bluuebunny/crossref_metadata_2025 huggingface dataset:
TOMATOES AND CUCUMBERS ARE A GOOD COMBINATION FOR A DOUBLE-CROPPING SYSTEM.
Authors: Hanna H.Y.
Published: February 2019

Several studies were conducted to determine the effect of using tomato (Lycopersicon esculentum Mill.) plant skeletons as a support for trellised cucumbers (Cucumis sativus L.) double-cropped with tomatoes. In addition, the effect of mulch color, drip irrigation, and root-knot nematodes on subsequent cucumber yield also were examined. The presence of tomato skeletons significantly reduced the total yield (U.S. Fancy, no. 1, and no. 2), but not the premium (U.S. Fancy, no. 1) yield of cucumbers. Black polyethylene mulch used for the previous tomato crop had no undesirable effect on cucumber yield compared to the white mulch. Drip irrigated cucumber using same tomato irrigation lines significantly increased cucumber yield compared to nonirrigated cucumber. Cucumbers planted after nematode resistant tomatoes produced significantly higher yields than cucumber planted after nematode-susceptible tomatoes.
IMPROVING QUALITY OF CONTAINER-GROWN PEPPER TRANSPLANTS THROUGH FERTILITY MANIPULATION
Authors: Granberry Darbie M. , Kelly William Terry
Published: February 2019

During summer in southern Georgia, greenhouses often reach or exceed 49C. Subsequently, transplants grown in these houses tend to exceed optimum height. To determine effects of N and P fertility levels on pepper (Capsicum annuum) transplant growth, applications of nutrient solutions with 58, 12, and 0 ppm N and 114, 57, and 0 ppm P205

were applied to recently emerged Capistrano bell pepper beginning 12 Aug. 1994. Plants were grown in polystyrene flats using a commercial noncharged artificial soil mix. Nutrient solutions were applied as needed to maintain adequate moisture until 31 Aug., except for two treatments that received only water after 22 Aug. Data were taken on 22 and 31 Aug. With 58 ppm N, 0 P decreased plant height, leaf count, leaf area, and plant weight. Higher N increased plant height, ratings of intact root plugs and washed roots, stem diameter, leaf count, leaf area, and plant weight. At 12 ppm N, P had no significant effect on transplant growth. Withholding fertilizer the final week reduced plant height, ratings of intact root plugs, stem diameter, number of leaves, leaf area, and plant weight.
IMPLICATIONS OF THE CONTINUOUS USE OF PLANT NUTRIENT SOLUTION ON GROWTH OF SWEETPOTATO IN NFT
Authors: Trotman Audrey A. , David P.P. , Mortley D.G. , Douglas D.
Published: February 2019

In developing a nutrition management strategy that reduces the quantity of products entering the waste management stream, gaining an understanding of the patterns and fluctuations of nutrient levels and crop growth characteristics is essential. In a greenhouse study, `TU-82-155' sweetpotato was grown hydroponically for 120 days in three nutrient application–replenishment treatments: l) REG-solution changed at 14-day intervals and volume allowed to fluctuate; 2) daily replenishment with 10× concentrate of a modified quarter Hoagland's solution (MQH) or with water to regain set volume (30.4 liters) and maintain set point of electrical conductivity [(EC); 1050 to 1200 μmho]; 3) daily replenishment with l0× concentrate of a modified half Hoagland's solution (MHH) or with water to regain the set volume and maintain the set point of EC. There were no statistically significant differences among nutrient application protocols for storage root count, fresh and dry weights, and percent dry matter. The MHH treatment consistently yielded significantly higher leaf biomass and pencil roots (>1 mm in diameter), indicating a higher potential for increased storage root yield. A nutrient application protocol using treatment 2 has potential for reduced waste production if used in hydroponic sweetpotato production. The plants from the MQH treatment initiated vegetative buds at a significantly later date than in the other treatments and generally showed evidence of suppressed plant development.
COVER CROPS AND PEST MANAGEMENT
Authors: Phatak S.C. , Sumner D.R. , Chalfant R.B. , Gay J.D. , Chandler L.D. , Bugg R.L , Brunson K.E.
Published: February 2019

Cover crops relay-cropped with vegetables with conservation tillage were compared with fallow conventional production for 10 years. Conservation till-relay received no pesticide and only one-quarter the recommended fertilizers. Winter cover provided significantly better weed control than conventional. Weed problems in relay occurred only in the rows where vegetables were planted. Legume winter covers increased soilborne organisms but did not influence root disease severity or postemergence damping-off. Thrips, aphids, and whiteflies were most frequent. These pests remained below the economic threshold with winter cover crop-relay. However, infestation of these pests and Colorado potato beetles was severe in conventional plots. Winter cover crops provided habitat for more than 14 beneficial insects.
EFFECT OF ROOTSTOCK ON LONGEVITY AND FRUIT AND TREE CHARACTERISTICS OF PLUM
Authors: Norton J.D. , Boyhan G.E. , Pitts J.A.
Published: February 2019

The dwarfing characteristics of St. Julien and Pixy rootstocks as measured by shoot growth and trunk cross-sectional area (TCSA) was evident. Tree survival was significantly reduced after 3 years on Nemaguard and Pixy rootstocks. None of the elements measured by foliar nutrient analysis were below the minimum for plums; however, significant multiple regression equations for total shoot growth, TCSA, and survivability were evident with R2 of ≈0.30 in all three cases.
COMBINING LONG-TERM PRODUCTION CURVES OF SEVERAL PECAN TREES OF SAME CULTIVAR WHEN SLOPE ESTIMATES ARE NOT EQUAL AND VARIANCES ARE HETEROGENEOUS
Authors: Mullinix Benjamin , Worley Ray
Published: February 2019

