bluuebunny/crossref_metadata_2025 huggingface dataset:
PHYSIOLOGY OF RIPENING IN BERRY CROPS
Authors: Knee Michael
Published: April 2024

Botanically, “berry crops” are not a homogeneous group, or distinct from other horticulturally defined groups of fruits. Many horticultural “berries” are not berries in a botanical sense and they originate from as wide a variety of floral structures as other fleshy fruits. Nevertheless there are many similarities in fruit development and physiology among horticultural berries and between these and other fruits. An early phase of cell division is followed by cell enlargement, with concomitant accumulation of sugars and organic acids. In the ripening phase, chloroplast to chromoplast transitions, accumulation of vacuolar pigments and cell wall alterations are general phenomena. The climacteric pattern of ripening and regulation by ethylene have attracted most attention in the literature on fruit ripening; this may be appropriate for tree fruits, but many berries are non-climacteric and we have to consider other regulatory mechanisms. Similarly, although cell wall degradation by polygalacturonase has captured attention in other fruits, other softening mechanisms need to be considered for fruits, such as strawberry.
DEVELOPMENTAL REGULATION OF PROTEINS IN ZYGOTICAND SOMATIC EMBRYOS OF PECAN.
Authors: Jeyaretnam Benjamin , Wetzstein Hazel Y. , Phatak Sharad C.
Published: April 2024

Soluble and insoluble proteins from pecan (Carya illinoensis) zygotic and somatic embryos were resolved on one dimensional SDS-PAGE to study the changes in expression patterns of proteins. Soluble proteins were extracted using 0.1M NaCl and 50 mM Tris-HCl buffer while insoluble proteins were recovered by treating the pellet with SDS in Tris-HCl buffer. Several new insoluble proteins appeared during early maturation (26-47 days post anthesis, DPA) of zygotic embryos. The insoluble protein profile from early somatic embryos resembled that of cotyledon expansion stage zygotic embryos. About 12 groups of insoluble proteins are abundantly expressed after 27 DPA in zygotic embryos and constitute major storage and structural proteins. In contrast, storage proteins were absent in all somatic embryo stages. The intensity and number of bands of zygotic embryo soluble proteins declined with maturation and 11 prominent groups appeared around post-abscission stage.
REGENERATION IN VITRO OF CUCUMBER (CUCUMIS SATIVUS L.) CULTURED FROM EXCISED SEEDS AND COTYLEDONS
Authors: Al-Juboory Karim H.
Published: April 2024

Seed and cotyledon explants of `Al-Mokhtar' hybrid (a new cultivar of cucumber) were prepared and disinfected. Explants were transferred to modified Murashige and Skoog (MS) medium supplemented with a combination of 6-benzylaminopurine (BA) and napthaleneacetic acid (NAA). Shoots regenerated best on medium supplemented with ≥ 2.0 mg/l BA. The BA concentration significantly interacted with NA with respect to shoot regeneration.
FOLIAR AND ROOT HEAT TOLERANCE OF THREE CONTAIN-ER-GROWN HOLLIES
Authors: Ruter John M.
Published: April 2024

The membrane thermostability of Ilex cornuta Lindl. & Paxt. `Needlepoint' (Chinese holly), Ilex aquifolium L. `Albo-marginata' (English holly) and Ilex × `Nellie R. Stevens', a hybrid between Ilex aquifolium and Ilex cornuta, was determined using electrolyte leakage procedures with excised foliage and root tissue. The critical midpoint heat-killing temperature (T m) after a 30 min exposure for the foliage of `Nellie R. Stevens' (54.4±0.4) was approximately 1C greater than for Chinese (52.9±0.3) or English holly (52.9±0.4). The Tm for root tissue of English holly was higher (53.9±1.5) than either `Nellie R. Stevens' (51.7±0.3) or Chinese holly (50.1±0.3). The results of this study suggest that English holly can withstand the same or a greater degree of direct heat injury compared to Chinese holly. The poor performance of English holly in the southeastern United States is suggested to be its inability to withstand prolonged but sublethal high temperatures which do not cause direct membrane injury.
STARCH ACCUMULATION AND GROWTH OF RHODODENDRON CATAWBIENSE IN RESPONSE TO DAY/NIGHT TEMPERATURE
Authors: Rowe D.B. , Warren S.L. , Blazich F.A. , Pharr D.M.
Published: April 2024

Seedlings of Rhododendron catawbiense Michx. were grown for 20 weeks under long day conditions with days at 18, 22, 26, or 30C for 9 hours with nights at 14 or 22C for 15 hours. Net leaf photosynthetic rates and exported carbohydrates increased with increasing day and night temperatures. Days of 22C and nights of 14C resulted in the highest starch levels. The greatest increase in daily starch accumulation occurred at days of 22C with considerably less starch accumulation at days of 30C. In plants grown at nights of 14C, the greatest daily increase in starch occurred at days of 18 and 22C. In contrast, for plants grown at nights of 22C, the greatest starch accumulation occurred at days of 26 and 30C. Photosynthetic rates and starch levels coincided with overall plant growth. Maximum total plant dry weights occurred at day/night temperatures of 22/22C with minimum levels at 30/14C.
YIELD RESPONSE OF GREEN BEAN and TOMATO TO DIFFERENT TILLAGE AND COVER CROP SYSTEMS
Authors: Prince Carolyn A.
Published: April 2024

