bluuebunny/crossref_metadata_2025 huggingface dataset:
Technique for Vital Staining of Tomato Pollen with Fluoroscein Diacetate
Authors: Peterson R. H. , Taber H. G.
Published: September 2022

Most methods of staining pollen grains overestimate the extent of pollen fertility. The traditional staining method used for tomato pollen has been acetocarmine or cotton blue, which allows for a clear distinction between pollen grains with and without cytoplasm (2). However, pollen grains with cytoplasm are not necessarily fully fertile, as shown by germination on artificial media (2). A factor likely to be closely correlated with the viability of the vegetative cell of the male gametophyte is the state of the plasmalemma (1). On the basis of plasmalemma integrity, the important distinction between viable and nonviable pollen grains can be made with a vital stain such as fluoroscein diacetate.
A Simple Tractor Mount for a Vegetable Plot Seeder
Authors: Beverly R. B.
Published: September 2022

Many researchers have discussed the need for precision planting in research plots and have designed new or have modified existing planters to fit their needs. Commercially available precision planters are very expensive and are best suited to planting small, round, or coated seeds, but are less adapted to large irregularly shaped seeds. Inexpensive planter mechanisms have been adapted for precision planting by various modifications (1, 4, 5). However, these planters were either hand-pushed, or failed to provide for wide seed spacing in the row.
Polymorphism of Isozymes Within Plant Introductions of Allium cepa L. and A. fistulosum L.
Authors: Peffley E. B. , Orozco-Castillo C.
Published: September 2022

Breeding programs depend upon genetic variation. Visual plant markers traditionally have been used in crop improvement. However, molecular markers provide additional selection criteria. Of the molecular markers available, isozymes are preferred by many researchers because they are expressed in young tissue as codominants and are easily extracted and detected. Mature plants may bias estimation of hybrid purity, whereas estimations of hybrid purity can be obtained at an early stage by enzyme analysis (1, 2, 4).
Deblossoming Stimulates a Second Bloom in ‘Golden Delicious’ Apple Trees
Authors: Schupp James R. , Ferree David C.
Published: September 2022

The inhibitory effect of cropping on return bloom in fruit trees is well-known. Previous work suggests the presence of fruit inhibits vegetative meristems from initiating flowers (2). Root pruning promotes flower formation in fruit trees (4). In 1984, we began a study to investigate the interactions between cropping and root pruning on flowering and other physiological processes in field-grown apple trees. In May 1986, the trees that had been deblossomed for three consecutive years underwent a second flush of bloom. This occurrence has not been documented adequately for apple.
‘Adirondack’ Crabapple
Authors: Egolf Donald R.
Published: September 2022

Malus × ‘Adirondack’ is a superior multiple-disease-resistant cultivar with a narrow obovate, upright-branched growth habit. Since there are relatively few crabapples with upright growth habit (i.e., ‘Centurian’, ‘Henningi’, Sentinel’ and ‘Silver Moon’) that have variable disease resistance or tolerance, ‘Adirondack’ is a significant introduction for nursery production. ‘Adirondack’, like ‘Naragansett’ (1), the first U.S. National Arboretum introduction, combines disease resistance and landscape characteristics.
Chemical Regulation in Tissue Culture: An Overview
Authors: Reynolds John F.
Published: September 2022

The influences of exogenously applied compounds on the growth and morphogenesis of plant tissue, cell, and organ cultures have been studied for more than 4 decades. Early work by Skoog (26) showed that the auxins 1H-indole-3-acetic acid (IAA) and 1-na-phthaleneacetic acid (NAA) inhibited shoot formation but not callus growth in tobacco (Nicotiana glauca × N. langsdorffii) cultures. Furthermore, Skoog and Tsui (27) noted that adenine stimulated shoot formation and counteracted auxin effects. Miller and Skoog (12) reported that the balance of auxin and adenine regulated shoot formation in tobacco. Later, adenine was replaced by the newly discovered cytokinin N-(2-furanylmethyl)-1H-purin-6-amine (kinetin) (13) as the factor that regulated shoot formation. These observations had general application for a wide variety of plant species; however, they were greatly modified by factors such as genotype, explant source, plant nutrition, and tissue growth environment.
Biological and Biochemical Effects of Cytokinin-active Phenylurea Derivatives in Tissue Culture Systems
Authors: Mok Machteld C. , Mok David W. S. , Turner Janet E. , Mujer Cesar V.
Published: September 2022

Plant growth regulator studies and plant tissue culture research have been closely related and mutually supportive. The manipulation of plant cells, tissues, and organs in culture, with important applications in propagation and genetic modification of plants, is highly dependent on the use of appropriate growth regulator regimes. Conversely, tissue culture systems are useful as bioassays to define the growth-regulating activity of many compounds. The discovery of the cytokinin N-(2-furanylmethyl)-1H-purin-6-amine (kinetin) by Miller et al. (17) was particularly relevant in this respect. Whereas the testing of this cytokinin and its structural analogues for biological activity was dependent on callus culture bioassays, the subsequent availability of synthetic cytokinins created many new opportunities in the field of plant tissue culture.
Efficient Methods for Testing Vegetable Cultivars
Authors: Wehner Todd C.
Published: September 2022

Horticultural scientists often use field trials to determine the value of cultivars and experimental lines in specific production areas. Questions arise as to the most efficient methods for running such trials in order to gather as much information as possible with the least cost in both time and money.
Apple Breeding in Brazil
Authors: Denardi F. , Hough L. F.
Published: September 2022

