bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic and Physiological Studies of Zinnia elegans, Z. angustifolia, and Their lnterspecific Hybrids
Authors: Stimart Dennis P. , Boyle Thomas H. , Terry-Lewandowski Veronica M.
Published: September 2022

Zinnia is a relatively small genus of the tribe Heliantheae (Asteraceae) comprising 17 species endemic to North and South America (19). Two cultivated species, Z. elegans Jacq. (2n = 24 or 48) and Z. angustifolia HBK (2n = 22), are classified within the subgenus Zinnia, a taxon of annual and perennial herbs with base chromosome numbers of n = 11 and n = 12. The subgenus Zinnia is subdivided further into sections, with Z. elegans in the section Zinnia and Z. angustifolia in the section Mendezia.
Increased Yield in Slicing Cucumbers with Vertical Training of Plants and Reduced Plant Spacing
Authors: Hanna H. Y. , Adams A. J. , Story R. N.
Published: September 2022

In the article “Increased Yield in Slicing Cucumbers with Vertical Training of Plants and Reduced Plant Spacing”, by H.Y. Hanna, A.J. Adams, and R.N. Story (HortScience 22:32–34, April 1987), in Table 1, the significance of G8M in 1983 should be at the 5% level by F test. The correct table in printed below.
The Origin, Inheritance, and Instability of Butternut Squash (Curcurbita moschata Duchesne)
Authors: Mutschler Martha A. , Pearson Oscar H.
Published: September 2022

One of the most popular types of winter squash is the butternut squash, a member of the species Curcurbita moschata Duchesne. Butternut squash has a buff-colored exterior and deep orange-colored flesh. Although winter squash of this species were cultivated before colonial times, the typical butternut fruit shape is a recent innovation. Crookneck (CR) types were widely used in the temperate United States until the origin in the early 1930s of the shortnecked butternut (BN) fruit type from a crookneck cultivar. The unstable nature of the butternut trait was soon noted, but could not be explained. The purpose of this paper is to summarize published and unpublished information concerning the origin, characteristics, and genetic behavior of the buttemut/crookneck fruit trait.
Effects of K, Ca, and Mg Levels and N Sources on Growth and Leaf Element Content of ‘Cheyenne’ Blackberry
Authors: Spiers J. M.
Published: September 2022

In sand culture studies, oxidized N (NO3-N) sources increased Ca and Mg and decreased Fe and Mn leaf concentrations in ‘Cheyenne’ blackberry (Rubus spp. L.). Leaf concentrations of K increased, and P, Mg, and Ca decreased with increased K fertilization. High Ca fertilization increased Ca in the leaves but did not affect leaf concentration of other elements measured. Increasing Mg fertilization decreased N and increased Mg leaf concentrations. After two growing seasons, high Mg and Ca fertilization increased, whereas high K decreased plant growth. Significant interactions indicated synergistic and/or antagonistic influences of K and Mg fertilization treatments on the Ca elemental leaf concentrations.
Synergistic Defoliation in Rutabaga with Mixtures of Ethephon and Ammonium Peroxydisulfate
Authors: Poapst P. A. , Anderson M. G. , McRae K. B.
Published: September 2022

The addition of 1.0% (wt/vol) ammonium peroxydisulfate to 0.125%, 0.25%, and 0.50% (wt/vol) ethephon sprays, applied before harvest to rutabaga (Brassica napus, Group Napobrassica Mill. cv. Laurentian) nearing commercial size, defoliated a greater percentage of leaves than would be anticipated from the effects of the individual components. Defoliation expressed on the logit scale was a linear function of the square root of the ethephon concentration, if ethephon was applied with or without ammonium peroxydisulfate. Chemical name used: (2-chloroethyl) phosphonic acid (ethephon).
Stomatal Density of Snapdragon as a Possible Determinant of Transpiration
Authors: Rutland Rufus Burr , Chang Hsiao-Lan Liang , Pallas James E.
Published: September 2022

Ten heat-resistant cultivars of Antirrhinum majus L. (snapdragon) were grown under summer greenhouse conditions. Transpiration was measured in relation to leaf area and stomatal density. Stomatal density did not correlate with daily transpiration. Total leaf area and the total number of stomata per plant did correlate with daily transpiration. One cultivar (Oklahoma) had high stomatal density, but wilted less and had lower stomatal specific transpiration than other cultivars. Superior growth and inflorescence of that cultivar was not explained on the basis of stomatal characteristics. The abaxial surface had higher stomatal density than the adaxial surface of a leaf. Stomatal densities were consistently lowest on leaves near the apex of stems and highest on leaves near the base.
Comparative Effects of Ancymidol, Propiconazol, Triadimefon, and Mobay RSW0411 on Lily Height
Authors: Wulster G. J. , Gianfagna T. J. , Clarke B. B.
Published: September 2022

Lilies (Lilium longiflorum Thunb.) were treated with ancymidol (A-Rest), propiconazol (Banner), triadimefon (Bayleton), or Mobay RSW0411 as a soil drench or as a preplant bulb soak. At high rates the fungicides triadimefon and propiconazol reduced Easter lily plant height. Neither propoiconazol nor triadimefon were as effective as Mobay RSW0411 or ancymidol in reducing plant height; however, results suggest that chemical treatments for disease and height control may be achieved with the same treatment. Chemical names used: α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidinemethanol (ancymidol); 1-(2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-ylmethyl)-1H-1,2,4-triazole (propiconazol); 1-(4-chlorophenoxy)-3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl)-2-butanone (triadimefon); β-(cyclohexylmethylene)-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol (Mobay RSW0411).
Root-zone Temperature Monitored at Urban Sites
Authors: Graves William R. , Dana Michael N.
Published: September 2022

