bluuebunny/crossref_metadata_2025 huggingface dataset:
Phthalimide-modification of Sex Expression in Gynoecious and Monoecious Cucumbers1
Authors: Xu Shao Ying , Bukovac Martin J.
Published: August 2022

Staminate flowers were induced in a gynoecious line (MSU 394G) and the pistillate phase was delayed in a monoecious cultivar (‘Sumter’) of cucumber (Cucumis sativus L.) with 2 phthalimide derivatives, 1-(3-chlorophthalimido)-cyclohexanecarboxamide and 1-(1-cyclohexene-1,2-dicarboximido)-cyclohexanecarboxamide. Single and multiple foliar sprays at 1000 mg liter−1 during expansion of the first true leaf (5–7 cm in width) delayed flowering as indexed by days from seeding to anthesis and the node of the first pistillate flower in monoecious ‘Sumter’. Repeat applications induced staminate flowers in gynoecious MSU 394G and staminate flower production continued over a wide range of nodes. Marked differences in response to the phthalimides appeared to be related to the season in which the experiments were performed. The greatest number of staminate flowers was induced when the gynoecious plants were exposed to an 8-hour photoperiod early in plant development and then grown under a 14-hour photoperiod.
Field Performance and Phenotypic Stability of Tissue Culture-propagated Thornless Blackberries1
Authors: Swartz Harry J. , Galletta Gene J. , Zimmerman Richard H.
Published: August 2022

Comparative field performance of thornless blackberry plants produced by tissue-culture (TC) and standard (ST) methods (tip layers or stem cuttings) was studied to determine any effect of TC propagation on clonal phenotypic stability. In general, TC plants performed as well as, and were phenotypically similar to, ST plants. Some differences in leaf size and pattern were observed; however, the differences were related to the increased vigor of TC plants of these cultivars. Total growth of TC and ST plants of ‘Black Satin’, ‘Hull Thornless’, ‘Thornfree’, and SI-US 68-6-17 was similar. ST plants of ‘Dirksen Thornless’ and ‘Smoothstem’ failed to grow as rapidly as TC plants of these cultivars or ST plants of the other cultivars, resulting in significantly reduced 2nd-year yields. First-year growth of all TC plants was more uniform than corresponding ST plants. On the average, fruit size was smaller on TC plants; however, this was true in both years only for ‘Black Satin’. The response varied for other cultivars with TC plants of ‘Dirksen Thornless’ actually having larger fruits in one year. No consistent differences in bloom date or median harvest date due to propagation method were observed. No variant plants were observed in the field; however, one sectorial leaf chlorotic variant was observed after TC propagation but prior to field planting.
CO2 Assimilation Characteristics of Five Prunus Tree Fruit Species1
Authors: DeJong T. M.
Published: August 2022

Photosynthetic CO2 assimilation characteristics of 5 Prunus species were compared with respect to leaf nitrogen content and water use. The mean maximum CO2 assimilation rates of peach, plum, and cherry were all very similar when expressed on a leaf area, leaf nitrogen, and water use basis (1.33–1.37 nmol CO2 cm−2s−1, 6.17–6.75 nmol CO2 mgN−ls−1, 0.19–0.21 nmol CO2 µgH2O−1). In comparison, the mean maximum CO2 assimilation rate of almond was higher when expressed on a leaf area basis (1.80 nmol CO2 cm−2s−1), the same when expressed on a leaf N basis (6.47 nmol CO2 mgN−1s−1), and lower when expressed on a water use basis (0.16 nmol CO2 µgH2O−1). The mean maximum rate of CO2 assimilation in apricot leaves was lower than that of peach, plum, and cherry when expressed on a leaf area (0.67 nmol CO2 cm−2s −1) and leaf N basis (3.76 nmol CO2 mgN−1s−1) but the same when expressed on a water use basis (0.19 nmol CO2 µgH2O−1). The interspecific relationship between leaf N content and leaf CO2 assimilation rate was found to be similar to that described previously for leaves of a single cultivar of peach.
Naphthaleneacetic Acid and Fruiting of Rabbiteye Blueberry ‘Tifblue’1
Authors: Austin Max E.
Published: August 2022