Eleven `Desirable' pecan trees with yield data for 22 to 47 years were selected from a database with data from three orchards. Cumulative yield were computed for each tree. Cumulative data was transformed using LOG10. Quadratic or cubic regression curves were fit for each tree and for all in a single analysis. In most cases, variances were not homogeneous among the 11 trees. Using the regression coefficients for each tree, an average of the five was made and appropriate standard errors were computed. Number of cases where homogeneity of variances were found increased. Younger trees benefiting from better orchard management had different variances than older trees moving across changing managements. LOG10-transformation tended to decrease variation, but variances were still heterogeneous.
ROOT PRUNING AND FERTILIZATION INFLUENCE GROWTH OF BAREROOT CORYLUS COLURNA
Authors: Knight Patricia R. , Harris James R. , Fanelli Jody
Published: February 2019

Bareroot Corylus colurna were grown in 7.5-liter containers from 11 Apr. until 27 June 1994. The growing medium was fritted clay. Fertility levels included no fertilization, 100 ppm N, or 200 ppm N. Plants were root pruned to remove none or one-quarter to one-half of the primary roots. Root pruning at any level resulted in decreased height, shoot, and root dry weights and number and length of new shoots. One-quarter primary root removal resulted in lower root: shoot ratios compared to plants that were unpruned. One-half primary root removal further reduced root: shoot ratios. One-half primary root removal also reduced total leaf area compared to unpruned controls. Fertilization at 200 ppm N increased leaf numbers and total leaf areas compared to plants receiving no fertilization.
OPTIMIZING RAPD MARKERS FOR ONION GENOMIC DNA ANALYSIS
Authors: Wettashinghe Ruwanthi C. , Peffley Ellen B.
Published: February 2019

Random amplified polymorphic DNA (RAPD) are genetic markers that facilitate selection in plant breeding. To obtain clear reproducible, and repeatable RAPD bands, four DNA extraction protocols and two Taq polymerases were compared using thirteen TG1015Y (Allium cepa) genotypes. Protocols for DNA extraction followed those of a modified Tai and Tanksley, 1989 (PMBR); a modified Dellaporta et al., 1983 (PMBR); a modified Guillemunt et al., 1992 (PMBR); and extracted with a plant tissue DNA isolation kit from Gentra System (Minneapolis). The modified Guillemunt protocol was selected due to ease of extraction and cost effectiveness. Polymerases compared were Taq and Taq Stoffel fragment. Results are based on three separate amplifications and electrophoretic assays. PCR amplifications of Stoffel fragment produced more scorable and reproducible RAPD bands compared to bands produced using Taq polymerase.
POTENTIAL FOR HIBISCUS CANNABINUS IMPROVEMENT VIA SOMACLONAL VARIATION
Authors: Reichert Nancy A. , Baldwin Brian S.
Published: February 2019

Adventitious regeneration protocols were developed for kenaf (Hibiscus cannabinus L.) using leaf tissue. Regenerants (R0) of three cultivars and R1 progeny from one cultivar were grown in greenhouse and field trials for assessment of various growth characteristics. R0 regenerants differed from control plants in the variety of stem colors displayed. On germination, a proportion of R1 seedlings were chlorophyll-deficient (albinos), whereas no control seedlings contained that mutation. Flowering date also was earlier in the R1 plants. The kenaf regeneration protocol also has been successful on H. syriacus (Althea, rose of Sharon), and other ornamental species are currently being evaluated. With kenaf data, the adventitious regeneration protocol potentially could be a useful tool for inducing mutations in various species of Hibiscus, including ornamentals.
MOLECULAR HYBRIDIZATION STUDIES IN ALLIUM
Authors: Kallemuchikkal Usha S. , Peffley E.B.
Published: February 2019

Total genomic DNA was isolated from study plants and was hybridized with 32P-labeled Allium fistulosum `Ishikura' genomic DNA; Southern blots were performed. Plant materials were Allium cepa `New Mexico Yellow Grano', the Allium fistulosum `Heshiko' and `Ishikura', and their F1 interspecific (Allium fistulosum × Allium cepa) hybrids. Sequences with high identity to the labeled DNA hybridized strongly (i.e., A. fistulosum `Ishikura' hybridized most strongly to itself, next with A. fistulosum `Heshiko'). The least hybridization was observed when A. fistulosum `Ishikura' was hybridized with A. cepa `New Mexico Yellow Grano'. Intensity of the signals observed when DNA of the F1 interspecific hybrids was probed with the `Ishikura' DNA was as expected, with the signals intermediate between those of A. fistulosum to A. fistulosum and A. fistulosum to A. cepa. A second study was performed to identify additional cytological markers in Allium. The 5srDNA and NOR genes from Triticum aestivum onto onion chromosomes using in situ hybridization. Evidence of hybridizations are the presence of fluorescing areas on the chromosomes.
INFLUENCE OF PLANTING DATE ON `CHANDLER' STRAWBERRY PRODUCTION
Authors: Patterson W.K.
Published: February 2019

