bluuebunny/crossref_metadata_2025 huggingface dataset:
Root Regeneration and Root Dormancy in Taxus spp.1
Authors: Lathrop J. K. , Mecklenburg R. A.
Published: August 2022

The annual cycle of root-regeneration potential (RRP) of 3 year old Taxus hunnewelliana Rehd., plants was evaluated by recording the number of new root initials produced 6 weeks after bare root transplanting. During the summer (June, July and August) few root initials were produced. The RRP increased throughout the fall (September to December) reaching a peak in January. This was followed by a drop in RRP through the spring and early summer (February to June).

Root dormancy of 1 year old Taxus cuspidata Sieb. and Zucc., can be broken in February by an exposure to 7 weeks of chilling at 35°F. Shoot bud dormancy can be broken by an exposure to 3 weeks of chilling at 28°F. The chilling treatment breaking root dormancy appears to be sensed primarily by the root system. Chilling shoots only increased growth of dormant roots but does not substitute for the chilling requirement of the dormant root.

The annual cycle of root-regeneration potential can be partially explained by root dormancy or root-shoot competition for photosynthate. The root-regeneration potential for transplanted Taxus hunnewelliana appears to be controlled by the same factors as the annual cycle of rooting for stem cuttings.
Injury of Snap Bean Pods Associated with Machine Harvesting and Handling1,2
Authors: Hoffman James C.
Published: August 2022

The harvesting of snap beans by machine caused obvious as well as unnoticed injury to the pods. All pods were injured, but injury varied in severity. Machine-harvested pods lost a significantly greater amount of weight than did corresponding samples of hand-picked pods. Cultivars differed in response to injury as well as ease with which they abscissed from the plant. The cv. Provider was easy to harvest by machine and received less injury than other cultivars studied. Snap bean cultivars with greater hair concentration per unit area lost weight more rapidly, and to a greater extent than those with sparse hairs. A small but significant amount of weight was lost through the pedicel and possibly the calyx. Pods with broken pedicel ends were similar in weight lost to pods having the pedicel removed. Broken shanks near the pedicel healed rapidly and did not contribute to a large amount of weight loss. Rubbing snap bean pods lightly caused a very significant amount of injury. The hairs on the pods were broken, split or pulled from the base, and these injured areas were the site of significant weight loss. Broken or split hairs did not heal, but continued to be a source of water loss.
Histological Observations on Chemical Pruning of Chrysanthemum With Methyl Decanoate1
Authors: Uhring Joseph
Published: August 2022

Spray applications of aqueous emulsions containing methyl decanoate killed the terminal meristem. This action stimulated the development of axillary buds producing branched stems. Early symptoms of spray activity occurred at the initial points of contact of the spray material. The direction of external damage was influenced by gravity as the path of cell destruction followed the flow of the runoff spray material. Spray runoff damage downward on the stem was confined largely to the two outer cell layers. Methyl decanoate entered through the epidermal cells and the trichomes. Cells with dense protoplasts were more visibly affected than cells with few or no protoplasts. The methyl decanoate acted as a destructive agent of the nucleus through some kind of change in the properties of the nuclear membrane; this was manifested by dispersion of the nucleoplasm. Changes were observed in the color of the stained nuclei indicating progressive stages of cell destruction. The nuclear and cytoplasmic components appeared as a homogenous mass in the late stage of damage. In highly specialized cells lacking protoplasts, damage was not apparent until the final stage of tissue and organ destruction.
Thinning Peaches with Bloom and Postbloom Applications of 2-Chloroethylphosphonic Acid1
Authors: Stembridge G. E. , Gambrell C. E.
Published: August 2022

Bloom or postbloom sprays of 2-chloroethylphosphonic acid (Ethrel) thinned peaches. Applications at full bloom did not produce consistent thinning in ‘Cardinal’. Postbloom sprays applied approximately at endosperm cytokinesis produced consistent thinning of 3 cultivars.

Degree of thinning was related to time of Ethrel application. Most thinning was obtained when Ethrel was applied near the end of Stage I or during Stage II. Ethrel sprays within a month after full bloom caused significant fruit size reduction that persisted 2 months or more after treatment. Ethrel sprays within 50 days of harvest accelerated maturity of several cultivars.
Influence of High Soil Temperatures on Five Woody-plant Species1
Authors: Wong Toynette L. , Harris Richard W. , Fissell Robert E.
Published: August 2022

Young plants of 5 woody-plant species (Fouquieria splendens, Parkinsonia aculeata, Prunus persica, Robinia pseudoacacia, and Rosa sp.) were grown in soil in clear, polyvinyl tubes. Roots were exposed to 30°–60°C soil temperatures for 4- or 6-hr once or on 2 or 4 successive days. Five stages of plant response occurred. A given response did not vary more than 5°C for the 5 species. These plant responses to high soil temperatues could account for the loss of roots in metal nursery containers exposed to the sun.
The Response of Grapefruit to Different Storage Temperatures1
Authors: Schiffmann-Nadel Mina , Lattar F. S. , Waks J.
Published: August 2022

To determine the optimal temperature for prolonged storage of ‘Marsh Seedless’ grapefruit, fruits were stored at 2, 4, 6, 8, 10, 12, 14, and 17°C for periods of 4, 8, 12, 16 and 20 weeks, followed by 2 weeks at 17°. Optimal results were obtained with storage at 12°. At this temperature storage of fruit could be extended for 16 to 20 weeks, followed by 2 weeks of shelf-life. At temperatures above 12°C the amount of decay increased, while below 10°, the fruit was pitted and attacked by mold decays and also by stem end decay after prolonged storage.

