodia Cano, Miguel-Angel Herrera, and Alberto Bago

Global climate change is increasing temperatures worldwide, which greatly affects all biological relationships. Plant and soil ecosystems are also suffering in this new scenario, especially in semi-arid areas where water resources are limited. Regarding agricultural crops, temperatures that increase dramatically negatively affect fruit production and quality, making it mandatory to find sustainable practices to cope with these new situations. Symbiotic microorganisms in general and arbuscular mycorrhizal fungi in particular have been revealed as promising methods of alleviating stress that are respectful of the environment and soil equilibrium. In this work, we demonstrate the suitability of an ultra-pure, in vitro-issued arbuscular mycorrhizal inoculant for alleviating severe heat stress when applied to three important agricultural crops (tomato: Solanum lycopersicum L.; pepper: Capiscum annuum L.; cucumber: Cucumis sativus L.) under agronomic conditions. Inoculated plants had greatly improved endurance under heat stress because of increased vigor, productivity, and fruit quality. Considering the actual scenario of global climate change, our results shed a light of hope and indicate more sustainable cultivation practices adapted to global change.

Open access

Paul M. Lyrene

Vaccinium stamineum (deerberry) is a highly variable diploid species in section Polycodium. Deerberry is native on excessively drained sandy soils from southeastern Ontario, south through the Florida peninsula to Lake Okeechobee, west to eastern Texas and southeastern Kansas. The V. stamineum used in this study were tall plants (2–4 m) native in north Florida, with a plant architecture similar to rabbiteye blueberry (V. virgatum). Starting in 2013 with crosses between tetraploid highbush cultivars (section Cyanococcus) and colchicine-doubled V. stamineum, hundreds of F1 and thousands of later-generation seedlings were grown and evaluated in high-density field nurseries at Citra in North Florida. The populations studied included F1, F2, backcrosses to each parent species, and BC1 × BC1 seedlings. The goal of the study was to assess the feasibility of introgressing into highbush blueberry cultivars desirable traits from V. stamineum (drought tolerance, red-flesh berries, new flavor components, open flowers with short corolla cups and exserted anthers and stigmas) without introducing horticulturally problematic characteristics (bitter skin, berries that shatter when ripe, difficult vegetative propagation). Vigor averaged very low in F1 seedlings, higher in F2 seedlings and in seedlings from backcrosses to V. stamineum, and highest in seedlings from backcrosses to highbush. Most crosses yielded numerous plump seeds, but crosses to produce F1 hybrids yielded fewer than 10% as many seeds as highbush × highbush crosses. Most vegetative, flower, and fruit traits that differentiate highbush from V. stamineum were intermediate in F1 seedlings. Backcross seedlings more closely resembled the recurrent parent. Variability in morphological characters was high in every generation, giving much opportunity for selection. Some seedlings from backcrosses to highbush (≈5%) appeared to have the vigor, berry quality, and yield potential required in commercial cultivars. Producing highbush cultivars that strongly express a particular V. stamineum trait might best be accomplished by growing large, segregating F2 populations from which parents for backcrosses can be selected.

Open access

Annika E. Kohler and Roberto G. Lopez

Domestic production of culinary herbs continues to increase in the United States. Culinary herbs are primarily propagated by seed; however, some herbs have poor germination rates and slow growth. Thus, there are advantages of propagating herbs by vegetative stem-tip cuttings as they lead to true-to-type plants and a shortened production time. Previous research of ornamental young plants and finished culinary herbs have shown a reduction in rooting time and increases in plant quality with increases in the photosynthetic daily light integral (DLI). To our knowledge, little to no research has addressed how the DLI influences culinary herb liner quality. Therefore, the objectives of this study were to quantify morphological traits of five economically important culinary herbs when grown under DLIs ranging from 2.8 to 16.4 mol·m−2·d−1. Stem-tip cuttings of Greek oregano (Origanum vulgare var. hirtum), rosemary ‘Arp’ (Rosmarinus officinalis), sage ‘Extrakta’ (Salvia officinalis), spearmint ‘Spanish’ (Mentha spicata), and thyme ‘German Winter’ (Thymus vulgaris) were excised from stock plants and rooted under no shade or aluminum shading of 36%, 56%, or 76% to create a range of DLI treatments. After 9 days (spearmint) or 16 days (all other genera) of DLI treatments, the root, shoot, and total dry mass of all culinary herb liners generally increased by 105% to 449%, 52% to 142%, and 82% to 170%, respectively, as the DLI increased from 2.8 to 16.4 mol·m−2·d−1 or genus-specific DLI optimums. Stem length of oregano, spearmint, and thyme decreased by 37%, 28%, and 27%, respectively, as the DLI increased from 2.8 to 16.4 mol·m−2·d−1. However, stem length of rosemary and sage were unaffected by the DLI. The quality index of all genera was greatest at DLIs from 10.4 to 16.4 mol·m−2·d−1. Furthermore, all culinary herbs grown under a DLI of ≤6 mol·m−2·d−1 had low root and shoot dry mass accumulation; and oregano, spearmint, and thyme were generally taller. Therefore, DLIs between 10 to 12 mol·m−2·d−1 should be maintained during culinary herb propagation, because a DLI ≥16 mol·m−2·d−1 may be deleterious and energy inefficient if supplemental lighting use is increased.

Open access

Orlando F. Rodriguez Izaba, Wenjing Guan, and Ariana P. Torres

Cucumber (Cucumis sativus) is one of the most important vegetables produced and consumed in the United States. In the midwestern United States, a major obstacle to spring cucumber production is low soil temperatures during plant establishment. High tunnel is a popular tool for season extension of vegetable production. Low soil temperature is a challenge for cucumber production even inside high tunnels. Grafting is a cultural practice known to help control soilborne diseases and improve plants’ tolerance to abiotic stresses. Recent studies found that using grafted cucumber plants with cold-tolerant rootstocks greatly benefited early-season seedless cucumber production in high tunnels. The objective of this study was to analyze the economic feasibility of growing grafted cucumber in high tunnels. A comparison of partial costs and returns between growing grafted and nongrafted cucumbers in a high tunnel in Vincennes, IN, was conducted. Data were used to develop a partial budget analysis and sensitivity tests. Data included production costs, marketable yield, and price of cucumber through different market channels. This study provided a baseline reference for growers interested in grafting seedless cucumber and for high tunnel production. Although costs of grafted transplants were higher, their yield and potential revenue helped to offset the higher costs. Results indicated that grafting can help farmers increase net returns through the increasing yield of grafted plants. Results from the sensitivity analysis illustrated how the increased yield of grafted cucumbers offsets the extra cost incurred in the technique while providing a higher revenue. While actual production costs for individual farmers may vary, our findings suggested that grafting can be an economically feasible tool for high tunnel seedless cucumber production.