bluuebunny/crossref_metadata_2025 huggingface dataset:
Ripening Behavior and Quality of `Brazilian' Bananas following Hot Water Immersion to Disinfest Surface Insects
Authors: Wall Marisa M.
Published: February 2019

The fruit quality and ripening response of `Brazilian' bananas (Musa sp., group AAB) were determined following hot water immersion treatments for surface disinfestation. Summer-harvested fruit were exposed to 47, 49, or 51 °C water for 10, 15 and 20 minutes and ripened at 20 °C. The summer experiment established the exposure time and temperature limits for fruit injury. Winter-harvested fruit were immersed in 48, 49, or 50 °C water for 5, 10 and 15 minutes, stored for 12 d at 14 °C, and ripened at 22 °C. The hot water exposure time had a greater effect than the water temperature on banana fruit ripening. Nontreated bananas ripened after 13 to 15 d, and ripening was delayed by 2 to 7 d when fruit were exposed for 15 or 20 minutes to hot water. Hot water treatments did not inhibit pulp softening, but peels tended to be firmer for bananas immersed in 49 to 51 °C water than control fruit. Heat-treated bananas were not different from control fruit in soluble solids content or titratable acidity, however the conversion of starch to sugars was reduced at higher temperatures and exposure times. Bananas exposed for 20 minutes to hot water had delayed respiratory peaks and ethylene production, especially at 51 °C. Mild peel injury was observed on fruit exposed to higher temperatures (49 to 51 °C) for longer durations (15 or 20 minutes).
Somatic Embryogenesis and Plant Regeneration from in-vitro-grown Leaf Explants of Rose
Authors: Kim C.K. , Oh J.Y. , Chung J.D. , Burrell A.M. , Byrne D.H.
Published: February 2019

Somatic embryogenesis was initiated from in vitro-grown leaf explants of rose using an induction period of 4 weeks on MS basal medium supplemented with auxin followed by several subcultures on MS basal medium with cytokinin. `4th of July' showed the highest regeneration frequency (24.4%) on 5.3 μm NAA followed by culture on medium containing 18.2 μm zeatin. `Tournament of Roses' produced somatic embryos when cultured for 4 weeks on medium containing dicamba, 2.3 μm followed by three subcultures on medium containing 18.2 μm zeatin. Embryogenic callus matured on MS media containing 0.5 μm NAA, 6.8 μm zeatin, and 2.9 μm GA3. Long-term cultures were established for both cultivars. Somatic embryos germinated on MS medium containing IBA and BA. Silver nitrate (58.8 μm) enhanced shoot formation and germination of somatic embryos. Plants derived from somatic embryos were acclimatized and successfully established in the greenhouse.
Plant Regeneration and an Analysis of Somaclonal Variation from TifEagle and TifSport Bermudagrass Cultivars
Authors: Goldman Jason J. , Hanna Wayne W. , Ozias-Akins Peggy
Published: February 2019

`TifEagle' (2n = 3x = 27) hybrid bermudagrass [Cynodon dactylon (L.) Pers. (2n = 4x = 36) × Cynodon transvaalensis Burtt-Davy (2n = 2x = 18)] is an ultradwarf cultivar for greens, and `TifSport' (2n = 3x = 27) is a more versatile hybrid used on fairways, athletic fields, and lawns. To develope a transformation system and determine if somaclonal variation was present in regenerated plants, both cultivars were tested for their ability to produce embryogenic callus from which plants could be regenerated. Sliced nodes of both cultivars and immature inflorescences from `TifSport' were used as the explant sources. Cultures were initiated on Murashige and Skoog medium supplemented with 6.79 μm 2,4-D and 0.044 μm BA (`TifSport' and `TifEagle') or 6.79 μm 2,4-D plus 200 mg.L-1 casein hydrolysate (`TifSport'). In total, 51 plants were regenerated from callus of a single node of `TifEagle'. Nodes from `TifSport' did not produce embryogenic callus. In total, 29 plants were regenerated from callus of `TifSport' produced from immature inflorescences. These plants were grown in the field for at least one season, and 5-cm-diameter plugs were harvested, repotted in a greenhouse, and allowed to reestablish. Data on canopy height, leaf width, leaf length, and number of stolons were collected. Seven `TifEagle'-derived entries (14%) were not significantly different (α = 0.05) from `TifEagle' harvested from the breeder plot in Tifton, Ga., for all measured traits, and 41%, 24%, and 22% differed by one, two, or three measurements, respectively. Flow cytometry indicated that 33% (13 plants) of the `TifEagle' regenerants were hexaploid (2n = 6x = 54) and the rest remained triploid. One `TifSport' regenerant was significantly different (α = 0.05) for plant height.
Commercial Application of a Photoautotrophic Micropropagation System Using Large Vessels with Forced Ventilation: Plantlet Growth and Production Cost
Authors: Xiao Yulan , Kozai Toyoki
Published: February 2019

A photoautotrophic or sugar-free medium micropropagation system (PAM) using five large culture vessels (volume = 120 L each) with a forced ventilation unit for supplying CO2-enriched air was developed and applied to commercial production of calla lily (Zantedeschia elliottiana) and china fir (Cunninghamia lanceolata) plantlets. The culture period of calla lily plantlets in the PAM was reduced by 50%, compared with that in a conventional, photomixotrophic micropropagation system (PMM) using small vessels each containing a sugar-containing medium. Percent survival ex vitro of calla lily plantlets from the PAM was 95%, while that from the PMM was 60%. The production cost of calla lily in the PAM was reduced by about 40%, compared with that in the PMM, and the initial investment per plantlet for the PAM was ≈10% lower than that for the PMM. The sales price of ex vitro acclimatized calla lily plantlet was increased by 25% due to its higher quality, compared with plantlets produced in the PMM.
Improved Rooting of Gisela-5 Softwood Cuttings following Banding and IBA Application
Authors: Gulen Hatice , Erbil Yasar , Eris Atilla
Published: February 2019

