bluuebunny/crossref_metadata_2025 huggingface dataset:
Somatic Embryogenesis and Plant Regeneration of Wiregrass (Aristida stricta) and Creeping Bluestem (Schizachyrium scoparium var. stoloniferum)
Authors: Chen Wusi , Norcini Jeffrey G. , Kalmbacher Robert S. , Aldrich James H.
Published: February 2019

Initiation of callus and induction of embryogenesis were achieved from both wiregrass and creeping bluestem. MS basal medium containing coconut milk, sucrose, and 2,4-D were used to initiate callus from young inflorescence of wiregrass and creeping bluestem. The presence of 2,4-D was found to be essential for the induction and early development of embryoids, possibly up to the globular stage. In the case of bluestem, initiation of embryogenic callus required the presence of a low concentration of BA; using only 2,4-D resulted in more non-embryogenic callus. More globular embryos were formed when embryogenic cultures grew rapidly without subculturing, or after being transferred to a hormone-free or a reduced 2,4-D medium. Plant regeneration was carried on a hormone-free MS medium. Initiation of cell suspension and induction of embryoid formation of wiregrass were achieved. However, maintaining cell suspensions seems to have some problems. A majority of the cells were thick-walled, elongated, and non-dividing. No embryos were formed in suspension cultures planted onto solid media. Reinitiation of cell suspension culture of wiregrass is in progress. Initiation of creeping bluestem cell suspension culture was carried out in MS basal medium containing coconut milk, sucrose, and 2,4-D. The maintenance of the cell suspension cultures and induction of embryoid formation were tested under different combinations and concentrations of growth regulators. Suspension cultures were selected and planted onto semi-solid MS basal medium with or without growth regulators. Somatic embryoids formed from suspension culture 3 to 4 weeks after being planted on semi-solid medium. Germination and plant regeneration of somatic embryoid of creeping bluestem are in progress.
On the Standardization of Seabuckthorn (Hippophae rhamnoides L) Oil
Authors: Lobacheva I. , Letchamo W.
Published: February 2019

Seabuckthorn (Hippophae rhamnoides, L) (Oblepiha, Siberian pineapple, Sandorn, Sha-ji), a perennial from the Eleagnaceae family, has attracted the interest of North American natural products industry because of its effective multiple applications in cosmetic, nutriceutical, and veterinary industries. The oil obtained from the berries, bark, and leaves, and is known to contain carotenoids, vitamins, and essential fatty acids. The objective of this investigation was to elaborate and establish reliable, but inexpensive, methods in the process of standardization of the quality of oblepiha oil. Data of the phytochemical analysis of oblepiha oil obtained from various research reports and industrial and experimental sources, located in different parts of Russia (ex-USSR), were extensively investigated and statistically evaluated. An indirect method of standardization of oblepiha oil, based on the content of carotenoids and unsaponifiable fraction of the oil, has been proposed. The correlation between total carotenoids and unsaponifiable lipids in extracted oil of oblepiha (r = 0.76; P ≤ 0.05) has been shown. The strong relationship between carotenoids, unsaponifiable lipids, and sterin fractions in the raw material and industrial oil indicates the possibility of using the level of total carotenoid concentration as a reliable and direct approach to indirectly determine the efficacy of oblepiha oil for nutritional, pharmacological, and cosmetic applications.
Development of Thymus vulgaris Varieties for North American Commercial Organic Cultivation
Authors: Letchamo W. , Kireeva T.
Published: February 2019

Five different cultivars of Thymus vulgaris originating from various geographical sources (Canada, F.R. Germany, former GDR, and Spain) were first propagated by cuttings from each cultivar in the greenhouse and then cultivated organically in the fields during the periods of 1993–1995 (Quebec, Canada) and 1996–1997 (Washington State). The field-grown plants were harvested in mid-September. The oils obtained through steam distillation of the dried leaves from each cultivar were analyzed by means of TLC followed by GC. The oil content varied from 1.38% to 2.04% in Quebec, and 1.41% to 2.25%, depending on the cultivar used. The highest oil content was obtained from `Madrid', followed by `RH-1' and `Laval-1'. More than 95% of the oil, with a total of 24 components, were identified in the samples. `Laval-1', recently developed in Quebec, `Madrid' from Spain, and `RH-1' from Germany were established to belong to thymol-chemotypes, while `RH-2' from Germany was found to be carvacrol-chemotype. `QDLB', from the former GDR, was characterized by its ≈39% thymol, 17% carvacrol, and 3.52% linalool content in the oil. The content of thymol and its ratio was found to change slightly with shifting cultivation of the cultivars from Europe to North America. Other important constituents in the essential oils were also p-cymene (10.87–22.89%), g-terpinene (2.21–8.85%), α-pinene (0.87–2.23%), sabinene (0.00–1.77%), borneol (0.00–3.69%), geraniol (0.59–3.48%), and terpinen-4-ol (0.21–3.08%). As `Laval-1' and `RH-1' showed better overwintering ability and produced relatively higher leaf yields. These two cultivars were found to be prospective cultivars for commercial organic cultivation for North America. Results obtained from various growing areas are presented.
The Selection and Development of High-quality Echinacea for Industrial Processing
Authors: Letchamo W.
Published: February 2019