In Brazil, apple culture is concentrated at high elevations in the southern states of Rio Grande do Sul, Santa Catarina, Paraná, and São Paulo. In 1986, there were 28,000 ha of apples. However, most plantings are quite new. For instance, in the state of Santa Catarina, which has 60% of the total production, there are now more than 13,000 ha of apples, compared to only 265 ha in 1970.
Breeding of Low-chill Peach and Nectarine for Mild Winters
Authors: Sherman W. B. , Rodriquez-AJcazar J.
Published: September 2022

Breeding low-chilling peach and nectarine cultivars began in Florida in 1953. Objectives were to produce low-chilling, early-ripening peach cultivars with fruit qualities equal to temperate-zone cultivars. Low chilling was essential for local adaptation (4). Early ripening was essential to allow production of the earliest-season peaches on the domestic market with little competition from other states and to allow harvest of the crop during the relatively dry period of late April and May. Feral selections descended from Spanish seed introductions through St. Augustine, Fla., seed importations from Okinawa, and ‘Hawaiian’, a South China clone, served as the main sources of low chilling (18). These sources were hybridized with high-chilling U.S. clones having commercial fruit qualities. Resultant seedlings were selected for best adaptation and improvement in fruit qualities above that of the low-chilling parents. Chilling requirements of progeny were near midparent values; chilling requirements of the F2 seedlings ranged from equal to the low parent to equal to the high parent (14), indicating that many genes are involved in chilling. Selections were intermated, and low-chilling progeny were hybridized with other high-chilling U.S. clones, resulting in more progenies for further selection. Commercial fruit size and satisfactory horticultural qualities were obtained after six generations of crosses and backcrosses. Clonal selections made during these six generations and in subsequent generations serve as the basis for most low-chilling cultivars currently grown in Florida, southern Texas, and southern California. Selections from this program are either grown commercially or being evaluated in many tropical and tropical highland areas of the world (11, 16, 19, 24).
Producing Temperate-zone Fruit At Low Latitudes: Avoiding Rest and the Chilling Requirement
Authors: Edwards Gordon R.
Published: September 2022

Commercial production of temperate-zone fruits is well established in localized areas in the tropics. This paper considers meteorological and cultural conditions necessary for success.
Flooding, Hydraulic Conductivity, and Root Electrolyte Leakage of Rabbiteye Blueberry Plants
Authors: Crane Jonathan H. , Davies Frederick S.
Published: September 2022

The relationship of root (RLp) and stem hydraulic conductivity (SLp), root electrolyte leakage (EL), and stomatal conductance (gs) to flooding was investigated using 2-year-old ‘Tifblue’ and ‘Woodard’ rabbiteye blueberry (Vaccinium ashei Reade) plants. Soil redox potentials (Eh) decreased to about — 225 mV within 4 to 10 days of flooding, whereas Eh of unflooded soils were always > 400 mV. Root hydraulic conductivity decreased by 44% to 60%, compared to that of unflooded plants after 4 to 6 days of flooding in two of three experiments, decreasing by 29% to 81% by the end of 2 to 3 weeks. Root electrolyte leakage increased and SLp decreased after 6 to 10 days of flooding. Stomatal conductance decreased by 49% to 93% compared with that of unflooded plants after 4 to 6 days of flooding. Decreases in RLp and gs for flooded plants occurred concomitantly and are two of the earliest physiological responses of rabbiteye blueberry plants to flooding.
Growth and Compositional Changes During Development of Lanzone Fruit
Authors: Pauli Robert E. , Goo Theodore , Chen Nancy J.
Published: September 2022

Lanzone (Lansium domesticum Correa) growth was sigmoidal after a delay of 100 days in which little growth occurred. Fruit growth was greatest between 115 and 130 days from anthesis, just before the pericarp changed color from green to yellow. During the 20 days that pericarp color changes occurred, there was an increase in total sugars from 30 to 180 mg·g−1 fresh weight. This change in sugars paralleled the increase in total soluble solids. Just before this period, total ethanol soluble phenols declined from 12 to 2 mg·g−1 fresh weight and was associated with loss of astringency. A slight decline in titratable acidity from 38 to 21 meq/100 g fresh weight was related to a loss of citric, malic, and succinic acids. At the edible stage, the citric and succinic acids were the major organic acids. Potassium was the major counter ion.
Effect of Supplementary Lighting on Transplant Growth and Yield of Greenhouse Tomato
Authors: Boivin Claire , Gosselin André , Trudel Marc-J.
Published: September 2022

Tomato plants (Lycopersicon esculentum Mill. cv. Carmello) seeded on 3 Dec. 1984 and 17 Jan. and 8 Mar. 1985 were grown under natural or supplementary lighting (high-pressure sodium) of 100 μ·mol·s−1·m−2 (photosynthetically active radiation) from pricking out to transplanting. Plants of the first, second, and third seeding dates grown under supplementary lighting had at transplanting dry weights 6.6, 3.5, and 2.5 times higher, respectively, than plants grown under natural light. The number of leaves formed below the first inflorescences was reduced significantly with supplementary lighting, which also reduced the incidence of flower abortion. Supplementary lighting increased early marketable yields for the 3 Dec. seeding by 100% (from 0.77 to 1.55 kg/plant) and total yields by 10% (from 3.55 to 3.91 kg/plant). No significant differences between lighting treatments could be observed in early and total yields of plants from the last seeding date.
Use of Slow-release Nitrogen and Phosphorus Fertilizers in Celery Transplant Production
Authors: Dufault Robert J.
Published: September 2022