A stock plant etiolation treatment was tested to improve rooting of the important cherry rootstock Gisela-5. To create the etiolation effect, at the beginning of the growing season, banding (blanching) was initiated on stock plants by placing black plastic tape at the base of new shoots for 6 or 10 weeks. Cuttings were excised so that the banded area was at the cutting base. IBA was applied at two concentrations (5 and 10 mm) to the cutting base following wounding and cuttings were placed in perlite (100%) rooting medium under mist. The rooting percentage, number of roots per cutting and root length were measured 4 weeks after planting. Banding and duration significantly stimulated rooting of leafy softwood cuttings. The highest rooting percentage (80.0%) was obtained on cuttings banded for 6 weeks and treated with 5 mm IBA.
Nitrogen Dynamics in the Olive Bearing Shoot
Authors: Fernández-Escobar R. , Moreno R. , Sánchez-Zamora M.A.
Published: February 2019

Olive shoots were collected at monthly intervals during an off and an on year from nonirrigated, mature `Picual' olive trees fertilized or nonfertilized with nitrogen. Young and mature leaves and stems and flowers and fruit developed during the on year were removed separately from the shoots to determine N concentration and N content per organ. N concentration decreased in young leaves and stems in spring and summer, and increased during the autumn in both off and on years. N concentration in old leaves and stems remained almost constant during the off year, and drops from April to October during the on year. The new tissues accumulated N during the off year and mobilized it during the on year to support growth. Leaves stored larger amounts of N than stems, and fruit developed during the on year became the main sink for N of the bearing shoot. Although the adjacent, mature leaves may have supported part of the N demand from the fruit, nitrogen must also have been mobilized from other storage organs to support fruit growth. No differences between fertilizer treatments were observed in the allocation pattern of N, although N reserves increased in shoots of fertilized trees.
Response of Pecan to Nitrogen Rate and Nitrogen Application Time
Authors: Smith Michael W. , Cheary Becky S. , Carroll Becky L.
Published: February 2019

Nitrogen was applied between 1996 and 2002 to grafted `Mohawk' pecan (Carya illinoinensis Wangenh. C. Koch.) trees at 75 or 150 kg·ha-1 either as a single application in March or as a split application with 60% applied in March and 40% the first week of June. In 1997 and 2001, a spring freeze damaged developing shoots and buds, resulting in a small, noncommercial crop and the June portion of the N application was withheld. Nitrogen was also applied during the first week in October at 0 or 50 kg·ha-1 N if the crop load before fruit thinning in August was ≥40% fruiting shoots. There were few differences in the percentage of fruiting shoots or cluster size associated with N rate or applying N as a single or split application. Leaf N concentrations were either not affected by treatment or the results were inconsistent. Omitting the June application when a crop failure occurred did not affect the percentage of fruiting shoots the following year. October N application either did not affect or reduced the percentage of fruiting shoots the following year, and had no influence on leaf N concentration in July or October. These results indicate that the only advantage of a split N application is the option of withholding the second portion in the event of a crop failure. However, the added expense associated with splitting the N application versus the risk of crop failure must be assessed for each situation to determine if this is a sound economic practice. These data do not support an October N application when the crop is ≥40% fruiting shoots to reduce irregular bearing.
Sodium Chloride in Nutrient Solutions Can Affect Onion Growth and Flavor Development
Authors: Chang Pai-Tsang , Randle William M.
Published: February 2019

Onion is classified as a salt-sensitive crop, though it is found in production on saline soils around the world. While onion flavor intensity has been studied in response to various growing conditions, little is known about its response to salt stress. To understand if NaCl affects growth, flavor development, and mineral content in onion, `Granex 33' plants were grown to maturity with six different concentrations of NaCl ranging from 0 (control) to 125 mm in nutrient solutions. NaCl affected onion fresh weight and altered onion flavor intensity and quality. Plants did not survive the 125 mm NaCl treatments and are not included in the results. As bulb Na+ and Cl- content increased in response to increasing NaCl concentrations, leaf and bulb fresh weight of mature plants decreased. Total bulb S content also decreased with increasing NaCl solution concentrations, while bulb SO42- content increasing linearly, indicating that less S was entering the S metabolic stream. Though bulb soluble solids content was not influenced by NaCl concentrations, pungency increased, but only at the highest NaCl concentration. Total flavor precursors and methyl cysteine sulfoxide content increased in response to NaCl, but only at the 100 mm treatment. 1-Propenyl cysteine sulfoxide was generally unresponsive to the salt treatment. Propyl cysteine sulfoxide content decreased then increased in responses to increasing NaCl levels, but was found as a minor flavor precursor. Peptide intermediates measured in the pathway leading to 1-propenyl cysteine sulfoxide and propyl cysteine sulfoxide decreased linearly with increasing NaCl exposure. While NaCl affected onion flavor in this study, severe reductions in growth would prevent onion production under similar saline conditions. For practical purposes, the effects of NaCl on flavor are, therefore, minimal.
Soil Pasteurization and Mycorrhizal Inoculation Alter Flower Production and Corm Composition of Brodiaea laxa `Queen Fabiola'
Authors: Scagel C.F.
Published: February 2019