Echinacea is one of the oldest medicinal plants that had been used by the native Indians of North America for bacterial and viral ailments. With the increasing scientific findings about the usefulness of Echinacea in natural immune stimulation of humans, the demand for high-quality echinacea product in natural food markets in the United States and Europe has been growing. However, most of the commercial supply of echinacea originates either from heterogeneous material or wild collections. Trout Lake Farm in Washington State is the leader in production and processing of echinacea. The objective of this investigation was to find and develop high-quality echinacea lines or cultivar for commercial biological production and processing. The variation in morphological traits, ripening period, the root and shoot yields, resistance to diseases and insects, and the content of active substances (cichoric acid, echinacoside, isobutylamides, and essential oil) in E. purpurea was carried out during the 1996 growing season. We found dramatic variations in plant height, color and size of the leaves, flowers and period of flower induction, yield, and the accumulation of the active substances.
Two Methods for the Rapid Assessment of Leaf Yields of Erythroxylum coca `Coca'
Authors: Acock Mary C.
Published: February 2019

To determine the extent of world coca (Erythroxylum) production, methods for rapid estimation of yield (leaf mass) are required. The objective of this research was to compare two methods for rapidly acquiring data to estimate yield. The plant canopy analyzer (PCA) method was based on measuring canopy light interception with the LI-COR PCA, calculating leaf area index (L), and converting L to leaf dry weight using specific leaf area (SLA) values. The canopy subsample method was based on calculating leaf dry weight of a subsample from leaf and branch number, leaf size, and SLA, then multiplying by the ratio of the canopy volume to the subsample volume. PCA measurements underestimated leaf yields when values of L were ≥1.0. PCA estimates could be corrected by adjusting for the observed difference between leaf yields and PCA estimates. The corrected PCA and canopy subsample methods had errors of similar magnitude, both slightly underestimating yield. Both methods performed well when tested against data from a subsequent harvest. The canopy subsample method uses simple equipment and can be ap-plied in almost any environmental condition, but requires more time in the field than the PCA method. The corrected PCA method has slightly less random error than the canopy subsample method but requires expensive equipment, uniform light conditions in the field of view, and cannot be applied when raining.
Interspecific Crossability of Nine Diploid Fragaria Species
Authors: Bors Bob , Sullivan J. Alan
Published: February 2019

As part of a wild species introgression program, Fragaria vesca, F. viridis, F. nubicola, F. nipponica, F. nilgerrensis, F. pentaphylla, F. gracilis, F. daltoniana, and F. iinumae were crossed in most combinations possible, the exceptions being F. daltoniana and F. iinumae, which produced only a few flowers each. Crosses with F. vesca as a female and either F. gracilis, F. nipponica, or F. iinumae as males produced good seed set, but seedlings died in the cotyledon stage in every case. No seed set occurred when F. iinumae was crossed with F. viridis or F. nubicola. F. pentaphylla, F. gracilis, and F. iinumae were observed to be self-incompatible while F. daltoniana was self-compatible. Three overlapping groups based on crossing data have emerged. Within the following groups, hybrid plants were obtained in all species combinations, although not necessarily for reciprocal combinations: Group A: F. vesca, F. viridis, F. nubicola, and F. pentaphylla. Group B: F. vesca, F. nilgerrensis, F. daltoniana, and F. pentaphylla. Group C: F. pentaphylla, F. gracilis, and F. nipponica. Fertile or semifertile diploid hybrids were obtained for all species combinations within group A indicating genomic similarity or that breeding at the diploid level could occur with these species. Fertility has not been determined for hybrids in groups B and C. It is interesting to note the presence of F. pentaphylla in all three groups, perhaps this species plays an important role in Fragaria evolution.
Toxicity, Uptake, and Distribution of Simazine in Canna hybrida `King Humbert': Implications for Phytoremediation
Authors: Wilson Patrick C. , Whitwell Ted , Klaine Steven J.
Published: February 2019

This research focuses on the potential use of Canna hybrida `King Humbert' for removing simazine from contaminated water generated at golf courses and ornamental nurseries. Because of simazine's herbicidal activity, it is important for levels in solution not to exceed plant tolerance levels. Tolerance levels for C. hybrida were determined by dosing plants for 7 d with 0, 0.01, 0.03, 0.1, 0.3, 1.0, or 3.0 mg simazine/L nutrient media. Measurements of 7-d fresh mass production and photosynthetic efficiency (Fv/Fm) were taken. Simazine uptake and distribution within the plant was determined by dosing plants with 2.03 mCi 14C-simazine (0.243 mg/L) for 1, 3, 5, or 7 d. Plant tissues were analyzed by combustion and liquid scintillation counting. Fresh mass production was reduced 66% and 78% for plants exposed to 1.0 and 3.0 mg/L, respectively. Likewise, photosynthetic efficiency was reduced to 66% and 40% of the controls at the same respective concentrations. Plant uptake of simazine accounted for 13%, 34%, 48%, and 65% of the original simazine in the dosing solution after 1-, 3-, 5-, and 7-d exposure, respectively. This simazine was distributed primarily between roots and leaves.
Induction of Chlorophyll-deficient Phenotypes in Tillandsia fasciculata Swartz Var. fasciculata by Physical and Chemical Mutagens
Authors: Koh Yong Cheong , Davies Fred T.
Published: February 2019