Studies were conducted to evaluate conventional and reduced-tillage systems for winter annual cover crops used for early season weed suppression in green bean (Phaseolus vulgaris L.) and tomato (Lycopersicon esculentum Mill.) grown in central Iowa. The tillage systems and cover crops were: 1) conventional tillage annual rye, 2) no-till annual rye, 3) no-till hairy vetch, 4) no-till annual rye + hairy vetch mixture, and 5) conventional tillage in fallow plots. Experimental treatment plots were established as a randomized complete block design with four replications at the Horticulture Research Station near Ames. Early and total yield of green bean were affected by the tillage and cover crop systems. Differences were also observed in pod tenderness. Early tomato yield was influenced by the tillage and cover crop treatments but total yields were similar among all treatments. Soil organic matter and root dry weights were similar among all treatments for both crops.
DEVELOPMENTAL STUDIES OF ARTEMISIA ANNUA L.: FLOWERING AND ARTEMISININ PRODUCTION UNDER GREENHOUSE AND FIELD CONDITIONS
Authors: Ferreira Jorge , Janick Jules , Simon James E.
Published: April 2024

Cuttings of a clone of Artemisia annua L., grown under 16 h daylength for 55 days, were transferred to six photoperiod treatments in the greenhouse. Under short photoperiod (8, 10, or 12 h), plants flowered after two weeks; plants under long photoperiod (16, 20, or 24 h), remained vegetative until termination of the experiment in 10 weeks. When plants grown under long photoperiod treatments were transferred to 8 h photoperiod, flowering occurred two weeks later. Flower induction in plants grown under field conditions occurred when photoperiod was ca. 13.5 h. Artemisinin levels in all studies were found to be highest at anthesis. Artemisinin content was 4- to 11-fold higher in inflorescences than in leaves. Artemisinin declined after flowering but then increased towards seed maturity.
INTERACTIONS OF UNIVERSITY INTERNATIONAL PROGRAM OFFICES WITH FUNDING AGENCIES; HOW HORTICULTURISTS CAN BECOME INVOLVED
Authors: Wilson L. George
Published: April 2024

The role of university international programs offices in facilitating involvement of horticulturists in international and national consulting opportunities will be discussed. Horticulturists and other faculty are frequently included in the implementation of contracts and subcontracts managed by universities, university consortia and public and private sector agencies. International programs offices serve as brokers by maintaining contact with faculty interested in consulting assignments and with a diversity of organizations who require consulting expertise. Experience is important to those seeking consultants' services. Therefore, it is recommended that those faculty wishing to get established in international and national consulting activities remain flexible and perhaps initially accept broader based assignments. Faculty should determine in advance the position of their university administration regarding consulting.
CRITICAL ZINC+2 ACTIVITIES FOR SOUR ORANGE SEEDLINGS DETERMINED USING A CHELATOR-BUFFERED NUTRIENT SOLUTION
Authors: Swietlik Dariusz , Zhang Linsen
Published: April 2024

Chelator-buffered nutrient solutions were used to study the effect of different levels of Zn+2 activity on the growth of various tissues of sour orange seedlings. Zn+2 activities were calculated with a computerized chemical equilibrium model, GEOCHEM-PC, and were buffered by adding 74 and 44 uM of diethylenetriamine pentaacetate (DTPA) in excess of the sum of Fe, Mn, Zn, and Cu in Exp. 1 and 2, respectively. Root dry wt. was least sensitive to Zn deficiency followed by leaf number and white root growth, stem dry wt., leaf dry wt., shoot elongation and leaf area. The critical Zn+2 activities in the nutrient solutions for these growth parameters ranged from 10-10.4 to 10-10.05M. Increases in growth were observed from Zn applications even when visible Zn deficiency symptoms were absent. Seedlings with > 23 ppm Zn in their leaves did not respond to further additions of Zn to the nutrient solution. Zinc foliar sprays were less effective than Zn applications to the roots in alleviating severe Zn deficiency.
THRESHOLD LEAF LEVELS OF ZINC INFLUENCING NUT YIELD AND VEGETATIVE GROWTH IN PECAN
Authors: Sparks Darrell
Published: April 2024

The modified Mitscherlich plant growth model was used to quantify the threshold leaf level of Zn influencing nut yield and vegetative growth on an orchard basis for pecan [Carya illinoensis (Wangenh.) C. Koch]. Four indexes of tree performance including number of trees without deficiency symptoms, vegetative growth, nut yield, and trees without leaf deficiency symptoms plus yield were analyzed with regard to the concentration of Zn in the leaf. Data available from both published and unpublished sources on any single performance index were combined for mathematical modeling. The threshold value for leaf Zn was determined to be ≈40 μgg-1 for these tree performance indexes. Thus, nut yield and vegetative growth in an orchard will be reduced with a leaf Zn concentration below ≈40 μgg-1, but will be unaffected above this value.
PARTITIONING AND RECOVERY OF FOLIAR AND SOIL NITROGEN IN `COMICE' PEAR
Authors: Khemira Habib , Righetti T.L. , Sugar D. , Azarenko A.N.
Published: April 2024

Mature `Comice' pear trees were given 4 l of a 5% urea solution enriched in 15N (0.6 atom percentage 15N) either as a soil application (S), a foliar application with the ground covered to prevent soil contamination (F), or as a foliar application with the ground uncovered (F+S). The treatments were applied in mid-October 1990 to 6 single replicate trees each. The following spring, flower buds from trees that received either F or F+S had 38% of their N from the applied fertilizer. Trees from the S treatment had no label in their buds. In 1991, half of the trees were removed and their components analyzed for total and isotopical N to estimate N recovery. The relative enrichment of different tree parts in 15N was similar for the three modes of application. This suggests that unlike fall foliar applied N, reserve N is more uniformly distributed within the tree. N recovery depended more on tree biomass (r2 = 0.89, P = 0.001) than on the mode of fertilizer application. There was also a positive correlation between tree vigor and fruit N content.
NATURAL RECYCLING OF NUTRIENTS vs. CHEMICAL FERTILIZERS ON SHADED COCOA PLANTATIONS
Authors: Delgado-Nuñez Victor H. , Saavedra J. Angel
Published: April 2024