Root-zone temperature (RZT) of 15 landscape planting sites in a metropolitan area was monitored from 13 June to 5 Sept. 1985. RZT was highest at urban sites associated with city surface materials, such as asphalt and concrete. The RZT was significantly lower at suburban and woodland sites. Temperature was uniform throughout the root zone at sites along urban streets; it decreased with increasing depth at all other sites. High temperature extremes may contribute to the decline of landscape plants at urban sites.
Effects of High Temperature on Lateral Shoot Growth of Salvia and Impatiens After Pruning
Authors: Higuchi Haruzo , Amaki Wakanori , Minami Meguri , Suzuki Shigetoshi
Published: September 2022

Seventeen-week-old plants of Salvia splendens Sello ex Nees and Impatiens sultanii Hook. f. were treated with high temperature for 1, 2, 3, 4, or 5 weeks. One week after the high temperature treatment, the plants were cut back to a height of 7 cm from the pot rim and grown in the greenhouse. The high-temperature treatment retarded the primary shoot growth of Salvia and Impatiens; however, after cutting back, lateral shoot growth was markedly stimulated in salvia and slightly increased in impatiens. Maximum growth of lateral shoots was attained at 850°C × hr of high temperature for salvia and at 400° × hr for impatiens, when expressed as the integrated temperature above 30° minus the temperature in the greenhouse.
Methods for Sterilizing Instruments Contaminated with Bacillus sp. from Plant Tissue Cultures
Authors: Singha Suman , Bissonnette Gary K. , Double Mark L.
Published: September 2022

Bacterial contamination can be a serious problem in plant tissue cultures (4, 6). Contaminants occur because bacteria may survive the explant surface-sterilization procedure (5) or are endogenous in the plant tissue (4). In certain instances, the bacteria may remain latent in the explant(s) and fail to exhibit visual symptoms for prolonged periods (5). Furthermore, Monette (7) recently reported on the inability to detect an Aerococcus sp. and Bacillus fastidiosus contamination in kiwifruit shoot-tip cultures initiated on agar-solidified medium. It is, therefore, imperative that bacterial contaminants are not spread through improperly sterilized instruments.
Mycorrhizal Status of Jojoba Seedlings
Authors: Khaliel A. S. , Elkhider K. A.
Published: September 2022

Jojoba [Simmondsia chinensis (Link) Schnied] was introduced into the Barah semiarid area (lat. 14°N, long. 30°30′E) in Sudan. Jojoba is of great economic importance because of its liquid wax content. Bloss (1) reported that jojoba was assumed to be nonmycorrhizal. However, in a later investigation, he concluded that jojoba is mycorrhizal under natural conditions, but added that jojoba plants produced from seeds in the greenhouse for field plantings were not usually mycorrhizal. Because jojoba has been found to be mycorrhizal and growth response to mycorrhizae has been reported in woody plants (2), further investigation of the mycorrhizal status of jojoba in the seedling state, especially in the Sudan, is needed.
Aroids Propagation by Tissue Culture: I. Shoot Tip Culture and Propagation of Xanthosoma violaceum
Authors: Quynh Nguyen Thi , Uyen Nguyen Van
Published: September 2022

The Araceae, which comprises 115 genera and more than 2000 species, is widely distributed in all tropical and subtropical regions of the world (2). Vietnam is represented by 26 genera and about 60 species (3). Despite the promise of taro and other aroids as a future food source, the Araceae remain an under-exploited plant family. Several workers have shown that in vitro selection of salt-tolerant plants in general (1), and aroids in particular (7), is possible. This report describes a method for shoot tip micropropagation of Xanthosoma violaceum (blue taro).
Light Treatments to Improve Efficiency of in Vitro Propagation Systems
Authors: Economou Athanasios S. , Read Paul E.
Published: September 2022

Plant growth and development depend on light for photosynthesis and photomorphogenesis (22, 31, 45). Plant tissue cultures also require light, but to a lesser degree, to regulate mainly morphogenetic processes (34, 43, 50). The effect of light on photosynthesis of in vitro cultures is of less importance than that of in vivo plants (16). Light influences micropropagation success through its three parameters of duration (photoperiod or day length), illuminance (intensity or photon flux), and spectral quality (wavelength). This influence can be exerted directly on the in vitro cultures or indirectly as an after-effect to the subsequent culture.
Storage Injury of Pome Fruit Caused by Stress Levels of Oxygen, Carbon Dioxide, Temperature, and Ethylene
Authors: Little C. R. , Peggie I. D.
Published: September 2022

Modification of the storage atmosphere to improve storage life of pome fruit began with storage in the presence of increased CO2 levels, was introduced by Kidd and West in 1927 (14), and was first used commercially for apples in England in 1929 (48). Controlled ventilation techniques were used in Australia to maintain CO2 at ≈5% and O2 ≈16% by monitoring air ventilation rates into sealed environments containing ‘Jonathan’ apples in 1940 (50) and apples and pears in 1947 (13). The same methods also were reported in the United States in 1941 (47) and in England in 1961 (10).
Quiescence in Monocotyledonous and Dicotyledonous Somatic Embryos Induced by Dehydration
Authors: Gray D. J.
Published: September 2022

Orthodox seeds enter an arrested growth phase during their final stages of development that follows closely after seed coat hardening, reduction of water content, and maturation of embryonic and storage tissues. This resting phase may last for a number of years, depending on species and environmental conditions (2), and is the major factor accounting for the efficient storage and handling qualities of seed. A similar resting phase induced in synthetic seed will be essential for propagation of many annual crop plants, especially those grown at high density over large areas (e.g., com, soybean, wheat, etc.) where planting efficiencies must be optimum. Additionally, a resting phase will be needed if synthetic seed is to be used for germplasm preservation.
Effect of Irrigation on the Growth and Yield of Okra
Authors: Singh B. P.
Published: September 2022