Seeds of Tillandsia fasciculata var. fasciculata were treated with gamma radiation, gamma and thermal neutron radiations, or ethyl methanesulfonate (EMS) and grown in vitro. Observed chlorophyll deficient phenotypes included yellowish-green, yellow, variegated and albino. The highest combined percentages of chlorophyll deficient phenotypes was 8.7% for the gamma radiation treatment (2.7 krad), 4.6% for the gamma and thermal neutron radiations treatments (combined dose of 2.7 krad at a gamma to thermal neutron ratio of 7.4:1.0), and 10.8% for the EMS treatment (0.4% EMS × 5 h). Some yellowish-green and yellow seedlings multiplied in half strength MS medium with 0.3 or 0.5 μM BA and IBA and the newly formed shoots retained their respective mutant phenotypes. However, the variegated seedlings were sectoral or mericlinal chimeras and when they multiplied, the newly formed shoots were not variegated. The chlorophyll a/chlorophyll b ratio of the wild type seedling was 1.1 whereas that of the yellowish-green and the yellow seedlings was 2.0. Electron micrographs showed that compared to the wild type chloroplasts, the chloroplasts of the yellowish-green and yellow seedlings had fewer grana and fewer thylakoids within each granum.
Moisture Soil Level Determination in Husk Tomato (Physalis ixocarpa Brot.) Crop in Western Mexico
Authors: Radillo-Juárez F. , Farias-Larios J.
Published: February 2019

When moisture conditions in soil are suitable, the husk tomato has good vegetative growth and high yield. The objective of this work was determine the minimum available moisture level to obtain the highest yield, and establish an irrigation calendar. Treatments evaluated were: 15%, 30%, 45%, and 60% of moisture reduction in soil, according to the gravimetric method, in a randomized complete-block design with four replications. The variance analysis and Duncan test were carried out at a 0.05 level of probability for following variables studied: Fresh fruit yield (kg/ha), plant height, root length, and fruit diameter. The results show that a 30% reduction moisture level was remarkable with a 28,610.67-kg/ha yield of fresh fruit. In relation to agronomics characteristics, the results show that, for plant height, root length, and fruit diameter were remarkable with the 15% and 60% reduction moisture, respectively. This was due to the greater interval of irrigation and tendency of root system to search for moisture. The greater vegetative growth and yield is with a moisture level of 65% to 80% present in soil, indicating that the husk tomato tolerates this 30% of reduction moisture, with higher values producing more stress in plants and modifying the vegetative growth and production.
Yard Trimmings–Biosolids Co-compost can Substitute for Sphagnum Peatmoss in Tomato (Lycopersicon esculentum Mill.) Transplant Media
Authors: Ozores-Hampton Monica P. , Vavrina Charles , Obreza Thomas A.
Published: February 2019

Large volumes of a compost made by mixing and co-composting yard trimmings (YT) and biosolids (BS) feedstocks have recently become available to the Florida vegetable industry. Compost used as vegetable transplant medium may be less expensive than traditional Sphagnum peatmoss, which is a non-renewable resource. `Agriset 761' tomato seed were planted in five combinations of compost, peat, and vermiculite media: 0:70:30 (control), 18:52:30, 35:35:30, 52:18:30, and 70:0:30 by weight, respectively. The presence of compost in the media increased leaf area, shoot dry weight, and number of leaves 21 days after treatment (DAT), and leaf area, shoot dry weight, root dry weight 28 DAT compared with the control. There were no differences in root dry weight 21 DAT and number of leaves 28 DAT between treatments containing compost and the control. Plants in the compost treatments had greater final leaf area, shoot dry weight, root dry weight, and stem diameter but less chlorophyll content compared with the control. There was no effect of compost rate on any of the response variables measured. Neither final leaf number nor stem length were affected by media composition. The results suggest that YT/BS co-compost can be used as an alternative to peat media for tomato transplant production, and that the rate of use is not critical.
Drought Behavior of Nonbearing Clingstone Peaches on GF 677 Rootstock Cultivated under Field Conditions
Authors: Zegbe Jorge A.
Published: February 2019

Water relations, chlorophyll and proline content, and vegetative growth were obtained from three clingstone peach genotypes (S135,) grafted on peach × almond hybrid (GF 677,) rootstock (S135/GF 677) and seedling trees from S135 (SPTS135). The experiment was carried out under field conditions during the dry season (April–June) to evaluate the influence of the GF 677 rootstock on scion in 1997. Leaf water and osmotic potentials tended to be lower in S135/GF 677 than SPTS135 trees and irrigated seedlings peach trees (control). Although S135/GF 677 trees developed the lowest osmotic potential, the turgency was similar to SPTS135 trees. Relative water content and transpiration rate were the lowest in S135/GF 677 trees; SPTS135 trees were intermediate between S135/GF 677 and control trees. Chlorophyll and proline levels were increased in S135/GF 677 and SPTS135 trees compared with the control. Shoot growth was significantly delayed in S135/GF 677 trees compared with SPTS135 and control trees. Even though some scion physiological variables were modified by the GF 677, rootstock, the effect was not big enough to confer significant drought resistance to the scion.
Growth of Container-grown Plants With and Without Azomite Soil Amendment
Authors: Ely Chris , Hubbard Mark A.
Published: February 2019