Naphthaleneacetic acid (NAA) treatments were applied to pruned and hedged vigorous plants of rabbiteye blueberry (Vaccinium ashei Reade). NAA application delayed shoot growth and resulted in earlier flowering and ripening of larger-sized fruit. NAA treatments effects lasted up to 3 years.
Mitotic Instability and 2n Gamete Production in Vaccinium corymbosum × V. elliottii Hybrids1
Authors: Lyrene P. M. , Sherman W. B.
Published: August 2022

Pollination of about 7000 flowers of tetraploid highbush blueberry clones with pollen from a wild diploid species, V. elliottii (Chapm.) Small, gave 25 phenotypically obvious hybrids. Examination of 18 of these hybrids showed that they included triploids, tetraploids, pentaploids, and aneuploids. Some hybrids appeared to be mosaics, as evidenced by chromosome-number variability in premeiotic flower buds. Most hybrids were highly vigorous. The triploids were completely female sterile and the pentaploids ranged from partially to completely female sterile when open-pollinated. Three of the tetraploids examined were highly fertile and extremely vigorous. The occurrence of 3x-4x mosaicism suggests that the 3x hybrids may have arisen from chromosome loss in 4x plants rather than from 3x zygotes. Morphological similarities between certain of the 5x hybrids and the west Florida race of the native allohexaploid species V. ashei Reade suggest V. corymbosum L.–V. elliottii allohexaploidy as one possible mode of origin for V. ashei.
Inheritance of a Leaf Distortion Tendency in Bush Lines of Beans, Phaseolus vulgaris L., of Blue Lake Background1
Authors: Rabakoarihanta A. , Baggett J. R.
Published: August 2022

‘Gallatin 50’, a bush cultivar not of ‘Blue Lake’ background, and ‘Oregon 1604’, a bush cultivar of ‘Blue Lake’ type, were crossed with distortion susceptible lines of ‘Blue Lake’ type. Environment affected distortion expression; the best expression was obtained in the greenhouse while expression was much reduced in the field. Ratios obtained suggested distortion is primarily controlled by a single dominant gene, designated Ld. ‘Oregon 1604’ carries the recessive allele for normal. ‘Gallatin 50’ carries a major dominant gene, designated Ds, that supresses the expression of the dominant gene Ld for leaf distortion tendency. Results also suggested that modifying factors are involved and are responsible for levels of susceptibility among parents and progenies. Additional crosses between susceptible lines showing severe to mild distortion indicated that these lines carried the same major genes for distortion, but differed in modifying factors.
Genetics and Nature of Resistance to Powdery Mildew in Crosses of Butternut with Calabaza Squash and ‘Seminole Pumpkin’
Authors: Adeniji Adeoye A. , Coyne Dermot P.
Published: August 2022