The effect of different amounts of irrigation on vegetative growth and fruit yield of okra (Abelmoschus esculentus Moench) was determined in field experiments. Irrigation increased vegetative growth and fruit yield in okra in comparison to an unirrigated control. Similar increases in vegetative growth were produced at all irrigation amounts, ranging from 40% to 100% of pan evaporation (Epan), but fruit yield differed with the amount of irrigation. Irrigation equal to 60% Epan produced maximum fruit yield, and significant decreases in yield were noted with an increase or decrease in the amount of irrigation.
Storability of Summer Squash as Affected by Gene B and Genetic Background
Authors: Sherman Mark , Paris Harry S. , Allen Judith J.
Published: September 2022

Three pairs of near-isogenic lines of summer squash (Cucurbita pepo L.) with and without gene B were compared for storability. The test included ‘Bareqet’ (B+/B+) and ‘Goldy’ (B/B+) of the zucchini type, ‘Caserta’ (B +/B +) and ‘Precocious Caserta’ (B/B) of the vegetable marrow type, and ‘Benning’s Green Tint’ (B +/B +) and the ‘Benning’s Yellow Tint’ (B/B) of the scallop type. Fruit were hand-harvested between 3 and 5 days past anthesis and stored for up to 22 days at 5°C and 85% to 95% RH. Weight loss was higher in the cultivar with gene B for two of the three types (vegetable marrow and scallop). Shrivel, chilling injury, and overall appearance ratings were worse for the cultivar with gene B for all three types. Weight loss was highest in the vegetable marrow type, intermediate in the zucchini type, and lowest in the scallop type. Shrivel, chilling injury, and appearance, 7 days after harvest, were most severe in the vegetable marrow type.
Effects of Simulated Insect Injury on Net Photosynthesis of Potted Grapevines
Authors: Boucher T. J. , Pfeiffer D. G. , Barden J. A. , Williams J. M.
Published: September 2022

Grape (Vitis vinifera L.) leaves on potted vines were injured artificially by removing leaf disks with a paper punch. The leaves showed decreased net photosynthesis (Pn) for the remaining leaf area as leaf area loss (LAL) increased. This reduced Pn in the remaining leaf area at low levels of injury was more pronounced after 12 days than after either 1 or 5 days. The effects of LAL and lowered Pn were additive by 20% LAL for all days tested.
Light Acclimatization Effects on Japanese Maple for Interior Use
Authors: Friendship-Keller R. A. , Tsujita M. J. , Ormrod D. P.
Published: September 2022

Acer palmatum thunb. (Japanese maple) plants were acclimatized under three light levels. The effects of acclimatization were observed in terms of: a) planar area, b) net photosynthesis rate, c) chlorophyll concentration, and d) leaf anatomy. Planar area was determined using two methods of nondestructive photographic planimetry. Plant size and photosynthetic area were not significantly different among the three light treatments. Plants grown under low light levels had higher net photosynthesis rates than those grown under high light. The leaves from the highest light level, which were significantly thicker, contained less chlorophyll a and b per gram of dry weight than did the leaves from lower light levels. The palisade cells were longest at the highest light level and shortest at the lowest light level.
Variation in Resistance of Geranium to Pythium ultimum in the Presence or Absence of Silver Thiosulphate
Authors: Hausbeck Mary K. , Stephens Christene T. , Heins Royal D.
Published: September 2022

Selected seed-propagated hybrid geranium (Pelargonium × hortorum Bailey) cultivars were evaluated for resistance to crown and root rot caused by Pythium ultimum Trow in the presence or absence of foliarly applied STS, a petal-shattering preventative that has been demonstrated to increase plant death due to P. ultimum. Plants were evaluated for resistance to plant death, plant stunting, and flower delay by comparing plant growth in P. ultimum-infested medium with plant growth in a noninfested medium. Although immunity to P. ultimum was not identified in the 42 cultivars screened, resistance appeared to be present and may provide a valuable source of germplasm for further screening and subsequent hybridization for resistance.
Segregation of Seven Traits in Pepper
Authors: Shifriss Chen
Published: September 2022

In pepper (Capsicum annuum L.), independent assortment was found between the genes within the following three pairs: male sterility (ms) and erect fruit position (up), ms and anthocyaninless (al), and up and al. The genetic system controlling pointed vs. inverted apex was hypothesized to segregate independently of al, ms, and up. The genes controlling premature fruit pigmentation segregate independently of al and up. Close linkage exists between round leaf (rl) and al+. Partial linkage is suggested between Ms1 and pointed (pt) and the genes controlling premature cream color, but independent segregation was found with the genes controlling deep green color. The expected brown phenotype was not realized in homozygous cl (brown fruit color) in the presence of cream and similar pigment genes; their fruit contained an insufficient amount of chlorophyll. Morphological and physiological traits may serve as marker traits in improving the production of hybrid seeds, particularly when recessive traits are bred into seed parent lines.
‘Triumph’ Dieffenbachia
Authors: Henny R. J. , Conover C. A. , Poole R. T.
Published: September 2022

Dieffenbachia species and cultivars are important tropical ornamental foliage plants due to their attractive foliar variegation, ease of production, and adaptability to interior environments. About 20 cultivars have been produced commercially in Florida. Previously, most new cultivars were obtained from private plant collections or as mutations of established cultivars. Because dieffenbachia occur naturally in a variety of sizes, growth habits, and variegation patterns, they were included as part of the foliage plant breeding program at the Central Florida Research and Education Center–Apopka. The hybrid Dieffenbachia cultivar Triumph was developed and selected as part of that program.
The Auxin Conjugates
Authors: Caruso John L.
Published: September 2022