Azomite is a mined, commercially available, hydrated sodium calcium aluminosiliclate soil amendment reported to act as a source of mineral elements. To determine its effect on plant growth, Dendranthema `Connie' rooted cuttings, Malus seedlings, and Citrus seedlings were grown in containers in one of two growing media: ProMix BX or ProMix BX with Azomite (1:1, v:v). Plant height was monitored weekly and after 6 weeks of growth, fresh and dry plant weights of roots and shoots were determined. There was no difference in any of the parameters measured as a result of the addition of Azomite. Any nutritional influence of the Azomite may only be evident in different conditions, e.g., field soil, or over an extended period of time. The Azomite altered the medium's physical properties and therefore bulk density and water-holding capacity of the Azomite were determined for consideration.
Establishment of In Vitro Genebank of Colombian Cultivars of Achira (Canna edulis Ker.)
Authors: Reyes Luz M. , Ligarreto Gustavo , Muñoz Germán , Bravo Pilar , Valbuena Edgar
Published: February 2019

Clonal propagation of an Andean tuber `Achira' (Canna edulis Ker.) is currently limited to budding. A tissue-culture system to rapidly produce clonal material would be valuable for both production and germplasm preservation. Thirteen cultivars collected at the provinces of Cáqueza (Cundinamarca) and Garzón (Huila) were utilized for the establishment of meristem-tips (5 mm) under in vitro conditions. Based on protocols reported for species of Musa sp., C. indica and Elletaria cardamomun, a complete random design was implemented with 10 treatments and six replications per clone. The analysis of variance showed no significant differences between cultivars, but significant differences among treatments. The variables measured were number of shoots, aerial roots formation, roots (relative amount), callus (absent or present) and degree of etiolation. Double disinfestation protocol was used in this study in order to reduce the degree of contamination of the explants during the culture. Organogenesis was obtained for the whole cultivars, without callus formation, with treatments 9 and 10. However the best results for shoot and root formation was detected for the treatment 10. This was constituted by MS (1/2) supplemented with 0.1 ppm BAP; 0.5 ppm IBA; 3% sucrose, and 2% phytagel. The explants were grown at 26 °C with photoperiod of 16 hours and 2000 lux. After 3 weeks the shoot formation was evident, while the rooting started after 4 weeks. Subcultures were done every 3 weeks after plantlets formation. The 13 cultivars established under in vitro conditions were placed at the active genebank of the Plant Genetic Resources National Program at CORPOICA, for their conservation under low growth conditions.
Cover Crops for San Joaquin Valley Row Crop Production Systems
Authors: Mitchell J.P. , Prather T.S. , Hembree K.J. , Goodell P.B. , May D.M. , Coviello R.L.
Published: February 2019

There is currently considerable interest in the use of cover crops to improve the productivity and sustainability of agroecosystems in California. Adoption of cover crops into San Joaquin Valley row cropping systems has been slow, however, largely because growth characteristics of potentially suitable cover crop species and mixtures have not been identified for the tight windows of opportunity that exist within the region's intensive rotations, and because of uncertainy about the amount of water required to grow a cover crop. In 1995–96 and 1997–98, we screened 15 potential late-summer and winter cover crop species and mixtures planted monthly from 1 Aug. through 1 Nov. and harvested at 30-day intervals through March. In 1995–96, Sorghum-sudan produced 36,543 lb dry matter/acre and was the highest-producing late-summer species in a December-harvested August planting. Triticale and Merced rye were highest-producing winter species, yielding 19,277 and 10,155 lb dry weight/acre, respectively, during the 5-month period from October to March.
Tillage and Mulch Effects on Yield of Bell Pepper (Capiscum annum L.)
Authors: Abdul-Baki Aref , Morse Ronald D.
Published: February 2019

In 1997, three tillage/mulch pepper production systems were compared on raised beds at the Beltsville Agricultural Research Center (BARC), Md., and at Kentland Agricultural Research Farm (KARF), Blacksburg, Va. The tillage/mulch treatments were no-till hairy vetch (Vicia vellosa Roth) mulch (NT-HV), black plastic mulch on beds that were conventionally tilled and reformed before transplanting the peppers (CT-BP), and untilled bare soil (NT-BS). `Camelot' bell peppers were planted in early June 1997 in double rows at both sites. Both the CT-BP and NT-BS treatments received approximately double the nitrogen fertilizer, compared to NT-HV. Nitrogen was applied throughout the growing season at BARC, while all the N fertilizer was applied during the first 3 weeks of plant growth at KARF. Nine weekly harvests were made at BARC and six at KARF. Fruit yield was high in all treatments at both sites. There were no significant differences among treatments in marketable yield or fruit weight at BARC. In contrast, yield was significantly higher with CT-BP than with NT-HV and NT-BS at KARF. Higher yield with CT-BP at KARF possibly occurred from enhanced soil temperature and reduced N leaching normally associated with black plastic mulch production systems.
Effect of Upright Shoot Removal on Fruit Size and Maturity of Four-year-old `Braeburn' Apple Trees
Authors: Garriz P.I. , Colavita G.M. , Alvarez H.L. , Alvarez A.J.
Published: February 2019

