bluuebunny/crossref_metadata_2025 huggingface dataset:
Bending Shoots Stimulates Flowering and Influences Hormone Levels in Lateral Buds of Japanese Pear
Authors: Ito Akiko , Yaegaki Hideaki , Hayama Hiroko , Kusaba Shinnosuke , Yamaguchi Isomaro , Yoshioka Hirohito
Published: February 2019

Flower development of the lateral buds was accelerated in Japanese pear [Pyrus pyrifolia (Burm.) Nak.] when vertical shoots were bent at a 45° angle in late June. The indole-3-acetic acid (IAA) concentration in lateral buds on vertical (control) shoots increased in mid-July, while remaining nearly constant in bent shoots. The abscisic acid (ABA) concentration of buds in bent shoots rose between 4 July and 15 Aug., whereas control shoots exhibited an increase in concentration followed by a decline. Gibberellin4+7 (GA4+7) concentration was high on 16 June, and then declined by 4 July, with the decline being greatest in bent shoots. Gibberellin4+7 concentration was higher in the buds on vertical shoots than in those on bent shoots for much of July. The concentrations of zeatin-type cytokinins (CKs) in lateral buds were higher in bent shoots than in vertical shoots. Bending of pear shoots may weaken competition between buds and other organs through altering hormone levels in lateral buds, resulting in acceleration of flower development.
In-row Plant Spacing and Date of Harvest of `Beauregard' Sweetpotato Affect Yield and Return on Investment
Authors: Schultheis Jonathan R. , Walters S. Alan , Adams Dennis E. , Estes Edmund A.
Published: February 2019

The effects of plant spacing (15, 23, 31, and 38 cm) and date of harvest on yield and economic return of `Beauregard' sweetpotato [Ipomoea batatas (L.) Lam.] were studied. For comparison, `Jewel' was included at one spacing. As in-row plant spacing decreased, yield of U.S. No. 1, canners, and total marketable root production increased when plants were harvested 103 days or later after transplanting. The yield of jumbo roots generally increased with in-row spacing because of less plant-to-plant competition. Total marketable and No. 1 grade yields of `Beauregard' at the closest spacing (15 cm) were greater than those of `Jewel'. `Beauregard' roots sized more quickly than `Jewel' roots regardless of spacing. The optimal time for harvesting `Beauregard' was 100 to 110 days after transplanting, while acceptable yields could be obtained as early as 90 days after transplanting depending on market prices. Economic analysis of `Beauregard' spacing data indicated that 23 cm would be the preferred spacing if a late harvest was anticipated, while the 15-cm spacing would be best if harvested at ≈110 days after transplanting. Thus, sweetpotato growers should place `Beauregard' at an in-row spacing of 15 or 23 cm, depending on projected date of harvest, on or before 10 June, to obtain the best yields with the highest return on investment.
Mineral Nutrient and Carbohydrate Status of Loblolly Pine during Mist Propagation as Influenced by Stock Plant Nitrogen Fertility
Authors: Rowe D. Bradley , Blazich Frank A. , Weir Robert J.
Published: February 2019

Hedged stock plants of four full-sib families [27-2 × 27-5, 27-3 × 27-1, 27-2 × 27-1, and 27-6 × 27-1 (designated B, G, R, and W)] of loblolly pine (Pinus taeda L.) were fertilized daily with a complete nutrient solution containing N at 10, 25, 40, 55, or 70 mg·L–1. In May, terminal softwood stem cuttings were taken and placed under intermittent mist. Families were combined to form composite poor-rooting (BR) and good-rooting (GW) families. At 0, 3, 6, 9, and 12 weeks after sticking, cuttings were evaluated for rooting and analyzed for mineral nutrient and carbohydrate content. Percent rooting by week 12 for cuttings from stock plants receiving N between 25 to 70 mg·L–1 was 28% to 33%, whereas significantly fewer (17%) cuttings from plants receiving 10 mg·L–1 had rooted. By week 12, 98% of cuttings taken from stock plants receiving N at 10 mg·L–1 were alive, while significantly fewer (81% and 82%) of the more succulent cuttings receiving 55 and 70 mg·L–1, respectively, had survived. Nearly all increases in cutting height occurred within the first 3 weeks. In contrast, top dry weight increased steadily throughout the experiment. There were no significant differences in rooting between the two composite families until week 12, when 32% of cuttings from family GW had rooted compared with 24% for family BR. Survival of cuttings was greater for the poor-rooting family (BR) (94%) than for the good-rooting family (GW) (82%) after 12 weeks. Levels of total nonstructural carbohydrates (TNC) and individual soluble sugars were initially higher in cuttings taken from stock plants that received higher rates of N, whereas the reverse was true for starch content. With the exception of sucrose, content of TNC and soluble carbohydrates generally increased over time. Starch was nearly depleted by week 3, but had increased by weeks 6 and 9. No correlation was found between TNC: N ratios and rooting percentage. Family GW contained greater quantities of myo-inositol, glucose, fructose, sucrose, total soluble carbohydrates (TSC), and TNC than did family BR. Mineral nutrient content was generally greater in cuttings taken from stock plants that received higher rates of N; these cuttings also maintained higher levels throughout the 12-week rooting period. As with the soluble carbohydrates, the good-rooting composite family (GW) contained greater amounts of all mineral nutrients than did the poor-rooting family BR.
Viability of Pollen of Two Fruit Crop Cacti of the Genus Hylocereus Is Affected by Temperature and Duration of Storage
Authors: Metz Christiane , Nerd Avinoam , Mizrahi Yosef
Published: February 2019