The inheritance of resistance in butternut squash (Cucurbita moschata Poir) to powdery mildew (Erysiphe cichoracearum DC) was studied under greenhouse and field conditions using F1 F2, and BC1 generations derived from crosses of ‘La Primera’ (resistant) (calabaza type) with 2 butternut cultivars ‘Ponca’ (susceptible), and ‘Waltham’ (susceptible), and ‘Ponca’ x ‘Seminole Pumpkin’ (intermediate resistance). The breath-blowing method of inoculation was effective in greenhouse tests. Petiole and stem reactions of plants in both field and greenhouse trials and leafblade reactions of plants in the field tests indicated that 3 alleles at a single locus determined resistance reactions in crosses involving ‘Ponca’, ‘Waltham’, and ‘La Primera’. Proposed genotypes for the susceptible ‘Ponca’ and ‘Waltham’ butternut squash are pm – lp pm – lp and pm – lw pm – lw, respectively, and for the resistant ‘La Primera’, pm – lL pm – lL. The partial and complete dominance relations of these alleles for the leaf-blade (field) and petiole/stem reactions (field/greenhouse), respectively, are pm – lp > pm – lL > pm – lw. A different gene, pm – 2s, controlled the intermediate resistance of ‘Seminole Pumpkin’. However, a quantitative inheritance pattern of disease reactions of leaf blades was observed in the greenhouse trials in all crosses, presumably because of the higher inoculum load and the increased intermediate ratings of the heterozygotes under these conditions. Leaf-blade and stem/petiole resistance was completely associated in segregating progenies in the field but not in the greenhouse because of the intermediate susceptibility of the leaf blades of heterozygotes under those conditions. Scanning electron micrographs of powdery mildew on compatible and incompatible hosts showed that differential compatibility occurred in conidial germination. Resistance in ‘La Primera’ involved delayed conidia germination, retarded hyphal growth, shorter conidiophores, and weak sporulation.
Effect of Photoperiod and Irradiance on Floral Development of Young Plants of a Semi-early and a Late Cultivar of Azalea
Authors: Bodson M.
Published: August 2022

For 2 cultivars of azalea (Rhododendron sp.), floral initiation was earlier when irradiance was increased from 80 to 160 µE m-2s-1. Buds aborted at an early stage of floral initiation in 8-hr days, but this was prevented by increasing the irradiance from 80 to 250 µE m-2s-1. A night interruption of 1.5-hr incandescent light allowed plants kept in 8-hr days to grow vegetatively for a longer time. Inflorescence development increased with increasing daylength and irradiance. In the late cultivar ‘Knut Erwén’, inflorescence development was reduced by low light intensities more than in the semi-early ‘Reinhold Ambrosius’.
In Vitro Acclimatization of Aseptically Cultured Plantlets to Humidity
Authors: Wardle K. , Dobbs E.B. , Short K.C.
Published: August 2022

A method is described whereby relative humidity is reduced in the atmosphere of agar-solidified tissue cultures. Plantlets of chrysanthemum (Chrysanthemum X morifolium Ramat.) cultured under low humidity exhibited a high mortality rate and those that survived were smaller and had few roots. Severe retardation of stomatal development occurred under reduced humidity and mature stomata had considerably narrower apertures than did plantlets grown at about 100% relative humidity. Plantlets of cauliflower (Brassica oleracea L. Botrytis group) cultured under reduced humidity also exhibited reduced growth but, in addition, developed large quantities of surface wax and had lower rates of water loss. The results are discussed in relation to the potential uses of the technique for acclimatization of plantlets prior to transfer to soil.
Promotion and Inhibition of Branching in Poinsettia in Grafts between Self-branching and Nonbranching Cultivars
Authors: Stimart Dennis P.
Published: August 2022

Axillary shoot growth on scions of poinsettia (Euphorbia pulcherrima Wild, ex Klotz) was regulated by grafting nonbranching (‘C-1’) and self-branching (‘Amy’, ‘Glory’, ‘Super Rochford’) cultivars on each other. Branching of ‘C-1’ was increased when scions were grafted onto self-branching rootstocks and branching was decreased on self-branching cultivars grafted onto ‘C-1’ rootstocks. Initiation of axillary bud growth was promoted on younger nodes of ‘C-1’ when grafted onto self-branching rootstocks. Increased branching propensity of ‘C-1’ scions grafted onto rootstocks of self-branching types continued even after vegetative cuttings were rooted. Axillary bud activity was unaffected by leaf removal. Results suggest that axillary bud activity is governed by shoot and root interactions of the plant and that axillary shoot growth is governed by some endogenous factors translocated from the roots across the graft union to the shoot.
Effects of Low Temperature and Light on Foliar Injury to Pinus sylvestris L.
Authors: Smit-Spinks Barbara , Swanson Bert T. , Markhart Albert H.
Published: August 2022