The effect of upright shoot removal on the progress of maturity and fruit size around the normal picking time were evaluated for apple fruits cv. `Braeburn' at the Experimental Farm of the Comahue National Univ., Rio Negro, Argentina, during the 1996–97 growing season. The experiment was conducted on 4-year-old trees, spaced 4.0 × 2.3 m and trained to palmette leader. Average fruit load was 80 fruits per tree. Five trees per treatment were randomly selected; they were: 1) select cuts: water sprouts were eliminated entirely at 78 days after full bloom (DAFB) and additional removal of newly formed shoots arising from the scaffolds was performed at 120 DAFB; 2) control: trees received no cuts. From 158 to 184 DAFB, a sample of four fruits was taken from each tree at weekly intervals. Fruit size and internal quality were measured. Loss of leaf surface by shoot removal significantly decreased fruit mass by 4.74%, for all data combined (P < 0.05). There was no treament effect on maturity, although the rate of firmness decline was lower for fruit from treated trees. At 172 DAFB, pressure, starch index (iodine test) and soluble solids concentration values for control fruits were 80.55 N, 3.72 and 12.35%, respectively. In the treated trees, fruit mass was 201.03 g at final harvest. It was concluded that reduction in photoassimilates following severe upright shoot removal may be a key factor in the negative effect of this practice on final fruit size. These results suggest some goals of pruning and training for optimizing apple yield.
Breeding for Leafminer Resistance within the Genus Betula
Authors: Hoch William A. , Zeldin Eric L. , McCown Brent H.
Published: February 2019

The birch leafminer (Fenusa pusilla) is an important insect pest of white-barked ornamental birches (Betula spp.). Although genetic resistance to birch leafminer exists within this genus, it has not been identified in the desirable white-barked species. Twenty-three interspecific crosses were performed in an attempt to combine ornamental white bark and leafminer resistance. The parental species and resulting hybrid populations were assayed for resistance. All assays utilized adult birch leafminers reared in our laboratory using a method we developed to provide a year-round supply of fresh leafminer adults. Previous studies viewed birch leafminer resistance as the unwillingness or inability of the female leafminer to oviposit eggs into the leaves of resistant Betula species. Our work has shown that female birch leafminers are unable to distinguish between suitable and nonsuitable host species. This work also has discovered two separate mechanisms of inherent resistance to the birch leafminer: leaf chemistry and a hypersensitive response. Two native species, B. alleghaniensis and B. lenta, kill the leafminer larvae shortly after hatching. Analyses suggest that a specific compound or class of compounds is responsible for leafminer mortality in these species and that this resistance is reduced in F1 hybrids that include a susceptible white-barked parent. The second resistance mechanism involves a hypersensitive response to the deposition of the leafminer egg and results in failure of the egg to hatch. Interestingly, this response is seen in one of our breeding lines (B. populifolia × B. maximowicziana), but has not been observed in either parental species. These hybrid progeny are currently in field test plots for further evaluation of leafminer resistance and ornamental characteristics.
San Luis (Chile Ancho pepper) with a Mixed Glomus spp. from Mexico and Glomus intraradices
Authors: Husain Javed , Davies Fred T. , Egilla Jonathan N.
Published: February 2019

The effect of a mixed isolate of arbuscular mycorrhizal (VAM) fungi [Glomus spp. from Veracruz, Mexico] and a pure isolate of Glomus intraradices was assessed on the growth and gas exchange of `Chile Ancho' (Capsicum annuum L. cv. San Luis) under phosphorus (P) stress. The experiment was carried out under glasshouse conditions in 1-L plastic pots containing a pasteurized mixture of 1 sand: 1 sandy loam (v/v). Plants were inoculated or noninoculated with VAM. Plants were fertilized with a modified Long Ashton nutrient solution (LANS) containing 0 or 11 (g phosphorus/ml). Gas exchange measurements were taken 21 and 70 days after the experiment was initiated. Mycorrhizal plants at both 0 and 11 (g P/ml) had greater leaf area, fruit, root, stem and leaf dry mass, and a lower specific leaf area and root/shoot ratio than nonmycorrhizal plants. Nonmycorrhizal plants not supplied with P had a higher leaf area ratio than plants colonized with G. intraradices. Net photosynthesis and stomatal conductance were not consistent with growth responses. There were no significant differences in growth and gas exchange between the two mycorrhizal isolates.
A Survey of Nursery Water Quality Best Management Practices
Authors: White Cody J. , Schnelle Michael A. , Cuperus Gerrit W.
Published: February 2019

A survey was designed to assess high-risk areas with respect to environmental contamination, specifically how it relates to water quality. Oklahoma growers of all economic levels, retail and/or wholesale, were queried at their place of business for their current state of implementing best management practices (BMPs) and other strategic actions that could potentially affect current and future water quality standards. Specific areas such as the physical environment of the nursery, primary pesticides and fertilizers used, Integrated Pest Management (IPM) practices, and employee safety training were covered as well as other aspects germane to preserving and protecting current water quality and related environmental issues. More than 75 nurseries were surveyed and given the opportunity to participate in future training at Oklahoma State Univ. Results indicated that nurseries have not fully implemented many BMPs, but have adopted fundamental IPM approaches. The stage is set for the implementation of the next phase of expansion and refinement into ecologically based programs such as propagation and sale of low pesticide input plant materials, improved cultural practices, and the integration of environmentally sound management approaches. As an example, many growers are in the process of phasing out calendar-based pesticide application programs in favor of aesthetic and/or economic threshold-driven pesticide spray programs.
Instructor Attitudes toward Interactive Television for Training Master Gardeners at a Distance
Authors: Warmund Michele R. , Schrock Denny
Published: February 2019