‘Utah 52-70R’ celery (Apium graveolens L.) seedlings were grown in a N- and P-deficient soilless medium amended with N and P slow-release fertilizers (Osmocote) in greenhouses maintained at either 21° to 32°C (warm house) or 14° to 24° (cool house). Generally, as N rate increased from 1.25 to 10 g N/kg of medium, plant stands, chlorophyll, shoot number, plant height, leaf area, and shoot and root dry weights increased; but, from 10 to 20 g N/kg of medium, these variables decreased. As P rates increased from 2.5 to 10.0 g·kg−1 of medium, only chlorophyll content decreased linearly. Temperatures in the warm house generally reduced celery growth compared to the cool house. At the experiment's termination, it was determined that as N and P rates increased, media conductivity, nitrate-N, and phosphorus levels increased, but pH decreased. A N rate of 1.25 and 2.5 g P/kg of medium was adequate to produce quality celery transplants in a cool house.
Celery Response to Foliar Nutritional Sprays and Acidification of a Histosol
Authors: Beverly R. B.
Published: September 2022

Response of celery (Apium graveolens L.) to soil acidification and foliar Mn application was evaluated in a field experiment on a Histosol of near-neutral pH. Acid sources varied in their effectiveness in reducing pH when broadcast at 1120 and 2240 kg·ha−1 or band-applied at ≈200 kg·a−1. Broadcast application increased yield compared to the control or band treatments, but band application of a granular S and Mn product proved superior to the other band treatments. Soil and foliar treatment interaction data showed that the strategies were substitutionary. Foliar Mn application is more economical than soil acidification but soil acidification, especially by band application of a low rate of S and Mn together, also may prove cost-effective.
Ammonia Volatilization from Foliar-applied Urea on Field-grown Kentucky Bluegrass
Authors: Wesely R. W. , Shearman R. C. , Kinbacher E. J. , Lowry S. R.
Published: September 2022

Ammonia (NH3) volatilization was determined from 15N-labeled urea applied foliarly in 35 ml·m−2 water at 1.7 and 3.4 g N/m2 to a ’Park’ Kentucky bluegrass (Poa pratensis L.) turf that was grown on Sharpsburg silty clay loam (Typic Argiudoll). Field measurements of NH3 volatilization were made 1, 5, 9, 13, and 25 hr after treatment (HAT). Additional volatilization measurements were made at 2, 3, and 4 days after treatment (DAT). Maximum NH3 losses of 9.7 and 23.0 mg N/m2 per hr at 5 and 25 HAT occurred with the 3.4 g N/m2 treatment. Maximum volatilization during 25 HAT coincided with periods of high leaf surface moisture followed by rapid drying. On the second day after treatment, the maximum NH3 loss of 14.0 mg N/m2 per hr occurred from the 3.4 g N/m2 treatment. Cumulative 4-day NH3 volatilization losses for foliar-applied urea at 1.7 and 3.4 g N/m2 were 35% and 31%.
Efficacy of Ancymidol, Daminozide, Flurprimidol, Paclobutrazol, and XE-1019 when Followed by Irrigation
Authors: Barrett James E. , Bartuska Carolyn A. , Nell Terril A.
Published: September 2022

Vegetative Chrysanthemum morifolium Ramat. ‘Nob Hill’ plants were treated with foliar sprays of ancymidol, daminozide, flurprimidol, paclobutrazol, or XE-1019 and then overhead-irrigated 0.5, 1, 2, 4, 8, or 24 hr later. Irrigation prior to 4 hr reduced the efficacy of daminozide but did not alter efficacy of other chemicals. Efficacy was not affected when similar plants were treated with a medium drench of the same chemicals, except daminozide, and followed with irrigation at 1,24, or 48 hr. Chemical names used: α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrmidinemethanol (ancymidol), butanedioic acid mono-(2,2-diemthylhydrazide) (daminozide), α-(l-methylethyl)-α-[4-(trifluoromethoxy)phenyl]-5-pyrimidinemethanol (EL-500) (flurprimidol), (±)-(R*,R*)-beta-((4-chlorophenyl)methyl)-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol (PP-333) (paclobutrazol), and (E)-(p-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-l-penten-ol (XE-1019).
Effect of Container Size and Shape on the Growth of Northern Red Oak Seedlings
Authors: Hanson P. J. , Dixon R. K. , Dickson R. E.
Published: September 2022

Northern red oak (Quercus rubra L.) seedlings were grown in six container configurations differing in diameter, length, and volume. More shoot and lateral root dry weight was produced in a cylindrical polyvinylchloride (PVC) container 15.4 × 36 cm containing 6333 cm3 of potting medium than in containers with less medium volume. Seedling growth did not increase in a 15.4 × 110 cm container even though the potting medium volume was increased. Of all container variables measured, the ratio of potting medium surface area to potting medium depth (SA:D) showed the best correlation to seedling dry weight accumulation. Water or nutrient deficiencies could not be eliminated as factors contributing to differences in seedling growth.
Factors Regulating Overwinter Survival of Newly Propagated Stem Tip Cuttings of Acer palmatum Thunb. ‘Bloodgood’ and Cornus florida L. var. rubra
Authors: Goodman Michael A. , Stimart Dennis P.
Published: September 2022