Hylocereus undatus (Haw.) and H. polyrhizus (Weber) are new fruit crops of the Cactaceae. In Israel, flowers of the two species, which are self-incompatible, are hand cross-pollinated. In order to ensure a current supply of compatible pollen and guarantee good yields, we have developed a procedure for long-term storage of pollen. Pollen for storage was collected in the evening or in the morning. Its moisture content ranged between 45% to 50% in the evening and between 18% to 22% in the morning. Pollen was first dehydrated in a vacuum desiccator until the moisture content was reduced to 5% to 10% and then stored at various temperatures (+4, –18, –70, –196 °C) for 3 or 9 months, after which it was used for cross-pollination. Percent fruit set and fruit fresh weight (FW) were affected by the temperature but not the duration of pollen storage; storage at +4 °C reduced fruit set, fruit FW, and seed number more than did storage at subfreezing temperatures. The FW of fruits produced by frozen pollen was similar to that produced by fresh pollen in commercial orchards. The rate of seed germination was high (≈90%) regardless of the temperature during pollen storage.
Pruning and Skirting Affect Canopy Microclimate, Yields, and Fruit Quality of `Orlando' Tangelo
Authors: Morales Paula , Davies Frederick S. , Littell Ramon C.
Published: February 2019

Pruning and skirting (removal of low-hanging limbs) effects on canopy temperature, relative humidity (RH), and fruit yield and quality of `Orlando' tangelo trees (Citrus paradisi Macf. × Citrus reticulata Blanco) on `Carrizo' citrange rootstock [Poncirus trifoliata (L.) Raf. × Citrus sinensis (L.) Osb.] were studied at the Univ. of Florida Fifield Farm in Gainesville, Fla., in 1996–97. In the first season, treatments consisted of skirted and non-skirted trees. In the second season, two skirting (skirted and non-skirted) and three pruning (gable-top, flat-top, and non-pruned) treatments were evaluated. Neither RH nor air temperature was affected in the lower canopy by any treatment. However, temperature in the upper canopy of flat-topped trees was higher than that in gable-topped or non-pruned trees, and reached >45 °C during spring and summer. Fruit number and yield were decreased by pruning and skirting in one season. Skirted, gable-topped trees had the lowest yields, followed by skirted, flat-topped and non-skirted, gable-topped trees. All other treatments produced yields similar to those of non-skirted, non-pruned trees. Pruning increased the percentage of large fruit and reduced the percentage of small fruit. Skirting and pruning had no effect on blemish incidence with the exception of wind scar, which was higher in skirted than in non-skirted trees in the first season. During both seasons the main causes of packout reduction were rust mite and wind scar damage. Regardless of treatment, rust mite damage was much higher in the lower than in the upper canopy because of lower average temperatures and higher RH. Pruning effects on fruit quality were similar to those reported previously, but skirting had no effect on most fruit quality factors.
Cultivar Influences Cranberry Response to Surface Sanding
Authors: Davenport Joan R. , Schiffhauer Daniel E.
Published: February 2019

Surface sand application to cranberry (Vaccinium macrocarpon Ait.) is commonly practiced for a combination of vine and insect management. However, the efficacy of sanding on crop production has been poorly documented. This study determined the effect of three rates of sand application using a barge sanding technique on two different cultivars—`Early Black' and `Stevens'. Beds were sanded to a depth of 0, 1.3, or 2.5 cm in November and monitored at the end of the following three growing seasons for yield, berry weight, and upright distribution. The 2.5-cm sanding rate adversely affected yield in `Early Black' during the first two growing seasons. In `Stevens' yields were not reduced until the third season and then only by the 2.5-cm rate. Although the 2.5-cm sanding rate increased vegetative upright density in both cultivars in the first growing season, yield and number of fruiting uprights were not significantly influenced the next year. Application of 1.3 cm of sand could improve insect pest management without negatively impacting yields of `Early Black' and `Stevens'.
Irrigation Criteria for Drip-irrigated Onions
Authors: Shock Clinton C. , Feibert Erik B.G. , Saunders Lamont D.
Published: February 2019

Long-day onion (Allium cepa L. `Vision') was subjected to five soil water potential (SWP) treatments (–10, –20, –30, –50, and –70 kPa) using subsurface drip irrigation in 1997 and 1998. Onions were grown on 1.1-m beds with two double rows spaced 0.56 m apart and a drip tape buried 13 cm deep in the bed center. Soil water potential was maintained at the five levels by automated, high-frequency irrigations based on SWP measurements at 0.2-m depth. Onions were evaluated for yield and grade after 70 days of storage. In 1997, total and colossal (bulb diameter ≥102 mm) yield increased with increasing SWP, but marketable yield was highest at a calculated –21 kPa because of greater decomposition in storage in wetter treatments. In 1998 total, marketable, and colossal-grade onion yield increased with increasing SWP. Onion profits were highest with a calculated SWP of –17 kPa in 1997, and at the wettest level tested in 1998. Storage decomposition was not affected by SWP in 1998. Maintenance of SWP at –10 and –20 kPa required, respectively, 912 and 691 mm of water in 1997 and 935 and 589 mm of water in 1998. Onion crop evapotranspiration from emergence to the last irrigation totaled 681 mm in 1997 and 716 mm in 1998.
A Leaf Disk Assay for Screening Sweet Cherry Genotypes for Susceptibility to Powdery Mildew
Authors: Olmstead James W. , Lang Gregory A. , Grove Gary G.
Published: February 2019