Phytohormones occur in bound and free forms. The bound form is designated by some as conjugated if the hormone is covalently linked to a small molecule and as bound if it is attached to a macromolecule or cell particle (39). However, the terms bound and conjugated will be used interchangeably here, as they are in many other treatises. There is more information published on the relationship between free and conjugated 1H-indole-3-acetic acid (IAA) than is available on similar relationships of other hormones. Free IAA is the active form of the hormone. This activity was seen, for example, when IAA conjugates were applied to the first internode section of bean (Phaseolus vulgaris L.). The promotion of curvature was traceable to the amount of free IAA released from the conjugates (4). Excellent reviews of conjugated auxins are available (3, 9). It is the purpose of this communication to acquaint the reader with some of the broader aspects of conjugated auxin and then to focus on the use of auxin conjugates in tissue culture.
Cultivar Testing: Public Point of View
Authors: Price Hugh C. , Zandstra Bernard H.
Published: September 2022

One of the most important decisions a grower makes when formulating plans for planting is what cultivar to select. The experienced grower has observed the evolution of cultivars and is intensely aware of the vast improvements that have been made through plant breeding. Much of the increase in crop productivity can be attributed to the disease resistance, environmental adaptability, and increased yield potential incorporated into cultivars by public and private plant breeders.
Producing Temperate–zone Fruits at Low Latitudes: An Overview
Authors: Dennis F. G.
Published: September 2022

Production of temperate-zone fruits in the tropics and subtropics may seem fanciful to the uninitiated, but it is a practice that has existed in localized regions for generations. Seedling peaches are grown in Venezuela (7), northern Thailand (11), and southern Mexico (5). No one knows precisely when these species were introduced, but local selection has produced cultivars adapted to areas with little or no chilling temperatures. Rest either does not occur (5) or is sufficiently shallow to be broken by stress induced by defoliation or drought.
Chilling Hour Requirement for Flower Bud Expansion of Two Rabbiteye and One Highbush Blueberry Shoots
Authors: Austin Max E. , Bondari K.
Published: September 2022

Three hundred shoots with flower buds were collected from three blueberry types to determine the influence of chilling hours on flower bud expansion. The three types were rabbiteye blueberry (Vaccinium ashei Reade) ‘Brightwell’ and clone T-110, and low-chill highbush blueberry (V. corymbosum L.) ‘Georgiagem’. Chilling hours in this study ranged from 0 to 700 and were defined as accumulated hours of temperatures < 7.2°C. Flower bud expansion of all three blueberry types was influenced significantly by levels of accumulated chilling. The mathematical relationships between bud width and chilling hours were either linear or quadratic. Largest bud expansion occurred after 400 chilling hours for ‘Brightwell’ and ‘Georgiagem’ and after 550 hr for T-110. Overall, ‘Brightwell’ had the smallest bud width, ‘Georgiagem’ was intermediate, and T-110 the largest.
Inarching of Swingle Citrumelo in Israel
Authors: Shaked A. , Cohen A. , Hamou M. , Hasdai D.
Published: September 2022

The presence of tristeza in Israel has prompted an interest in inarching citrus trees grafted on sour orange (C. aurantium L.) or Palestine sweet lime (C. limettoides Tan.) rootstocks. Tests conducted since 1976 at several locations in Israel have shown that: a) Swingle citrumelo (C.P.B. 4475) [C. paradisi Macf. × P. trifoliata (L.) Raf.] outperforms other rootstocks when used for inarching citrus trees; b) Swingle inarches of small diameters grow faster than those of large diameter; c) inarches on young trees grow faster than those on older trees; and d) the effect of Swingle citrumelo, C. volkameriana, and, to a lesser extent, of sour orange on ‘Shamouti’ fruit quality are similar to their effect when used as rootstocks.
Irrigation Management Effects on Spring Pea Seed Yield and Quality
Authors: Raymond Michael A. , Stark Jeffrey C. , Murray Glen A.
Published: September 2022

Seed yield and quality of four spring pea cultivars (Pisum sativum L.) were evaluated when subjected to deficient, optimal, and excessive irrigation levels. Irrigation at 100% of the estimated optimal irrigation amount (IR) resulted in the greatest seed yields, whereas irrigation at 60% or 140% IR reduced yields by 468 and 222 kg·ha−1, respectively. Yield reductions for individual cultivars were as large as 694 and 350 kg·ha−1 for deficient and excessive irrigation, respectively. Increased yields for the 100% IR treatment resulted from increases in pods per plant and seeds per pod. Irrigation at 140% IR reduced germination of pea seed by 5% to 13%. Deficient irrigation reduced seed yield more than did excessive irrigation, whereas excessive irrigation caused the greatest reduction of seed quality.
Poinsettia Tolerance of Molybdenum
Authors: Hammer P. Allen , Bailey Douglas A.
Published: September 2022

Plants of Euphorbia pulcherrima Willd.‘Glory’ received seven biweekly 236.5-ml soil drenches, each containing either 0, 10, 40, 80,160, or 320 mg Mo/liter (0, 2.4, 9.5, 18.9, 37.8, and 75.7 mg/pot). No visible phytotoxic effects due to excess Mo were observed on any plants, and no treatment differences were evident for plant height at anthesis, days from start of short days to anthesis, or display bract diameter at anthesis. Foliar nutrient analyses indicated no effect on nutrient uptake due to treatment for any element except Mo. A level of 806 mg Mo/kg dry weight were recorded for poinsettia leaves without adverse effects on plant growth or appearance. Results suggest Mo toxicity is not a real threat in poinsettia production.
Production System Comparisons for Selected Woody Plants in Florida
Authors: Ingram Dewayne L. , Yadav Uday , Neal Catherine A.
Published: September 2022