Master Gardener training was delivered via interactive television (IT) or face-to-face (FTF) in 1996 and 1997. Following 1997 training, instructors were surveyed to determine if the method of program delivery influenced their perceptions of Master Gardener training. Most instructors preferred FTF program delivery as compared to IT training. More preparation time was spent in developing lecture notes, text slides, and visual aids for IT vs. FTF training. Although instructors were more comfortable with FTF training than IT programming, their comfort level with IT training increased with experience. A major reason for instructor discomfort with IT was the lack of personal contact with trainees. Although lack of interactivity was identified as a limiting factor with IT training, trainees monopolizing time during sessions was a major constraint for FTF training. In spite of instructor preference for FTF Master Gardener training, nearly all instructors indicated a willingness to teach IT training again. Motivating factors for future IT training included less night time instruction, less need to travel, job efficiency, and the opportunity to use new technology.
Schools, Children, and Gardening: The Results of a Children's Garden Competition among Florida Elementary Schools
Authors: Skelly Sonja M. , Bradley Jennifer Campbell
Published: February 2019

Children's contact with nature is slowly diminishing as we progress towards a more technology-orientated society. While computers and other technology provide students with valuable skills, children are becoming more detached from nature and the unique opportunities nature can provide. School gardens offer teachers and students a “down to earth,” hands-on approach they might not otherwise gain in the classroom. In Spring 1998, the Univ. of Florida in conjunction with the 1998 Epcot® International Flower and Garden Festival hosted a competition for the best elementary school garden among Florida elementary schools. The competition called for schools to construct or use an already existing garden and for teachers to incorporate the garden in their classroom instruction. Approximately 100 elementary schools throughout Florida participated in the competition. From these schools a random sample of 500 students were selected to answer an environmental attitude survey. Students completed the survey at the beginning of the spring semester and at the completion of the competition in April to examine the effects of the garden competition on their environmental attitudes. In addition, teachers were asked to complete a survey detailing the use of the garden in their classroom and the effect it had on their students. This session will discuss the details of the competition, the findings and implications of the competition, and suggestions on how to promote student and school participation in similar horticultural programs.
The Development of Web-based Searchable Databases for the Green Industry
Authors: Lea-Cox John D. , Michaels Tamela D. , Dutky Ethel M. , Sinderman Anne Bird
Published: February 2019

Despite the explosion of resources on the World Wide Web (Web) over the past 3 years, there are still relatively few sites that provide easily accessible diagnostic information on horticultural subjects. For members of the Green industry, (i.e., greenhouse and nursery growers, landscape contractors, and scouting professionals) there is a real need for Web-based resources that provide detailed information on specific subjects that can be accessed at any time. The creation of diagnostic pictorial databases with self-learning capabilities (e.g., hyperlinked glossaries to technical terms) that are carefully designed to include expert diagnostic advice, with methods of control specifically keyed to the diagnosis, will be a powerful method to educate and inform users from the industry and in the classroom. One such database, called Tospovirus, has been developed by the authors that can be searched by host species and tissue type, since this important virus has a wide host range and symptomatology. Since at the present time the only control measure for this virus is eradication, growers can use this database to immediately identify suspicious plants in the greenhouse or nursery before further infection occurs. The development process of this database will be outlined to give the audience an idea of the decision-making process involved in this rapidly evolving method of information transfer.
Using Chlorophyll Fluorescence (Fv/Fm) as an Objective, Sensitive, and Efficient Method to Determine Cane Tissue Hardiness of Grapevines
Authors: Jiang H. , Howell G.S.
Published: February 2019

Determining hardiness levels of plant tissues is a prerequisite for cold hardiness research. LT50 determined by browning or regrowth tests is reliable and the most widely used means for assessing woody vegetative tissue viability. It is, however, time consuming and subjective. Although chlorophyll fluorescence (Fv/Fm) has been recently proposed to measure tissue injury for leaf and bud tissues, there are no reports on use for assessing viability of freezing-stressed woody tissues. We investigated the Fv/Fm changes of 1- and 2-year-old canes of Concord grapevines during the cold acclimation and compared these with browning and regrowth tests. The data showed that: 1) There were statistically significant, positive relationships between Fv/Fm changes and freezing temperature treatment that caused tissue injury. The best fit curvilinear equations were obtained; 2) The time of measuring chlorophyll fluorescence post-stress was important. Immediate assessment was not as precise in separating cold hardiness difference as when the tissue was measured 1 week later (at the time of browning test evaluation) or 4 weeks later (at the time of regrowth test evaluation). Assessment 20–26 h post-stress was equivalent to the 1-week or 4-week assessment. These data suggest that chlorophyll fluorescence (Fv/Fm) is a useful practical tool for assessing vegetative tissue viability. Importantly, it is rapid, simple, and objective.
Influence of Pruning and Irrigation on Root Longevity of `Concord' Vines
Authors: Comas L.H. , Eissenstat D.M. , Lakso A.N. , Dunst R.
Published: February 2019