Eight-year-old cocoa trees growing under shade of different tree species were treated during three years with foliar and soil fertilizers and compared to non fertilized trees. We hypothesize that non fertilized trees under shade condition recycle their own nutrients by using fallen foliage from the shade trees and, in a fertile soil, they do not need addition of chemical fertilizers. Eight treatments, selected from growers' technology were evaluated under a randomized complete block design with 4 replications and 12 trees per experimental unit. Fertilized treatments did not differ from the non fertilized treatment in dry bean production and tree growth. This indicates that shaded cocoa plantations established in good fertile soils sustain their own nutrient requirements. The results also showed that foliar urea (1%) reduced cherelle wilt (yellowing and subsequent shriveling of young fruits).
INHERITANCE OF BACTERIAL CANKER RESISTANCE IN THE TOMATO LINE HAWAII 7998
Authors: McCarthy William H. , Gardner Randolph G.
Published: April 2024

Clavibacter michiganensis subsp. michiganensis (Smith) Davis et al. incites bacterial canker of tomato and is a significant disease in many tomato growing areas of the world. In previous studies, the accession Hawaii 7998 displayed a high degree of resistance to bacterial canker in North Carolina. Hawaii 7998 and the bacterial-canker-susceptible breeding line NC EBR-3 were crossed to develop reciprocal F1, F2 and BC populations for genetic analysis of bacterial canker resistance. Plants were evaluated for resistance in field and greenhouse studies. The field study indicated no maternal effect. Generation means and variance analysis indicated that foliar resistance was moderate and quantitative. Narrow sense heritability (h2) was estimated as 0.24. By regressing F3 progeny means onto F2 plant values, h2 for foliar resistance was calculated as 0.35. When data for both F2 and F3 generations were transformed into standard units, h2 was 0.44. In greenhouse studies generation means and variance indicated wilt resistance to be quantitative in nature, but h2 was estimated as low (0.09). The F1 generation mean was similar to the resistant parent.
RECOMBINATION OF TOMATO FUSARIUM WILT-RESISTANCE GENES
Authors: Scott J.W. , Jones John Paul , Brommonschenkel S.H. , Tanksley S.D.
Published: April 2024

Tomato (Lvcopersicon esculentum) line E427 contains Fusarium wilt resistant gene I-3 on chromosome 7 and I-2 (and presumably the linked I) genes on chromosome 11. E427 was crossed with `Bonny Best' (i, i-2, i-3) and backcrosses (BC) to `Bonny Best' and F2, seed were obtained. Self pollination of 187 BC and 150 F2 plants were made. Progeny were screened against Fusarium races 1, 2, and 3 and lines with recombinant ratios were self-pollinated and rescreened until homozygous. Five lines were resistant to races 2 and 3 but susceptible to race 1. These had the isozyme band got-2 linked to I-3, RFLP markers linked to I-3 and no RFLP markers linked to I-2. Five lines were resistant to race 1 but susceptible to races 2 and 3. These had the susceptible qot-2 band and no RFLP markers linked to I-3 or I-2. F2 complementation tests of 2 of these lines with `Manapal' (I) indicated they contained I. Three lines were resistant to race 2 but susceptible to races 1 and 3. These had the susceptible qot-2 band, I-2 linked RFLP markers, and no I-3 linked RFLP markers.
BREEDING TOMATOES RESISTANT TO TOMATO YELLOW LEAF CURL VIRUS.
Authors: Kasrawi M. A. , Mansour A.
Published: April 2024

Over a 2-year period, disease incidence and severity caused by tomato-yellow-leaf-curl-virus (TYLCV) in lines of tomato (Lycopersicon esculentum) derived from interspecific hybridization with wild species of L. pimpinellifoliuim, L. hirsutum and L. peruvianum ranged from non to intermediate. The average fruit weight of these lines ranged from 25 to 90 grams. Crosses between TYLCV-resistant lines derived from the same wild species produced progenies similar to their parents in the level of resistance. However, progenies of 2-wild species combination showed little higher in levels of resistance than their parents. Analysis of F1, F2 and backcross populations from crosses of the most promising TYLCV-resistant lines with the susceptible cultivar showed that resistance appeared to be incomplete dominant and controlled by few genes.
OPTIMIZING NITROGEN EFFICIENCY IN DRIP-IRRIGATED VEGETABLE PRODUCTION.
Authors: Hartz T.K. , Smith R.F. , Schulbach K.F.
Published: April 2024

Drip irrigation, by removing nitrogen application from other cultural restraints, allows efficient N management. In intensive work with commercial vegetable operations in California's central coastal valleys, we have formulated a nitrogen management plan for drip-irrigated vegetable production. The main elements of the plan are: a) estimation of net N mineralization potential of a field, b) suction lysimetry to monitor early-season soil N availability, c) weekly tissue sampling for conventional laboratory analysis or on-farm `quick test' analysis of petiole sap, and d) irrigation scheduling based on valid evapotranspiration estimates. Net N mineralization estimates can be made from in-situ incubations, soil test information, and/or previous cropping history. Suction lysimetry provides a mechanism to delay or minimize early-season N applications. The development of on-farm technology for NO3-N analysis of petiole sap has broadened the acceptance of routine tissue testing.
GREEN CAULIFLOWER (BROCCOFLOWER•), BRASSICA OLERACEA L., BOTRYTIS GROUP, CV. ALVERDA, RESPONSE TO N AND K RATES AND PLANT SPACING ON SAND
Authors: Csizinszky Alexander A.
Published: April 2024