Propagation time, N, and shoot growth were studied for their effects on overwinter survival of newly rooted stem tip cuttings of Acer palmatum Thunb. ‘Blood-good’ and Cornus florida L. var. rubra. Propagation of A. palmatum and C. florida in May and June, respectively, resulted in a greater number of plants with shoot growth after rooting compared to those propagated later. Removal of a terminal leaf on A. palmatum after rooting increased the percentage of plants with shoot growth. Nitrogen application after rooting decreased survival before winter storage for A. palmatum propagated in May and C. florida propagated in June and July. May propagation of A. palmatum reduced overwinter survival, whereas propagation date did not affect overwintering of C. florida significantly. Plants with shoot growth and not given N had best overwinter survival, followed by plants with shoot growth given N. Poorest overwintering occurred on both species given N that failed to grow prior to winter storage. Nitrogen application to these plants when newly propagated should be avoided until the role of N is better understood.
Changes in Longan and Rambutan During Postharvest Storage
Authors: Paull Robert E. , Chen Nancy J.
Published: September 2022

Compositional changes of longan [Euphoria longan (Lour.) Stend] and rambutan (Nephelium lappaceum L.) collected in two seasons were measured during storage at two temperatures. Seasonal variation reflected both preharvest conditions and maturity at harvest. Total sugars and titratable acidity of longan aril showed little change after harvest at 4° and 22°C. Sucrose of rambutan aril increased from 51 mg·g−1 to 76 mg·g−1 when fruit were stored at 12°, and no change occurred when stored at 22°. Titratable acidity, 20.8 meq·g−1 at harvest in rambutan aril, first declined and then increased at both storage regimes. Succinic acid was found in rambutan aril only at harvest and declined rapidly to an undetectable level. No malic acid was detected in rambutan. A high level of citric acid (≈175 meq·g1) was maintained during storage. The organic acids in longan aril were succinic, malic, and citric acids, present in a ratio of 10:5:1. Ascorbic acid content declined in aril tissue of both longan and rambutan during storage. Total phenols showed little change in either fruit during storage. Except for the changes noted, there were only minor compositional changes in longan fruit stored for 35 days at 4° and rambutan stored for 20 days at 12°.
Tolerance of Tomato Strains to Phosphorus Deficiency in Root Culture
Authors: Coltman Robert R.
Published: September 2022

Root culture was adapted for screening a diverse collection of tomato (Lycopersicon esculentum Mill.) strains for tolerance to low supplies of P. Fifty-one tomato strains were screened in 10 consecutive experiments for root fresh weight (RFW) production with high non-growth-limiting (25 μm) and low growth-limiting (7 μm) concentrations of P in a sterile, liquid medium. Twenty strains showing the most and least restricted root growth at low P in the initial 10 experiments were grown simultaneously in three final screening experiments. Restrictions in RFW at low P averaged 51% for four strains, consequently classed as low-P “intolerant”, and averaged 27% for three strains, consequently considered low-P “tolerant”. At high P, RFW of tolerant strains averaged 17% less than RFW of intolerant strains. At low P, RFW of tolerant strains averaged 23% greater than RFW of intolerant strains. The greater RFW production of intolerant strains at high P was due to higher internal P use ratios (IPUR = mg root dry weight (RDW) per mg P adsorbed). Differences in growth at low P were due primarily to differences in P uptake. However, the relative contributions of P use and P uptake efficiencies to low-P tolerance were different among strains. Root hairs of tolerant strains at low P were longer and covered a greater proportion of the root length than root hairs of intolerant strains. The pH of the culture medium of one tolerant strain was significantly lower than the medium pHs of the other strains.
Stimulating Productivity of Hydroponic Lettuce in Controlled Environments with Triacontanol
Authors: Knight Sharon L. , Mitchell Cary A.
Published: September 2022

Triacontanol (1-triacontanol) applied as a foliar spray at 10−7 m to 4-day-old, hydroponically grown leaf lettuce (Lactuca sativa L.) seedlings in a controlled environment increased leaf fresh and dry weight 13% to 20% and root fresh and dry weight 13% to 24% 6 days after application, relative to plants sprayed with water. When applied at 8 as well as 4 days after seeding, triacontanol increased plant fresh and dry weight, leaf area, and mean relative growth rate 12% to 37%. There was no benefit of repeating application of triacontanol in terms of leaf dry weight gain.
Reconsideration of the Cause of Inflorescence Bud Abscission in Pistachio
Authors: Crane Julian C. , Iwakiri Ben T.
Published: September 2022

Data collected 2 consecutive years revealed that 30% to 38% of the inflorescence buds of ‘Kerman’ pistachio (Pistacia vera L.) abscised mainly during an initial 5- to 6-week period from trees devoid of fruit. Bearing trees, by contrast, progressively dropped 99% of their buds during a 10- to 12-week period. Abscission during the initial 5- to 6-week period in bearing and nonbearing trees is apparently the result of a stimulus originating in the roots. Continued abscission during the subsequent 5- to 6- week period coincided with the initiation and growth and development of the kernel. It appears, therefore, that a stimulus originating in the fruit (kernel) is responsible for the second phase of a two-phased abscission process.
Possible Rejuvenation of Adult Avocado by Graftage onto Juvenile Rootstocks in Vitro
Authors: Pliego-Alfaro Fernando , Murashige Toshio
Published: September 2022

Avocado (Persea americana Mill.) seedlings germinated aseptically were used as rootstocks. Lateral buds excised from greenhouse-grown flowering-age plants and disinfested, were used as scions. About 50% of the shoots that emerged from the scions showed restored rooting competence. The shoots continued to root when the terminals of rooted shoots were severed and retested. Nodal sections from grafted adults also produced rootable shoots. It is suggested that the restored rooting competence reflected a developmental phase reversal from adult to juvenile rather than a simple transfer of rooting cofactors from rootstock to scion.
In Vitro Regeneration of Stangeria eriopus
Authors: Osborne R. , van Staden J.
Published: September 2022