A detached leaf disk assay for screening sweet cherry (Prunus avium L.) genotypes for susceptibility to powdery mildew (PM) [Podosphaera clandestina (Wallr.:Fr.) Lev.] was developed by evaluating the effects of photoperiod (24 hours light, 0 hours light, 14 hours light/10 hours dark), substrate nutrient content (sterile distilled water, 1% sucrose), leaf age (old, young, emergent), and leaf explant size (intact leaf, 30 mm, 20 mm) on PM growth on leaves from the susceptible cultivar Bing. The only parameter described that had a significant (P ≤ 0.001) effect on PM growth was leaf age. Old leaves, designated as the third fully expanded leaf from the basal end of current-year's shoot growth, were never infected with PM under controlled inoculations. In the absence of significant differences between treatments, those parameters with the highest treatment means were selected for subsequent evaluation. To test the leaf disk assay, 14 sweet cherry cultivars were screened in two experiments, and rated according to level of PM susceptibility. Rank sum comparison of results from cultivars used for leaf disk screening agreed with earlier field rankings of the same cultivars. The developed leaf disk assay greatly reduced the space required to screen sweet cherry cultivars, and was a repeatable and objective predictor of field resistance that may be useful for screening germplasm or breeding populations.
Propagation of Alnus maritima from Softwood Cuttings
Authors: Schrader James A. , Graves William R.
Published: February 2019

Alnus maritima (Marsh.) Nutt. (seaside alder) is a rare, woody-plant species with potential for use in managed landscapes. Information on the propagation and production of this species is not available. Our objective was to evaluate the use of softwood cuttings to propagate A. maritima, with emphasis on how indole-3-butyric acid (IBA), plant provenance, and time of collection affect cutting survival, rooting percentage, the number of roots produced, and their length. Propagation trials were conducted with cuttings from seven trees on the Delmarva Peninsula (Eastern Shore of Maryland and southern Delaware) and seven trees in Oklahoma. Cuttings from mature plants in both provenances were collected on 14 June and 23 Aug. 1998; wounded; treated with IBA at 0, 1, or 8 g·kg-1; and placed under intermittent mist in a greenhouse for 9 weeks. Use of IBA at 8 g·kg-1 caused a greater rooting percentage (68%), root count (7.2), and root length (39.2 mm) than did the other IBA rates when applied to cuttings from Oklahoma in June, but IBA had little effect on cuttings from the Delmarva Peninsula. Across IBA treatments, rooting of cuttings from Oklahoma (55% in June and 12% in August) was greater than the rooting of cuttings from Delmarva (27% in June and 3% in August). Cuttings from Oklahoma had greater survival, callus development, root length, and root count than did cuttings from the Delmarva Peninsula during June and August trials. Averaged over IBA treatments and provenances, cuttings collected on 14 June rooted more frequently (41%) than did cuttings collected 23 Aug. (8%). We conclude that softwood cuttings from mature plants are an effective way to multiply clones of A. maritima, particularly when cuttings are collected early in the season and treated with IBA at 8 g·kg-1.
Cold Hardiness of Phellodendron sachalinense Friedr. Schmidt Seedlings Increases with Age
Authors: McNamara Steve , Pellett Harold
Published: February 2019

Seedlings of several landscape tree species frequently experience cold injury at temperatures that are noninjurious to older specimens of the same species. However, there are few published reports quantifying age-related differences in hardiness. In this study, the stem cold hardiness of a mature, 35-year-old female Sakhalin corktree was compared with that of half-sib seedling progeny of different ages. Ten-, 22-, and 34-month-old seedlings were hardy to -4 °C on 9 Oct., while the 35-year-old parent withstood -12 °C. Ten-month-old seedlings exhibited no further increase in hardiness on 26 Oct., whereas the 34-month-old seedlings and the mature parent were hardy to -16 °C. The 22-month-old seedlings were intermediate in hardiness on this date. The 10- and 22-month-old seedlings had died back to the snowline by late January, but the 34-month-old seedlings and the mature tree were uninjured. The corktree seedlings did not attain midwinter hardiness levels comparable to the adult tree until the winter following their fourth season of growth. The absence of flower buds on cold-tolerant 4- and 5-year-old seedlings suggests that physiological maturation is not a prerequisite for full expression of the cold acclimation capability of this species.
063 Detection of Putatively Stress-activated Ty1-copia-like Retrotransposon Sequences in Virus-infected Sweetpotato [Ipomoea batatas (L.) Poir.] Clones
Authors: Villordon A.Q. , Clark C.A. , Valverde R.A. , Jarret R.L. , LaBonte D.R.
Published: February 2019