The ornamental flowering bulb Brodiaea laxa Benth. `Queen Fabiola' was grown with or without arbuscular mycorrhizal fungal (AMF) inoculum in pasteurized or nonpasteurized soil to determine if inoculation altered flower and corm production. The first growing cycle after planting, mycorrhizal inoculation decreased the days to anthesis and increased the number of flowers produced per inflorescence and flower longevity. It also affected the quality of the daughter corm, which influenced flowering the following year. Inoculated plants produced larger daughter corms and more cormels than uninoculated plants, and allocated more biomass to the corms than the cormels, which lowered the average weight of the cormels. Corms produced by inoculated plants also had higher concentration of nitrogen, potassium, zinc, and nonreducing sugars than those produced by uninoculated plants. The beneficial effects of AMF inoculation on flowering and corm/cormel production were generally increased by soil pasteurization. The results indicate that mycorrhizal inoculation may enhance commercial cut flower and corm production of this crop.
Effect of Dazomet on Annual Bluegrass Emergence and Creeping Bentgrass Establishment in Putting Green Turf
Authors: Landschoot Peter J. , Park Bradley S. , McNitt Andrew S. , Fidanza Michael A.
Published: February 2019

Fumigation of annual bluegrass (Poa annua L.)-infested putting greens before seeding creeping bentgrass (Agrostis stolonifera L.) prevents stand contamination due to annual bluegrass seedling emergence. Dazomet is a soil fumigant labeled for use in putting green renovation; however, limited data are available on efficacy of dazomet controlling annual bluegrass seedling emergence following surface-applications. The objectives of this study were to determine the influence of rate and plastic covering of surface-applied dazomet on annual bluegrass seedling emergence in putting green turf; and safe creeping bentgrass seeding intervals following applications of dazomet to putting green surfaces. Treatments were applied in late summer to the surface of a 20-year-old stand of turf maintained as a putting green and plots were watered immediately after application and throughout each test period. Plastic-covered dazomet treatments had fewer annual bluegrass seedlings than noncovered dazomet treatments. Three plastic-covered dazomet treatments (291, 340, and 388 kg·ha-1) provided complete control of annual bluegrass seedlings during 2000 and 2001. None of the noncovered dazomet treatments provided complete control of annual bluegrass seedling emergence. Results of the seeding interval experiment revealed that creeping bentgrass seedling development was not inhibited in both plastic-covered and noncovered dazomet treatments, when seeded 8, 10, 13, and 16 d after dazomet was applied to the turf surface. Results of this study demonstrate that dazomet, applied at rates ≥291 kg·ha-1 to the surface of a putting green in summer and covered with plastic for 7 d, can control annual bluegrass seedling emergence. Chemical name used: tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione (dazomet).
Assessing the Resistance of Red Raspberry (Rubus idaeus L.) Genotypes to Phytophthora fragariae var. rubi in Hydroponic Culture
Authors: Pattison J.A. , Wilcox W.F. , Weber C.A.
Published: February 2019

A hydroponic method was developed and tested for screening red raspberry genotypes for resistance to Phytophthora fragariae var. rubi, the most common causal agent of Phytophthora root rot in raspberry. Plants of `Titan' and `Encore' exhibited typical disease symptoms, with the latter developing significantly smaller stem lesions and fewer petiole lesions. The resistant cultivar, `Latham', regenerated healthy root tissue from the crown and older-order roots after initial infection and necrosis of young roots and exhibited no other symptoms beyond minor leaf chlorosis. This component of the resistance reaction has not been documented previously. A segregating F1 population from the cross of `Latham' × `Titan' had a survival rate of 56% with 42% classified as resistant, exhibited minimal symptoms, and produced varying amounts of healthy root tissue. This screening method allows multiple observations of all plant tissues, including roots, under repeatable and definable growth chamber conditions. It should be useful for classifying the phenotype of individuals in segregating red raspberry populations to investigate the inheritance of Phytophthora root rot resistance using molecular markers.
Influence of Daughter Plant Weight and Position on Strawberry Transplant Production and Field Performance in Annual Plasticulture
Authors: Takeda Fumiomi , Hokanson Stan C. , Enns John M.
Published: February 2019

Strawberry (`Chandler') plants were grown in a greenhouse hydroponic culture system from 28 Apr. to 20 July to produce runners (stolons) with several daughter plants. By mid-July, each `Chandler' plant had developed about 30 daughter plants on 12 runners with 1 to 6 daughter plants on each runner. Daughter plants varied in weight from <0.9 to >10 g. Daughter plant weight and position on the runner affected new root development on plug plants during the first 7 days under mist irrigation. At 3 weeks, 87% of daughter plants that weighed <0.9 g and at least 96% of daughter plants that weighed >1.0 g were rated acceptable for field transplanting, respectively. The percentage of daughter plants from second to tenth node position that were rated acceptable for field planting ranged from 98% to 88%, respectively. Runner production in the fall was not affected by either position on the runner or weight at the time of daughter plant harvest. But, larger daughter plants produced more branch crowns than did smaller daughter plants in the fall. Transplant survival in the field was 100%. In the spring, `Chandler' plants produced a 10% greater yield from daughter plants that weighed 9.9 g compared to those that weighed only 0.9 g.
Pattern of Exotherm and Electrolyte Leakage Measured at High Frequency of Satsuma Mandarin Exposed to Subfreezing Temperatures
Authors: Ebel R.C. , Carter P.A. , Dozier W.A. , Findley D.A. , Nesbitt M.L. , Hockema B.R. , Sibley J.L.
Published: February 2019