In South Africa, the indigenous cycads comprise 28 species of Encephalartos (Za-miaceae) and Stangeria eriopus (Kunze) Baillard (3), the latter species being the sole representative of the Stangeriaceae. Present cycad populations are under severe pressure from combined effects of agricultural and urban development, exploitation by the tribal “medicine-men”, activities of plant collectors, and demands from scientific and educational institutions. In addition, the relatively slow growth rate, limited potential for vegetative propagation, and the restricted supply of viable seed further exacerbate the delicate conservation status of these dioecious plants (2).
Controlled-release Fertilizers Effect on the Growth of Bed-grown Woody Landscape Plants
Authors: Torres Kenneth C.
Published: September 2022

The effects of controlled-released fertilizers in container production have been evaluated (1,2), but little work has been reported on the effects of controlled-released fertilizers for field production techniques. Surface band and pre-plant fertilizer incorporation are the most common application methods for field-grown landscape plants. The major drawback of current field application methods are applications must be repeated every 4 to 6 months and a considerable amount of fertilizer is used inefficiently. The purpose of this research was to evaluate the effects of preplant applications of controlled-released fertilizers on the growth of field-grown landscape plants.
A Program for Transmission of Data Between the LI-6000 Photosynthesis System and MS-DOS Computers
Authors: Senalik Douglas , Kane Robert , Staub Jack
Published: September 2022

Estimates of photosynthetic rates are obtained routinely in many plants using a number of techniques (1-3). Until recently, however, accurate field estimates of net CO2 exchange have been difficult to obtain, partially because of the limited mobility of the apparatus and the time involved in data collection (4-6). LI-COR, Inc. (Lincoln, Neb.) has developed an integral infrared gas analyzer system (IRGA), which is incorporated in their LI-6000 series of commercially available portable instruments (7). This system consists of a battery powered nondispersive IRGA, a porometer, an RS-232C serial communications interface, and a dedicated datalogger with battery-powered nonvolatile memory. This unit automatically stores measurements of CO2 concentration, chamber relative humidity, chamber temperature, leaf temperature, photosynthetically active radiation, time, and optional operator-supplied comments. Time required for a single measurement is between 30 to 180 sec, with various types of leaf chambers spanning a range of volumes between 250 and 3900 ml (7).
Horticultural Therapy for Special Education Students
Authors: Airhart Douglas L. , Tristan John
Published: September 2022

Horticultural Therapy (HT) is a dynamic and expanding profession (3) using plants during the training or rehabilitation of persons with mental or physical disabilities (1, 4). Although it is an old concept (5), only recently has horticulture become recognized as a therapeutic treatment for patients (7). The special feature of HT is adapting horticultural activities to therapeutic goals (2). Traditional horticulture strives to produce healthy plants, whereas, in HT, plants may be allowed to die if this meets a client's needs. This Note describes the structure of one HT program that was used with very positive results.
Beauregard’ Sweet Potato
Authors: Rolston L. H. , Clark C. A. , Cannon J. M. , Randle W. M. , Riley E. G. , Wilson P. W. , Robbins M. L.
Published: September 2022

‘Beauregard’ sweet potato [Ipomoea batatas [L.] Lam.] was developed by the Louisiana Agricultural Experiment Station to combine resistance to diseases and insects of local importance with good horticultural and culinary characteristics. This cultivar, first designated L82-508, is named after Louisiana's renowned civil engineer and “Napo-lean in Grey,” Gen. P.G.T. Beauregard.
Evaluation of New Peach Rootstocks for High-Density Planting Systems
Authors: Guerriero R. , Loreti F. , Massai R.
Published: September 2022

In the genetic improvement of fruit tree rootstocks, researchers must take into account the evolution of cultural techniques so that the selections obtained are appropriate to trends in modern fruit production (10). In Italy and in other areas where peaches [Prunus persica (L.) Batsch.] are grown on a large scale, the recent trend towards intensification of planting has increased (1, 4, 11). There is a growing need for rootstocks with a range of vigor control to allow cultivation of peaches in a variety of soil conditions, as is now possible with apple, by adopting, in each instance, the most appropriate training system and planting distance (5, 7, 9, 10).
Breeding Pickling Melons for a Concentrated Yield
Authors: Nerson Haim , Paris Harry S. , Edelstein Menahem , Burger Yosef , Karchi Zvi
Published: September 2022

An Oriental pickling melon (Cucumis melo var. conomon) was crossed with a hermaphroditic melon, and the hermaphroditic form also was crossed with a birds-nest-type melon, with the goal of producing pickling melon breeding lines possessing a concentrated yield. Hermaphroditic and birdsnest breeding lines derived from these crosses produced markedly more fruits per plant and per unit area in a once-over harvest than did the pickling cucumber cultivars tested.
Growth Analysis of Three Cucumber Lines Differing in Plant Habit
Authors: Ramirez Denis R. , Wehner Todd C. , Miller Conrad H.
Published: September 2022

Growth analyses were conducted in the greenhouse on two commercial lines, ‘Calypso’ and M 21 [of cultivated cucumber (Cucumis sativus L. var. sativus] differing in growth habit and one line, LJ 90430, of the wild cucumber Cucumis sativus L. var. Hardwickii (R.) Alef., to determine relationships between morphological characteristics and fruit yield. Multiple fruiting in LJ 90430 was associated with high leaf area and multiple branching. The standard commercial pickling cultivar, Calypso, which usually produces one to two fruit per plant per harvest, had less leaf area and fewer branches per plant than LJ 90430. Competition between early fruit development and vegetative growth was possible in ‘Calypso’ and M 21, but not in LJ 90430, which did not begin fruit development until vegetative growth was completed. Dry weight percentage in the fruit of LJ 90430 was low initially and increased steadily until the final harvest. Dry weight percentages in the fruit of ‘Calypso’ and M 21 were high initially and decreased generally thereafter. Relative growth rates of the whole plant followed similar trends in LJ 90430, ‘Calypso’, and M 21.
Effect of Fertilizer Rate on Growth of Ficus lyrata and Susceptibility to Pseudomonas cichorii
Authors: Chase A. R.
Published: September 2022