Quercus virginiana Mill., Magnolia grandiflora L., Liquidambar styraciflua L., Ulmus parvifolia Jacq. ‘Drake’, Lagerstroemia indica L., Ilex opaca Ait. ‘East Palatka’, and Pinus elliottii Engelm. were transplanted from 3-liter containers into 36-cm-diameter fabric Field-Gro containers, directly in the field into 36-cm-diameter auger-dug holes, or into 36-cm-diameter × 33-cm-tall black plastic containers. After 1 year, measured growth parameters of the Magnolia, Ulmus, Lagerstroemia, and Pinus were not affected by production system. Dry weight of Quercus and Liquidambar roots in the “harvest zone” were greater for trees grown in the fabric Field-Gro containers than those grown directly in the field. Quercus height and total carbohydrate content of Quercus and Magnolia primary root samples were increased by the fabric container. The above-ground container system clearly was inferior to the field-grown systems for production of the Quercus and Liquidambar under the conditions of this study.
Relationship Between Extractable Chlorophyll and an in Situ Method to Estimate Leaf Greenness
Authors: Marquard Robert D. , Tipton Jimmy L.
Published: September 2022

Traditional quantification of leaf chlorophyll requires destructive sampling of leaves and tedious extraction in 80% acetone (1,2), whereas N, N-dimethylformamide (DMF) is an alternative solvent that does not require tissue grinding (3). Minolta has recently marketed a portable meter (SPAD-501) for a rapid and nondestructive estimate of leaf greenness. Earlier results indicate a weak but significant correlation (r2 = 0.48) between SPAD readings and leaf chlorophyll extracted in acetone from data pooled from 22 species (5). The purpose of this study was to address three questions: a) is there a species-specific relationship between the SPAD readings and extractable chlorophyll; b) is the relationship of SPAD readings stronger when chlorophyll is expressed on a leaf area-or fresh-weight basis; and c) what is the consistency between two individual SPAD-501 instruments?
A Vacuum Multi-point Seeder for Pots
Authors: Townshend J. L.
Published: September 2022

Many horticultural studies require precise placement of numerous seeds in individual pots of soil. In my experiments on the relationship of inoculum densities of plant parasitics nematodes to alfalfa (Medicago sativa L.) seedling stand and growth (1), and the efficacy of a nematicide applied to alfalfa seeds (2), 20 seeds were planted per pot of soil. This seeding was tedious and time-consuming. Seeding time was reduced somewhat with the use of a multi-point dibble that made 20 evenly spaced depressions in the surface of the soil in 11.5 cm diameter styrofoam pots. However an alfalfa seed still had to be placed in each depression using forceps, the most time-consuming phase of planting. The vacuum multi-point seeder was developed to simplify these operations.
Differential Thermal Analysis for Large-scale Evaluation of Pear Cold Hardiness
Authors: Montano J. M. , Rebhuhn M. , Hummer K. , Lagerstedt H. B.
Published: September 2022

More than 4500 accessions of eight genera including Pyrus at the National Clonal Germplasm Repository, Corvallis, Ore., require testing for cold hardiness. Since pear xylem deep supercools (7), differential thermal analysis (DTA) would be a suitable test if large numbers of samples could be examined simultaneously. The object of this study was to produce a method of multichannel DTA for defining cold hardiness of pear accessions. Visual browning was also examined to confirm cold hardiness values.
Flat-podded Snap Bean Breeding Line VR-Romano
Authors: Silbernagel M. J.
Published: September 2022

ARS/USDA and the Agricultural Experiment Station of Washington State Univ. announce the germplasm release of an Italian-style, flat-podded snap bean (Phaseolus vulgaris L.) line, VR (Virus Resistant)-Ro-mano, VR-Romano is unique in this class of snap beans because it is resistant to curly top virus and carries the dominant I gene resistance to bean common mosaic virus (1).
‘Guam Super Hot’ Chili Pepper
Authors: Lee C. T.
Published: September 2022

‘Guam Super Hot’ chili pepper (Capsicum frutescens L.) is well-adapted to Guam and Northern Marianas Islands, which possess a tropical climate. It reaches the mature-red harvest stage at about 75 days and can be harvested continually up to 1 year. This cultivar appears to be tolerant to most pests, based on field observation. The major attribute of this cultivar is its exceptionally hot pungent fruit. The fruit, either green, orange, or red in color, are used as a spice in cooking, pickling, and in sauces (1). In Guam, a spicy sauce called “finadene” is prepared with these peppers, onions, soy sauce, and the juice of a lemon or lime. The leaf is also edible and is sometimes cooked with fish.
U.C. Top Mark Fusarium Wilt- resistant (Fom-1) Muskmelon Breeding Line
Authors: Zink F. W. , Gubler W. D.
Published: September 2022

U.C. Top Mark fusarium wilt-resistance (Fom-1) is an andromonecious, salmon orange-fleshed, western shipping-type musk-melon (Cucumis melo L.) breeding line. It has value as a germplasm source for selection as well as the development of commercial hybrids.
Horticulture, Science, and Society; Presidential Address1
Authors: Janick Jules
Published: September 2022

Alexis de Tocqueville (1805-1859), in his perceptive Democracy in America written after a year’s tour of our young republic in 1831, commented about the proclivity of Americans to band together:
Diploid Plum × Peach Hybrid Rootstocks for Stone Fruit Trees
Authors: Renaud R. , Bernhard R. , Grasselly Ch. , Dosba F.
Published: September 2022