The current study was conducted to relate ice formation to the pattern and rate of leaf and stem injury of Satsuma mandarins on trifoliate orange rootstock. Potted trees were unacclimated, moderately acclimated or fully acclimated by exposing trees to 32/21 °C, 15/7 °C or 10/4 °C, respectively. Freezing treatments consisted of decreasing air temperature at 2 °C·h-1 until ice formed as evidenced by exotherms determined using differential thermal analysis of stems. Air temperature was then decreased, held constant, or increased and held constant to simulate severe, moderate and mild freeze conditions, respectively. All treatment exhibited exotherms at -2 to -4 °C, which were smaller with milder freezing treatments. Only the fully acclimated trees exhibited multiple exotherms. Leaf watersoaking, an indication of ice formation, occurred concurrently with stem exotherms except for fully acclimated trees where there was up to a 30-min delay and which corresponded with the second exotherm. Electrolyte leakage of leaves began to increase near the peak of the stem exotherm, but increased more slowly with milder freezing temperature treatments. In some treatments, electrolyte leakage reached a plateau near 50% but leaves survived. Leaves died when whole-leaf electrolyte leakage exceeded 50%. These data are discussed within the framework of a proposed mechanism of injury of Satsuma mandarin leaves by subfreezing temperatures, especially multiple exotherms of fully acclimated trees, and the plateau of electrolyte leakage of leaves at the critical level for survival.
Efficacy of Heat-based Treatments in Eliminating the Recovery of the Sudden Oak Death Pathogen (Phytophthora ramorum) from Infected California Bay Laurel Leaves
Authors: Harnik Tamar Y. , Mejia-Chang Monica , Lewis James , Garbelotto Matteo
Published: February 2019

Phytophthora ramorum (Oomycota) (Werres et al., 2001) is the plant pathogen responsible for the lethal disease of several oak species in California known as sudden oak death. The pathogen also causes a foliar disease on Umbellularia californica (bay laurel or simply bay). Bay leaves have been identified as the major source of natural inoculum in California coastal woodlands. Because of the epidemiological relevance of bay leaves, their movement needs to be regulated. Our study shows that P. ramorum is highly heat tolerant and can be reisolated from artificially inoculated bay laurel leaves placed at 55 °C for up to 1 week. The pathogen cannot be recovered after 2 weeks at 55 °C. Prolonged heat treatments, however, are impractical for bay leaves intended to be sold commercially as a spice, since they negatively impact the quality of the leaves. Here we describe a treatment involving a progressive and gradual heating process combined with the application of moderate vacuum. This method can be completed in 22 hours and is shown here to eliminate the recovery of P. ramorum without having a negative impact on the quality of the bay leaves.
Survey of Arbuscular Mycorrhizal Fungal Communities in Northern California Vineyards and Mycorrhizal Colonization Potential of Grapevine Nursery Stock
Authors: Cheng Xiaomei , Baumgartner Kendra
Published: February 2019

Indigenous arbuscular mycorrhizal (AM) fungal communities were characterized by examining spores in five fumigated and five nonfumigated vineyards in Northern California. None of the vineyards surveyed lacked spores, but species composition differed among the vineyards. Most of the fungi were in the genus Glomus; Paraglomus occultum Morton & Redecker, G. etunicatum Becker & Gerd., and G. aggregatum Schenck & Smith emend. Koske were the most common species identified. Fungal diversity was greater in nonfumigated than in fumigated vineyards. Field-propagated grapevine nursery stock was examined as a potential source of AM fungi for fumigated vineyards. We quantified fungal colonization of new roots initiated from field-grown benchgrafts and potted benchgrafts of Cabernet Sauvignon on three rootstocks (101-14, 110R, and St. George). After 7 months of growth in the greenhouse, new roots initiated from dormant roots of field-grown and potted benchgrafts were colonized by AM fungi. Mycorrhizal colonization of new roots of field-grown benchgrafts was significantly higher than that of potted benchgrafts. Our results suggest that field-propagated nursery stock can serve as a source of AM fungi and may be better suited for fumigated and/or low phosphorus soils than potted benchgrafts.
Fertigation Method Affects Performance of `Lapins' Sweet Cherry on Gisela 5 Rootstock
Authors: Neilsen Gerry , Kappel Frank , Neilsen Denise
Published: February 2019

`Lapins' sweet cherry (Prunus avium L.) trees on Gisela 5 (Prunus cerasus × Prunus cansecens) rootstock were maintained for the first four growing seasons with eight different fertigation treatments. Treatments involved N application at low (42 mg·L-1), medium (84 mg·L-1), and high (168 mg·L-1) concentrations via sprinkler-fertigation of Ca(NO3)2 each year about 8 weeks after bloom. The medium N treatment was also applied with P fertigation in early spring or with K fertigation in June. Nitrogen was also broadcast in early spring at 75 kg·ha-1 or followed with medium N sprinkler-fertigated postharvest in August. As a final treatment the medium root zone N concentration was maintained for 8 weeks postbloom via drip fertigation. Throughout the study, irrigation was scheduled to meet evaporative demand based on an electronic atmometer. Drip fertigation, which wet a smaller portion of the orchard floor, considerably reduced per-tree water applications. Tree vigor and pruning weights were reduced for drip-fertigated as compared to sprinkler-fertigated trees although cumulative yield was not significantly different during the study. Fruit size, however, was smaller for this treatment when crop load was at a maximum at year 4. Future research is warranted to insure fruit size can be maintained for heavily cropping drip-fertigated trees. Leaf and fruit N increased linearly as N concentration of sprinkler-fertigating solution increased from low to high values. Optimum yield and highest fruit quality were associated with the medium N treatment. Sprinkler fertigation of P and K did not increase leaf and fruit concentration of either nutrient or meaningfully affect tree performance.
Turfgrass Monoculture, Cool-Cool, and Cool-Warm Season Seed Mixture Establishment and Growth Responses
Authors: Salehi Hassan , Khosh-Khui Morteza
Published: February 2019