Mold decay fungi were Penicillium italicum Wehmer and to a lesser extent P. digitatum (Pers.) Sac. Fungi isolated from stem-end decay in fruit stored at 12–17° were Diplodia natalensis P. Evans, and Phomopsis citri Fawc, Alternaria citri Pierce and Fusarium sp. at 4–10°.
Phloem Regeneration Across Girdles of Grape Vines1
Authors: Sidlowski Julian J. , Phillips W. S. , Kuykendall J. R.
Published: August 2022

Callus bridges are formed across girdle wounds on ‘Cardinal’ grape vines within 16 days following girdling. Anatomical studies show that phloem connections are re-established across such wounds within a few days following bridging by callus pads. Callus development was always faster and more extensive from the upper than the lower edge of girdle wounds.
Endogenous Auxin and Gibberelliu-like Activity in Highbush Blueberry Flowers and Fruit1
Authors: Mainland Charles M. , Eck Paul
Published: August 2022

‘Coville’ and ‘Jersey’ blueberry (Vaccinium) flowers and fruit from screened bushes treated with 500 ppm of gibberellic acid (GA) at bloom and from bushes subject to insect pollination were sampled and measured at weekly intervals. Extracts of these organs were partially purified by chromatographic separation on paper, then bioassayed for auxin and gibberellin-like (GA-like) activity. Endogenous levels of both auxin and GA-like substances were higher in ‘Jersey’ than in ‘Coville’ flowers. Auxin concentration in unpollinated flowers was 4 times greater in ‘Jersey’ than in ‘Coville’. A large increase in extractable auxin followed GA treatment in both cultivars. The increase in extractable auxin coincided with the more rapid initial growth rate characteristic of GA-treated fruits. Auxin level coincided with fruit growth rate much better than did level of GA-like substances. By 6 weeks after GA treatment, GA-like substances in the fruits decreased to a level no higher than that in pollinated fruits.
Propagating Apples in Peru by an Improved Mound Layering Method1
Authors: Medina Cesar , Duarte Odilo
Published: August 2022

It was found possible to produce grafted apple plants (Malus sylvestris Mill.) on quince rootstock (Cydonia oblonga L.) in 1 year, by introducing an improvement to the classic mound layering method, this improvement was based on the grafting of the mound layered shoots while still attached to the mother plant using single or double grafting.

Spring is the normal season for starting the process, but satisfactory results were also obtained when starting in the fall. This study emphasizes the potential of this improved method in relation to the number of plants that can be obtained per area and the time that can be saved.
Influence of Genetic Background on Sex Conversion by 2-Chloroethylphosphonic Acid in Monoecious Cucumbers1,2
Authors: George William L.
Published: August 2022

Six monoecious cultivars, ‘Marketer’, ‘Wisconsin SMR18’, ‘Marketmore’, ‘Ashley’, ‘Spot Free’, and ‘Tokyo’, listed in decreasing order of their potential female tendency, were treated with 2-chloroethylphosphonic acid (ethrel). Ethrel applied as a single spray at concentrations between 125 and 500 ppm increased significantly the number of pistillate leaf axils in ‘Marketer’, ‘Wisconsin SMR18’, ‘Ashley’, and ‘Spot Free’, listed in decreasing order of cultivar response. The sex expression of ‘Marketmore’ and ‘Tokyo’ was not changed significantly by ethrel. With the exception of ‘Wisconsin SMR18’, the treated cultivars exhibited a significant delay in the onset of flowering. It is suggested that the differential response of monoecious cultivars to sex conversion by ethrel is affected by the genetic system which controls female tendency in these cultivars.
Embryo Sac Development in Relation to Virus Infection of Four Red Raspberry Cultivars1,2
Authors: Eaton G. W. , Turner N.
Published: August 2022

In a factorial experiment each of 4 red raspberry cultivars was treated with each of 4 viruses. Embryo sacs were examined in treated and control flowers collected at anthesis and 4 days later. A numerical index was devised to quantify stages of embryo sac development, and thus facilitate statistical analysis. Effects on embryo sac development of cultivar differences, viruses, and year difference were observed. The virus effects on embryo sac development as such were not considered severe enough to account for failure of fruit-set or yield reduction. Embryo sacs of the ‘Sumner’ cultivar were retarded in development compared to the other cultivars.
The Effect of Shading Rhododendron Stock Plants On Flowering and Rooting1
Authors: Johnson C. R. , Roberts A. N.
Published: August 2022

Partial shading, as a means of preventing or decreasing flower development, was used to study the influence of flowering on leaf rootability. Reduced light intensity decreased the size of flowers and sugar levels in leaves. The rooting-potential of leaves from plants grown under 25 percent shade was reduced compared to full sunlight controls; but was increased in the ones from under 95 percent shade. Exogenous hormone application improved rooting of leaves from full sunlight and 25 percent shade treatments, but reduced rooting in those from 95 percent shade. It was suggested that the reduction or prevention of flowering improves rooting-potential because of less active competition for materials necessary in rooting.
Disc Electrophoresis of Proteins of Senescing and Fresh Leaves and Petals of Certain Ornamental Plants1
Authors: Parups E. V.
Published: August 2022

The acrylamide gel electrophoretic band patterns of proteins from young or fresh and old, senescing leaves or petals of roses, carnations, chrysanthemums, and snapdragons showed generally that with aging the initial and prominent, distinct bands near the origin became less distinct and were located at a distance thus indicating the presence of a more heterogeneous admixture of apparently smaller molecular weight protein units. There was also less protein in the senescing tissues. Kinetin treatment tended to maintain the electrophoretic pattern of leaf proteins similar and comparable to proteins from fresh leaves.
Effect of Heterosis and Alleles at the d and sp Loci on the Response of the Tomato to Population Pressure1
Authors: Fery Richard L. , Janick Jules
Published: August 2022