Many peach orchard sites in southwestern France have calcareous soils and cold, wet, springtime growing conditions. On these sites, the ordinary peach seedling stock tends to be short-lived. The Grande Ferrade station has been engaged for more than 30 years in developing rootstocks for such soils; ‘Pecher × Amandier’ (GF 677) and ‘Damas’ (GF 1869) are examples of successful introductions from this program.
Machine Harvest of Eastern Thornless Blackberry Cultivars
Authors: Takeda Fumiomi , Peterson Donald L.
Published: September 2022

Separation pull force of thornless blackberries (Rubus spp.) decreased at a rate insufficient to allow adequate mechanical harvest differentiation between the black ripe and red fruit. When a force sufficient to remove 80% of black ripe fruit was applied to floricanes, green and red fruit comprised as much as 50% of detached fruit. Ethephon, applied at 500 and 1000 ppm 4 days prior to harvest, reduced fruit size and total soluble solids, but increased the ripe/unripe harvest ratio more than two-fold. Two shaker models tested were effective in removing black ripe fruit. Of the two, the unit with higher frequency (40 vs. 25 Hz), but with shorter stroke (1.7 vs. 5.0 cm), was more efficient, as it removed fewer unripe fruit. Chemical name used: (2-chloroethyl) phosphonic acid (ethephon).
Yields of Greenhouse Tomatoes Managed to Maintain Specific Petiole Sap Nitrate Levels
Authors: Coltman Robert R.
Published: September 2022

‘Caruso’ tomatoes (Lycopersicon esculentum Mill.) were grown in peat-perlite-vermiculite in a greenhouse with five nitrate-nitrogen (NO3-N) fertilization concentrations in irrigation waters managed to maintain 200, 400, 600, 900, or 1200 µg NO3-N/ml in petiole sap as determined by weekly NO3-N quick tests. Nitrate-N fertilization concentrations immediately were increased 50% when petiole sap NO3-N levels first fell below these target levels; thereafter, NO3-N fertilization concentrations were increased only after petiole sap levels fell below target levels for 2 consecutive weeks. The critical target level of sap NO3-N was defined as the lowest petiole sap NO3-N target level producing maximum marketable fruit yields. Total fruit yields increased with increasing petiole sap NO3-N target levels through 1200 µg·ml–1. Marketable fruit yields were maximized at 3.2 kg/plant, with an estimated critical sap NO3-N target level of 1105 µg·ml–1. Application of the sap NO3-N management rules used in this experiment resulted in five adjustments in N fertilization concentrations over the 27-week crop cycle, with an average of 4.5 weeks between adjustments. This approach to the management of N fertilization based on the sap NO3-N level of the crop has potential to provide significant benefits in improved N use and crop productivity at a modest cost.
Fenoxaprop Combined with Preemergence Herbicides for Crabgrass and Goosegrass Control in Turf
Authors: Dernoeden Peter H.
Published: September 2022

Fenoxaprop is an effective postemergence herbicide for summer annual grass weed control in cool-season turfgrasses. Following emergence of smooth crabgrass [Digitarla ischaemum (Schreb.) Muhl.] and goosegrass [Eleusine indica (L.) Gaertn.], fenoxaprop was applied alone or in combination with one of several preemergence herbicides. The objective of these field studies was to determine whether these herbicide combinations would provide both effective postemergence control of smooth crabgrass and goosegrass, as well as subsequent preemergence control of annual grass weed seed germinating thereafter. When fenoxaprop was applied alone in June or July to smooth crabgrass, the level of control ranged from poor (40%) to excellent (99%), depending on herbicide rate and timing of application. Smooth crabgrass control was erratic where plants had more than four tillers, particularly on a droughty site. When fenoxaprop (0.17, 0.20, or 0.39 kg·ha–1) was applied in combination with bensulide, benefin, DCPA, oxadiazon, pendimethalin, or prodiamine, excellent (90% to 100%) season-long smooth crabgrass control was achieved. Fenoxaprop + preemergence herbicide combinations exhibited complementary action, particularly in tank mixes applied to tillered smooth crabgrass. Fenoxaprop applied alone controlled goosegrass (two-leaf to three-tiller stage), but goosegrass reinfested treated plots from seed germinating after the herbicide application. When fenoxaprop (0.20 kg·ha–1) was applied with oxadiazon (2.2 kg·ha–1) to nontillered goosegrass, exceptional (99%) season-long goose-grass control was achieved. Chemical names used: (±)-ethyl 2-[4-[(6-chloro-2-benzoxazolyl)oxy]phenoxy] propanoate (fenoxaprop); N-butyl-N-ethyl-2,6-dinitro-4-trifluoromethyl)benzenamine (benefin); O,O-bis(l-methylethyl)-S-[2-[(phenylsulfonyl)amino]ethyl]phosphorodithioate (bensulide); dimethyl 2,3,5,6-tetrachloro-1,4-benzenedicarboxylate (DCPA); 3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-l,3,4-oxadiazol-2-(3H)-one (oxadiazon); N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine (pendimethalin); 2,6-dinitro-N1,N1,-dipropyl-6-(trifluoromethyl)-1,3-benzenediamine (prodiamine).
Fertilizer Applications on Field-grown Statice
Authors: Paparozzi Ellen T. , Hatterman Harlene M.
Published: September 2022