Ficus lyrata Warb. ‘Compacta’ plants were grown with various rates of Osmocote 19N-2.6P-10K for 2 months prior to inoculation with Pseudomonas cichorii (Swing.) Stapp. Optimal plant growth occurred at rates from 4 to 13 g/12.5-cm pot in the spring, and 4 to 16 g/12.5-cm pot in the summer and fall. Percentage of leaf area affected with Pseudomonas cichorii was correlated to fertilizer level at rates between 4 and 16 g/12.5-cm pot. Disease rating was lowest for underfertilized plants (1 g/12.5-cm pot) increased at the 4-g rate and decreased at higher rates according to the following equation (y = 14.39 - 0.72x, R2 = 0.86).
Effect of Nitrapyrin on Mineralization of Urea and Isobutylidene Diurea in a Highly Organic Medium
Authors: Nash M. A. , Mazur A. R. , Wagner D. F.
Published: September 2022

Mineralization of nitrogen fertilizers was determined in an organic medium composed of 6 pine bark : 3 sand : 1 soil (by volume). Nitrification was evident by day 7 following treatment with urea and isobutylidene diurea (IBDU) and increased rapidly after day 14. Nitrification was not evident until day 56 in medium treated with urea + nitrapyrin (NI). Medium treated with urea or IBDU were depleted of NH4+ within 1 month, which corresponded to a peak in NO2– + NO3– accumulation. Only a small amount of NH4+ was not accounted for by nitrification and was assumed to be adsorbed by bark particles. Chemical names used: 2-chloro-6-(trichloromethyl)pyridine (nitrapyrin), 1,1-diureido isobutane (IBDU).
Evaluation of Preemergence Herbicides for Control of Oxalis dillenii Jacq. in a Pinebark-amended Medium
Authors: Berchielli D. L. , Gilliam C. H. , Fare D. C.
Published: September 2022

Selected herbicides were evaluated for control of southern yellow wood sorrel (Oxalis dillenii Jacq.) in three experiments. Control varied depending on rate of application and the time interval after application. Herbicides providing excellent control (less than one weed/pot) 8 weeks after treatment with the 0.5 × rate included: oxyfluorfen, 1.1 kg·ha–1; oryzalin, 2.2 kg·ha–1; and oxyfluorfen + oryzalin, 1.7 kg·ha–1. Control 18 weeks after treatment was excellent at the 1× rate with oryzalin (4.5 kg·ha–1) and at the 2× rates with oryzalin (9.0 kg·ha–1), oxyfluorfen (4.5 kg·ha–1), and a combination of the two. Chemical names used: 2-chloro-l-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene (oxyfluorfen); 4-(dipropylamino)-3,5-dinitrobenzenesulfonamide (oryzalin).
Fruit Quality of Rabbiteye Blueberries as Influenced by Weekly Harvests, Cultivars, and Storage Duration
Authors: Miller W. R. , McDonald R. E. , Crocker T. E.
Published: September 2022

Fruit of ‘Bonita’ and ‘Beckyblue’ rabbiteye blueberry (Vaccinium ashei Reade) cultivars were harvested weekly, then stored in two different types of consumer baskets and subjected to five time/temperature storage regimes. Fruit increased in total soluble solids (TSS) and pH and decreased in acidity (Ac) with advancing harvest dates. Total soluble solids and pH of ‘Bonita’ fruit were significantly lower and Ac higher than for fruit of ‘Beckyblue’. After 3 weeks of storage at 1°C plus 3 days at 16°, ‘Beckyblue’ had higher (8 times) decay than fruit of ‘Bonita’. There were no cultivar differences in fruit firmness or weight loss due to storage, but fruit weight was reduced significantly when packaged in molded pulp fiberboard baskets. Fruit of ‘Bonita’ can be used for both domestic and export markets, requiring long storage duration, but ‘Beckyblue’ fruit should be limited to domestic markets.
Thermal Blast Peeling of Tomatoes
Authors: Smith Durward A. , Rymal K. S. , Turner J. L. , Harris H.
Published: September 2022

Thermal blast peeling yielded products of comparable quality to freeze–heat-peeled tomatoes (Lycopersicon esculentum Mill.). Both methods resulted in higher peeled yields and firmer fruit than did caustic, steam-peeling, or peeling by scalding. Thermal blast peeling may thus be a practical alternative to traditional methods.
A Photosynthetically Active Radiation Sensor
Authors: Grappadelli L. Corelli , Coston D. C.
Published: September 2022

A sensor for measuring photosynthetically active radiation was constructed using a silicon photocell in combination with a glass absorption filter. A trimmer potentiometer was used for standardization of sensor output. The sensors were calibrated using a commercially available quantum sensor. Average correlation coefficient between constructed sensors and the standard was 0.94. The sensors had a quantum response, were sensitive only in the wavelengths between 400 and 700 nm, exhibited a linear response to varying PAR light levels, and were inexpensive to construct.
Pollen Germination in Aglaonema Flowers of Different Ages
Authors: Henny R. J.
Published: September 2022