Previous work by our group has detected the presence of a heterogeneous population of Ty1-copia-like reverse transcriptase retrotransposon sequences in the sweetpotato genome. Recently, we detected the presence of putatively active Ty1-copia-like reverse transcriptase sequences from a virus-infected `Beauregard' sweetpotato clone. In the current study, we report the differential detection of putatively stress-activated sequences in clones from seedling 91-189. The clones were infected with different combinations of virus isolates followed by extraction of leaf RNA samples at three sampling dates (weeks 2, 4, and 6) after inoculation. After repeated DNAse treatments to eliminate contaminating DNA, the RNA samples were subjected to first strand cDNA synthesis using random decamer primers followed by PCR analysis utilizing Ty1-copia reverse transcriptase-specific primers. Through this approach, we detected amplified fragments within the expected size range (280-300 bp) from clones infected with isolates of sweetpotato leaf curl (SPLC) and feathery mottle viruses (FMV) (week 2 and 6) and FMV (week 4). We were unable to detect PCR products from the noninfected clones or the other infected samples. The data suggests that specific viruses may be involved in the expression of these Ty1-copia-related reverse transcriptase sequences. It also appears that sampling at various dates is necessary to detect putative activity over time. This preliminary information is essential before proceeding to the construction and screening of cDNA libraries to isolate and fully characterize the putatively active sweetpotato Ty1-copia-like retrotransposon sequences. Through the partial or complete characterization of sweetpotato Ty1-copia elements, sequences that correspond to cis-regulatory element(s) can be identified and further studied for their roles in responding to specific stress factors.
111 Effect of Harvesting Methods, Waxes, Storage Temperature, and Fruit Size on Stem End Rind Breakdown (SERB) of Valencia Oranges
Authors: Dou Huating , Ismail Mohamed A. , Petracek Peter. D.
Published: February 2019

The effect of clipping vs. pulling, wax application, storage temperature, and fruit size on Stem End Rind Breakdown (SERB) of Valencia oranges was studied in four experiments during the 1998–1999 and 1999–2000 seasons. For harvesting methods, clipping reduced SERB rate of Valencia oranges over pulling from 10.2% to 5.9%. Wax application increased fruit SERB compared to non-waxed fruit. However, there was no consistent difference in effect on SERB incidence between shellac and carnauba waxes in all studies. Small fruit (size 100#) tended to be associated with high incidence of SERB, whereas large fruit (size 64#) were less susceptible to SERB of Valencia oranges. The most significant factor that influenced SERB incidence was storage temperature. Fruit stored at 70 °F had 23% and 96% SERB if fruit were examined in the 2nd and 8th weeks after packing; whereas 0.5% and 2% SERB was found if fruit were stored at 45 °F and examined at the same times. The effect of the above treatments on fruit peel anatomy and postharvest physiological behavior will also be discussed.
207 Mycorrhizal Enhancement of the Physiology and Growth of Micropropagated Chile Ancho Pepper (Capsicum annuum L. cv. San Luis) Plantlets during Acclimatization and Post-acclimatization
Authors: Estrada-Luna Andres A. , Davies Fred T. , Egilla Jonathan N.
Published: February 2019

The role of mycorrhiza fungi during acclimatization and post-acclimatization of micropropagated chile ancho plantlets was characterized through physiological and plantlet development changes. Regardless of mycorrhizal colonization, the pepper plantlets had initially low photosynthetic rates and poor growth following transplanting ex vitro. During the first days of acclimatization, water deficits occurred as evidenced by drastic reductions in relative water content. Consequently, transpiration rates and stomatal conductance (gs) declined, confirming that in vitro formed stomata were functional, thus avoiding excessive leaf dehydration and plant death. Mycorrhiza had a positive effect on gas exchange as early as day 7 and 8, as indicated by increasing photosynthesis (A) and gs. Mycorrhizal plantlets had reduced levels of abscisic acid (ABA) during peak stress (6 days after transplanting ex vitro), which corresponded with subsequent increases in gs and A. During acclimatization, A increased in both non-colonized and colonized plantlets, with greater rates observed in mycorrhizal plantlets. During post-acclimatization, mycorrhiza colonized 45% of the roots of pepper plantlets and enhanced plant growth by increasing leaf area, leaf dry mass, and fruit number. Mycorrhiza also enhanced total leaf chlorophyll content, A, and nutrient uptake of pepper plantlets, particularly N, P, and K. Early mycorrhizal colonization produced important benefits, which helped ex vitro transplanted plantlets recover during acclimatization and enhance physiological performance and growth during post-acclimatization.
247 Early Growth and Development of Container-grown Pawpaw Seedlings in Various Potting Media and Nutrient Regimes
Authors: Pomper Kirk W. , Jones Snake C. , Reed Eddie B.
Published: February 2019

The pawpaw [Asimina triloba (L.) Dunal] is a native American tree fruit with potential in edible landscapes and as a new fruit crop. A split-plot experiment (main plot: fertilizer level and subplot potting medium) was conducted in the greenhouse to identify the best growing medium for production of pawpaw seedlings. Seeds were sown in rootrainers containing one of the following media: 1) Promix (control); 2) 6 pine bark:1 mason sand (v/v); 3) 1 mason sand: 1 sphagnum peat; and 4) 4 pine bark:1 mason sand:1 sphagnum peat. When seedlings had at least two to three leaves, weekly fertigation of seedlings began, using 0, 250, or 500 ppm Peters 20N-20P-20K. Germination rate at 10 weeks was similar in all media, at about 80%. The plants were destructively harvested 10 weeks after imposition of fertigation treatments. Both potting media and fertigation influenced leaf number and height; however, there was a significant interaction between these main effects. Leaf number and height for plants in medium 3 were similar to those of the control (medium 1), at about 11 leaves and 18-cm plant height, respectively, at 500 ppm fertigation. Plants in media 2 and 4 were about half as tall and had about half as many leaves as control medium plants at 500 ppm fertigation. Plant leaf area and biomass data will be discussed.
302 Comparative Effectiveness of Cytokinins on Quality of Soybean Sprouts
Authors: Bang Hae-Jeen , Hwang Soo-Jung , Chung Hee , Lee Jung-Myung
Published: February 2019