The relationship of foliar injury in Pinus sylvestris (Scots pine) to low temperature and irradiance levels was studied in growth chambers at –l°C(warm) and –7°(cold) under 3 light treatments: 1) nonshaded (1000 watt, Metalarc), 2) 47% shade cloth, and 3) 4-mil white polyethylene. During the 9-week treatment period, plants were tested for hardiness, electrolyte leakage, chlorophyll content, and relative water content. Foliar injury was observed in plants under the cold treatment but the degree of injury was not related to irradiance level. After 6 weeks, electrolyte leakage levels were greater than 50% for all cold-treated plants. No foliar injury occurred on warm-treated plants regardless of light treatment. Minimizing desiccation and rapid temperature fluctuations did not prevent injury. Needle water content of plants from both temperature regimes decreased about 6% over the duration of the experiment. Maximum foliar temperature fluctuations were 5.5° (l.l°/minute) and 4° (0.8°/minute) in the cold and warm chambers, respectively. Although warm-treated plants showed no injury during the treatment period, they deteriorated after several weeks in the greenhouse. Severe root injury to the warm-treated plants may have caused this deterioration.
Water Relations and Frond Curl of Cut Leatherleaf Fern
Authors: Nell Terril A. , Barrett James E. , Stamps Robert H.
Published: August 2022

Leatherleaf fern [Rumohra adiantiformis (G. Forst) Ching] fronds became desiccated rapidly after harvest with water potential decreasing from -0.45 to -1.75 MPa within 30 minutes. Partial closing of stomates 30 minutes after harvest accounted for a decrease in the rate of frond desiccation and frond water potential was -2.26 MPa after 180 minutes. Postharvest frond desiccation to water potentials of -1, -2, and -3 MPa in the field prior to water dip and cold storage resulted in frond curl of 32, 56, and 84%, respectively, when placed in postharvest rooms. Water uptake decreased during the first 4 days in postharvest rooms. Declining frond water potentials suggested reduced rate of water uptake was due to blockage of the xylem. However, no obstructions were observed at cut end of stipe from fern with frond curl or those not exhibiting frond curl. Frond water potentials were lower one hour after harvest than when undergoing normal postharvest senescence. Fronds did not exhibit normal drought-imposed wilt or frond curl during prestorage stress. Desiccation resulted in frond curl in some experiments but had little effect in others. These results indicate that frond curl can be triggered by desiccation stress but other factors are predisposing fronds to this disorder.
Effect of Shade on Photosynthesis, Specific Leaf Weight, Leaf Chlorophyll Content, and Morphology of Young Peach Trees
Authors: Kappel Frank , Flore J.A.
Published: August 2022

One-year-old peach [Prunus persica (L.) Batsch cv. Redhaven] trees were grown outdoors under 4 different shade levels (100%, 36%, 21%, and 9% of full sun). Shoot length, internode length, and node number were unaffected by shade, but heavy shade (9% full sun) reduced stem diameter 24%. Compared to those in full sun, average leaf areas were increased 18%, 30%, and 20% by 36%, 21%, and 9% shade, respectively. Shading caused a more horizontal leaf orientation and lower specific leaf weight. Both average and maximum photosynthetic rate per unit area or per mg chlorophyll decreased with shading, but increased with shading when expressed per unit dry weight. Chlorophyll content per unit leaf area increased with shading, but stomatal resistance was unaffected. Leaves from shade treatments became light-saturated between 400 and 600 µEs-1m-2; full-sun leaves became light-saturated at 700-900 µEs-1m-2.
Polysomal Population in Relation to Ethylene Production and the Senescence of Cut Carnation Flowers and Floral Parts
Authors: Bufler G. , Romani R.J. , Reid M.S.
Published: August 2022