Previous reports have shown that Aglaonema can be induced to bloom with gibberellic-acid treatment (2), and seed set can be increased by maintaining flowers at 100% RH for 24 hr following pollination (1). Both techniques have greatly aided the production of Aglaonema hybrids. Occasionally, however, desirable crosses cannot be made due to unavailability of sufficient pollen or receptive pistillate flowers. In such cases, it would be helpful if pistillate flowers could be pollinated 1 or 2 days after anthesis, because Aglaonema pollen cannot be stored more than 1 day.
Correlation of Callus Weight to Volume of Two Woody Species
Authors: King S. M. , Morehart A. L.
Published: September 2022

In vitro studies dealing with callus cultures usually involve monitoring callus growth. Volume estimates can be used to determine growth and estimate callus fresh weight (1). The use of volume as a measurement of growth as well as the estimation of volume from one or more linear dimensions has been used for years in field studies of trees and shrubs (4). Measuring linear dimensions of the callus through the test tube is nondestructive and simple to perform, but precise measurements are not possible.
‘Aphrodite’ Rose of Sharon (Althea)
Authors: Egolf Donald R.
Published: September 2022

The pink-flowered ‘Aphrodite’ is the fourth U.S. National Arboretum triploid cultivar of Hibiscus syriacus L., commonly known as rose of sharon. In the past, rose of sharon, although it flowered heavily in early summer when few other shrubs bloom, produced abundant seed and, subsequently, weed seedlings in the garden. The development of nearly sterile triploid cultivars eliminated the source of weed seedlings and elevated the plant to an elite summer flowering shrub. Triploid cultivars previously introduced are ‘Diana’, NA 32224 (1), with pure white flowers; ‘Helene’, NA 41786 (2), with white flowers and a prominent dark red eye spot; and ‘Minerva’, NA 54984 (3), with lavender flowers.
Yield: Future Research Challenges
Authors: Wyse Roger
Published: September 2022

Research to increase the yield of crop plants is of great long-term importance if we are to continue to meet the food and fiber needs of a rapidly expanding world population. In the short-term, the problem facing agriculture in the United States is not one of production but of profitability. Only improved efficiency and stability of production can ensure the survival of the American farmer in an increasingly competitive world market. The challenge facing agricultural research is to develop new knowledge of basic plant processes and to apply that knowledge toward improved production efficiency. This work must be done in the context of current crop surpluses and reductions in federal spending for such research. In this article, I discuss critical research needs in fields such as horticulture and agronomy in order to meet the challenge of increasing both the productivity and profitability of the producer. This result can be accomplished only by bringing the best technology to bear on the complex problems facing U.S. agriculture.
Sampling for Germplasm Collections
Authors: Namkoong Gene
Published: September 2022

The person who samples for germplasm collections occupies a very narrow temporal interface between the genetic resources that history has left as our endowment, and the potential uses of those resources with which we endow the future. It is a narrow interface because the genetic resource is eroding rapidly, and because our future needs are large and unpredictable. Given the structural complexity of most plant populations and the many possible ways that they may be used in the future, it is obviously impossible to prescribe simple, optimal sampling schemes for all species. However, a single unstructured sample of modest size would be sufficient for a species that is structured simply. Such a species would have to be structured homogeneously with complete inbreeding or with independently and uniformly distributed alleles in Hardy–Weinberg genotypic frequencies. Future breeders would have to reassemble any allelic combinations. If specific alleles were identified as useful, the needed sample number might be smaller than if the allelic distribution was heterogeneous and unknown in the population and if the potential uses of many such alleles were uncertain. Unfortunately, we are usually in the latter position with respect to what is presently known about frequencies and distributions. We are often ignorant of which alleles are desirable at specific loci. Even for primary grain crops, little is known of which populations to target for sampling and enhancement for future development in breeding programs. For less-studied plant species, it is necessary to consider the biological problem of how alleles are distributed in populations and the kinds of collections that might be useful to future conservators, breeders, or other users. Nevertheless, it is possible to derive some bounds for requisite sample sizes, despite the complex factors that influence sampling design.
Intracellular Calcium Dynamics, Cell Development, and Stress Tolerance
Authors: Polito Vito S.
Published: September 2022

Intracellular Ca2+ and regulation of cell Ca2+ play important roles in cell development and in the maintenance and modulation of various cell functions. This report will describe research on the role of membrane and free cytoplasmic Ca2+ in cell development and stress tolerance. Results to be presented include microscopic fluorometric data obtained using fluorescent probes for Ca2+ and cytoskeletal proteins within individual cells to investigate the role of Ca2+ in membrane organization, establishment of cell polarity, and maintenance of cytoplasmic streaming under stress conditions.
Challenges to Plant Growing in Space
Authors: Langhans R. W. , Dreesen D. R.
Published: September 2022

Picture yourself a million miles from earth; it’s lunch time. What will you eat: meat, fish, bread, fresh vegetables (cooked or uncooked), or food from a tube? What will happen to the waste products from the processed food or even from yourself? What will you breathe? These and hundreds of detailed questions must be answered. At present, we have little knowledge about a totally closed environment life support system (CELSS). We have developed in this paper a list of references that are pertinent to the problem. It is divided into subject areas and listed chronologically, rather than alphabetically.
Growth and Root Colonization of Grapevines Inoculated with Different Mycorrhizal Endophytes
Authors: Schubert A. , Cammarata S. , Eynard I.
Published: September 2022