Soybean sprouts are one of the most-favored traditional vegetables around the world. The sprouts are usually consumed 7 to 10 days after sowing depending upon the growing conditions. High-quality sprouts should have less secondary roots, short and well-swollen hypocotyls in pure white color, and small cotyledons in hooked position. Cytokinins were reported to be effective in producing such sprouts by promoting sprout growth while inhibiting the excessive hypocotyl elongation and secondary root growth. Seeds of four soybean cultivars with different characteristics were soaked in water for 4 h and, 2 to 3 h after the imbibition, the seeds were soaked again in solutions of different cytokinins such as benzyladenine (BA), BA-riboside (BAR), BPA, 2iP, 2iP-riboside, 4-CPPU, and kinetin-riboside (KR) for 10 min. After the treatment, the sprouts were grown in a plastic tube (25 cm height × 10.5 cm diameter) a dark culture room with ample watering every 4 h. After 7 days of growth, uniform samples were taken from each treatment and the sprout characteristics were examined. Some cytokinins such as BA, BAR, 4-CPPU were highly effective in promoting the sprout growth (fresh weight) even though the hypocotyl length was markedly reduced. Other cytokinins such as 2iP, 2iPR, and KR had no effect on sprout growth. Hypocotyl diameter was markedly increased by BA and 4-CPPU treatment, thus resulting in short, strong and good quality sprouts. Cultivars responded differently to cytokinin treatment by showing different growth promotion depending upon the sprout parts. Injury-like symptoms, abnormal and twisted heads or cotyledons, appeared in cytokinin-treated sprouts at high concentrations and the symptoms were severe when the sprouts were grown at high temperatures. In all the cultivars tested, BAR appeared to be better than others in terms of sprout quality and growth promoting characteristics.
Yield Response of Herbs to N and K Fertilizers and Compost Rates in Multiple Harvest
Authors: Csizinszky Alexander A.
Published: February 2019

Sweet marjoram [(marjoram) Origanum majoranna], Italian parsley [(parsley) Petroselinum crispum], Summer savory [(savory) Satureja hortensis], and thyme (Thymus vulgaris) were evaluated for their yield potential during Fall–Winter–Spring (Oct.–May) 1998–99. The herbs were grown in a light sandy soil with the full-bed polyethylene mulch-micro(trickle) irrigation system. Experimental design was a split-plot replicated three times. Main plots were two N–P–K treatments: 0 N–P–K or N and K from a liquid 4–0–3.32 (N–P–K) fertilizer injected at 0.77 N and 0.64 K kg·ha–1·day–1. Sub-plots were four compost rates at 0x, 1x, 2x, and 4x (1x = 4.5 t·ha–1). Early and seasonal total yields of marjoram and savory were similar with injected N + K and 0x compost to yields with compost and with or without injected N + K fertilizer. Yields of parsley and thyme increased with increasing compost rates and were best with compost plus liquid N + K. Postharvest soil concentrations of NO3-N were lower in the parsley, than in the marjoram, savory and thyme plots. Residual concentrations of all other elements were similar with or without injected N + K or compost treatments.
Preliminary Evaluation of Float Bed Culture for Selected Salad Vegetables
Authors: Reich Vernon H. , Coffey David L.
Published: February 2019

Float bed culture, common in the production of tobacco transplants, was investigated for the production of the salad vegetables leaf lettuce and radicchio. Experiments were conducted during Spring and Summer 1999. Seeds were planted on 61 cm × 61 cm, 2.54-cm-thick expanded foam sheets and floated on nutrient solution until plants were ready for harvest. Lettuce plants of the four cultivars evaluated were harvested 53 days after planting. Yields ranged from 99 to 181 g/plant. In the same experiment, aeration of the solution was compared with static solution with plants grown in aerated nutrient solution yielding significantly better than those grown in static solution. There was not a significant cultiva × aeration interaction for yield. Radicchio plants were seeded on expanded foam sheets at 20 plants per sheet. Plants were harvested 69 days after seeding. Those that had been aerated had significantly higher number of heads and leaf, head, and root weight than the nonaerated ones. There were no differences in total leaf weight among the five cultivars evaluated, but `Red Treviso' had significantly fewer and lower weight heads and more root weight than the other four cultivars.
Using Hanging Baskets and Containers in Garden Trials at the University of Tennessee
Authors: Starman Terri W. , Hamilton Susan L.
Published: February 2019

Many new vegetative annuals are available in the floriculture market today. Their growth habits may be trailing or vigorous and more conducive to hanging basket or container garden culture. Today's gardeners are living busy lives and housing is sometimes confined, with little land on which to garden. These factors all contribute to the popularity of hanging baskets and container gardens. Whereas container garden trials are more common in industry, few universities have added container gardens and hanging baskets to their trial gardens. The objective of the hanging basket and container garden trials at Univ. of Tennessee (UT) initiated in Summer 1999 was to demonstrate and promote this timely trend to commercial growers, landscapers, and the public. An attractive brick walkway and wooden arbor were built by a UT landscape construction class to display the containers and hanging baskets. Several challenges had to be met: funding the purchase of expensive containers; planting and placing the heavy containers in the garden; combining plants within the containers; grouping containers together; labeling plants within the containers; displaying the hanging baskets; maintenance and pruning; and most of all, keeping the containers watered throughout the summer. The color wheel proved to be a useful tool for grouping plants and containers. A handout was developed to guide visitors through the container garden. Despite the challenges, the container garden and hanging basket trials proved to be a successful demonstration and were popular among visitors.
Earthworm Castings as a Media Amendment for Chrysanthemum Production
Authors: Hidalgo Pablo R. , Harkess Richard L. , Matta Frank
Published: February 2019