Turfgrass seeds can be sown individually, in mixes, or overseeded to provide green color and uniform surfaces in all the seasons. This investigation was conducted to compare different turfgrass species and their seed mixtures. In this research, the turfgrasses—perennial ryegrass (Lolium perenne L. `Barball'), kentucky bluegrass (Poa pratensis L. `Merion'), common bermudagrass (Cynodon dactylon [L.] Pers.), and strong creeping red fescue (Festuca rubra L. var. rubra `Shadow')—in monoculture or in mixtures of 1:1 (by weight) and a 1:1:1:1 (by weight) and two sport turfgrasses—BAR 11 (Barenbrug Co.) and MM (Mommersteeg Co.)—were used. The seeds were sown in March and October (spring and fall sowing) in 1998 and 1999. The experiments were conducted in a split-split block design with year as main plot, sowing season as subplot, and turfgrass types as subsubplot. The turfgrasses were compared by measuring visual quality, chlorophyll index after winter and summer, rooting depth, verdure and/or root fresh and dry weight, tiller density, and clippings fresh and dry weight. Fall sowing was superior to spring sowing and resulted in greater root growth, clipping yield, and chlorophyll content. Poa+Cynodon seed mixture was the best treatment and had high tiller density, root growth, and chlorophyll content. Lolium and Festuca monocultures, and Poa+Festuca and Cynodon+Festuca seed mixtures were not suitable with regard to low tiller density, sensitivity to high temperatures, low root growth, and low tiller density, respectively. The cool-warm-season seed mixture (Poa+Cynodon) can be used alternatively in overseeding programs in the areas with soil and environmental conditions similar to this research site.
Regional Differences in the Relative Competitive Ability of Annual Bluegrass (Poa annua L.)
Authors: McGuan M.J. , Danneberger T.K. , Gardner D.S.
Published: February 2019

Annual bluegrass (Poa annua L.) and creeping bentgrass (Agrostis palustris Huds. syn. A. stolonifera L.) coexist on golf greens as a dynamic ecosystem in the temperate regions of the United States. In a two year field study, the competitive ability of different populations of annual bluegrass was investigated both in and out of their native environment. In April 2000, at both The Country Club in Cleveland, Ohio, a temperate environment, and Camargo Club in Cincinnati, Ohio, a transition zone environment, 72 plugs of annual bluegrass were removed from golf greens and inserted into polyvinyl chloride pipe measuring 10.2 cm in diameter and 15 cm in length to eliminate root competition between species. Thirty-six plugs then were reestablished into one of three greens at the same golf course, and the remaining 36 plugs were transported to the opposite location and also established into one of three preselected greens. Each plug was centered in a 20.3-cm-diameter sward of `L-93' creeping bentgrass to provide an initial point of reference. Competitive ability was measured as the rate of increase or decrease in average diameter of each plug. Measurements initially were taken on a bimonthly basis and then on a monthly basis for the remainder of the study. Significant (P < 0.05) differences in the location × population interaction were seen in the first 2 months of the study and then not seen again until the last 2 months. The most frequent occurrence of significant (P < 0.05) differences was in the variability between greens within a particular location. At each location the native population of annual bluegrass outperformed the imported population. Differences at the beginning of the study are attributed to an additional acclimation period required by the exported population following transportation to the opposite location. From our study, annual bluegrass performance was similar across populations, suggesting that management recommendations can be made on a regional basis.
(183) Effects of Colored Plastic Mulches on Tomato Growth and Yield
Authors: Ogutu Maurice
Published: February 2019

Different colored plastic mulches can influence tomato (Lycopersicon esculentum L.) growth and yield. A study was carried out to compare the effects of different colored plastic mulches and bare ground on growth and yield of tomato. Ten treatments, namely, control (bare ground), and plastic mulches (black smooth, red, black embossed, blue, olive, yellow, clear, white, and reflective) were replicated four times in a randomized complete-block design. Tomato variety `Sunstart' seeds were planted in flats filled with Jiffy Mix in a greenhouse in late Apr. 2004 and seedlings transplanted in early June 2004. The seedlings planted in white and reflective plastic mulches were taller than seedlings planted in black smooth, black embossed, clear, blue, red, and olive mulches by 24 July 2004. Weeds were growing underneath clear, yellow, and red plastic mulches, and squash bugs were observed in yellow plastic mulch treatment on 2 July. Cumulative marketable tomato yield was highest in plants grown in reflective and white plastic mulches, and lowest in plants grown in yellow plastic mulch. Marketable fruits from plants grown in reflective and white mulches were larger than fruits from other treatments. In comparison with black embossed plastic mulch, plants grown in reflective and white plastic mulches had 2 and 1.2 tons/acre higher marketable yields, respectively, than plants grown in black embossed plastic mulch.
(164) Effect of a Non-leguminous Cover Crop, Tillage Practices, and Inorganic Nitrogen on Aboveground Biomass Production and Yields of Southernpea
Authors: Whitehead Wayne F. , Singh Bharat P.
Published: February 2019