The response of lines of ‘Fireball’ and ‘Gardener’ differing at the sp and d loci as well as inter-and intracultivar F1 crosses and F1 crosses with ‘Heinz 1370’ were investigated in regards to total and early yield at populations ranging from 2,178 to 52,272 plants per acre with sequential harvests in row spacings. Heterosis for total yield was found in ‘Fireball’ x ‘Gardener’ only at the lowest population level but was not found in crosses of ‘Fireball’ or ‘Gardener’ x ‘Heinz 1370’. Heterosis was found in ‘Fireball’ x ‘Gardener’ crosses for early yield but this response appeared to diminish as population increased. Heterosis for early yield was observed with the dwarf locus in heterozygous condition (d+ d)within and between ‘Gardener’ and ‘Fireball’. Indeterminate plants (sp+–) gave higher total yields than the determinate (spsp); determinate plants gave higher early yields than indeterminate although this effect decreased as population increased.
Some Mechanical Properties of Developing ‘Delicious’ and ‘Golden Delicious’ Apple Fruits as Influenced by N-Dimethylaminosuccinamic Acid1
Authors: Tukey Loren D. , Camba Juan J.
Published: August 2022

Treatment with a 1000 ppm solution of N-dimethylaminosuccinamic acid (DMAS) at 30 days after full bloom to bearing apple trees caused a significant increase in resistance of ‘Delicious’ both to bruising and to rupture injury. The onset of increased resistance to bruising by DMAS occurred before that of increased resistance to rupture. Such effects were not found on ‘Golden Delicious’.
Chemical Induction of Suberization in Cut Potato Seed Pieces1
Authors: Dainello Frank J. , Fontenot James F.
Published: August 2022

Only one of 12 chemical compounds was effective in stimulating suberization and wound periderm activity in cut potato seed pieces. Polyram applied as a 7% dust had a consistently favorable effect on suberization. However, it did not stimulate wound periderm activity as efficiently as it did suberization in cut seed pieces from any of the clones.
Induction of Multilocular Ovary in Tomato By Gibberellic Acid1
Authors: Sawhney V. K. , Greyson R. I.
Published: August 2022

Gibberellic acid (GA3) applied to pre-floral tomato plants stimulated a significant increase in the number of ‘carpels’ and locules per ovary. In ‘Vantage’ the number of locules was doubled by this treatment whereas in ‘Viceroy’ a 30% increase was obtained. The styles of treated flowers were thicker and contained more vascular bundles than did those of untreated flowers. Ovary size of treated flowers at anthesis was also increased by this treatment. The significance of chemical manipulation of locule number in tomato ovaries and the possible mode of action of GA3 in this system is discussed.
Effects of Exogenous Gibberellin on the Development of Lilium longiflorum Thunb. ‘Ace’1,2
Authors: Kays Sandra , Carlson William , Blakely N. , De Hertogh A. A.
Published: August 2022

Potted ‘Ace’ lily bulbs were treated with gibberellic acid (GA3) as a soil drench using varying concentrations, numbers of applications and at different stages of development. There was no consistent effect on the forcing days to flower, plant height or the number of leaves, however, specific treatments with 1000 ppm significantly reduced the number of floral buds initiated. It appears that the most sensitive stage of application is that period just prior to flower initiation and that the GA3 must be applied at this time in order to reduce the number of floral buds initiated. A preliminary experiment indicated that GA4+7 was more effective than GA3. GA4+7 influenced plant height and leaf length as well as the number of floral buds but had no effect on the forcing days to flower.
Volatiles from ‘McIntosh’ Apple Fruits as Affected by Phosphorus and Potassium Nutrition1
Authors: Forsyth F. R. , Webster D. H.
Published: August 2022

The volatile substances, carbon dioxide, ethylene, acetaldehyde, ethyl acetate, ethyl alcohol, ethyl propionate, ethyl-n-butyrate and caproaldehyde produced by the fruit from 4-year-old ‘McIntosh’ apple trees on EM 26 rootstocks in sand culture supplied with 3 levels of P and 2 levels of K in factorial combination were studied by infrared gas analysis and gas chromatography. Increased P supply increased the rate of ethylene production from apples stored for both 111 and 158 days, reduced the output of most of the other volatiles, and increased the levels of scald and core-browning. Increased K supply had little effect other than to decrease the C2H4 production in the 111-day (January) analysis.
The Incorporation of Herbicides into Organic Mulches for Weed Control in Ornamental Plantings1
Authors: Fretz Thomas A. , Dunham Charles W.
Published: August 2022

N, N-dimethyl-2, 2-diphenylacetamide (diphenamid) and α, α, α,- trifluoro-2, 6-dinitro-N, N-dipropyl-p-toluidine (trifluralin) caused no injury to transplanted petunias (Petunia hybrida Vilm.) or marigolds (Tagetes patula L.) when incorporated in a mulch. Satisfactory broadleaf and grass weed control as denoted by indicator crops was achieved with both of these herbicides. Dichlobenil, 2,6-dichlorobenzonitrile, caused severe injury to both petunia and marigold transplants when applied in the herbicide-mulch combination. Control of broadleaf and grass indicator weeds with dichlobenil was excellent at all rates. Dimethyl tetrachloro terephthalate (DCPA) resulted in no visible injury to the marigold or petunia transplants when used in the herbicide-mulch combination, but control of grass and broadleaf indicator weeds was poor. When diphenamid and dichlobenil at the same rates were incorporated on peat moss, licorice root, pine bark or sugar cane mulches, no differences were observed among the mulches in regard to their ability to control weed growth.