Ribosomes were isolated from styles, receptacles, and petals of cut ‘White Sim’ carnation flowers (Dianthus caryophyllus L.) during flower senescence. In all flower parts the percentage of polysomes decreased for a few days after cutting and then increased coincident with the surge of ethylene production in the final stages of floral senescence. Changes in the polysomal population in petals excised from the same flower at progressive stages of its senescence were identical with those obtained from petals excised from different flowers at similar stages of senescence. The polysomal data confirm the occurrence of increased protein synthesis coincident with ethylene production and the senescence of cut carnation flowers.
An Analysis of Several Climatic Temperature Variables Dealing with Olive Reproduction
Authors: Denney James O. , McEachern George R.
Published: August 2022

Of several temperature variables that have been suggested to account for flowering and fruiting in the olive (Olea europaea L.) only one—days on which the mean temperature is > 12.2°C and < 13.3°—finds significant expression in the climates of olive-producing regions. Study sites show a mean value of 17.1 ± 4.5 of such days in the period from October 1 to May 31 per year. It can be assumed that vernalization leading to flowering in the olive proceeds when active growth has ceased and when progress of the day’s temperature leads through approximately 12.5°. In olive-producing regions, when mean daily mean temperature is approximately 12.5°, mean daily maximum temperature is 18° and mean daily minimum temperature is 7°.
Effects of Soil pH, Phosphorus Rates, Deep Tillage Practices, and Clay Additions on Peach Tree Performance in Deep Sandy Soils of North Carolina
Authors: Cummings George A.
Published: August 2022

Effects of soil pH, tillage practices, P application, and the addition of clay at the planting site on tree size, fruit yield, fruit size, and tree longevity of peaches [Prunus persica (L.) Batsch] for 20 growing seasons are reported. Because of widespread tree death, ‘Loring’ trees were removed after 9 years and the orchard replanted to ‘Winblo’. Soil pH below 5.6 resulted in poor tree growth, low fruit yield, and small fruit size compared to trees grown in soils at higher pH. In the final 10 years of the experiment, marked improvement in tree size, fruit yield, fruit size, and longevity were evident as soil pH increased. The effect of 3 tillage practices—normal plow to a depth of 20 cm, normal plow to a depth of 20 cm plus a 75-cm-diameter ⨯ 122-cm-deep hole at the planting site, and deep plowing to a depth of 58 cm—varied with cultivar. Both methods of soil profile modification (which penetrated the A2 horizon) resulted in increased yield and tree size compared to normal plowing to 20 cm with ‘Loring’ during the first 9 years. During the final 10 years, fruit yield was lower and tree death greater in the deep-plow plots, but there were no differences in fruit yield, tree size, or tree longevity between the other tillage treatments. Phosphorus rates (0, 15, and 30 kg/ha annually) or clay additions did not influence tree size, fruit yield, or tree survival. Results of this study lend strong support for the maintenance of soil pH above 5.6 and good evidence that increase in tree growth, fruit yield, and tree longevity is further enhanced when soil pH is maintained above 6.0.
Results of Eight Years with CGA-15281 as a Postbloom Thinner for Peaches
Authors: Gambrell C.E. , Coston D.C. , Sims E.T.
Published: August 2022

The ethylene-releasing agent CGA-15281 (2-chlorethyl-methylbis (phenylmethoxy) silane) effectively thinned fruit of several cultivars of peach [Prunus persica (L.) Batsch.]. Thinning varied with cultivar, stage of development, concentration, and application technique. Negligible (<1%) leaf injury and drop occurred even at the higher (720 ppm) concentration over the 8-year period.
Dehydration Effects on Freezing Characteristics and Survival in Liquid Nitrogen of Desiccation-tolerant and Desiccation-sensitive Seeds
Authors: Becwar Michael R. , Stanwood Phillip C. , Leonhardt Kenneth W.
Published: August 2022