Green cauliflower, cv. Alverda, was raised on light sand during the winter-spring (Jan.-Apr.) 1992. Experimental design was a split-plot. Main plots were 4 N rates: 0, 49, 98 and 196 N kg ha-1; sub-plots were the same K rates, and sub-sub plots were two within-row spacings: 23.0 and 30.5 cm. Seedlings were transplanted in double rows on the polyethylene mulched bed at 30.5 cm between row spacing. Treatments were arranged in a randomized complete block, replicated four times. Nitrogen source was NH4NO3 and K sources were KCl and K2SO4. Phosphorous rate was 34 P kg.ha-1 for all N and K rates. Yield of marketable curds (≥0.34 kg/curd) increased linearly and quadratically with increasing N rates from 0.1 t.ha-1 with 0-N to 6.7 t.ha-1 with 196 N kg.ha-1. Early yields declined linearly and quadratically with increasing K rates (P≤0.01). Total yields were similar with all four K rates. Yields were higher at 30.5 than at 23.0-cm spacing (P≤0.05). At the 23-cm spacing 23% and at the 30.5-cm spacing 35% of the plants had marketable size and quality curds.
VARIATION IN BIRCH PLANTS DERIVED FROM ORGANOGENIC CALLUS AND AXILLARY SHOOT PROLIFERATION
Authors: Chanon Ann M. , Lineberger R. Daniel
Published: April 2024

Betula plantlets have been produced in vitro from axillary shoots, organogenic callus, and somatic embryos. Organogenic callus and somatic embryos involve cultural conditions that promote rapid, unorganized cell growth. The auxin 2,4-D is used frequently in these cultural systems. This study examined the effect of 2,4-D exposure on the ability to regenerate birch callus using thidiazuron (TDZ) and compared the subsequent rate of somaclonal variation in the plants produced via organogenesis and axillary shoot proliferation. Tissue which had not been exposed to 2,4-D differentiated shoots within five weeks after transfer to Woody Plant Medium containing 10-6M TDZ. Increasing the time of exposure to 2,4-D delayed differentiation. Calli exposed to 2,4-D for more than 18 weeks rarely differentiated shoots regardless of the concentration of TDZ used. Increasing concentrations of TDZ on increasing the time of exposure to TDZ increased the number of calli regenerating shoots. The most frequently observed somaclonal variation was albino shoots. The highest frequency of albino shoot production occurred in leaf tissue cultured directly on TDZ. Plants regenerated from callus and axillary proliferation were rooted, acclimated, and are being grown simultaneously in the greenhouse to allow estimation of other types of somaclonal variation.
IN VITRO REGENERATION IN ASCLEPIAS TUBEROSA
Authors: Vyapari L. Sudeep , Khatamian H. , Albrecht M.L.
Published: April 2024

Successful shoot and root morphogenesis was achieved in butterfly flowers (Asclepias tuberosa L.). Surface-sterilized nodal explants were initially pulsed in Murashige and Skoog (MS) medium supplemented with 2,4-D (2.0 mg/l) in combination with BA (0.1 mg/1) for one week. Organogenic calli transferred to MS medium containing BA or kinetin (2.0 mg/l) in combination with thidiazuron (0.01 mg/l) resulted in multiple shoot formation in 8-10 weeks. The cultures were incubated at 26°C under 16-hr photoperiod with 46 μEm-2.S-1 light.

Effect of number of weeks of 2,4-D pulse on induction of organogenic calli was also studied. One or two weeks of pulse treatment (2,4-D 2.0 mg/l and BA 0.1 mg/l) promoted 15 or more shoots in 60-80 % cultures in some treatments. Kinetin based medium maintained the organogenic potential of calli for a longer duration (16-18 weeks). Explants obtained from in vitro grown material induced more shoots than from the greenhouse grown liners. Rooting of the microshoots was best achieved in MS medium either supplemented with NAA (1.0 mg/1) or containing no hormones.
SIMPLE IMPROVEMENTS FOR INCREASED EFFICIENCY OF RESEARCH MICROPROPAGATION LABORATORIES.
Authors: Huetteman Carl A. , Preece John E.
Published: April 2024

There are many ways in which small research or academic micropropagation laboratories can increase their efficiency. The standardization of stock solution aliquots and the use of repipetters for distribution greatly simplifies media preparation when using more than one medium or volumes of less than 1 liter. This is especially important if several graduate students and/or researchers are using the same laboratory and supplies. Peristaltic pumps are ideal for accurate dispensing of prepared media to culture vessels. A grocery-store type labeling gun can practically eliminate the use of marking pens for culture vessel identification. Colored tape may be used to determine visually the schedule for culture transfer to fresh media. Glass bead sterilizers are cooler and less damaging to transfer tools than bacticinerators. Commercially prepared peat plugs and high humidity flats provide a uniform environment for root development and acclimatization.
MULCH AND IRRIGATION DELIVERY EFFECTS ON WATER MASS IN MM 350 AT SATURATION (SWHC), CONTAINER CAPACITY(CCWHC), AND AFTER IRRIGATION (EWHC).
Authors: Khoury N.S. , Holcomb E.J. , White J.W.
Published: April 2024

A 2 by 4 factorial design was used to determine the effect of 4 mulches (Plastic cover, hydrophilic polymer, rockwool and none) and 2 irrigation delivery methods (surface and subirrigation) on the mass of water in MM 350 at saturation, container capacity and after irrigation on 4, 5 and 6 inch standard pots. An analysis of covariance was conducted with pot volume as the covariant.

With all treatments SWHC>CCWHC>EWHC. No significant differences resulted for SWHC with any mulch treatment or irrigation delivery method. There was no significant difference in CCWHC if either sub irrigated or surface irrigated for the same mulch. When subirrigated, gel mulch results in significantly more CCWHC than the plastic mulch - subirrigated treatment or the no mulch - surface irrigated - treatment.