Three cultivars of annual statice (Limonium sinuatum mill, and L. bonduelli Kuntze) were grown in a fertile, silty clay loam field and fertilized with varying amounts of granular 12N–5.3P–10K. Mean individual stem weight, flower stem number, and mean and total fresh weight increased significantly due to fertilizer applications. Cultivar differences limited increases in rosette diameter, mean stem length, individual stem weight, and flower stem number. Field fertilizer application rates between 45.4 and 68.1 kg N/ha increased total fresh weight of ‘Iceberg’ and ‘Kampf's Blue’, but did not affect ‘Gold Coast’. Number of subsequent fertilizer applications beyond the initial application was not as critical as total amount applied.
Rehydration Characteristics of Cut White Pine and Norway Spruce Christmas Trees
Authors: Seiler John R. , Nichols Thomas J. , Paganelli David J.
Published: September 2022

Rehydration characteristics of cut eastern white pine (Pinus strobus L.) and Norway spruce [Picea abies (L.) Karst.] Christmas trees were evaluated over a wide range of xylem water potentials and storage periods. Cut pines failed to rehydrate fully when initial xylem water potential was less than –3.00 MPa. Norway spruce trees completely rehydrated at xylem water potentials as low as –3.50 MPa, with partial rehydration occurring below –4.0 MPa. Twig water content closely paralleled xylem water potential. All sample trees rehydrated fully when outdoor storage periods were < 6 weeks during the months of December and January.
Effects of Dolomitic Lime and Alkaline Water in Sphagnum Peat-based Container Growing Media
Authors: Williams Barbara J. , Peterson John C. , Utzinger James D.
Published: September 2022

A container growing medium of 2 peat : 1 perlite (v/v) was limed with 0, 0.9, 1.8, 2.7, 3.6, 5.4, 7.2, and 9.0 kg·m–3 dolomite. Media were irrigated with water, providing alkalinity equivalent to 0, 38, and 371 mg·liter–1 CaCO3. Samples were incubated at 25° ± 3°C and pH determined at days 2, 5, 7, 14, 28, 56, and 84. Irrigating with even moderately alkaline water over three months increased pH substantially above levels resulting from dolomite amendments alone.
Influence of and Recovery from High-temperature Stress on Harvested Mature Green Tomatoes
Authors: Inaba Makoto , Chachin Kazuo
Published: September 2022

Mature green (MG) tomatoes (Lycopersicon esculentum Mill. cv. Kyoryoku toko) were stored at 40°C for 1 to 3 days, then held at 25° for 8 days or stored at 35° for 1 to 6 days, then held at either 25° or 30° for an additional 12 days. During storage, respiration rate, C2H4 production, and color development were measured. The effect of temperature stress at 40° could be reversed if the fruit was exposed for < 1 day and then immediately cooled to 25°. At 35°, fruit ripening was suppressed but could have been reversed if exposure at 35° was < 3 days before the fruit was cooled to 25°. Holding at 30° did not completely reverse the suppression caused by 3 days at 35°C.
Compositional Changes in Yam Bean During Storage
Authors: Pauli Robert E. , Chen Nancy Jung
Published: September 2022

Composition of yam bean (Pachyrrhizus erosis L. Urb) tubers stored at 22° and 12.5°C was monitored monthly for up to 5 months. A continual loss of moisture occurred in tubers at both storage temperatures—after 4 months tubers stored at 22° lost 14.5% of their original weight; those stored at 12.5° lost 9.6%. A higher respiration rate of 15 to 28 ml·kg–1·hr–1 occurred during the first 2 months of storage at 12.5°. This was nearly double the respiration rate of tubers stored at 22°. Ethylene was not detected at any time. There are a continual breakdown of starch in tubers. After 3 months, tubers stored at 12.5° had one-sixth the harvest content of starch. At 22°, starch declined to two-thirds the harvest content. The decline in starch content at 12.5° was related to an increase in total sugars in the tuber, particularly sucrose. The sucrose content of the tuber stored at 12.5° tripled over a 3-month period. Glucose and fructose levels declined over the same period irrespective of storage temperature. The results suggest a chilling response that led to a sweeter tuber. Titratable acidity was very low, as was total phenols, and both did not change after harvest.
Photosynthetic Response Curves for Chrysanthemum Grown at Different PPF Levels
Authors: Holcomb E. Jay , Flore J. A. , Heins R. D.
Published: September 2022

Chrysanthemum morifolium Ramat. ‘Bright Golden Anne’ cuttings were grown in a controlled environment at 50, 325, or 600 µmol·s–1·m–2 for 5 weeks at a 10-hr photoperiod. Photosynthetic rates were determined on individual leaves with an open gas analysis system at a range of photosynthetic photon flux (PPF) levels. Plants grown at low PPF (50 µmol·s–1·m–2) had a maximum net photosynthetic rate (Pn) that was about 39% of that for plants grown at 325 µmol·s–1·m–2. Pn of plants grown at 325 or 600 µmol·s–1·m–2 did not differ significantly.
Response of Tobacco Callus to Shoot Tip Exudation from Five Species
Authors: Compton Michael E. , Preece John E.
Published: September 2022