`Chandler' strawberries were planted on four dates to ascertain optimum planting time under central Arkansas conditions. Greenhouse-rooted plugs were planted in four replications in a randomized complete-block design. Each replication was planted in double rows 6 m long on beds with 1.4-m centers. Plots were established on 9/28, 10/7, 10/26, and 11/5. Number of branch crowns, yield, and number of runners/plant indicated that the earliest planting date was too late, and thus, the optimum date was missed. Equivalent yields of 16,173 kg·ha–1 were obtained from the earliest date, dropping to 8539 kg·ha–1 when planted 10 days later.
EFFECTS OF POLLEN SOURCES ON OVULE AND BERRY DEVELOPMENT OF SOUTHERN HIGHBUSH BLUEBERRIES
Authors: Huang Yuehe , Lang Gregory A.
Published: February 2019

To study the effects of pollen sources on ovule and berry development in southern highbush blueberries (Vaccinium corymbosum hybrids), 5-year-old `Sharpblue' plants were moved into a greenhouse for self- and cross-pollination experiments. Cross-pollination with `Gulfcoast' and `O'Neal' as pollen sources increased fruit weight by 58.2% and 54.9%, respectively, compared to self-pollination. Cross-pollination did not affect the number of total and small ovules significantly but did double the number of fully developed ovules and increase the average ovule size by 14%. The increase in number and size of fully developed ovules correlated with the significant difference in berry fresh weight between self- and cross-pollination. Cross- and self-pollination showed good correlations between fruit fresh weight and number or cross-sectional area of fully developed ovules. There was a poor correlation between fruit fresh weight and the number or cross-sectional area of partially developed ovules. This study provides further evidence that berry size in southern highbush is influenced strongly by the development of fully developed ovules.
COLD HARDINESS OF RABBITEYE BLUEBERRY
Authors: Matta Frank B. , Silva Gena R. , Spiers James M.
Published: February 2019

Cold acclimation of `Tifblue' rabbiteye blueberry was determined using differential thermal analysis (DTA). Electrolyte leakage and tissue browning test results were correlated with DTA. DTA showed that three exotherms occurred: exotherm 1 (ET) associated with extracellular freezing, exotherm 2 (CT) associated with tissue injury, and exotherm 3 (LTE) not associated with tissue injury. Maximum hardiness (–20C) occurred in January. The LT50 measured by electrolyte leakage and tissue browning was about –17C and –15C, respectively. Acclimation began in November and deacclimation in mid-Feb. 1994.
TRANSPLANTING DEPTH OF PEPPER—BARE GROUND VS. MULCH EFFECTS
Authors: Kelley William Terry , Granberry Darbie M.
Published: February 2019

Bell pepper (Capsicum annuum) has traditionally been transplanted to the top of the root ball or to the cotyledons of the transplant. Recent studies have shown increased and earlier yields are obtained by transplanting pepper deeper. Thus, a study was initiated to investigate effects of transplanting depth on pepper yield and plant growth. Pepper was transplanted to the top of the rootball, the cotyledons, and the first true leaf in two locations in 1994. `Camelot' hybrid and `Jupiter' (open pollinated) cultivars were planted into bare ground on Mar. 24 in Tifton, Ga. Only `Camelot' was transplanted into a plastic mulch with drip irrigation on Mar. 28 in Cool Springs. Plots consisted of single rows of seven plants with data collected from the internal five plants. Treatments were replicated three times. Normal cultural and pest control practices were used at both locations. Plant measurement data were taken 5 weeks after transplanting. Yield data were collected at harvest. Total weight per plant of three harvests was significantly greater with peppers planted to cotyledons and first true leaf than those planted to the rootball in `Jupiter'. There was no significant effect of planting depth on `Camelot', although there was a distinct trend toward greater yield with deeper planting on plastic. The same trend was evident for average weight per plant and average number of fancy-grade peppers per plant. Average stem diameter, plant height, and length of largest leaf were all greater among deeper planted peppers. Deeper planting seems to have a positive effect on yield and plant growth, particularly with hybrid pepper planted into a plastic mulch.
EFFECTS OF LEONARDITE AND SEAWEED ON TOMATO, ZINNIA, AND MARIGOLD SEEDLINGS
Authors: Pertuit A.J.
Published: February 2019

Leonardite additions (0, 1/16, l/8, 1/4, or 1/3 volume leonardite/volume medium) were more effective if applied only before (Expt. 1) than if applied before and after transplanting (Expt. 2). In Expt. 1, root dry weight (4 weeks after transplanting) of marigold increased 58% to 152% with 1/3 leonardite (by volume) best; zinnia, 15% to 150%, with no differences from 1/8 to 1/3 volume; tomato, a 64% increase at 1/8, a 57% increase at 1/4, and a 47% increase at 1/3 volume, with no differences among 1/8 to 1/3 volume. In Expt. 2, 1/3 leonardite addition inhibited potential root growth. No differences in stem caliber or shoot length or dry weight were found in Expts. 1 or 2. Maxicrop soluble-extract powder seaweed drenches increased roots by ≈21%, as did Maxicrop cold processed seaweed extract liquid (1:500). All extracts were applied 4 times beginning a week after transplanting. The most significant find was a 65% increase in root dry weight and a 7% increase in stem caliber with Maxicrop cold processed seaweed extract drenches (1:200). No differences in shoot length or dry weight were found.
WATER AND NITROGEN RETENTION IN ANNUAL LANDSCAPE BEDS AMENDED WITH A HYDROPHILIC POLYMER
Authors: Boatright Jennifer L. , Zajicek J.M. , Mackay W.A.
Published: February 2019