On established nursery stock, 2-chloro-4, 6-bis (ethylamino)-s-triazine (simazine) plus DCPA, simazine plus diphenamid, and 3-(3, 4-dichlorophenyl)-1, 1-dimethylurea (diuron), applied directly to the soil surface performed better than the herbicide-mulch combination at the lower rates. At higher rates, both the direct spray on the soil surface and the herbicide-mulch combination performed satisfactorily.
Effect of Shade Treatments on ‘McIntosh’ Apple Shape1
Authors: Webster D. H. , Crowe A. D.
Published: August 2022

Shade treatments increased the length to diameter ratios and decreased stem-cavity depth of ‘McIntosh’ apples. Full-shade was more effective than partial-shade, and shading all year and early in the growing season affected apple shape more than shading after July 15.
Differential Sensitivity to Waterlogging and Cyanogenesis by Peach, Apricot, and Plum Roots1
Authors: Rowe R. N. , Catlin P. B.
Published: August 2022

Individual plants varied considerably, but peach and apricot were more sensitive to waterlogging than was plum. No differences were established between peach and apricot. All 3 species became more sensitive as temperature was increased between 17 and 27°C. More than half of the plum seedlings survived at 17°C whereas all plants of the other 2 species died. A scion of a more tolerant species did not overcome the sensitivity of the roots.

Both cyanogenic glycoside content and the proportion of it that was hydrolyzed during waterlogging were higher in peach than in plum roots. Exposure of detached root systems of all 3 species to anaerobic conditions caused HCN to be released. The rate of cyanogenesis increased with both temperature and time. Peach and apricot roots were alike in HCN evolution whereas plum roots were lower, with release of HCN being barely detectable at 22°C. Cyanogenesis was significant in peach and apricot at as low as 17°C.

A close association exists among differential sensitivity, glycoside hydrolysis, and cyanogenesis in the absence of O2. However, the latter may be secondary, though contributory, to cellular disorganization as a cause of sensitivity.
Monoploid Peaches, Prunus persica Batch: Description and Meiotic Analysis1
Authors: Hesse Claron O.
Published: August 2022

Two monoploid peaches are described. Analysis of one showed that the chromosomes were distributed at random in the first meiotic division, and that some irregularities occurred because chromosomes are occasionally excluded from the spindle, divide precociously, or show other irregular behavior. Only one bivalent was observed in 236 division figures. The second division was normal. Due to varying orientation of the second division spindles a significant percentage of diad sporads formed, which yielded normal, haploid isogenic gametes. Some pollen germinated and fruit was set following pollination of diploid plants with pollen from the monoploid.
Effect of Soil Incorporation on Selectivity, Movement, and Persistence of Herbicides in Cabbage Plantings1
Authors: Menges R. M. , Hubbard J. L.
Published: August 2022

The performances of several herbicides incorporated to a depth of 2.5 and 7.6 cm in sandy loam and sandy clay loam were studied in cabbage plantings in 3 field experiments. Herbicidal activity of O, O-diisopropyl phosphorodithioate S ester with N -(2-mercaptoethyl) benzenesulfonamide (bensulide) and a,a,a-trifluoro-2, 6-dinitro-N,N-dipropyl-p-toluidine (trifluralin) was outstanding. These herbicides controlled Palmer amaranth (Amaranthus palmeri S. Wats.), redroot pigweed (Amaranthus retroflexus L.), common purslane (Portulaca oleracea L.) and barnyardgrass [Echinochloa crusgalli (L.) Beauv.] without reducing yields of cabbage (Brassica oleracea, var. capitata L.) ‘Improved Globe YR’. Dimethyl tetra-chloroterephthalate (DCPA) and 2-chloroallyl diethyldithiocarbamate (CDEC) were less effective. Trifluralin performed more efficiently when depth of incorporation was 7.6 cm compared to 2.5 cm. CDEC performed better when incorporated at a depth of 2.5 cm. Performance of bensulide and DCPA was unaffected by depth of incorporation.

Bioassays indicated that regardless of rainfall, bensulide, DCPA, and trifluralin remained within the original soil zones of incorporation. Trifluralin persisted longer in the soil as depth of incorporation was increased. Under high temperatures, infrequent rainfall, and furrow irrigation, the half-life of trifluralin treatments was 1 to 2 weeks; there was no measurable biological activity in treatments incorporated to 2.5 cm after 3 to 6 months, or after 9 months when treatments were incorporated 7.6 cm. The half-life of DCPA was 1 month with no activity after 6 months regardless of incorporation depth. Bensulide was most persistent, with no activity 12 months after the 2.2 kg/ha rate, and 24 months after the 4.5 and 9.0 kg/ha rate of application, regardless of incorporation depth.
Attempts to Increase the Red Coloration of Apples with Chemicals1
Authors: Smock R. M.
Published: August 2022

Seven compounds with some common groupings increased the anthocyanin production of apples in the laboratory. None of these compounds were better than 3 (3,4 dichlorophenyl)-1,1 dimethylurea (diuron). Color responses from diuron were increased by modification of the pH to 3 to 4. While orchard sprays with diuron gave increases in red color in 6 of 8 field trials with ‘McIntosh’, the increases probably were not large enough to be of commercial interest. There were no secondary effects from the diurbn sprays on respiration, firmness or storage disorders.
Evaluation of Phosphorus Nutrient Status in Seedling Lettuce1
Authors: Berry Wade L.
Published: August 2022

Lettuce seedlings were grown in a modified Hoagland’s solution, with 9 treatments ranging from 0.06 to 16.0 mM/liter of H2PO4. In the low P solutions the deficiency symptoms shown by lettuce seedlings consisted of leaves showing a darker green and reduced growth. Tissue levels of soluble PO4–P in these deficient seedlings dropped to a low of 379 ppm PO4–P and a high of 13770 ppm PO4–P for plants well supplied with P. The critical level for the evaluation of the P nutrient status of seedling lettuce plants in the conductive, lamina, and root tissue were respectively: 780, 600, 580 ppm soluble PO4–P on a dry wt basis.
The Combining Ability of Two Degenerative Sweet Com Mutants1
Authors: Lachman W. H.
Published: August 2022