Dehydration effects on freezing characteristics and survival in liquid nitrogen were studied in 11 species of tropical seeds and in silver maple (Acer saccharinum L.) seeds. Differential thermal analysis was used to determine the threshold moisture level below which seed tissue water was in an unfreezable state. Desiccation-sensitive seeds, areca palm [Chrysalidocarpus lutescens (Bory) Wendl.] and silver maple, did not survive dehydration below the threshold moisture level and did not survive exposure to liquid nitrogen. Nine of 10 desiccation-tolerant seeds [strawberry guava, Psidium cattleianum Sabine; passion fruit, Passiflora edulis f. flavicarpa Deg.; Ceara rubber, Manihot glaziovii Mull. Arg.; dwarf schefflera, Schefflera arboricola (Hayata) Merrill; common guava, Psidium guajava L.; papaya, Carica papaya L., apple of sodom, Solarium sodomeum L.; prickly poppy, Argemone glauca Pope; and seamberry, Sabalparviflora Becc.] survived dehydration to as low as 2% to 12% moisture content (below the threshold moisture levels determined) and in the dehydrated state survived exposure to liquid nitrogen. Coffee (Coffea arabica L. var. Bourbon) seeds tolerated dehydration to as low as 8% moisture content but did not survive exposure to liquid nitrogen. These results demonstrate the feasibility of cryopreserving seed germplasm of several tropical species.
Growth of Lettuce, Spinach, Mustard, and Wheat Plants under Four Combinations of High-pressure Sodium, Metal Halide, and Tungsten Halogen Lamps at Equal PPFD
Authors: Tibbitts T.W. , Morgan D.C. , Warrington I.J.
Published: August 2022

Plants of lettuce (Lactuca sativa L. cv. Grand Rapids), spinach (Spinacia oleracea cv. Bouquet), white mustard (Sinapis alba L.), and wheat (Triticum aestivum L. cv. Karamu) were grown at 2 photosynthetic photon flux densities (PPFD 400 to 700 nm at 320 and 700 μmol s−1m−2 under 4 lamp treatments: metal halide lamps alone, high-pressure sodium lamps alone, metal halide plus tungsten halogen lamps (ca. 1:1 installed wattage), and metal halide plus high-pressure sodium lamps (ca. 1:1 installed wattage). Plants of all species grew well under all treatments and no growth abnormalities were apparent at harvest. It is concluded that dry-weight increase was determined by PPFD and not by spectral irradiance. However, lettuce, spinach, and mustard hypocotyl elongation was greater in young plants grown under the high-pressure sodium lamps in comparison with those grown under the metal halide or metal halide plus tungsten halogen treatments. A strong negative relationship between hypocotyl length and blue photon flux density (400–495 nm) was demonstrated. Anthesis of wheat occurred at the same time under all lamp treatments, but anthesis of mustard differed by 2 days at the higher PPFD and 4 days at the lower PPFD among lamp treatments. The time of anthesis for mustard was found to be weakly but positively correlated with the calculated phytochrome photoequilibrium. Chlorophyll concentrations in young lettuce and spinach plants growing under the high-pressure sodium lamps were 55% and 26% lower, respectively, than those in plants growing under metal halide lamps at the high PPFD level. However, final dry weight was unaffected by any of these morphological differences in the early growth stages.
Influence of Time of Summer Pruning and Limb Orientation on Yield, Fruit Size, and Quality of Vigorous ‘Delicious’ Apple Trees
Authors: Myers S.C. , Ferree D.C.
Published: August 2022

Vigorous, 5-year-old trees of apple [Malus domestica Borkh. cv. Red Prince Delicious/Malling (M) 9] were unpruned or pruned on July 3, August 3, or September 3 in 1979 and 1980. July and August pruning maintained number of fruit/tree and July pruning increased the number of fruit borne in the canopy interior compared to the unpruned control. September pruning decreased fruit numbers compared to July and unpruned trees. July and August but not September pruning reduced cork spot. Pruning reduced fruit size, soluble solids, and watercore but did not affect fruit color or flesh firmness. Limb orientation had no effect on fruit number, soluble solids, or watercore, but fruit on vertical limbs were better-colored and smaller than those on horizontal limbs. Spur-borne fruit in the canopy interior were larger, but less colored, compared to fruit on horizontal and vertical limbs located near the canopy periphery.
Response of Young ‘Topred Delicious’ Apple Trees to Orchard Floor Management and Fertilization
Authors: Miller Stephen S.
Published: August 2022