A study was conducted to test the ability of hydrophilic polymers to retain moisture in annual bedding plant beds in addition to reducing NO3 and NH4 leaching. Petunia plants were transplanted into raised concrete benches containing a drainage pipe that allowed for excess leachate to be collected. Beds that were treated with 0 or 366 g·m–2 of hydrogel and 0 or 186 g of ai N. Watering of beds followed a strict irrigation schedule and soil moisture was monitored daily. At termination, plant dry weight was measured and analyses of plant tissue and leachate were conducted for NO3 and NH4 concentrations. Results from this study demonstrated that, under suboptimal conditions of minimal irrigation and fertilization, polymer incorporation had a significant effect on water, NH4, and NO3 retention in soils. Water leaching was decreased by 17%; NH4 retention was increased by 83%; and NO3 retention, where additional N was added, was increased by 64% due to polymer incorporation. In addition, a 47% reduction in NO3 concentration of water leachate was detected when polymer was incorporated under minimal fertilization. Growth or N levels of petunia were not significantly affected by polymer incorporation.
CORNUS FLORIDA POLLEN ONTOGENY
Authors: Malueg K.R. , Schlarbaum S.E. , Graham E.T. , Trigiano R.N.
Published: February 2019

Development of Cornus florida L. pollen was monitored using standard paraffin histological techniques and light microscopy. Terminal buds (putative floral buds) were collected over a 6 weeks from mature landscape trees located on The Univ. of Tennessee Agricultural Campus, Knoxville. Examination of samples taken at 3- to 7-day intervals revealed variations in development representing 1- to 2-week differences between florets in a single inflorescence, florets on the same tree, and florets from different trees. Floral initiation occurred before 19 July in the 2 years of this study. Pollen development followed typical angiosperm stages: tapetal cells were multinucleate, pollen tetrads were tetrahedral, and meiosis occurred late in the developmental period. Pollen grains appeared morphologically mature by early September in both years.
FATTY ACID COMPOSITION OF PLASMALEMMA LIPIDS ASSOCIATED WITH GENETIC VARIABILITY IN COLD TOLERANCE OF SWEETPOTATO IPOMOEA BATATAS. (L). LAM
Authors: Abesinghe Arambage , Garner James O.
Published: February 2019

Storage roots of `Beauregard' and `Centennial' were used to identify varietal differences in fatty acid composition in plasmalemma lipids during storage conditions. Total plasmalemma fatty acid composition of glycolipids and phospholipids in storage roots of `Beauregard' and `Centennial' did not differ. The fatty acid composition of MGDG and DGDG in storage root plasmalemma was >50% unsaturated fatty acids in `Beauregard'. The high percentage of 18:2 (65.44%) fatty acid compared to `Centennial' (19.70%) and 79.35% total unsaturated fatty acid content in MGDG may contribute to low temperature tolerance in `Beauregard'. The higher percentages of 16:1 and 22:1 fatty acids in `Centennial' compared to `Beauregard' contributed to MGDG fatty acid unsaturation. However, these fatty acids have not been related to chilling tolerance.
MATURITY SEQUENCE OF PINKEYE TYPE SOUTHERNPEA VARIETIES
Authors: Chambliss Oyette L. , Hunter A. Gene
Published: February 2019

Twenty-two southernpea (Vigna unguiculata L. Walp.) cultigens were evaluated in field plots in southern, central, and northern Alabama to establish a set of varieties that would reach harvest stage sequentially. As first pods reached the dry stage, subjective ratings were made to estimate percentages of the following pod maturity stages: presnap, snap, mature green, and dry. Mature-green and dry stages were combined to give the total percentage of mature pods. From a general linear model analysis on SAS, lines were highly significant sources of variation in percentage of mature pods up to 83 days after planting. At least three maturity groups were apparent: >80%, 50% to 80%, and <50% mature pods. These are represented by `Santee Early Pinkeye', `Coronet', `Texas Pinkeye', and `Pinkeye Purplehull BVR'; `C.T. Pinkeye Purplehull', `Epoch', and `Pinkeye Pinkpod'; and `Mississippi Pinkeye' and `Corona', respectively. All the plant introductions were in the late category and generally are not characteristic of commercial pinkeyes; they may be valuable in breeding for lateness in southernpeas.
SUSTAINABLE NITROGEN ALTERNATIVES FOR SWEETPOTATO PRODUCTION
Authors: Little William E. , Schultheis Jonathan R. , Mikkelsen Robert L.
Published: February 2019

North Carolina is a leading poultry producer in the United States. Thus, much waste by-product also is produced and must be handled in an environmentally responsible way. Using poultry and similar waste products as a fertilizer source for vegetables, such as sweetpotatoes, might serve as a viable use option. Our purpose was to determine the effectiveness of animal wastes and sludges as nutrient sources for sweetpotatoes. The effects of municipal solid waste, composted litter, fresh litter, and synthetic fertilizers were compared for their effects on yield and quality of `Regal' and `Beauregard' sweetpotato varieties. The test was planted as a split-plot randomized complete-block design with each treatment replicated four times. Planting was 3 June, and harvest was 27 Sept. 1994. Yields were similar when fertilized with either organic or synthetic nutrient sources. Root quality was excellent, regardless of fertilizer, because few culls resulted, and there were no differences between treatments. Sweetpotatoes can be successfully grown with various organic nutrient sources without affecting quality or yield and might be marketed as “organically grown” produce. This label may command a higher market price than sweetpotatoes grown traditionally with synthetic nutrient sources.
INFLUENCE OF SOIL AERATION ON PECAN TREE PERFORMANCE
Authors: Chapman Dan , McEachern G.R. , Sistrunk Laurence , Lipe John , Stein Larry , Storey J.B.
Published: February 2019