Castings from earthworm (Eisenia fetida) when fed on sheep (SC), cow (CC), or horse (HC) manures were evaluated on growth of Dendranthema `Miramar' cuttings. Castings were produced placing 100 L of manure and 1 kg of earthworms in a 212-L plastic container for each animal manure. Mixtures of peat moss and castings at 0:1, 1:3, 1:1, or 3:1 were evaluated for each animal waste with 100% peat and Sunshine Mix 1 used as the controls. Each media treatment was replicated eight times with each replication consisting of four cuttings per 1-L (15-cm diameter) plastic container. Leachate pH and nutrient content increased as the amount of castings in the media increased. Plant growth index, leaf area, and number of flowers were greatest in media consisting of SC at 1:1 and 3:1 peat:castings. Similar results for growth index and leaf area were obtained with CC at 3:1 and 1:1, respectively. Increasing the amount of castings in the substrate reduced the plant dry weight and increased shrinkage of the media.
Analysis of (Allium cepa × A. fistulosum) × A. cepa Fourth-generation Backcross Populations for A. fistulosum Introgression
Authors: Mangum Paul , Peffley Ellen
Published: February 2019

(Allium cepa × A. fistulosum) × A. cepa breeding lines have been established to the fourth generation. The aim is to develop an A. cepa-like bulbing onion carrying A. fistulosum genes. Seven populations were characterized for morphological traits and three isozyme markers. Each bulb from the populations was characterized for maturity, soluble solids content, bulb shape, and bulb color. All the populations produced A. cepa-like bulbs. Significant variation was observed within each population for each morphological trait. All the bulbs were screened for the presence of A. cepa and A. fistulosum alleles of alcohol dehydrogenase (Adh-1), esterase (Est), and phosphoglucoisomerase (Pgi-1). Allium cepa Adh-1, Est, and Pgi-1 alleles were observed in all the populations. One population, 951026-8, contained plants heterozygous for A. cepa and A. fistulosum Pgi-1 alleles. Recovery of these fourth generation Allium backcross plants demonstrates introgression of the A. fistulosum genome into an A. cepa-like bulbing onion.
Transplanting Depth Affects Pepper Lodging and Maturity
Authors: Mangan Francis X. , Vavrina Charles S. , Howell John C.
Published: February 2019

The effects of transplant depth on lodging and yield were evaluated in five experiments in Florida and Massachusetts. `Cherry Bomb', `Jupiter', and `Mitla' pepper (Capsicum annuum L.) transplants were set at three depths so that the soil surface was even with the top of the rootball, the cotyledon leaf, or the first true leaf. Seedlings set to the depth of cotyledon leaves or to the first true leaf lodged less than did those set to the top of the rootball. No yield differences were recorded among treatments in Massachusetts; however, total weight of red fruit was greater in treatments that lodged less in 1 of the 2 years, suggesting that lodging delayed maturity. Soil temperature in Massachusetts declined at the level of the rootball as planting depth increased.
Is Fall Burning Preferable to Spring Burning for Promoting Growth Characteristics Favorable for Mechanical Harvesting in Vaccinium myrtilloides Michaux?
Authors: Kloet S.P. Vander , Pither J.
Published: February 2019

Periodic prescribed burns of lowbush blueberry barrens promote high yield, aid in weed control, and reduce fungal and insect damage. Whether such prescribed fires should be set in the autumn or the spring has been a matter of some dispute. Previous research on Vaccinium angustifolium Aiton suggested some advantages to autumnal burning, but few data have been collected on V. myrtilloides Michaux. To evaluate whether time of burning affected plant qualities most favorable for mechanical harvesting, such as stem length and lateral branching, a series of experiments was conducted on V. myrtilloides. Differences in stem length, numbers of lateral branches, and buds per stem were nonsignificant among plants burned in fall vs. those burned in spring. In three of four experiments, however, fall burns resulted in the growth of fewer lateral branches. Furthermore, among the four experiments, growth responses were more uniform following fall than following spring burns. We therefore suggest that, where possible, fall burns should be prescribed for blueberry plants that will be mechanically harvested.
Cytokinin Expression in Campanula Transformed with Isopentenyl Transferase Gene
Authors: Joung Young Hee , Roh Mark S. , Kamo Kathryn , Song Jeoung Seob
Published: February 2019