The effect of auxin and cytokinin on shoot tip explant exudation, and the effect of such exudation on the growth of tobacco callus, were studied. Shoot tips of Rubus sp. ‘Dirkson Thornless’ (blackberry), Juglans nigra L., Euphorbia Lathyris L., and Hibiscus Rosa-sinensis L. were cultured on Murashige and Skoog medium. Rhododendron ‘P.J.M. Hybrids’ shoot tips were cultured on Anderson medium. Media contained a factorial combination of IBA and BA (2iP for rhododendron), each at 0, 1, and 10 µM. IBA reduced stem necrosis of hibiscus and rhododendron shoot tips, whereas BA increased length of browning of hibiscus shoot tips on average of 1.1 mm. The shoot tips were removed after 1 week and replaced with tobacco callus (Nicotiana tabacum L. ‘McNair 944’). After 3 weeks, callus growth was reduced on media that previously had black walnut and Euphorbia shoot tips (2939 and 532 mm3 of visible stain). Blackberry, hibiscus, and rhododendron shoot tips had no influence on tobacco callus growth (576, 0, and 1046 mm3 of visible staining). Chemical names used: 1H-indole-3-butyric acid (IBA); N-(phenylmethyl)-1H-purin-6-amine (BA); N-(3-methyl-2-butenyl)-1H-purin-6-amine (2iP); and 1H-indole-3-acetic acid (IAA).
Yield: A Challenge for all Seasons
Authors: Daie Jaleh
Published: September 2022

Human existence and civilization have always depended on an adequate supply of food. Throughout history, agriculturists have been at the helm of a remarkably successful enterprise to increase the quantity and improve the quality of the world food supplies. The giant achievements of the past, however, are dwarfed by the tasks that still lie ahead. As a reminder, the 5 billionth, currently living, individual of the human race was born in July 1986.
New Opportunities in Breeding
Authors: Austin Roger B.
Published: September 2022

Long before the days of modern plant breeding, farmers and gardeners had selected improved forms of wild plant species and had established, for many crops, productive cultivars giving goodquality produce. For example, most of the fruits and vegetables now grown in England, including the introduced species, have been established items of diet for at least several centuries. Many of the cultivars of fruits and vegetables that are grown today have changed little from the forms that were cultivated a hundred or more years ago. Where there have been substantial changes, often these have been made to adapt cultivars to make them suitable for new agronomic practices; to improve the uniformity of size, shape, color, and time of maturity; and to increase resistance to pests and diseases. Some of these improvements have increased marketable yields and economic returns to the grower, but there is little evidence that there have been genetic increases in total biological productivity. However, substantial increases in biological yields have been achieved by improved cultural practices, including the use of herbicides and crop protection chemicals and of more fertilizer, although in recent years there has been an increasingly vociferous environmental lobby to reduce the use of agrochemicals.
Nomenclature of the Meiwa and Changshou Kumquats, Intrageneric Hybrids of Fortunella
Authors: Fantz Paul R.
Published: September 2022

The Meiwa and Changshou kumquats originally were described as species, bearing the names Fortunella crassifolia Swingle and Fortunella obovata Tanaka, respectively, Authoratative references of citrus taxonomy do not recognize a scientific name for these kumquats. Botanical names were rejected when data proposed that these two kumquats were intrageneric hybrids of Fortunella, not true species. Application of the International Code of Botanic Nomenclature indicates the correct name of the Meiwa kumquat should be Fortunella × crassifolia Swingle (pro sp.) and the correct name of the Changshou kumquat should be Fortunella × obovata Tanaka (pro sp.). A key is provided for the six taxa of Fortunella.
NASA's Controlled Ecological Life Support Systems (CELSS) Program
Authors: Bredt James H.
Published: September 2022

NASA is interested in extraterrestrial crop production because it is expected that some future missions may require life support systems that can regenerate food as well as air and water. Such systems must produce a nearly complete human diet within very stringent limits on size and energy consumption. Although many problems remain to be solved by further research, CELSS based on crop production by higher plants appear to be feasible. The feasibility of this approach will be tested in the next several years by a project to build and operate a preprototype system that can recycle oxygen, carbon, water, and nitrogen. If this project succeeds, it will be followed by Space Station experiments to develop cultural methods for weightless plants and ground-based tests of more sophisticated prototypes with human occupants. Readiness to build operational space systems may be achieved as early as the turn of the century.
Economic Evaluation of Different Cultural Systems for Muskmelon Production
Authors: Berle D. , Estes E. A. , Sanders D. C. , Lamont W. J.
Published: September 2022

Sixteen management systems for early muskmelon production were compared for marketable yield, gross revenue, treatment cost, net economic value, and benefit-cost index. Black plastic mulch and/or transplants increased yields, gross return, and net economic value over a conventional practice of bare soil, direct-seeded production. Row covers did not increase yields or gross returns. When net economic value and benefit cost criteria were evaluated, yield maximization was not necessarily the best strategy. Instead, careful analysis should be given to added costs of production practices and the added revenue these practices will generate.
Planting Dates Related to Tuberous Root Yield, Vine Length, and Quality Attributes of Yam Bean
Authors: Paull Robert E. , Chen Nancy Jung , Fukuda Steven K.
Published: September 2022

Plant growth and tuberous root development in yam beans (Pachyrrhizus erosus L. Urb) were investigated using a series of 2-week plantings from April to December. Decreasing daylength at time of planting initiated tuberous root development, whereas increasing daylength inhibited tuberous root development and promoted vine and leaf growth. Once tuberous root formation and flowering began, stem and leaf growth ceased. At the time of planting, the critical daylength for tuberous root formation and flowering was 11 to 12 hr. The optimum planting date in Hawaii for maximum tuber yield of 24 t·ha–1 for yam beans was found to be September to October. Tuberous root development was sigmoidal, with dry matter percentage declining from 17.5% to 9%. There was little change in tuberous root acidity or total sugars during growth. Titratable acidity was about 20 meq·g–1 fresh weight if not induced to form tuberous roots, and ≈15 meq·g–1 fresh weight in plants forming tuberous roots. Total sugar was in the range of 30 to 50 mg·g–1 fresh weight during tuberous root growth of induced plants. Total phenols in the tuberous root declined during development, whereas roots from plants uninduced to form tuberous roots had an increased level of total phenols.