Five Texas orchards were selected in Spring 1993 in commercial pecan counties for testing three types of soil aeration equipment. Mechanical aeration spikes were either 20 or 46 cm long, and a pneumatic spike was 20 cm long. The mechanical spikes are on a rolling cylinder that can be manufactured in sufficient lengths to fit the tree spacing in different orchards. The pneumatic probe is manually inserted into the soil so that a quick burst of 130-psi air can be delivered to effect soil profile fracturing. The fourth replicated treatment was an nontreated control. There were no differences in trunk diameter increases and yield in 1993 between May-applied replicated treatments. The May treatments and November measurements will continue for two more years to allow for differences in soil aeration to influence growth and yield. Shoot growth measurements will be taken in Spring 1995. Irrigation water has penetrated the soil under aerated trees more readily than in nonaerated controls.
OKLAHOMA GARDENING—TWENTY YEARS OF HELPING PEOPLE AND PLANTS GROW
Authors: Dobbs Steve
Published: February 2019

Oklahoma Gardening, a television program produced by the Oklahoma Cooperative Extension Service, Departments of Horticulture and Landscape Architecture and Agricultural Communications, is tied for the longest running consecutively taped gardening program in the nation. The program airs weekly on Oklahoma's PBS affiliate and ranks as the top locally produced program in the viewing region, with a dedicated weekly audience of 150,000 gardening enthusiasts. As an Extension constituent, Oklahoma Gardening is successful at program identification, development, and evaluation—a new twist for most television programs. In addition to television programming, educational opportunities are available through tours of the 5-acre studio gardens located in the Oklahoma Botanical Gardens and Arboretum on the Oklahoma State Univ. campus where most of the shows are taped. Visitors touring the gardens increased 204% from the previous year. Extension fundamentals of l) program development and coordination, 2) volunteer training and activities, and 3) community and business involvement and support can be implemented effectively into television programming as shown by Oklahoma Gardening's productive 20-year history!
Datability of Pecan Tree Rings
Authors: Stokes Marvin , Harlan Tom , Harris Marvin , Storey J. Benton
Published: February 2019

Analyses of stem cross sections of 97 pecan [Carya illinoinensis (Wangenh.) K. Koch] and 22 post oak (Quercus stellata Wangenh.) trees from seven sites showed tree rings were sensitive to the environment and were datable by tree, among trees within a site, among sites, and between species. Pecan had well-defined annual growth rings averaging from 1.25 to 3.36 mm in width and that varied synchronously among trees. Pecan had a mean sensitivity of about 0.3 compared to 0.4 for post oak, indicating a smaller but adequate response of pecan to reflect climatic variations and to use pecan tree rings in other dendrological studies.
Shading Timing and Intensity Influences Fruit Set and Yield in Cranberry
Authors: Roper Teryl R. , Klueh John , Hagidimitriou Marianna
Published: February 2019

Cranberry (Vaccinium macrocarpon Ait.) vines were shaded with either 72% or 93% shadecloth (28% or 7% of full sun) for 1 month before flowering, after flowering, or before harvest. Fruit set was reduced by heavy shade (93%) before flowering in 1991 but not in 1992 or 1993. Heavy shade following flowering reduced fruit set in 1991 and 1992 but not 1993. The number of flowers per upright was generally not affected by shading but was reduced by prebloom shading at either level in 1993. Mean berry weight was usually conserved. Yield was reduced by shading at either level following flowering in 1991 and 1992. Shading just before harvest had no effect on the characteristics measured. Total nonstructural carbohydrate concentration was reduced to about half relative to the controls by either shading level at all treatment dates. Carbohydrate concentrations recovered to control levels by 4 to 8 weeks following removal of shading. Shading always reduced carbohydrate concentrations but did not always reduce fruit set or yield.
Time of Nitrogen Application and Phosphorus Effects on Growth, Yield, and Fruit Quality of Pecan
Authors: Smith Michael W. , Cheary Becky , Carroll Becky
Published: February 2019

March vs. October N applications in factorial combination with two P rates were evaluated on two pecan [Carya illinoinensis (Wangenh.) C. Koch] cultivars. Leaf N concentrations were not affected by N application time. However, yield of `Hayes' was increased during 4 of 7 years and cumulative yield was increased 37% when N was applied during October compared to March. Yield of `Patrick' and individual nut weight and kernel percentage of `Hayes' and `Patrick' were not affected by N application time. Phosphorus application increased leaf P concentration 5 of 7 years during the study. Shoot growth, yield, individual nut weight, and kernel percentage were not affected by P application.
Growth, Yield, and Water Use Responses of Peach to Repeated Root Pruning in a Sub-humid Climate
Authors: Glenn D.M. , Miller S.S.
Published: February 2019

The objectives of this 7-year study were to determine the effect of repeated root pruning and irrigation on peach (Prunus persica L. Batsch) tree growth and soil water use. Root pruning began in the year of planting. Peach trees trained to a freestanding “Y” were root-pruned at flowering for 4 years (1985 to 1988) and subsequently at flowering and monthly through July for 3 years (1989 to 1991). Irrigation was withheld or applied the full season or only during stage 3 of fruit growth on root-pruned and non-root-pruned trees. Root pruning limited soil water availability throughout most of the growing season when irrigation was withheld; however, when irrigation was applied, there was no difference in soil water availability. The root length density of peach roots was greatest in the 0 to 30-cm depth, was promoted by irrigation, and was reduced by root pruning in the 0 to 90-cm root zone. Full-season irrigation increased vegetative growth over the nonirrigated treatments. Root pruning had no effect on vegetative growth measured as fresh pruned material. The treatments had no effect on leaf nutrient content, except that root pruning reduced Zn in five consecutive years. Fruit yield was reduced 1 in 5 years by root pruning, and full-season irrigation reduced yield in 3 of 5 years. Repeated root pruning restricted the lateral spread of the root zone and the use of soil resources, yet on the deep soil of this site, restricting the lateral extent of the root zone did not reduce vegetative tree growth.
Growth-regulator-induced Alleviation of Chilling Injury in Green and Red Bell Pepper Fruit during Storage
Authors: Lurie Susan , Ronen Reuven , Aloni Beny
Published: February 2019