The main goal of this research was to develop Campanula glaumerata `Acaulis' plants transformed with the isopentenyl transferase (ipt) gene for increased growth of the axillary buds and en-hanced insect resistance. Isopentenyl transferase is a first enzyme in the cytokinin biosynthetic pathway. For Campanula transformation, leaf discs were co-cultivated with Agrobacterium tumefacience LBA4404, which harbored the binary vector pBC34 (A. Smigocki, Beltsville, Md.) that codes for the nos-nptII gene and the ipt gene controlled by the CaMV35S promoter. The transformation frequency was about three times higher when leaf blade explants were infected with LBA4404 containing pBC34 as compared to infection with pGUSINT, which contains the gusint gene instead of the ipt gene. This difference in transformation frequency was attributed to expression of cytokinin from the ipt gene. Transgenic plant lines containing the ipt gene were verified by southern hybridization and divided into three groups by phenotype following culture in vitro on MS medium: 1) yellow/large leaves, no rooting; 2) green/large leaves, no rooting; 3) green/normal leaf size, rooting. These different phenotypes could be due to different levels of cytokinin expression in the transgenic plants.
Use of a Food-processing Residual Compost for Salad Green Production on Organic Farms: Soil Response and Crop Yields
Authors: Worden Christopher , Elliott George , Bible Bernard , Guillard Karl , Morris Thomas
Published: February 2019

A composting facility in New Milford, Conn. (NMF), utilizes food-processing residuals, including spent tea leaves, coffee grounds, cocoa shell and cleanings, wastewater treatment sludge from a food ingredients manufacturing plant, and past-expiration processed vegetable products. Materials are composted in aerated, frequently turned windrows under cover. The range of inputs, combined with time constraints on the composting process, has resulted in a variable, immature compost product with a high rate of microbial activity. Users have expressed concern about potential phytotoxicity or nutrient immobilization from using NMF compost. Therefore, research was conducted to determine the influence of cured and uncured NMF compost amendments on potentially sensitive crops with high nutrient requirements. Arugula (Eruca vesicaria) and green bibb lettuce (Lactuca sativa) were grown on two Connecticut organic farm research sites in 1998 and 1999. Both sites have soils classified as coarse loamy over sandy or sandy-skeletal, mixed, mesic, typic, Dystraudepts. Farms differed in the length of time under organic farm management. One farm has been an organic farm since 1988 and consequently has high soil fertility, while the other was a first-year organic farm in 1998, and had relatively low soil fertility. Three amendment types were applied: cured compost, uncured compost, and organic fertilizer (5N-3P2O5-4K2O). Amendment application rates were estimated to provide a comparable range of plant-available nutrients for the amendments and a control without fertilizer. Compost application rates were 3.4, 6.8, 20.2, 35.8, and 71.7 Mg·ha-1 (dry-weight basis) in 1998 and 11.2, 22.4, 44.8, and 89.6 Mg·ha-1 (dry-weight basis) in 1999. Organic fertilizer application rates were 1.34, 2.68, 5.36, 10.72, and 21.44 Mg·ha-1 in 1998 and 1.34, 2.68, 5.38, and 10.72 Mg·ha-1 in 1999. Soil organic matter and nutrients increased with amendment application rate at both locations. Crop yields increased with amendment rate at the new, lower-fertility farm, but yields did not respond to amendments at the older, higher-fertility farm. Yield differences were minor between the uncured and cured compost treatments at both locations. This indicates that either cured or uncured NMF food-processing residual compost can be successfully used as an organic soil amendment for salad green production.
Seedless Watermelon Production: Extension's Role in Supporting a New Crop Enterprise
Authors: Wootten Tracy , Kee Ed
Published: February 2019

In response to a national increase in the consumption of triploid (seedless) watermelons, seedless watermelon production in Delaware has increased to 43% of the total watermelon acreage. Cultural practices for triploid watermelon production are similar to seeded (diploid) types. However, poor seed germination, high seed costs, erratic performance, and inadequate varieties limited their adoption until the early 1990s in Delaware. Univ. of Delaware Cooperative Extension has worked with Delaware growers to develop a “recipe” for successful triploid production. Extension programs, such as on-farm demonstrations, research trials, educational seminars, and one-on-one consultations, have enabled producers to provide high-quality fruit and yields. Intensive management and marketing are the keys tosuccess as Delaware producers have become leaders of triploid production in the Northeast region. As demand for triploid watermelon continues to increase, extension will remain a vital part of the $4.5 million industry. Growers continually deal with marketing issues in a supply and demand-driven market. As more seedless are on the market and profits lessen, growers will have to be diligent in their marketing and management practices.
Improving Mechanical Harvest Pickle Production
Authors: Kee Ed , Wootten Tracy , Adkins James , Glancey James
Published: February 2019

Proper variety selection and production practices are critical to obtaining profitable yields of mechanically harvested pickling cucumbers (Cucumis sativus L.). On the Delmarva peninsula, the tractor-mounted harvester, which utilizes the pinch-roller system for separating the pickles from the vine, was used exclusively for harvest until 1998. The pull-type forced-balance shaker machines have been introduced as an alternative harvest system. Replicated commercial-size variety trials have been conducted for four consecutive years. The trials are planted twice during the growing season, reflecting the climactic differences associated with early-season and late-season plantings. `Vlaspic' and `Lafayette' are standard varieties. Promising new varieties include `EX 1914' and `SQRP 1882'. Investigations to determine optimum plant populations and row spacing have determined that three-row beds with 60,000 plants per acre provide the highest yields and best quality fruit. Optimal operating speeds and picking reel speeds of 1.4 mph and 45 rpm, respectively, have been determined for the tractor-mounted machine. Additional design improvements have been implemented and evaluated to reduce damage. Fifty-nine replicated commercial tests evaluating the tractor-mounted harvester and the forced-balance shaker type indicate much greater harvest and throughput efficiencies are associated with the forced-balance shaker harvester, resulting in improvements between $65 and $100 per acre.
Tomato Growth in Spring-sown Cover Crops
Authors: Akemo Mary C. , Bennett Mark A. , Regnier Emilie E.
Published: February 2019