Higher EWHC resulted when pots were surface irrigated. No mulch resulted in the lowest mass of water when either surface or sub irrigated. When subirrigated, no significant difference in water mass after irrigation resulted among either the gel, plastic or rockwool mulches.
SCHEDULING IRRIGATION FOR GREENHOUSE PRODUCTION OF CUT ROSES IMPROVES QUALITY AND WATER USE
Authors: Woerner Steven E. , Hopper Douglas A.
Published: April 2024

Four irrigation scheduling techniques for greenhouse production of three cultivars of hybrid tea rose, Rosa hybrida L., were examined for their effect on bloom quality. The irrigation scheduling techniques examined in this study included: a time clock based method; an accumulated radiation based method; an accumulated vapor pressure deficit (VPD) based method; and a combination method, which used an accumulated combination of VPD and radiation. Results from the study indicate that roses grown under the time clock method were poorer in length, fresh weight and dry weight. The other three treatments did not differ in a discernable pattern for their effect on quality. We hypothesize that the time clock method, while supplying as much or more water, was not able to apply water at the right time.

The three non-control treatments differed significantly in the amount of water that they applied to benches, as the VPD method supplied as much as 60% less water during the Valentine's Day period, and as much as 80% less water during the Mother's Day harvest, without reductions in quality. These differences were mainly due to the selection of the irrigation event threshold values.
LEVEL AND FREQUENCY OF WATER STRESS DURING FORCING AFFECT FLOWERING OF `GLORIA' AZALEAS
Authors: Womack William M. , Nell Terril A. , Barrett James E.
Published: April 2024

Dormant-budded 'Gloria' azaleas (Rhododendron sp.) were used to determine the effect of water stress level and frequency during forcing. Budded plants were cooled at 2°C for 6 weeks, then placed in a fan and pad cooled greenhouse for forcing. Plants were thoroughly watered then allowed to dry 1, 2, or 3 times to -15 or -25 bars during forcing. Stress to -25 bars 2 or 3 times delayed time to marketability (8 open-flowers) by 3 and 11 days, respectively, and reduced flower diameter by 7% and 18%, respectively. Increasing stress levels (-15 to -25 bars) delayed marketablility up to 4 days and reduced flower diameter up to 9%. Increasing number of stress periods (1, 2, or 3 times) delayed marketability up to 6 days and decreased flower diameter up to 10%. Stress levels of -15 and -25 bars increased the percent of buds showing color by 11% and 21%, respectively, at 8 open flowers. Increasing number of stress periods increased buds showing color by 10%, 15% and 23%, respectively. Stress level and number of stresses did not have synergistic effects on percent of buds showing color.
EFFECTS OF NITROGEN APPLICATION RATES AND IRRIGATION SETPOINTS ON NITRATE LEACHING AND LEATHERLEAF FERN
Authors: Stamps Robert H.
Published: April 2024

Leatherleaf fern (Rumohra adiantiformis) was grown in 36 in-ground 1.2 m × 0.6 m × 0.9 m lysimeters located in a shadehouse fernery to determine the effects of nitrogen application rate (392, 532, 672 or 812 kg N·ha-1·yr-1) and irrigation setpoint (-8, -12 or -16 kPa soil moisture tension) on nitrogen leaching and fern frond yield (number and weight) and quality (color and vase life). Liquid fertilizer was applied more or less weekly as is done commercially. Average NO3-N concentrations in leachate from the lysimeters were below the 10 mg NO3-N/l maximum contamination level only for the 392 kg N·ha-1·yr-1 treatment; however, maximum leachate NO3-N concentrations ranged from 29 at the lowest N rate to 65 mg/l at the highest rate. Irrigation setpoint did not affect leachate NO3-N concentrations. Treatments had no effect on number of fronds produced or frond average weight, color or vase life. These results suggest that reduced N fertilization rates (approximately ½ the current commercial rate) could be used successfully to produce leatherleaf fern if similar fertilization and water management practices were employed.
CITRUS FRUIT WITH LOW SHRINKAGE RATE
Authors: Hagenmaier Robert D. , Baker Robert A.
Published: April 2024

Citrus fruit was coated twice, using two different wax microemulsions composed of FDA-approved ingredients. Oranges, grapefruit and tangerines thus coated exhibited shrinkage rates less than 50% those of fruit coated in commercial packinghouses. Internal CO2 of double-coated fruit was lower than packinghouse fruit, thus suggesting that gas exchange was not overly restricted. The double-coated fruit had good gloss.
GOLDENSEAL: CULTIVATION OF A RARE BOTANICAL
Authors: Davis Jeanine M.
Published: April 2024

Goldenseal (Hydrastis canadensis L.), a native herbaceous perennial, is a highly valued medicinal herb which has been collected from the forests of the eastern United States for generations. Used to treat a wide variety of disorders ranging from sore throats to cancer, its pharmacological properties are attributed to the alkaloids hydrastine and berberine. Due to its popularity, native goldenseal populations have been seriously depleted in some areas. In North Carolina, for example, goldenseal is classified as an endangered species, making collection from the wild illegal. To meet the increasing demand and prevent further depletion of native populations, goldenseal cultivation is being tested and encouraged. Goldenseal cultivation is similar to that of ginseng, although somewhat easier because goldenseal is less prone to disease than ginseng. Goldenseal can be grown under natural forest canopy or under artificial shade. It is easily propagated by rhizome divisions or rootlet cuttings. It can also be propagated by seed, which must be kept moist and stratified before germinating the spring following harvest. Seed grown plants are ready to harvest in four or five years; plants grown from rootlets or rhizome divisions may be harvested in three or four years.
TRANSFORMATION OF PLUM (PRUHUS DOMESTICA L.) WITH POTYVIRUS COAT PROTEIN GENES AND THE REACTION OF TRANSGENIC PLANTS TO INOCULATION WITH PLUM POX VIRUS
Authors: Scorza R. , Levy L. , Damsteegt V. , Yepes M. , Cordts J. , Haddidi A. , Slightom J. , Gonsalves D. , Callahan A. , Ravelonandro M.
Published: April 2024