The objective of this study was to examine how a non-leguminous cover crop, three tillage practices, and two synthetic nitrogen rates influence aboveground biomass, and yields of southernpea. The following fall–spring fertility treatments were applied using randomized complete-block design with four replications: 1) fall-0 N+abruzzi rye; spring-conventional till+0 N; 2) fall-0 N+abruzzi rye; spring-strip till+0 N; 3) fall-0 N+abruzzi rye; spring-No till+0 N; 4) fall-0 N+abruzzi rye; spring-conventional till+30 kg×ha–1 N; 5) fall-0 N+abruzzi rye; spring-strip till+30 kg×ha–1 N; 6) fall-0 N+ abruzzi rye; spring-No till+30 kg×ha–1 N. In Spring 2004, `Mississippi Purple' southernpea was drill planted in all plots. Pod yields were harvested at the fresh-market mature green stage and dry pod stage, while total vegetative dry matter was collected at the mature green stage. Optimal aboveground biomass (32.7 g/plant) was produced by fall-0 N+abruzzi rye; spring-strip till+30 kg×ha–1 N

treatment, while maximum fresh-market pod yield (4.9 Mg×ha–1) and dry pod yield (2.2 Mg×ha–1) were produced by fall-0 N+abruzzi rye; spring-strip till+0 N. Minimum aboveground biomass (15.6 g/plant), fresh-market pod yield (2.6 Mg×ha–1) and dry pod yield (0.9 Mg×ha–1) were produced by fall-0 N+ abruzzi rye; spring-conventional till+0 N treatment. Spring-strip till at 0 N produced fresh-market pod yield, dry pod yield, and plant biomass similar to spring-strip till at 30 kg×ha–1 N.

Results suggest strip-till provided adequate tilth and nitrogen fertilizer was not needed for producing southernpea in middle Georgia.
(296) Effects of Lighting Intensity on the Yield of Tomato and Pepper Crops Grown under Space Station (ISS) Environmental Conditions
Authors: Sisko Matthew , Richards Jeffrey , Edney Sharon , Yorio Neil , Stutte Gary , Wheeler Raymond
Published: February 2019

Of the many environmental variables, light intensity (PPF) has primary effect on photosynthesis and significantly influences crop yield. With the eventual use of a crop production system on the International Space Station (ISS), Mars transit vehicle, or in a lunar/Martian habitat, there exists certain engineering constraints that will likely affect the lighting intensity available to plants. Tomato and pepper are candidate crops being considered by NASA that were selected based on their applicability to such mission scenarios. To study the effects of lighting intensity, tomato (Lycopersicon esculentum L. cv. Red Robin) and pepper (Capsicum annuum L. cv. Hanging Basket) plants were grown under cool-white fluorescent (CWF) lamps with light intensities of 8.6, 17.2, or 26 mol·m-2 ·d-1, with a constant air temperature of 25 °C, 65% relative humidity, and CO2 supplementation of 1200 μmol·mol-1 in order to duplicate conditions plants might be subjected to in an open environment of a space cabin. Following 105 days of growth, edible and total mass for both tomato and pepper increased with increasing light levels. Fruit development and time to ripening was also affected by light treatments. The effects of lighting when combined with other environmental factors typical of spaceflight systems will help define crop production for future missions that incorporate plant-based life support technologies.
(299) Comparison of Growth of Salad Crops under ISS Baseline Environmental Conditions in Mixed Crop versus Monoculture Hydroponic Systems
Authors: Edney Sharon , Richards Jeffrey , Sisko Matthew , Yorio Neil , Stutte Gary , Wheeler Raymond
Published: February 2019

Development of a crop production system that can be used on the International Space Station, long duration transit missions, and a lunar/Mars habitat, is a part of NASA's Advanced Life Support (ALS) research efforts. Selected crops require the capability to be grown under environmental conditions that might be encountered in the open cabin of a space vehicle. It is also likely that the crops will be grown in a mixed-cropping system to increase the production efficiency and variety for the crew's dietary supplementation. Three candidate ALS salad crops, radish (Raphanus sativus L. cv. Cherry Bomb II), lettuce (Lactuca sativa L. cv. Flandria) and bunching onion (Allium fistulosum L. cv. Kinka) were grown hydroponically as either monoculture (control) or mixed-crop within a walk-in growth chamber with baseline environments maintained at 50% relative humidity, 300 μmol·m-2·s-1 PPF and a 16-hour light/8-hour dark photoperiod under cool-white fluorescent lamps. Environmental treatments in separate tests were performed with either 400, 1200, or 4000 μmol·mol-1 CO2 combined with temperature treatments of 25 °C or 28 °C. Weekly time-course harvests were taken over 28 days of growth. Results showed that none of the species experienced negative effects when grown together under mixed-crop conditions compared to monoculture growth conditions.
(300) Effect of Planting Density, CO2, and Harvest Intervals on Biomass of Three Allium Species
Authors: Broome Amanda L. , Peffley Ellen B.
Published: February 2019