Improved cultural practices in grape require a better understanding of root growth and physiology. Seasonal root dynamics were examined in mature `Concord' vines with balanced or minimal-pruning, and with or without supplemental irrigation in Fredonia, N.Y. Fine roots were continuously produced during the growing season starting in mid-June around time of bloom. Roots began to die in September at verasion. Minimal-pruned vines produced more roots than balanced-pruned vines, with the minimal-pruned/unirrigated vines producing the most roots. Irrigation and pruning delayed fine root production at the beginning of the growing season. Peak fine root flush was 16 June to 21 July 1997 for the minimal-pruned/unirrigated treatment, while peak flush was 7 July to 2 Sept. 1997 for balanced-pruned/irrigated treatment. In minimal-pruned vines, many roots were observed down to depths of 120 cm. In contrast, balanced-pruned vines had very few fine roots deeper than 40 cm. From initial observations, median lifespan of fine roots was 5 to 9.5 weeks, depending on treatment and depth in soil. Fine roots lived longer in the top 15-cm than in the 16- to 30-cm layer of soil in all treatments. Both minimal pruning and irrigation increased root lifespan. Fine roots had the shortest lifespan in the balanced-pruned/unirrigated treatment and the longest lifespan in the minimal-pruned/irrigated treatment.
Prelimary Report on the Apparent Control of Pierce's Disease (Xylella fastidiosa) with Admire (Imidacloprid) Insecticide
Authors: Krewer Gerard , Dutcher Jim , Chang C. J.
Published: February 2019

Pierce's Disease is the major limiting factor in the production of European and American bunch grapes in the Coastal Plain and Lower Piedmont of the Southeastern United States. Pierce's Disease is also a significant problem in some areas of California. The disease has been impossible to control with insecticide sprays up to this point, because the leaf hopper vectors are xylem feeders and have minimal plant/insecticide contact. Admire was cleared for use on grapes 3 years ago, and an experiment was started near Tifton, Ga. Cultivars of European and American bunch grapes in this experiment include `Flame Seedless', `J. Riesling', `Cabernet Franc', `Reliance', `Mars' and `Canadice'. Experimental design is a randomize complete block with two replications and six vines per replication and treatment for a total of 72 vines in the experiment. Treatments are untreated control and vines treated with Admire (3.26 g/vine per application) in an aqueous solution of 1 to 2 L applied as a basal drench. Vines were planted in Mar. 1996 and applications of Admire have been applied in the early spring and mid summer of each year. Apparent Pierce's Disease symptoms became evident on some of the control vines in mid-summer 1997. By Fall 1997, some of the control vines were dead. This trend has continued in Spring 1998. Some vines treated with Admire show slight Pierce's Disease symptoms, but rate of disease development is much slower than in the control vines. Based on company research with virus transmission on other crops, even better results can be expected when large blocks are treated with Admire. Current results on this experiment will be presented. Larger scale experiments are underway as well as experiments to determine the effect of Admire on the development of phony peach disease and plum leaf scald disease.
Heat Tolerance of Selected Provenances of Atlantic White Cedar
Authors: Jull Laura G. , Blazich Frank A. , Ranney Thomas G.
Published: February 2019

Uniform seedlings of six provenances (Escambia Co., Ala.; Santa Rosa Co., Fla.; Wayne Co., N.C.; Burlington Co., N.J.; New London Co., Conn.; and Barnstable Co., Mass.) of Atlantic white cedar [Chamaecyparis thyoides (L.) B. S. P.], were transplanted in Apr. 1997 into 0.95-L plastic containers with a medium of 1 peat: 1 perlite: 1 vermiculite (v/v). Plants were acclimatized at 26/22 °C under a 16-hr photoperiod for 2 weeks before treatment initiation. Fourteen seedlings per provenance were then transferred to each of five growth chambers maintained at 16/8 hr thermoperiods of 22/18 °C, 26/22 °C, 30/26 °C, 34/30 °C, or 38 /34 °C with a 16-hr photoperiod of 550–600 μmolμm–2μs–1. Seedlings were arranged in a split-plot design with a 5 × 6 factorial arrangement of treatments (5 temperatures × 6 provenances). Plants were harvested 12 weeks after treatment initiation and data recorded. Temperature had a significant effect on overall growth with responses to temperature varying according to provenance. There was a highly significant (P ≤ 0.0001) temperature × provenance interaction for height, stem caliper (measured below the lowest leaf), and foliar, stem, root, and shoot (foliar dry weight + stem dry weight) dry weights. Top and root dry weights were maximized for the northern provenances (Connecticut and Massachusetts) at 22/18 °C. At 26/22 °C and 30/26 °C, the northern provenances (Connecticut and Massachusetts) had the lowest top and root dry weights. However, the southern provenances (Alabama, Florida, and North Carolina) had the greatest top dry weights at 26/22 °C. At 30/26 °C, the southern provenances (Alabama and Florida) and the New Jersey provenance had the greatest top dry weights but they were not significantly different from 26/22 °C. Root dry weights were not significantly different between 26/22 °C and 30/26 °C for the Alabama and New Jersey provenances, but were significantly different for the North Carolina and Florida provenances. Regardless of provenance, dramatic reductions occurred for all growth measurements when temperatures exceeded 30/26 °C. For top and root dry weights, there were no significant differences among the six provenances at 34/30 °C and 38/34 °C. All plants at the highest temperatures of 38/34 °C did not survive by week 8.
Overwinter Survival of Plants in Closed, Insulated Rootzone Containers
Authors: Shirazi A.M. , Green J.L.
Published: February 2019