Growth of ‘Topred Delicious’ (Malus domestica Borkh)/Malling Merton (MM) 111 apple trees during the first 5 years in the orchard was significantly affected by the orchard floor management system. Trees grown in a mowed sod were smaller and had a significantly lower yield efficiency (kg/cm2) than those grown under cultivation or a herbicide strip system. N source or rate did not influence growth or average yield/tree; fruit size and bitter pit development were significantly greater where a complete fertilizer (10N-4P-8K) was applied. N increased tree growth under sod but not under a cultivated or herbicide strip managment system. Growth response in the first year was increased when larger-sized trees were planted under a weed-free management system and trees were headed to 76 cm.
Decomposition and Metabolism of the Ethylene-releasing Compound CGA-15281 in Peach Orchard Soils
Authors: Kays Stanley J. , Arrendale Richard F. , Seeley Schuyler D. , Couvillon Gary A.
Published: August 2022

Decomposition and metabolism of the ethylene-releasing plant growth regulator, (2-chloroethyl)methylbis(phenylmethoxy)silane (CGA-15281), was studied over a 14-month period in 3 peach orchard soils. The molecule decomposed rapidly when exposed to a soil environment. Major decomposition products were: ethylene, benzyl alcohol, and low levels of (2-chloroethyl)methyl(phenylmethoxy)chlorosilane and (dichloromethyl)(chloroethylmethylphenylmethoxy)disiloxane which appear to be formed in side reactions of CGA-15281 breakdown. The compounds have molecular ions of 247 and 341 and display molecular ion isotope patterns consistent with molecules containing 2 and 3 chlorine atoms, respectively. Methoxy positions on the parent molecule were largely metabolized to CO2, while the ethyl group was primarily liberated as ethylene. The methyl group on the parent molecule remained bound to the silicon atom, forming insoluble organosilicates; little was metabolized by soil microorganisms to CO2. Soil type had a small but statistically significant effect on degree of release of ethylene from the chloroethyl positions; however, it did not affect metabolism of the methoxy group or degree of partitioning of the methyl group into insoluble compounds. This difference in ethylene release could not be explained by differences in pH, percentage of organic matter, or cation exchange capacity of the soils tested. Soil pH had a pronounced effect on the rate of breakdown of the parent molecule with the most rapid decomposition at low pH.
Effect of Plant Population and Planting Date on Root and Starch Production of Buffalo Gourd Grown as an Annual
Authors: Nelson J.M. , Scheerens J.C. , Berry J.W. , Bemis W.P.
Published: August 2022

In the paper “Effect of Plant Population and Planting Date on Root and Starch Production of Buffalo Gourd Grown as an Annual” by J.M. Nelson, J.C. Scheerens, J.W. Berry, and W.P. Bemis [J. Amer. Soc. Hort. Sci 108(2): 198–201, 1983), 2 incorrect quadratic equations are given. In Fig. 3 and on page 199, column 2, line 11, the equation Y = 676 + 0.8X - 0.000072X2 should be Y = 6.8 x 103 + (8.0 x 10-2)X - (7.2 x 10-8)X2. In Fig. 4, the equation Y = 462 + 1.27X - 0.000145X2 should be Y - 4.6 x 102 + (1.3 x 10-2)X - (1.5 x 10-8)X2.
Use of Freeze-drying and Acetone Impregnation with Natural and Synthetic Anti-oxidants to Improve Storability of Onion, Pepper, and Parsley Seeds
Authors: Woodstock L.W. , Maxon Susan , Faul Karen , Bass Louis
Published: August 2022