Plants transgenic for potyvirus coat protein (cp) genes have been shown to be resistant to viruses homologous and heterologous to the cp source virus. We have produced plum plants transgenic for the papaya ringspot virus (PRSV) cp gene. PRSV is a potyvirus related to plum pox virus (PPV). PRSVcp transgenic plants have been inoculated with PPV under containment conditions at the USDA Foreign Diseases-Weed Science Research Facility, Frederick, MD, and evaluated for two years. At least one plant is apparently resistant or tolerant to PPV based on symptomology, ELISA and RT-PCR assays. This suggests the potential utility of cp-mediated virus protection in tree fruits. To further test this potential, both short and long-term studies are in progress to evaluate resistance and cp expression in various organs, throughout the year and over the commercial life of individual trees. Plum plants have also been transformed with the PPVcp gene. Studies are underway to evaluate the protection derived from this cp gene.
COAT PROTEIN-MEDIATED RESISTANCE AGAINST APPLE MOSAIC VIRUS INFECTION
Authors: Korban Schuyler S.
Published: April 2024

Apple mosaic virus (ApMV) is transmitted by grafting to various Rosaceae plants including apple, rose, and plum, among others. ApMV reduces apple tree growth, yield, and fruit size; it causes mosaic symptoms on rose, and line patterns on plum and birch. ApMV is a member of ilarviruses, and it is characterized as isometric, labile, and producing ring spots. ApMV is a tripartite virus; RNA1 and RNA2 are monocistronic; whereas RNA3 contains two cistrons, one of which is the coat protein. The coat protein is translated from a subgenomic messenger, RNA4, which is derived completely from RNA3. We isolated and purified ApMV; virions containing RNA3 and RNA4 were separated from those containing RNA1 and RNA2. The sizes of RNA1 and RNA2 were estimated equal to 3 kb and 2.7 kb, respectively; the sizes of RNA3 and RNA4 were estimated equal to 2 kb and 0.9 kb, respectively. Inserts of clones from the 3′-end of RNA3 were sequenced and the 3′-primer was used to synthesize cDNA of RNA3. Overlapping cDNA clones were used to determine the nucleotide sequence of RNA4. Characterization and sequencing of the coat protein gene as well as transfer of this gene into apple will be discussed.
CONSUMER RESEARCH IN THE FLORAL INDUSTRY
Authors: Behe B.K.
Published: April 2024

Worldwide floral sales exceed $25 billion annually and the U.S. ranked 12th of 15 countries in per capita floral consumption. The objective of this paper is to summarize published consumer research in the floral industry. Floral purchases are often correlated to demographic characteristics. Age and income are positively correlated to floral expenditures. Research has investigated differences in purchasing behavior by gender and nationality. Studies have documented consumer preferences for flower and color preferences. Consumer purchase frequency and retailer patronage have also been investigated. Multivariate analyses have enabled researchers to relate many variables simultaneously to floral purchases yielding market segments and perceived product value. Consumer research in the floral industry began in 1956, yet less than 100 studies have been published to date.
ECONOMIC IMPACTS ON CHANGING MARKETS DUE TO PUBLIC PERCEPTIONS: TURFGRASS AND LANDSCAPE
Authors: Culpepper William H.
Published: April 2024

Turfgrass and landscape combine to form the surroundings for, not only our homes, parks, and recreational areas, but the workplace in which we spend much of our time. Home lawns, roadsides, parks, golf courses, and common areas are important as places for play and relaxation for children and adults as well. This desire for a more beautiful, natural surrounding has led to a continuing growth in the demand for both products and services for the turfgrass and landscape industry. Better maintained turfgrass and landscape benefit the public in four ways: 1) personal gardening satisfaction 2) aesthetics 3) property value enhancement 4) an environmentally friendly cover for the soil. To obtain these benefits, research and industry have combined to provide a continuing stream of enhancement. This paper discusses the benefits the American public receives from turfgrass and landscape, and attempts to quantify their value and future direction.
A SUPPLY AND DEMAND APPROACH TO MODELING ANNUAL REPRODUCTIVE AND VEGETATIVE GROWTH OF DECIDUOUS FRUIT TREES
Authors: DeJong Theodore M. , Grossman Yaffa L.
Published: April 2024

An approach to developing a simulation model of the annual carbon supply and demand for reproductive and vegetative growth in peach trees will be presented. This modeling approach simulates photosynhetic carbon assimilation using seasonal canopy light interception and daily minimum and maximum temperature and solar radiation inputs. Simulation of carbon partitioning and crop growth is based on the hypothesis that plants grow as collections of semi-autonomous, but interacting organs. The plant genotype, triggered by internal and environmental signals, determines current organ specific growth potentials. Daily environmental conditions interact with organ specific growth potentials to determine the conditional growth capacity and maintenance respiration requirement (i.e. the carbon demand) of each organ type. Then the daily carbon available for growth after maintenance requirements are met is partitioned to leaves, fruits, stems, and branches based on their relative conditional growth capacities. Remaining carbohydrate is partitioned to the trunk based on its conditional growth capacity and all residual carbohydrate is partitioned to roots after above-ground demands are met. The methods used to determine organ specific growth potentials and the usefulness of using the supply and demand approach to modeling the carbon economy of deciduous fruit crops will be discussed.
DEVELOPMENTAL PHYSIOLOGY OF SHOOT FORMATION FROM VARIOUS EXPLANT SOURCES
Authors: Sutter Ellen
Published: April 2024