Two degenerative sweet corn mutants, C30, a mutant of P39, ‘Pee Wee’ a mutant of C30 and P39 were crossed with each other and with 4 unrelated inbreds to ascertain their relative abilities to promote heterosis in hybrids. In these tests C30 often exceeded P39 in the promotion of hybrid vigor but ‘Pee Wee’ was relatively inefficient in stimulating heterotic effects.
Interaction of Ethylene, Auxin, and Succinic Acid-2,2-Dimethylhydrazide in Apple Fruit Ripening Control.1
Authors: Looney Norman E.
Published: August 2022

Succinic acid-2,2-dimethylhydrazide (SADH) was applied 3 times, at monthly intervals beginning 2 weeks after full bloom, to ‘McIntosh’ apple trees (Malus sylvestris L.). In the month preceding normal harvest, control and SADH treated trees were sprayed on 3 different dates with 2-chloroethylphosphonic acid (ethephon) as an ethylene source and/or 2,4,5-trichlorophenoxypropionic acid (2,4,5-TP), a synthetic auxin. Fruit samples harvested one and two weeks after each treatment revealed that without SADH: 2,4,5-TP moderately advanced ripening as evidenced by enhanced ethylene production, softening, and respiration, but prevented fruit abscission; ethephon greatly advanced ripening, red color development and abscission; and 2,4,5-TP + ethephon resulted in a striking increase in coloration accompanied by the highest rates of respiration, ethylene production and softening, but no abscission. With previous SADH treatment the effect of the other materials was reduced or, as in the fruit coloring response to ethephon, delayed. SADH exerted a pronounced effect on endogenous ethylene formation. It is suggested that SADH specifically inhibits autocatalytic ethylene formation, possibly by maintaining membrane integrity.
Effects of Telone and Nemagon on Essential Nutritive Components and the Respiratory Rates of Carrot (Daucus carota L.) Roots and Sweet Corn (Zea mays L.) Seeds1,2
Authors: Salunkhe D. K. , Wu M. , Wu M. T. , Singh B.
Published: August 2022

Soil fumigations with Telone (1,3-dichloropropene and other chlorinated hydrocarbons) at the rates of 10, 20, and 30 gal/A and Nemagon (1,2-dibromo-3-chloropropane) at the rates of 1, 2, and 3 gal/A, one week before planting carrot and sweet corn seeds brought about significant increases in the content of total carotenes, β-carotene, and total sugars in carrots and the total carotenoids in sweet corn seeds and decreases in respiratory rates of the carrot roots.
Interspecific Hybrids of Zinnia peruviana and Z. elegans through Embryo Culture1
Authors: Shahin Soad S. , Campbell W. F. , Pollard L. H. , Hamson A. R.
Published: August 2022

Two species of Zinnia (Z. elegans Jacq. 2n = 24 and 4n = 48; and Z. peruviana (L.) L. 2n = 24) were utilized in a series of crosses in an attempt to develop new types of Zinnia. Embryos were apparently normal and increased in size during the early stages of development, however, during the second week after pollination there was a breakdown of the endosperm cells followed shortly by degeneration of the embryos. By using IAA and embryo culture techniques, mature F1 plants were produced. The F1 hybrids, which resembled Z. elegans more than Z. peruviana, were more vigorous than either parent. They were sterile.
Anatomy of the Bud Union in Mango (Mangifera indica L.)1
Authors: Soule James
Published: August 2022

Details of mango (Mangifera indica L.) stem anatomy and formation of the bud union were observed in 4 combinations of 2 scions and 3 stocks chip budded at 5 stages of stock growth from first flush to 1 year old. ‘Haden’, ‘Saigon’, and ‘Turpentine’ stems of equivalent age and growth rate were indistinguishable anatomically. Four stages in formation of the bud union were: pre-callus, where 4 days after budding only a wound periderm was present; callus, where 8 days after budding proliferation from tissues mainly near the cambium resulted in firm attachment of the components; cambial bridge, where 12 days after budding cambial layers from stock and scion formed a bridge and vascular tissues were differentiated within 36-48 days; and, the healed union, where after 6-8 months several cylinders of new tissues were present and the lateral shift of the scion to align with the stock had begun.
Hastening the Fruiting of Apple Seedlings1
Authors: Way Roger D.
Published: August 2022

An analysis of the initial fruiting in nearly 50,000 apple seedlings grown over a 29-year period showed that 12% had fruited by their 8th year from seed. For 18 carefully studied crosses, 82% of the seedlings had flowered by their 11th year. Parent cultivars producing the most precocious progenies were ‘Fyan’, ‘Haralson’, ‘Red Melba’, ‘Golden Delicious’, and ‘Idared’.

Early fruiting of seedlings was enhanced by large seedling size and wide spacing in the row, but season of transplanting had no significant effect.

Fruiting of apple seedlings was hastened by 2 methods of trunk ringing: scoring with a knife or saw and spraying trunks with 2-sec-butyl-4,6-dinitrophenol (Dow General). Ringing caused precocious bearing in 4-year-old seedlings but 3-year-old seedlings were too young to be stimulated by ringing and a large portion of 5-year-old seedlings bore without ringing.