Bell pepper (Capsicum annuum L.) plants were sprayed at full bloom with paclobutrazol (50 and 100 mg·liter–1), uniconazole (20 and 50 mg·liter–1), or mefluidide (20 and 50 mg·liter–1). Mature-green and red fruit were harvested 4 and 8 weeks after spraying, respectively. Paclobutrazol and uniconazole, but not mefluidide, affected plant growth and fruit morphology. All three growth regulators alleviated chilling injury that developed on green and red peppers after 28 days at 2C. Potassium leakage was lower from tissue disks, and weight loss less, from treated fruit than from control fruit. Ethylene and CO2 production at 20C were similar in control and paclobutrazol-treated fruit after 28 days at 2C. These results are consistent with previous findings that showed these growth regulators are able to increase tolerance to low temperatures in whole plants. Chemical names used: N-[2,4-dimethyl-5-trifluoromethyl sulfonyl amino phenyl acetamide] (mefluidide); (2RS, 3RS) 1-(4-chlorophenyl)-4,4 dimethyl-2-(1,2,4-triazol-1-yl)-pentan-3-ol (paclobutrazol); (E)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4 triazol-1-yl)-pentan-3-ol (uniconazole).
Harvest Date and Storage Quality of Herbaceous Perennials
Authors: Hanchek Anne M. , Cameron Arthur C.
Published: February 2019

The effect of harvest dates between September and December on regrowth after storage of field-grown Coreopsis grandiflora Hogg × Sweet `Sunburst' and `Sunray', Geum quellyon Sweet `Mrs. Bradshaw', Gypsophila paniculata L. `Snowflake', Iberis sempervirens L. `Snowflake', and Dicentra spectabilis (L.) Lem. crowns was determined. After 0 to 7 months of storage at 0C, stored crowns were repotted and grown in a greenhouse. Plants from later harvests were of higher quality than those from earlier harvests, showing higher rates of survival after longer storage periods, less mold development in storage, and stronger regrowth after storage. Late field harvest is recommended for optimum storage quality.
Biological Control of Root Pathogens in Rockwool and Other Hydroponic Systems
Authors: Matheny M.L.
Published: February 2019

One of the main difficulties in controlling root diseases biologically has been the inability of biocontrol agents to establish and persist in the rhizosphere. The inability of biocontrol agents to establish and persist is often attributed to competition from indigenous microorganisms for space and nutrients and to fluctuations in environmental conditions. The use of biocontrol agents over the entire geographic range of a crop also has been limited by differences in environmental and edaphic conditions from field to field and region to region. An advantage of hydroponic crop production in greenhouses is that environmental conditions such as temperature, moisture, pH, and growth medium can be consistently controlled in a house and from site to site. An additional advantage of many hydroponic systems is that they are virtually sterile upon planting. This initial period of virtual sterility greatly reduces competition for an introduced biocontrol agent. In addition, these systems are usually pathogen-free upon planting allowing the establishment of a biocontrol agent prior to pathogen introduction. Last, the temperatures, high moisture levels, and pH ranges of hydroponic systems can be ideal for the proliferation of many biocontrol agents. With all of these advantages for the use of biocontrol agents in hydroponic systems, our company, and many labs around the world, have focused their attention on developing biological control agents for these systems. I will provide a review of research focused on controlling root diseases of vegetables grown in rockwool and other hydroponic systems.
Photoautotrophic Micropropagation of Triploid Melon. I: Sucrose, Light, and CO2 Affect Growth and Net Photosynthetic Rates of Shoot Buds
Authors: Adelberg Jeffrey , Fujiwara Kazuhiro , Kirdmanee Chalermpol , Kozai Toyoki
Published: February 2019

Growth and net photosynthetic rates of shoots of a triploid melon clone, `(L-14 × B) × L-14', were observed over 21 days following transfer from a multiplication MS medium containing 3% sucrose and 10 μM BA to a shoot development medium containing 1 μM BA at varying levels of sucrose in the medium (0%, 1%, and 3%), and light (50, 100, and 150 PPF) and CO2 (500, 1000, and 1500 ppm) in the headspace. Largest numbers of shoot buds were observed in media with 3% sucrose. Increased light and CO2 had a positive interactive effect. Fresh and dry weights were greatest at highest levels of sucrose, light, and CO2. Although there was less growth in the absence of sucrose, fresh or dry weight of shoot buds grown without sucrose in the media still doubled over the 21 days of culture. Net photosynthetic rates of buds were negative 4 days after initiation of culture and approximately zero after 20 days of treatment. When transferring buds to fresh, sugar-free media, net photosynthetic rates became highly positive. Buds that had been cultured in the absence of sucrose and at highest light levels had the highest net photosynthesis rates upon transfer to fresh, sugar-free media.
Advancing From Learning to Action Through Writing
Authors: Haque Mary Taylor
Published: February 2019