Most micropropagation (MP) is based on meristem or shoot tip culture, methods thought to result in a lower incidence of genotypic and phenotypic alterations than methods that proceed through callus first. The use of somatic embryogenesis, especially as artificial seed, is promising because of the very large numbers of propagules that may be produced from an initial explant. A limiting factor in the commercial utilization of MP has been the high labor cost. The use of automation could reduce costs and increase productivity using MP techniques. Each MP method has positive and negative aspects associated with it. In shoot production from non-apical meristematic tissue, time to form shoots, chance of off types, and ability of the automated system to distinguish developing tissue from desirable shoot propagules could limit application of automation. Somatic embryogenesis suffers from varied degrees of phenotypic and genotypic alterations as well as from difficulties in germinating embryos. We will survey several of these difficulties in terms of the morphological and physiological development of shoots and plants from different explants as they apply to automation of MP.
THE ENVIRONMENT UNDER WHICH THE STOCK PLANT IS GROWN INFLUENCES EXPLANT PERFORMANCE IN VITRO
Authors: Read Paul
Published: April 2024

Environmental factors under which the stock (mother, donor) plant has been grown, including temperature; light duration, quality, and intensity; mineral nutrition; and ambient gases can have significant impact on explant responses in vitro. Bulblet production in hyacinth has been influenced by mother bulb storage temperature. Shoot proliferation and rootability of microshoots of rhododendron have been modified by light intensity and light quality. Photoperiod has been demonstrated to affect tuber and callus formation on potato and dahlia. Furthermore, plant growth regulator treatments of the stock plant can strongly influence in vitro responses of explants taken from such plants. Implications of these latter responses will be discussed with regard to possible endogenous hormonal activity.
IMPACT OF INTELLECTUAL PROPERTY PROTECTION ON PUBLIC RESEARCH AGENDAS
Authors: Bliss Fredrick A.
Published: April 2024

Novel ideas and plant materials developed as a result of individual and collective investigations of biological phenomena may in some cases be protected as intellectual property. Depending on the circumstances surrounding each situation, plant patents, utility patents, plant varietal protection (PVP) and trade secrets may be used to limit unauthorized use of and to collect royalties on one's intellectual properties. In addition to these instruments, agreements over use and distribution of materials not formally protected often are requested before ideas and biological materials are exchanged. Although public-supported institutions usually promote exchange of information, these legal and informal arrangements often impact “free” exchange if they are not well understood. Ways to utilize intellectual property protection and to avoid unnecessary constraints will be discussed.
THE IMPACT OF INTELLECTUAL PROPERTY PROTECTION ON PRIVATE RESEARCH AGENDAS
Authors: Stevens M. Allen
Published: April 2024

The rulings that utility patents can be granted for plant varieties has had a profound effect on the research agendas of seed companies. Although there is confusion on utility patents, most major seed companies are concerned about how they will affect their competitive position. Strategic alliances are common; these may involve a seed company (germplasm resources) and a biotechnology company (gene constructs). Licensing agreements are frequently used to access new technologies and genes. Material transfer agreements are being used to access genes for proof of concept studies. Commercial agreements have thus far been elusive. Seed companies strongly favor revision of the Plant Variety Protection Act to conform to the 1991 International Union for the Protection of New Varieties of Plants (UPOV) Convention.
UV COLOR SORTING TO IMPROVE BRASSICA GERMINATION
Authors: Taylor A.G. , Churchill D.B. , Lee S.S.
Published: April 2024

The purpose of color sorting by fluorescence was to upgrade seed quality by removal of fluorescent coatings that were attributed to sinapine leakage from nonviable seeds. Nine seed lots (three seed lots each of broccoli, cabbage and cauliflower) were custom coated. Seed samples were pretreated prior to coating with or without 1.0% NaOCl for 10 minutes to enhance leakage. Fluorescence, as measured by fiber optic spectrometry, was expressed from 400 to 560 nm with peak emission being from 430 to 450 nm. A UV color sorter was employed to separate fluorescent (reject) from non-fluorescent (accept) coatings. The percent non-fluorescent coatings (averaged over seed lot and NaOCl pre-treatment) before and after sorting was 89.5 and 95.9, respectively. There was a six percent loss of non-fluorescent coatings after sorting (averaged over all treatments). An increase in the percent germination was recorded in 8 of the 9 seedlots following color sorting and the greatest improvement was obtained with seed lots of medium quality. The germination of three medium quality lots was increased from 10 to 15 percentage points. The average increase in germination with or without NaOCl pre-treatment was 8.2 and 5.5 percentage points, respectively. In conclusion, the combination of coating technology with seed conditioning by UV color sorting was effective in improving Brassica seed performance.
EFFECT OF PLANT DENSITY AND NAA ON BUTTERNUT SQUASH YIELD
Authors: Ibrahim Aly M. , Majeed Mohammed A. , Al-Rabiah Abdul-Rhman A.
Published: April 2024

Butternut squash is a newly introduced crop in Saudi Arabia and is gaining very much popularity.

An experiment to evaluate the productivity of butternut squash using different plant spacings and trailed vs untrailed plants was conducted in tunnel greenhouse.

Results showed that trailed plants produced 100% more yield than the untrailed plants with better quality and uniformity in size. Among spacings, the plants in 120 cm produced 82% higher yield/plant than the plants in 40 and 80 cm. NAA increased yield by 14%. NAA treated or untreated trailed fruits had no seeds as compared to the untrailed fruits which did produce small amount of seeds.
CANE GIRDLING AS A MEANS TO IMPROVE EASTERN SEEDLESS TABLE GRAPE QUALITY
Authors: Bartholomew Henry M. , Cahoon Garth A.
Published: April 2024

Seedless table grapes are of increasing interest to fruit growers in the Eastern U.S. The flavor of many cultivars is excellent, but fruit quality, from an appearance standpoint, needs improvement to be competitive with California grapes. This paper will summarize results from a two year study of cane girdling Einset and Vanessa cultivars. Cane girdling was applied as whole vine treatments at pre-bloom, shatter, veraison, double girdle at both shatter and veraison, and control. The experiment was replicated on both single and double curtain training systems.