Pure and biculture stands of rye `Wheeler' (Secale cereale L.) and field pea (Pisum sativum L.) were established and killed for mulch in Spring 1996, 1997, and 1998, in Columbus, Ohio. Treatments were five rye to pea proportions, each with a high, medium, and low seeding rate. Their effects on tomato (Lycopersicon esculentum Mill.) growth and yield were compared with those of a weedy check; a tilled, nonweeded check; and a tilled, hand-weeded check. Tomato tissue and soil were sampled for nutrient analysis. Number of leaves, branching, height, leaf area, dry weight, rate of flowering and fruit set, and fruit yield of tomato plants varied directly with the proportion of pea in the cover crop and decreased with reduced cover crop seeding rates. In 1997, yields of tomato were as high as 50 MT·ha–1 in the 1 rye: 3 pea cover crop; yield was poorest in the weedy check (0.02 MT·ha–1 in 1996). Most of the cover-cropped plots produced better yields than did the conventionally weeded check. No consistent relationship between levels of macro-nutrients in tomato leaf and soil samples and the cover crop treatments was established. Spring-sown rye + pea bicultures (with a higher ratio of pea) have a potential for use in tomato production.
Objective Method for Measuring Firmness of Iceberg Lettuce
Authors: Schofield R. Andrew , DeEll Jennifer R. , Murr Dennis P.
Published: February 2019

Traditional hand compression firmness scores of iceberg lettuce (Lactuca sativa L.) heads were compared with force-deformation data collected from parallel-plate compression tests conducted with a universal testing machine. Sample deformation was measured over a load range of 30 to 40 N. A quadratic response surface best described the relationship between hand firmness scores (1 to 5 scale) and three measurements of sample deformation (mm). Sample deformation was as precise as hand compression in measuring lettuce firmness, and it provided improved reproducibility by eliminating much of the human error. Although adequate for most firm heads, the predictive ability of the statistical model was weak for soft heads (when the hand firmness score was <2), and for heads with inconsistencies in firmness because of uneven leaf distribution. The minimum sample size required to determine accurately the mean firmness score (±0.5 units) of a population of harvested lettuce was ≈20 heads. This may be a disadvantage, since sampling one head requires ≈1.5 minutes. Overall, the instrument-based method measures lettuce firmness as precisely as the hand compression method, and provides a standardized, objective measurement for postharvest researchers when exchanging or reporting firmness data.
Volatile Emissions and Chlorophyll Fluorescence as Indicators of Freezing Injury in Apple Fruit
Authors: Forney Charles F. , Jordan Michael A. , Nicholas Kumudini U.K.G. , DeEll Jennifer R.
Published: February 2019

Use of volatile emissions and chlorophyll fluorescence as indicators of freezing injury were investigated for apple fruit (Malus ×domestica Borkh.). `Northern Spy' and `Delicious' apples were kept at -8.5 °C for 0, 6, or 24 h, and then at 20 °C. After 1, 2, 5, and 7 d at 20 °C, fruit were analyzed for firmness, skin and flesh browning, soluble solid content, titratable acidity, ethanol, ethyl acetate, ethylene, respiration rate, and chlorophyll fluorescence. Freezing caused skin and flesh browning and a loss of fruit firmness, which was greater in `Northern Spy' than in `Delicious'. In `Northern Spy' fruit subjected to the freezing treatments, ethanol and ethyl acetate concentrations were as much as 37- and 300-fold greater, respectively, than in control fruit. `Delicious' fruit showed similar patterns of ethanol and ethyl acetate increase, but of lower magnitude, as a result of freezing. Higher fruit respiratory quotients were associated with increased ethanol and ethyl acetate concentrations. Ethylene production and chlorophyll fluorescence of fruit were reduced by freezing.
Assessment of Severity of Powdery Mildew Infection of Sweet Cherry Leaves by Digital Image Analysis
Authors: Olmstead James W. , Lang Gregory A. , Grove Gary G.
Published: February 2019

A personal computer-based method was compared with standard visual assessment for quantifying colonization of sweet cherry (Prunus avium L.) leaves by powdery mildew (PM) caused by Podosphaera clandestina (Wallr.:Fr.) Lev. Leaf disks from 14 cultivars were rated for PM severity (percentage of leaf area colonized) by three methods: 1) visual assessment; 2) digital image analysis; and 3) digital image analysis after painting PM colonies on the leaf disk. The third technique, in which PM colonies on each leaf disk were observed using a dissecting microscope and subsequently covered with white enamel paint, provided a standard for comparison of the first two methods. A digital image file for each leaf disk was created using a digital flatbed scanner. Image analysis was performed with a commercially available software package, which did not adequately detect slight differences in color between PM and sweet cherry leaf tissue. Consequently, two replicated experiments revealed a low correlation between PM image analysis and painted PM image analysis (r2 = 0.66 and 0.46, P ≤ 0.0001), whereas visual assessment was highly correlated with painted PM image analysis (r2 = 0.88 and 0.95, P ≤ 0.0001). Rank orders of the 14 cultivars differed significantly (P ≤ 0.05) when PM image analysis and painted PM image analysis were compared; however, rankings by visual assessment were not significantly different (P > 0.05) from those by painted PM image analysis. Thus, standard visual assessment is an accurate method for estimating disease severity in a leaf disk resistance assay for sweet cherry PM.