Grapevine seedlings (Vitis berlandieri Planch. × Vitis riparia Michx., 420 A) were inoculated with the mycorrhizal fungi Glomus caledonium (Nicol. & Gerd.) Trappe & Gerd., G. fasciculatum (Thaxter sensu Gerd.) Gerd. & Trappe, G. monosporum Gerd. & Trappe, G. occultum Walker, and Glomus sp. E3 in three sterile soils. G. monosporum and G. occultum were the most infective endophytes. G. monosporum, G. occultum, and Glomus sp. E3 increased shoot dry weight and, to a lesser extent, root length. Some of the efficient symbionts in pot culture were not naturally present in the experimental soils. Significant growth responses could be observed also with endophytes inoculated at low concentration.
Yields of Tomato Phenotypes Modified by Planting Density, Mulch, and Row Covers
Authors: West Jennifer , Peirce L. C.
Published: September 2022

Bare ground (BG), black polyethylene mulch (ML), and polyester row covers with mulch (MRC), combined with three planting densities, provided increasing levels of cropping intensity to study phenotypic response. Four tomato (Lycopersicon esculentum Mill) phenotypes, ‘Sub Arctic Maxi’ (SAM), ‘New Yorker’ (NY), UNH-328 (328), and ‘Westover’ (WVR) represented combinations of small and large plant size and early and late maturity. Early and total yield responses to planting density were linear whether in ML, MRC, or BG treatments, and each phenotype also showed predominantly linear yield increases with increasing density. These linear increases were enhanced in SAM by ML and MRC, but the same mulch and row cover treatments tended to reduce the density response in other phenotypes. The difference was believed to relate to flowering pattern and time relative to vegetative development. Within MRC, compact plants were the most responsive to density in total, but not in early, yield. The predominant effect of ML and MRC was to improve earliness, with each treatment contributing an increment increase in early yield. However, the performance of one phenotype (328) was unchanged by ML or MRC, perhaps reflecting inherent stability.
Thermal Properties of Wraps Used for Freeze Protection of Young Citrus Trees
Authors: Rieger Mark , Davies Frederick S. , Jackson Larry K.
Published: September 2022

Thermal properties of tree wraps commonly used for freeze protection of young citrus trees were measured in the laboratory using a newly developed method to determine which factors are most important in wrap design and performance. Thermal diffusivity was lowest for wet fiberglass and styrofoam wraps with water containers attached to their inner surface, intermediate for dry fiberglass, and highest for thin-walled polyethylene and polystyrene wraps. Thermal diffusivity was inversely related to freeze protection capacity observed under field conditions for the tree wraps tested. Addition of water, either throughout the wrap material or in containers inside wraps, decreased thermal diffusivity three- and ten-fold, respectively. Minimum trunk temperatures of 2-year-old ‘Hamlin’ orange trees [Citrus sinensis (L.) Osb.] were up to 2°C lower under ventilated tree wraps compared to similar nonventilated wraps on mild freeze nights. An ideal tree wrap should have low thermal diffusivity and lack free airspaces and ventilation holes, while allowing for gas exchange and expansion of the tree trunk.
Temperature Affects Seed Germination of Four Florida Palm Species
Authors: Carpenter William J.
Published: September 2022

Temperature ranges for seed germination were determined for palm species Acoelorraphe wrightii (Griseb. & H. Wendl.) H. Wendle ex. Becc., Coccothrinax argentata (Jacq) L. H. Bailey, Sabal etonia Swingle ex Nash, and Thrinax morrisii H. Wendl. Total germination was highest with fewest days to 50% of final germination at 35°C Temperatures 5° to 10° above or below 35° frequently caused delayed, irregular, and reduced total germination. Temperatures exceeding 10° from 35° generally were inadequate for germination.
Screening Rootstocks of Prunus for Relative Salt Tolerance
Authors: Ottman Yvonne , Byrne David H.
Published: September 2022

A nondestructive method for evaluating the salt tolerance of Prunus seedlings was devised for greenhouse sand-culture with 60 days of saline drip irrigation. The treatments contained half-strength Hoagland's solution using distilled water and supplementary chloride and sulfate salts of Na, Ca, and Mg to reach 1.5 dS·m–1 for control, 4.5 dS·m–1 for the first trial, and 6.0 dS·m–1 for the second and third trial screenings. After 60 days of irrigation with 6.0 dS·m–1 Nemaguard, the standard peach [P. persica (L.) Batsch] rootstock averaged 46% of the fresh weight, 53% of the volume, 66% of the height, and 74% of the foliar health ratings of the control seedlings. Percent of control values were compared for a tentative ranking of salt tolerance: ‘Titan’ almond × Nemaguard and P. mexicana Wats. > Nemaguard and Nemared > Myrobalan plum (P. cerasifera J.F.Ehrh.) and bitter almond (P. amygdalus var. amara Focke.). Correlation coefficients were used in selecting useful sets of evaluation parameters. Height was rejected as a screening parameter. Final fresh weight and a final foliar health rating are recommended for cursory screenings of Prunus germplasm. The last three weekly foliar health scores are useful for comparing rates of decline. Volume displacements are useful for comparing root vs. shoot growth.
Root Tissue Development Around Wire-Basket Transplant Containers
Authors: Lumis Glen P. , Struger Steven A.
Published: September 2022

Wire baskets are an integral part of transplanting landscape trees and are designed for many types and sizes of mechanical tree spades. The wire basket functions as support for the root ball and as a means of lifting the tree (3). Most baskets are made from galvanized wire and are left intact at planting (P. Braun, personal communication), although some specifications require their removal (1). The potential longevity of the wire in the soil has led to concern and speculation about adverse effects of the basket on tree growth (4). Root girdling, tree instability, reduced shoot growth, and premature decline have been suggested as possible effects on trees planted in intact wire baskets (2, 5).