This research evaluated, for the NASA ALS program, the effect of spacing and harvest intervals on edible biomass of green salad onions grown at two CO2 levels. Shoot biomass of Japanese bunching onion (Allium fistulosum), bulbing onion (A. cepa), and chives (A. schoenoprasum) grown at 10-, 15-, and 20-mm spacings harvested at 7- and 14-day intervals, seven and four harvests, respectively, over 70 days were compared. Onions were grown hydroponically in growth chambers, 16-hour light/8-hour dark, 24/20 °C, 75/99% at ∼450 and 1200 ppm CO2. The design was a completely randomized block with repeated measures; subsamples were plants completely surrounded by neighboring plants. Weekly shoot removal began 28 days after planting (dap); destructive harvest was 70 dap. Length and diameter of longest leaf, weight, and number of leaves/tillers were taken at each harvest; bulb caliper and weight were taken 70 dap. Bunching and bulbing onion leaves were longest at 28 dap and decreased over time; chives were slow to establish but 70 dap had longest leaves. Leaf diameter of all species increased as spacing increased. At 56 through 70 dap chives at all three spacings produced more leaves. Mean weight of shoots differed significantly at 20-mm spacing: chives the least, bulbing onion the most. Bulb weight for bulbing onion and chives increased with increased spacing; bulbing onion weighed significantly more at 15- and 20-mm spacings compared to the other species and spacings. Chives grown at 20-mm spacing had tillering clumps of rhizomes. Total edible biomass weight (bulb, pseudostem, and shoots) of bulbing onion grown at 10-mm spacing exhibited similar ontogeny to chives grown at 10- and 15-mm spacings; bulbing onion grown at 20-mm spacing had the most edible biomass. On average, biomass was greatest in plants grown at 1200 ppm CO2.
(302) Photoautotrophic Micropropagation Systems Demonstrate Rooting Stage Improvement of Laelia purpurata var. alba
Authors: Jones Hope , Kubota Chieri
Published: February 2019

In vitro culture of orchid plantlets within conventional photomixotrophic micropropagation (PMM) systems (sucrose containing media in a non-enriched CO2 environment) often induces vigorous growth and multiplication. However, transition to ex vitro conditions frequently results in significant plantlet loss during the acclimatization process. Recent studies investigating micropropagation within photoautotrophic (PAM) systems (sucrose-free media in enriched CO2 conditions) have demonstrated improved plantlet survival during the acclimatization period due to greater root growth and stomata adaptation. Laelia purpurata var. alba, an orchid with many endangered relatives, was chosen as a model orchid species to investigate if plantlet culture within PAM in vitro systems has the potential to improve propagation success and ex vitro survival of endangered Laelia species. Protocorm-like bodies with developed two fully extended leaves were transferred into PMM (photosynthetic photon flux 50 μmol·m-2·s-1 under non-enriched CO2 conditions) and PAM (photosynthetic photon flux 150 μmol·m-2·s-1, CO2 level enriched to 1500 μmol·mol-1) systems. After 6 weeks, plantlet rooting within the PMM system was variable and inconsistent, while all PAM plantlets produced healthy robust root systems. Average fresh weights and percent shoot development were not significantly different between treatments. Induction of improved root growth by PAM systems may improve orchid plantlet survival rates during acclimatization and advance our ability to increase endangered orchid populations.
(75) Quantifying the Vernalization Response of Dianthus gratianopolitanus `Bath's Pink'
Authors: Padhye Sonali , Runkle Erik S. , Cameron Arthur C.
Published: February 2019

Two experiments were conducted to quantify the effect of vernalization temperature and duration on flowering of Dianthusgratianopolitanus `Bath's Pink'. In Expt. 1, plants were vernalized at 5 °C for 0, 3, 6, 9, 12, or 15 weeks and in Expt. 2, plants were vernalized at 0, 5 or 10 °C for 0, 2, 4, 6 or 8 weeks. After treatments, plants were forced in a greenhouse at 20 °C. Node development, days to first visible bud (DVB), days to first open flower (DFLW), number of buds and height at FLW were recorded. In Expt. 1, 10% of nonvernalized plants flowered and 100% of vernalized plants flowered. As vernalization duration increased from 3 to 15 weeks, DTVB decreased from 24 to 13. Average DFLW were 114, 41, 34, 33, 33, and 28 for 0-, 3-, 6-, 9-, 12-, and 15-week treatments, respectively. In Expt. 2, 40% of plants flowered without vernalization. Following 2 weeks of vernalization at 0 °C, 80% of plants flowered and as the duration of vernalization increased to ≥4 weeks, all plants flowered. Average DFLW decreased from 38 to 28 following 2 or 4 weeks of vernalization at 0 °C. Longer vernalization did not further reduce DFLW. All plants cooled at 5 °C flowered and vernalization duration did not affect DFLW. Percent flowering after vernalization at 10 °C for 2, 4, 6, and 8 weeks was 20%, 60%, 90%, and 100%, respectively, and average DFLW were 46, 45, 35, and 33, respectively. In conclusion, vernalization is required to force D.`Bath's Pink'. To achieve complete flowering, plants should be vernalized at 5 °C for ≥2 weeks or at 0 °C for 4 weeks or at 10 °C for 8 weeks. Qualitative effects of vernalization such as node development and number of buds and height at FLW will be discussed.
(78) Establishment and Growth of Begonias in the Landscape as Affected by Root Ball Condition at Transplant
Authors: Scheiber Sloane M. , Beeson Richard C. , Vyapari Sudeep
Published: February 2019

Root ball slicing is often recommended for root-bound woody ornamentals to promote new root development during establishment in the landscape. It is a common practice among gardeners, but not necessarily landscapers, to disrupt root-bound annuals during transplant. However, little if any evidence exists for such practices. Therefore, this study evaluated the effect of root ball condition of annual bedding plants on landscape establishment and growth. Begoniasemperflorens were transplanted from 0.72-L (#1) containers into field plots in an open-sided clear polyethylene covered shelter and managed with Best Management Practices. Three root ball conditions were evaluated: non root-bound (6-week-old plants), root-bound (10-week-old plants), and root-bound with the bottom 1 cm of the root ball removed. Shoot and root dry masses and growth indices were collected weekly for 12 weeks and evaluated relative to root ball condition by linear regression analysis. Nonroot-bound plants had significantly greater biomass, growth indices, height, and root dry weights than the other treatments tested. No significant differences were found between root-bound and manipulated root-bound plants for any parameter examined. The data indicate that the practice of disrupting root-bound plants has no benefit on establishment or growth of annual bedding plants in the landscape.
(249) Evaluation of Five Genotypes of Tomato (Lycopersicon esculentum Mill.) in Greenhouse
Authors: Tene Marcelino Bazan , Gonzalez Juan Manuel González , Juarez Francisco Radillo , Castillo Pablo Enrique Ramírez
Published: February 2019