Growth and overwinter survival of tree–shrub–groundcover plant combinations in above-grade closed, insulated rootzone containers (CIRCs) are being evaluated at Morton Arboretum where winter air temperatures below –11.1 °C (12 °F) are not uncommon. Two-inch-thick extruded polystyrene foam board insulating liner enclosed the rootzone compartment. Triple expanding foam applied where the top insulating board surrounds the above-container plant stems completed the seal preventing heat-moisture transfer and separating the root and shoot environments. Water reservoirs (6-inch depth) in the base of the containers provide additional volume heat capacity. Three plants (tree, shrub, groundcover) were installed in each CIRC. In this preliminary experiment, two 300-gal CIRCs are planted with Picea glauca `Conica' (Dwarf Alberta Spruce), Pinus mugo pumilio (Dwarf Mugo Pine), and Potentilla fruiticosa `Goldfinger'. The two 200-gal CIRCs are planted with Acer ginnala `Mondy' TM (Red Rhapsody Maple), and Hedera helix `Bulgaria' and `Silver Dust'. Control plants are in a field nursery. Within the insulated containers, temperature fluctuations are less extreme than outside. Temperatures within the CIRC have not been below –2.22 °C (28 °F) even when exterior temperatures have hovered at below –11.1 °C (12 °F). Shoot cold hardiness of plants in the closed, insulated containers and of control plants in the field nursery will be compared.
Effects of AVG, NAA, Ethephon, and Summer Pruning on Preharvest Drop and Fruit Quality of `McIntosh'
Authors: Stover E.W. , Watkins C.B. , Fargione M.J. , Iungerman K.A.
Published: February 2019

Ethylene production increases dramatically during maturation and ripening of `McIntosh' apples, frequently resulting in preharvest drop and accelerated fruit softening. As harvest approaches, commercial growers must balance the need for color development with minimizing fruit softening and drop. The effects of plant growth regulators and summer pruning on this balance were evaluated in this study. Treatments were applied to trees in the Mid-Hudson in 1995 and 1996 and a subset of growth regulator treatments was applied in the Champlain Valley in 1996. NAA (naphthalene acetic acid) significantly reduced drop on only one sample date in only one of the three trials. Ethephon (2-chloroethylphosphonic acid) at 150 ppm plus 10 ppm NAA, accelerated ripening and permitted harvest before substantial drop occurred, but earlier harvest resulted in smaller fruit size. AVG (aminoethoxy vinyl glycine) at 124 gram a.i./ha, on otherwise untreated trees, significantly delayed drop compared to the controls in two of three trials and resulted in better fruit firmness out of storage. Use of ethephon on AVG-treated trees significantly enhanced red color but also accelerated drop, although drop was reduced compared to ethephon only treatment. Late summer pruning significantly accelerated red color development, drop and ripening in both years. Pruning 16 Aug. 1996 significantly accelerated drop compared to pruning 1 Aug. 1996. Combining AVG application and pruning on 16 Aug. 1996 resulted in improved color without increasing drop compared to controls.
Effect of Seed Number on Preharvest Drop and Fruit Mass of Three Apple Cultivars
Authors: Ward Daniel L. , Marini Richard P. , Byers Ross E.
Published: February 2019

The factors controlling preharvest drop are poorly understood. The number of viable seeds in apple fruit has been associated with fruits retained following June drop. Three experiments were conducted to determine the effect of seed number on time of preharvest drop. In two experiments treatments were imposed to induce variability in seed numbers. Trees of `Redchief Delicious' were covered with 92% shade fabric for 0, 1, 2, or 3 days when fruits averaged 13 mm in diameter. In a second experiment `Redchief Delicious', `Smoothee', and `Commander York' flowers had 0, 1, 2, 3, 4, or all 5 stigmas excised at early “popcorn” stage and the remaining stigmas were hand-pollinated. The third experiment investigated drop of the same three cultivars as affected by the natural variability in seed number. Fruits were gathered from under the trees daily from 26 Aug. until all the fruits had fallen from the trees. Fruits were weighed and the number of filled, large aborted and small aborted seeds were counted. Neither total number of seeds, number of filled seeds, total number of aborted seeds, number of large aborted seeds nor number of small aborted seeds explained any appreciable amount of the variation in date of drop (R2 < 0.13). Fruit mass was positively related to seed number for `Delicious', but not for `Smoothee' or `York'.
Identification of PCR-based Molecular Markers Linked to B, A Carotenoid-related Gene in Tomato
Authors: Zhang Yiping , Stommel John R.
Published: February 2019

β-carotene is the principal provitamin A caroteniod found in tomato fruits and makes a significant contribution to the fruits nutritional value. The dominant B gene conditions high levels of β-carotene in ripe tomato fruits. PCR-based molecular markers, including random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP), were used to identify marker linkage to the B locus. The study was conducted using a near-isogenic line (NIL) of the cultivar Rutgers isogenic for the B locus and bulk segregant analysis of an interspecific F2 population segregating for the B locus, which was derived from the cross of Lycopersicon cheesmanii accession LA 317 × L. esculentum cv. Floradade. Sixty-four AFLP primer pairs and 1018 arbitrary RAPD primers were screened for polymorphism between the pair of NILs and between the two bulks. A number of amplified RAPD and AFLP products were identified that were present in one line or bulk but not the other. Marker linkage with the B locus was confirmed by checking individual samples from the F2 and BC populations. Two RAPD markers were confirmed tightly linked with the B phenotype using the interspecific F2 population. Similarly, a single AFLP marker was identified with close linkage to the B phenotype using the NIL F2 population. The markers identified in this study can be useful in breeding programs with marker assisted selection and, if very tightly linked, as a starting point to isolate the gene.