Seedling fruiting was advanced about 1¼ years by grafting onto established 10-year-old trees having M.IX roots. This small advance was not enough to justify the considerable effort required to do the grafting. The presence of a fruiting branch of the stock tree did not hasten fruiting of seedling scions grafted onto the stock tree.
The Effect of Plant Growth Regulating Chemicals on Rose Shoot Development from Basal and Axillary Buds1
Authors: Carpenter W. J. , Rodriguez R. C.
Published: August 2022

2,3,5-triiodobenzoic acid (TIBA), (2-chloroethyl) phosphonic acid (ethephon), 6-(benzylamino) - 9 - (2-tetrahydropyran-yl) - 9 H-purine (PBA), and N6 benzyl adenine (N6BA) were applied to greenhouse rose cvs. Red American Beauty, Forever Yours, Mary DeVor and Jack Frost as sprays, lanolin paste, and in solutions in floral foam. Axillary shoot development was significantly increased when PBA and N6BA were applied as sprays, in paste or in solutions in floral foam. The most significant response was obtained when the chemical solutions were absorbed from floral foam cubes attached to a cutback rose cane. Most of the axillary buds broke dormancy when the growth regulating chemicals were applied by this method, however, many of the developing buds stopped growth before becoming shoots. Chemicals PBA and N6BA significantly increased the development of flowering and blind shoots for all rose clones. Plant growth regulating chemicals, methods of application, and concentrations favorable for the development of axillary shoots had no comparable effect on basal shoots developing from the rose bud union.
A Numerical Taxonomic Study of the Avocado (Persea americana Mill.)1
Authors: Rhodes A. M. , Malo Simon E. , Campbell Carl W. , Carmer S. G.
Published: August 2022

Principal components and cluster analyses, based on 67 characters, were applied to 38 cultivars, which collectively exemplified the 3 races of avocado and their racial hybrids. Diagrams constructed from principal component analysis clearly showed the phenetic diversity of the 3 races and their racial hybrids. Correlation and distance phenograms from cluster analyses did not show overall phenetic diversity as well as principal component diagrams. The phenograms were most useful, however, in showing phenetic similarities among closely related cultivars, which were obscure in principal component analysis. The 2 methods are, thus, complementary, and both methods are recommended in studying patterns of variation with species such as avocado.
The Effect of the Modified Munson and 4-Arm Kniffin Training Systems on Changes in Pectic Substances of ‘Concord’ Grapes1
Authors: Smit C. J. B. , Couvillon G. A.
Published: August 2022

‘Concord’ grapes were harvested at weekly intervals from vines trained to either the Modified Munson (M.M.) or 4-arm Kniffin (4-A.K.) training systems. Total pectic substances and protopectin increased until about 7-9% soluble solids was reached and then decreased during further maturation. As maturity approached, water and oxalate soluble pectins increased. The M.M. system gave higher values for total pectic substances, protopectin, and water soluble pectins than the 4-arm Kniffin system.
Arginine and Total Free Amino Acids As Indicators of the Nitrogen Status of Grapevines1
Authors: Kliewer W. Mark , Cook J. A.
Published: August 2022

Growth and composition of ‘Thompson Seedless’ rootings grown in a perelite-vermiculite mixture (1:1 v/v), and receiving Hoagland nutrient solutions containing 0, ½, 1, 2, 4, or 8 mM NO3 were investigated over a 3-year period. Dry wt, no. of nodes, and total leaf area per vine, trunk circumference, and chlorophyll concn in leaves increased linearily with increasing concn of NO3 from 0 to 4 mM, and then remained relatively constant at 4 and 8 mM. Control vines (no NO3) had significantly less area per leaf blade and dry wt per unit leaf area than vines receiving ½ to 8 mM NO3. However, among vines irrigated with ½ to 8 mM NO3 differences in leaf area and leaf wt were not statistically significant. Highly significant linear (correlation coefficients 0.76 to 0.98) and 4th degree polynomial (correlation coefficients 0.92 and 0.99) regression equations were obtained between the levels of NO3 in the nutrient solution and the concn of arginine in canes, trunk, and roots at 3 different stages of vine development; i.e., mid-dormancy, budbreak, and bloom. Total free amino acids and NO3 in petioles and leaf blades were also positively correlated with the level of N in the Hoagland solutions, and with each other. The increases in concn of arginine and total free amino acids (relative to the control) in various parts of vines irrigated with different levels of NO3 were greatest at bloom, followed by budbreak and then dormancy, and were generally in the order of roots>trunk>canes>leaves. The relative increases of arginine reserves in vines following budbreak was first from canes, then from trunk, and lastly from roots.
Effects of Urea and Nitrate Nitrogen on Growth and Composition of Cranberry Vines1
Authors: Leschyson M. A. , Eaton G. W.
Published: August 2022

A greenhouse experiment was carried out to observe the effects of NO3 and urea N sources at several rates on ‘McFarlin’ cranberry vines. Nitrogen applied as NO3 enhanced vegetative growth, and treatments which increased vegetative growth also increased foliar N, P and Mg, but decreased foliar K and Ca. Growth measurements obtained 2 weeks after differential N applications correlated with tissue Mg or Mg and Mn, while 14 weeks later growth measurements were correlated with leaf N, P and K content.
Factors Affecting Floral Stalk Elongation of Flowering Tulips1
Authors: op den Kelder P. , Benschop M. , De Hertogh A. A.
Published: August 2022

Factors affecting floral stalk elongation of tulips during the period from floral bud coloring (budded flower) to the senescence of the perianth were studied. All internodes elongated, however, the greatest elongation occurred in the internode directly beneath the flower and most of the elongation occurred in the upper two-thirds of the internode. Cut tulips elongated less than plants left in the forcing flats. Removal of the budded flower inhibited elongation of the last internode while removal of the leaves was stimulatory with some cultivars. With cut tulips, the perianth appeared to be the primary organ controlling floral stalk elongation followed by the gynoecium and androecium. When the flowers were left intact on the plant the gynoecium exerted the greatest control followed by the perianth and androecium. When the complete flower was removed and IAA or NAA was applied as a lanolin paste to replace the flower, the last internode elongated in a manner similar to the intact flower. Similar applications of kinetin and GA3 were ineffective.
Bud-Graft Incompatibility of Rosa multiflora Seedling Understock1
Authors: Buck Griffith J.
Published: August 2022