The tomato (Lycopersicon esculentum Mill.), is native to South America. It occupies the second place in worldwide vegetable consumption. Because of this, the evaluation of tomato varieties for the fresh consumption is important. The Mexican production is 1,908,607 tons of fresh product (SAGARPA, 2004). In the state of Colima, production has a mean efficiency of 18.13 t·ha-1 (INEGI, 2000). The following genotypes were evaluated `Peralta', `Montijo', Pavia', `Grande River', and `Yaqui' (control). A randomized experimental block was used, with five treatments and four repetitions. The obtained results indicate that `Yaqui' (control) had the better yield of fresh fruit, with 37.5 t·ha-1, followed by `Peralta' (27.2t·ha-1), and `Montijo' (12.6 t·ha-1), respectively. The height of plant in `Yaqui' was 68.8 cm and 60.26 cm in `Pavia'. In the days to flowering, after showing a homogenous behavior, pronouncing itself up to 27 days after the transplant; whereas the variety `Grande River' was pronounced up to 40 days. With respect to the number of total fruits by plant, a highly significant difference was observed. `Yaqui' produced 91 fruits, with `Pavia' and `Peralta' producing 50 and 37 fruits per plant, respectively. In conclusion, `Yaqui' was the genotype with greater yield and vigor.
(364) Evaluation of Beneficial Microorganisms for Controlling the Wilt Caused by Fusarium oxysporum f. sp. melonis on Cantaloupe Plants under Greenhouse Conditions
Authors: Orozco-Santos Mario , Farías-Larios Javier , Molina-Ochoa Jaime , López-Aguirre José Gerardo
Published: February 2019

Development of resistance to chemical pesticides has been reported in about 150 plant pathogenic species, mostly fungi. Biocontrol of plant pathogens is an alternative to chemical pesticides. Actually, there are products formulated with beneficial microorganisms, such as mycorrhizal fungi, rhizobacteria, antagonistic fungi, and others. The objective was to evaluate the development of Fusarium oxysporum f. sp. melonis (FOM) on melon plants inoculated with commercial biological formulations based on beneficial microorganisms. Twelve treatments were evaluated: T1) VAM media nursery + FOM; T2) Hortic Plus + FOM; T3) BioPak F + FOM; T4) Glomus intraradices + FOM; T5) FOM; T6) control; T7) VAM media nursery; T8) Hortic Plus; T9) BioPak F; T10) Glomus intraradices; T11) FOM + Mancozeb wp80; and T12) FOM + BioPak F. The melon cultivar used was `Colima' (Peto Seed Co.). Seeds were planted in Styrofoam growing containers containing coconut fiber powder as substrate. One seed was planted per cell and maintained until transplanting. Plants were transplanted to pots containing sterile soils 13 days postemergence. Inoculation of treatments with Fusarium was made with a concentrated suspension at 1 × 106 conidia/mL. For inoculation with beneficial microorganisms, manufacturer specifications were followed. A completely randomized design with 12 treatments and 12 replications was used to estimate the incidence of Fusarium, number of leaves, leaf area, root biomass, and percentage of roots colonized by mycorrhizal fungi. Overall, T10 showed the best behavior in all variables. Inoculation of cantaloupe plants with Fusarium affected their performance, but those treatments including mycorrhizal fungi enhanced their performance withstanding the damage by Fusarium.
(357) GIS Tools for Documentation and Analysis of Germplasm Collections from a Secondary Center of Diversity: A Case Study for East African Sweetpotatoes
Authors: Villordon Arthur , Njuguna Wambui , Gichuki Simon , Kulembeka Heneriko , Simon Jeremiah , Yada Bernard , Tukamuhabwa Phinehas , LaBonte Don
Published: February 2019

The East African region in sub-Saharan Africa (SSA) is widely considered as one of the secondary centers of diversity for sweetpotatoes [Ipomoea batatas (L.) Lam.]. Farmers in the region typically grow landraces, but hybridizations occasionally result in new genotypes. Factors such as regional conflicts, natural disasters, disease, and land pressure continually threaten the SSA sweetpotato gene pool. Despite this threat, very little updated information is easily accessible about SSA germplasm collections. Such information is valuable for purposes of management, exploration, and conservation. Using germplasm collection data from Kenya, Tanzania, and Uganda, we demonstrate how publicly available GIS-based tools, e.g., DIVA-GIS, can be used to document current collections as well as make this information easily accessible, searchable, and portable. First, collection data from each country were compiled and known collection sites were georeferenced using available gazetteers. Following data cleaning and verification, georeferenced data were then converted into a GIS-compliant format, primarily as shapefiles. All files were then copied into storage media for exchange among stakeholders. To further demonstrate the portability of the GIS database files, available World Wide Web GIS web viewers enabled real-time access to GIS files uploaded to an experimental web site. This work demonstrates that with very little expense, access to extant SSA germplasm information for sweetpotatoes can be improved using publicly available GIS tools.