Teaching is a process that incorporates active participation from both teacher and student. As the students' development progresses, they should formulate questions themselves that provoke thought and compel them to seeks answers and should become adept at identifying problems and seeking solutions. Have students write “Persuasive Letters to get Action” provides opportunities for students to achieve these learning goals while refining communication skills. Students select and research a landscape issue or problem in depth; but instead of writing a paper for only the teacher to read, they determine whom they could write to with solutions to the problem. Letters are peer-reviewed and revised before being mailed to the government officials, CEOs, and others in a position to follow through on the proposed actions. Students experience a sense of empowerment when they take action on an issue. They are motivated by a larger audience that goes beyond the teacher. They receive feedback from individuals outside the classroom as well as within the classroom, and they are being recognized and asked to serve on committees as a result of their letter writing. They are being heard nationwide and are experiencing the power of the written word as a means of both identifying and solving problems.
Effect of Differential Rates of Nitrogen Fertilization on Subsequent Recovery of Isotopically Labeled Fertilizer Nitrogen by Mature Almond Trees
Authors: Weinbaum Steven A. , Asai Wesley P. , Goldhamer David A. , Niederholzer Franz J.A. , Muraoka Tom T.
Published: February 2019

There is legitimate concern that excessive fertilizer nitrogen (N) application rates adversely affect groundwater quality in the San Joaquin Valley of California. A 5-year study was conducted to assess the interrelationships between N fertilization rates, tree productivity, leaf [N], soil [NO–3], tree recovery of isotopically labeled fertilizer N, and NO–3 leaching. High N trees recovered <50% as much labeled fertilizer N in the crop as did trees previously receiving low to moderate fertilizer application rates. Our data suggest that the dilution of labeled N in the soil by high residual levels of NO–3 in the soil had a greater effect than tree N status (as expressed by leaf N concentration) on the relative recovery of fertilizer N.
Commercial Plant Tissue Culture in India—Current Status
Authors: Thomas J.
Published: February 2019

In recent years, there has been an explosion in the number of commercial plant tissue culture (TC) units in India. More than 25 such companies have production capacity of two to five million plants per annum. Almost all units are export oriented, but the target crops are the same. Indoor foliage plants dominate the export market. Micropropagation industry in India is providing major support to Indian agriculture in four crop groups: Fruits, ornamentals, spices, forestry/plantation crops. Banana is the largest selling TC fruit crop. TC papaya plants are now marketed for extraction and processing of papain. TC anthuriums, orchids, and gerberas have attained commercial importance. TC rose plants are used as pot plants. Nearly 500 ha are under TC cardamom cultivation in southern India recording 20% to 30% increase in yield. Vanilla cultivation is expected to increase from the existing 50 ha to more than 400 ha in the coming years using TC plants. Sugar companies have in-house units for micropropagation of sugarcane. There is demand for bamboo and eucalyptus for selective reforestation. The TC Industry is constrained by the non-availability of international varieties, high infrastructure and electricity costs, and lack of managers with commercial experience. A shake-up is imperative, during which many of the existing TC units may not survive the year 2000.
The Plant Tissue Culture Information Exchange: A Web Site for Teachers, Researchers, Practitioners, and Students
Authors: Lineberger R. Daniel
Published: February 2019

The World Wide Web is the most rapidly growing communication tool in use today. The Web links networked computers of all sizes and types through use of a hypermedia application known as a “browser.” Hypermedia technology allows research-based information related to plant tissue culture to be disseminated world-wide rapidly and cheaply, and to audiences that previously had difficulty accessing the information through scholarly journals (practitioners, secondary school students, consumers). The Plant Tissue Culture Information Exchange resides on the Aggie Horticulture homepage (http://aggie-horticulture.tamu.edu). Present contents include information on suppliers of tissue culture equipment and media, research reports on micropropagation of several ornamental species, and links to tissue culture related material at other universities. Hardware, software, and network requirements to access the Information Exchange and the construction of hypertext documents for inclusion in the Information Exchange will be presented.
Internal Disinfection for in Vitro Culture of Chrysanthemum
Authors: Kämpf Atelene N. , Kraemer Katia H.
Published: February 2019

Asymptomatic contaminated cuttings were used in two trials to test 1) the effects of antibiotica (streptomycin and penicillin) included in MS culture medium and 2) the internal disinfection employing germicide pulsing solutions, used for cut flowers, as a pretreatment. Before the regular disinfestation, cuttings were immersed to 3 h in the preservative solutions (treatments): 1) 818 mg·liter– 1 silver thiosulfate; 2) 1000 mg·liter–1 NaOCl; 3) 800 mg·liter–1 8-hydroxyquinolin sulfate; 4) 600 mg·liter–1 potassium sulfate. The addition of penicillin to MS medium reduced bacterial contamination by 50% on chrysanthemum nodal explants. Streptomycin showed similar results, but not promoted undesirable morphological alternations such as chlorotic, deformed leaves and shoots. All treatments except silver thiosulfate solution reduced the contamination by more than 50%. The highest efficiency (87%) was obtained with aluminum sulfate, without negative side effects.
Effects of the Worker Protection Standard on Vegetable and Fruit Production—A Trainer/Extension Agent's Perspective
Authors: Lamberts Mary , Balerdi Carlos F. , Nesheim O. Norman
Published: February 2019