Three degrees of scion-understock compatibility were used to describe the rose bud-graft combinations ‘Charlotte Armstrong’–R. multiflora Thunb. seedlings: the compatible, the rapidly failing, and the slowly failing union in which cambiform tissue did not develop in callus of scion origin. In the slowly failing union, callus contact between understock and scion was sufficient to maintain the scion in a dormant condition, but was not sufficient for its maintenance under climatic stress or growth stress induced by heading-back the understock. Symptoms of bud-graft failure could be identified by the 4th day after grafting.
An Evaluation of the Excised Root Tip Method for Determining the Resistance of Pisum sativum to Aphanomyces euteiches1
Authors: Morrison R. H. , Johnson J. K. , King T. H. , Davis D.
Published: August 2022

Resistance in Pisum sativum to Aphanomyces euteiches was evaluated in the laboratory by the number of oospores formed in excised root tips inoculated with zoospores of the pathogen. Significantly lower mean numbers of oospores formed in root tips of 3 moderately resistant breeding lines than in those of 3 susceptible cultivars. Results were reproduceable if test procedures were adequately controlled. A sample size of 40 root tips gave 95% confidence in detecting a 40 oospore/root tip difference between means of resistant and susceptible genotypes.

Lower mean numbers of oospores formed in excised root tips of genotypes which were resistant in greenhouse tests. Inoculum concentrations of 10 to 100 zoospores/plant caused severe disease in susceptible cv. New Era, while greater amounts of inoculum were needed to cause comparable disease in 2 resistant breeding lines.
Genetics and Heritability of Resistance to Thielaviopsis basicola in Beans1
Authors: Hassan Ahmed A. , Wilkinson Robert E. , Wallace Donald H.
Published: August 2022

Resistance to T. basicola was found in Phaseolus vulgaris lines P.I.203958 (N203) and 2114-12. To determine the inheritance of resistance, these 2 lines were crossed with each other and with the susceptible cv. Redkote. Greenhouse tests were conducted on parental, F1, F2, and backcross progenies of each of the 3 crosses, and on F3 progenies of crosses ‘Redkote’ × 2114-12 and ‘Redkote’ × N203. The data indicate that N203 and 2114-12 possess the same genes for resistance, that resistance is partially recessive, and that resistance is controlled by approximately 3 genes. Broad sense heritability was estimated as 59% and the additive variance as 39%.
Radioisotopic Evidence of Immobilization of Iron in Azalea by Excess Calcium Bicarbonate1
Authors: Rutland Rufus B.
Published: August 2022

The redistribution of 59Fe in azalea plants was followed after allowing root absorption of the isotope under favorable conditions. During the 12 weeks of redistribution, high lime (Ca(HCO3)2) was found to have an inhibitory effect of redistribution of Fe. A marked interveinal pattern of chlorosis developed under high lime and autoradiographs demonstrated a localization of 59Fe along the veins of the chlorotic leaves. Distribution of Fe within green leaves grown under low lime was more uniform than in those grown under high lime.
Copper Deficiency in Chrysanthemum: Critical Level and Symptoms1
Authors: Nelson Paul V.
Published: August 2022

A series of experiments was conducted with chrysanthemum cv. Giant Betsy Ross grown in acid-washed quartz sand. The nutrient solution was buffered at pH 7.8 to induce Cu deficiency while Fe, Mn and Zn were supplied in high quantities to avoid simultaneous deficiencies. Nutrient levels in the tissues were monitered by atomic absorption analyses.

The critical range of Cu was established at 6.7 to 7.4 ppm for the first fully expanded leaves of the plant. The deficiency first appeared on the terminal leaves as chlorosis most intensely developed at the leaf blade base. As the leaf became more chlorotic the margin, and particularly the lobes toward the leaf apex, retained a normal green color. Tissues over and adjacent to the vascular tissue did not become as chlorotic as the leaf lamella giving rise to the second symptom which was interveinal chlorosis. At that stage the green pigmentation associated with the vascular tissue occurred in a broader pattern than in Fe deficiency. In the third stage of deficiency veinal chlorosis appeared, followed by necrosis of leaves located immediately below the first fully expanded leaf. There was a concomitant regreening of foliage at the terminal end of the shoot which lasted for a short time. In the final stage the shoot apex died.
Effects of Mechanical Pruning of Apple Hedgerows with a Slotting Saw on Light Penetration and Fruiting1
Authors: Cain John C.
Published: August 2022

Annual cutterbar and slotting saw hedging were compared after 3 years. Fruiting was measured as the number of spurs per twig on 3 year old growth, number of spurs flowering and fruiting, and bushels per tree. Integrated light energy quantities were measured for 6- to 14-day periods for various positions within the tree and correlated with fruiting.

A hydraulic “slotting saw” mounted on a boom on a fork lift hedged a slot in the side of the tree. By cycling the slots any one position was cut only once every 4 years, permitting the regeneration of fruiting wood and the penetration of light.

‘McIntosh’ apples pruned as 10 ft high hedges with (a) cutterbar and (b) with a slotting saw, show that annual cutterbar hedging reduces the generation of new fruiting spurs, produces a dense outer periphery shading interior spurs and reduces bearing. The slotting saw mechanical pruning technique increases light penetration into the tree, produces nearly 3 times as many new spurs and about a 4-fold increase in the percentage of spurs flowering. Light measurements within the tree indicate that spur leaves require about 50% of available light for suitable flowering.