Cluster length, cluster weight, berry weight, berries per cluster were all improved with cane girdling at shatter and double girdling. Juice quality was minimally affected by the successful treatments. Vine vigor when measured as pruning weights were not affected. Grape cluster and berry size was better on the double curtain training system.
ONE-SIDED SHIFT-TRELLISING FACILITATES HARVEST AND REDUCES SUNSCALD (ULTRA VIOLET RADIATION INJURY) IN BLACKBERRIES
Authors: Stiles Herbert D.
Published: April 2024

Nearly all berries were isolated on one side of the row, and sunscald was reduced to 6% (from 47% on vertically trained canes), by “post-bloom” shifting of blackberry floricanes from a horizontal pre-bloom position to a west-facing, slanted (20° from vertical) configuration. This was made possible by our specially designed, single-sided shift-trellis (SSST).
SURVEY AND ECONOMIC ANALYSIS OF MECHANICAL RAISIN HARVESTING SYSTEMS
Authors: Berg Greg T. , Striegler R. Keith
Published: April 2024

The harvest and production of natural Thompson Seedless raisins traditionally has been a very labor intensive process. Current practices require significant labor inputs for harvest, turning, rolling, and retrieval of raisins. A disruption of labor supply during the harvest and drying period would be detrimental for raisin growers.

During the 1992 raisin harvest, a small-scale demonstration trial was conducted in the CSU Fresno campus vineyard. Two mechanical raisin harvesting systems were utilized in a side-by-side comparison with the traditional method of raisin harvesting. Each system was used to harvest a six-row block in two vineyard locations. Data were collected regarding the procedures, costs of operation, and labor requirements for each system from pre-harvest practices to the boxed, farm-level product.

When the actual time and motion data collected from our 1992 research were adjusted to reflect industry average vineyard situations (i.e., yields of 5.6 metric tons/hectare and 402m row lengths), the mechanical harvest systems exhibited significant economic and labor-saving advantages over the traditional hand raisin production system.
DRIP IRRIGATION OF MULCH STRAWBERRY USING CARBONATED WATER-A GREENHOUSE STUDY
Authors: Shore Margaret L. , Hughes Harrison G. , Moore Frank D. , Smith Danny H.
Published: April 2024

Carbonated water has recently been under study as a potential means of increasing photosynthesis in the field situation. Cahn (1989) and Novero (1991) have demonstrated that carbonated water lowers soil pH in strawberries and tomatoes, respectively. Novero showed greater uptake of zinc and increased marketable fruit yields. Currently, we are evaluating the influence of carbonated water on strawberry (Fragaria × ananassa cv Muir) growth using a high pH, high calcium soil and a low pH, low calcium soil in the greenhouse. Carbonated water applied to a high pH, high calcium soil significantly increased leaf, bud and open flower number, as well as greater crown and leaf dry weights.
FERTILIZER LEVELS MAXIMIZING YIELDS AND ECONOMIC RETURNS FROM VEGETABLE AMARANTH IN THE MIDSOUTH.
Authors: Downes J. D. , Makus Donald J.
Published: April 2024

In an Arkansas mineral soil with pH of 5.7 and testing 59, 14, and 84 kg/ha of N, P and K, respectively, two cultivars of vegetable amaranth (Amaranthus tricolor L.), `Hinn Choy' and `RC 241' were grown in a fertilizer (3N × 3K × 4P) field experiment. Fertilizer P accounted for 90% of leaf fw yield variations, followed by K, 3%; and N, 2%. Multiple regression equations summarize the yield responses: Yhc = .528 + .00658 N + .146 P − .0000293 N2 − .001537 P2 + .0001351 N*P + .0001854 P*K, R2 = .964 Yrc = .63 + .2085 P − .001349 P2 + .0003497 P*K, R2 = .954 where Y = mt/ha, N, P, K = kg/ha of N, P and K. Fertilizer levels maximizing yields, and optimum levels under varying fertilizer cost/crop price situations were estimated using the derivatives and cost/price ratios. In RC estimated Pmax = 101 kg and estimated Popt = 93 kg at $1.33/kg P and $66/mt of crop.
GENETIC ADAPTATION OF VEGETABLE CULTIVARS TO NUTRIENT-DEFICIENT SOILS.
Authors: Bowen John E. , Macomber Patricia
Published: April 2024

Cultivars of many vegetable crops; e.g., tomato and Chinese cabbage, differ genotypically in rates of uptake and accumulation of various essential nutrients. Indeed, selection of a nutrient-inefficient cultivar can cause crop failure. The physiology and kinetics of some of these differences have been studied. Excised tomato roots (Lycopersicon esculentum L.) cv Kewalo absorbed Zn2+ and Cu2+ much more rapidly than did cv Sel 76252. Uptake of each cation was competitively and reciprocally inhibited by the other. Root apices from the two tomato cvs did not differ in their affinities for Zn2+ and Cu2+, however. Vmax values for Zn2+ and Cu2+ uptake in cv Kewalo roots were three-fold greater than those for cv Sel 7625-2.

Chinese cabbage cvs Nozomi and Aichi have significantly higher requirements for B and K, respectively, than do 11 other cvs. Cv WR Green 60 requires more P and Ca but cv Nagaoka 50 has a significantly lower Mg requirement than the other cvs tested. No significant differences occurred among the 12 cvs with regard to their Zn, Mn and Cu requirements.