The Dade County Extension Service has conducted three types of training classes related to the new Federal Worker Protection Standard (WPS): Train-the-Trainer sessions, WPS Worker Training, and WPS Handler Training. All of these must follow rigid course outlines to comply with requirements of the U.S. Environmental Protection Agency. At the end of training classes, growers and other audience members are often confused as to how this Standard actually affects their operation. The discussion will describe: a) materials and supplemental training classes developed by extension agents to help growers comply; b) operational changes that local growers have made as a result of this new law; c) the effects of this Standard on field visits and demonstration-research projects; and d) interactions between agents and non-traditional clientele groups.
Enhancing Potato Tuber Calcium Concentration Through Calcium Application May Reduce the Incidence of Internal Brown Spot and Hollow Heart
Authors: Kleinhenz Matthew D. , Gunter Christopher C. , Palta Jiwan P.
Published: February 2019

A direct comparison was made of several commercially available calcium sources applied on two different schedules for their effectiveness in increasing tuber medullary and periderm tissue calcium concentrations in 170–284-g tubers of the cultivar Atlantic grown on a Plainfield sandy loam. Plots (6 x 3 m) were arranged in a CR design in 1993 and a RCBD in 1994 (eight replications). Paired measurements of tuber Ca concentration and internal quality (±hollow heart, ±internal brown spot) were made on individual tubers produced in plots with no additional or additional Ca (168 kg Ca/ha) supplied from either gypsum, liquid calcium nitrate, or NHIB. Two Ca and N application schedules were compared: 1) application at emergence and hilling (non-split), 2) application at emergence, hilling, and 4 and 8 weeks after hilling (split). All plots received 224 kg H/ha balanced with ammonium nitrate. In general, tuber yield and grade were unaffected by treatments in 1993 and 1994, but overall percent A-grade was lowest and percent B-grade highest in 1993 compared with 1994 data. In 1993, all treatments receiving Ca had greater mean tuber medullary and periderm tissue Ca concentration values and a greater percentage of tubers with an elevated Ca concentration compared with non-Ca-supplemented controls. The overall incidence of tuber internal defects was 5% in 1993. All split schedule treatments receiving Ca showed 0% internal defects. In contrast, nearly 8% of the tubers from control plots showed some defect. The medullary tissue Ca concentration of 65% of the tubers having either defect was below the median value of Ca concentration for the entire experiment in 1993. Similar evaluations are underway for the 1994 crop. These data suggest that tuber calcium concentration may be related to the incidence of these internal defects.
A Three-phase Model for the Analysis of Sigmoid Patterns of Growth
Authors: Lieth J.H. , Fisher P.R. , Heins R.D.
Published: February 2019

A growth function was developed for describing the progression of shoot elongation over time. While existing functions, such as the logistic function or Richards function, can be fitted to most sigmoid data, we observed situations where distinct lag, linear, and saturation phases were observed but not well represented by these traditional functions. A function was developed that explicitly models three phases of growth as a curvilinear (exponential) phase, followed by a linear phase, and terminating in a saturation phase. This function was found to be as flexible as the Richards function and can be used for virtually any sigmoid data. The model behavior was an improvement over the Richards function in cases where distinct transitions between the three growth phases are evident. The model also lends itself well to simulation of growth using the differential equation approximation for the function.
Response of New Guinea Impatiens to Various Levels of Salinity in a Subirrigation System
Authors: Todd Nancy K. , Reed David Wm.
Published: February 2019

Concerns over groundwater contamination due to greenhouse runoff have caused many growers to turn to subirrigation as an alternative watering method. One reported problem is the movement of salts to the top layer of the rootzone due to zero leaching. Many growers are faced with the added challenge of subirrigating plants with poor-quality water than contains a high salt content before the addition of fertilizer. An experiment was conducted to investigate the movement of salts in the root zone and the effects on root development and overall plant growth. Plants were grown using water treated with NaCl + CaCl2 (1:1 equivalent basis) at the following total concentrations: 0, 2, 4, 6, 8, 10, 14, and 18 mM. Treatment time was 10 weeks (marketable stage). At harvest, height was measured and plants were cut off at the soil line and divided into shoots (stems and leaves) and roots for fresh and dry weight. Leaf area was measured. The root zone was divided into three layers—top, middle, and bottom (≈3 cm each). Roots were separated from each soil layer and soil samples collected for measuring EC and pH using 1:2 dilution. Soil samples showed EC in the top layer of the root zone was much higher than the middle and bottom layers. Root weight also decreased substantially in the top layer of the root zone. Height, FW, DW, and leaf area of plants did decrease with increasing salt concentration, indicating that the detrimental effects of poor-quality water on subsequent plant growth, especially in a subirrigation system.
Effect of June Yellowbuds on Yield, Fruit Weight, and Fruit Quality in `Blomidon' Strawberry
Authors: Jamieson Andrew R. , Sanford Katherine
Published: February 2019

Twelve clones of `Blomidon' strawberry (Fragaria xananassa) exhibiting a range of severity of June Yellows symptoms were grown in field plots to measure effects on productivity. Field plot layout was a randomized block design with four blocks. Plots were matted rows developed from five plants spaced at 45 cm inrow. Fruit samples were frozen and later analyzed for soluble solids concentration, total acidity, and pH. In the greenhouse, self-pollinated seedlings grown from these clones were rated for symptom expression as an additional measure of severity of June Yellows. Large differences in marketable yields were recorded, ranging from 1.94 t·ha–1 to 14.67 t·ha–1. Clones with severe symptoms produced smaller fruit. Small clonal differences were measured in total acidity and pH. A strong correlation was observed between the percentage of symptomless seedlings and the yield of the parental clone. This may lead to a test to predict whether a new cultivar will succumb to June Yellows.