Light values in trees hedged 3 years with the cutterbar were reduced to less than this value within the outer 2 ft of tree canopy where few spurs exist.
Influence of Cucurbitacins, Sugars, and Fatty Acids on Cucurbit Susceptibility to Spotted Cucumber Beetle1,2
Authors: Sharma Govind C. , Hall Charles V.
Published: August 2022

Seedlings of 18 plant types from 5 genera of Cucurbitaceae were analyzed for cucurbitacins, total sugars, and fatty acids and these were correlated with spotted cucumber beetle feeding. The species were: Citrullus colocynthis L. (Schrad.), C. lanatus (Mansf.) Matsumara: Cucumis anguria L., C. dipsaceus Ehrenb., C ficifolius Bouche’C. longipes Hook f., C. melo L., C. myricarpus Naud., C. prophetarum L.: Cucurbita foetidissima H. B. K., C. pepo L.; Lagenaria siceraria (Mol.) Stamdl.; Luffa acutangula (L.) Roxb., and L. cylindrica Roem. Seedling injury ranged from 0 (none) to 3 (severe). Regression analysis indicated that cucurbitacins, total sugars, and the fatty acids (palmitic and linolenic) except linoleic contributed to insect feeding; correlation between concn and feeding was positive. Cucurbitacins, which cucumber beetles were able to locate without feeding, played the major role in seedling susceptibility; next in importance were palmitic acid, linolenic acid, and total sugars. All apparently related to the preference of beetles for specific strains or cultivars. In non-preferred seedlings, preference was induced by topical application of cucurbitacins A, B, C, D, E, and 1 and by the glycosides from C. foetidissimma roots. A barrier seemed to obstruct feeding of the beetles on the upper surface of the cotyledons, even when the attractant cucurbitacins were applied.
Inheritance of Growth Habit and Time of Flowering in Beans, Phaseolus vulgaris L.1
Authors: Bliss F. A.
Published: August 2022

Four true bush snap bean cultivars were hybridized with OSC410, a determinate, sprawling ‘Blue Lake’ bush breeding line. Observed segregation data fit a single gene hypothesis with the sprawling habit completely dominant to true bush type. Crosses of OSC410 to 2 indeterminate cultivars provided evidence for 2 additional patterns of inheritance. When ‘Polaris’ was used as the indeterminate parent, segregation ratios indicated that indeterminance was dominant and controlled by a single gene. Epistasis of 2 genes was suggested from the cross Mexico 80R' (normal) × OSC410, with indeterminance dominant.
Effect of (2-Chloroethyl)phosphonic Acid (Ethephon) on Maturation of Vitis vinifera L.1
Authors: Weaver Robert J. , Pool Robert M.
Published: August 2022

Application of ethephon at 200 to 2,000 ppm was made to the grape cvs. ‘Tokay’ and ‘Emperor’, and at 1,000 ppm to ‘Thompson Seedless’ and ‘Carignane’. The soluble solids were significantly increased in some fruits of ‘Carignane’ but not in the other cultivars. Ethephon treatment resulted in reductions in acidity in some fruits of all cultivars. This increased soluble solids to acidity ratios in some ethephon-treated fruits. An increase in anthocyanin content of the colored berries occurred, but not significantly so in ‘Tokay’. Optimum time for treatment was about 2 weeks after initiation of coloring.
Sugar and Organic Acid Concentrations in Cultivars of Muscadine Grapes1
Authors: Carroll Daniel E. , Hoover Maurice W. , Nesbitt William B.
Published: August 2022

Individual and total sugar and organic acid concn in the juice of 12 cultivars of muscadine grapes (Vitis rotundifolia Michx.) were determined in each of 3 years. Fructose ranged from 3.35 to 9.28% and averaged 5.51%; glucose 3.52 to 7.70% and averaged 5.16%; sucrose 0 to 5.20% and averaged 1.89%; soluble solids 10.20 to 17.85% and averaged 13.21%; malate 0.17 to 1.16% and averaged 0.50%; tartrate 0.15 to 0.52 and averaged 0.26%; citrate ranged from a trace to 0.06% and averaged 0.04%; total titratable acidity 0.39 to 1.549% and averaged 0.839%; pH ranged from 3.50 to 2.88. ‘Roanoke’ was significantly lower in soluble solids (11.18%) than most of the other cultivars over the 3-year period. It was also exceptionally high in malic acid (0.70%) and contained significantly more malate than 7 other cultivars. ‘Roanoke’ and ‘Pamlico’ averaged the highest titratable acidities with 1.099 and 1.049%, respectively. ‘Magoon’ contained significantly more tartrate (0.41%) than all other cultivars except ‘Hunt’. When total titratable acidity values for the 12 cultivars were pooled for each season, it was apparent that yearly differences in these values were primarily due to differences in malate levels since tartrate levels were similar in each of the 3 seasons.
Morphological and Anatomical Aspects of Oedema in Eggplants (Solanum melongena L.)1
Authors: Eisa H. M. , Dobrenz A. K.
Published: August 2022

Oedema in eggplant occurred in 2 of 6 cultivars grown in warm, humid air-supported plastic greenhouses located in Puerto Peñasco, Mexico. Oedema was observed when plants reached the fruiting stage and its occurrence was limited to the upper side of young and old leaves, including the petioles. Anatomically, hypertrophy of the palisade cells, followed by rupturing in the upper epidermis, was characteristic of oedemata. Hypertrophied cells apparently contained fewer chloroplasts than normal cells, although chlorophyll determination for susceptible and resistant cultivars did not suggest a correlation with this oedema. Differences in chlorophyll, fruit number, and yield were characteristic of the different cultivars.