Seeds of onion (Allium cepa L.), pepper (Capsicum annum L.), and parsley [Petroselinum crispum (Mill.) Nym. ex A.W. Hill] were freeze-dried to moisture levels of 2% to 5% and stored in desiccators over zeolite for 6 to 9 years at 21°, -12°, -70°C, during the entire period, or at 40° for 2 years followed by ambient temperatures. Freeze-drying improved storability of onion at 21°. A 2-year period at 40° killed the pepper seed and accelerated subsequent deterioration of onion and parsley at ambient temperatures. Freeze-drying prior to storage was effective in reducing the rate of deterioration of onion and pepper seeds during and after 40° exposure, but did not reduce deterioration of parsley seeds. Storage at —70° did not improve storability over that at —12° for any of the 3 species studied. Impregnation for 4 hours with 20 units/ml Vitamin E and 10-l m butylated hydroxytoluene (BHT) [2,6-bis(l,l-dimethylethyl)-4-methylphenol] in acetone improved storability of parsley and onion seeds. Although these natural and synthetic anti-oxidants may be used alone or with freeze-drying to prolong seed storability, improvements over that obtained by freeze-drying alone were minimal. The data indicate that freeze-drying markedly improves the long-term storability of onion and pepper seeds, particularly when seeds are exposed to warm (40°) or moderate (21°) temperatures during part or all of the storage period. Potential applications of the freeze-drying technique are discussed.
Selection and Genetics of Nectary Development in Cytoplasmic Male Sterile Brassica campestris
Authors: Leung H. , Niu Xin-ke , Erickson E.H. , Williams P.H.
Published: August 2022

Nectary development in cytoplasmic male sterile (cms) Brassica campestris L. was partially restored through 3 cycles of selection for nectary size and number. No major anatomical differences between nectaries of normal and cms plants were apparent under light and scanning electron microscopes (SEM). Half-sib family analysis of nectary development showed negligible additive genetic variance but a prominent maternal effect. Differential response to selection observed in 3 pedigrees suggests the possibility of capitalizing on nuclear-cytoplasmic diversity for the improvement of nectary function.
Effects of GA3 and NAA on Leaf Lamina Unfolding and Flowering of Cyclamen persicum
Authors: Lyons Robert E. , Widmer Richard E.
Published: August 2022

Treatments with gibberellic acid (GA3), naphthaleneacetic acid (NAA), or their combination to Cyclamen persicum Mill. ‘Swan Lake’ plants resulted in separate, antagonistic, or cooperative effects on leaf lamina unfolding, days to flowering, number of leaves at first flower, and length of the first flower's peduncle. Generally, GA3 accelerated plant growth nonspeciflcally, resulting in plants which flowered earlier than untreated plants, but with a similar number of leaves at first bud flowering. The combination of GA3 plus NAA specifically accelerated flowering, but this effect diminished as the treatment frequency or quantity of the NAA application increased.
Influence of Seed Quality on Ethylene Production of Germinating Snap Beans
Authors: Samimy Cyrus , Taylor A.G.
Published: August 2022

Deterioration of snap bean (Phaseolus vulgaris L.) seed quality during accelerated aging at 42°C and 100% relative humidity was accompanied by a decline in germination, radicle emergence, hypocotyl length, and ethylene production. Field emergence of 5 seed lots had a highly significant correlation with ethylene production rates when measured after 22 to 23.5 hours of imbibition at 25°. Seed lots that produced low levels of ethylene emerged poorly in the field. Results indicate that determination of ethylene production of imbibed seeds might be a useful method for detecting changes in seed vigor.
Utilization of Recycled Irrigation Water on Marigolds Fertilized with Osmocote and Constant Liquid Fertilization
Authors: Koch Gary M. , Holcomb E. Jay
Published: August 2022

Nitrate and K ions did not accumulate significantly in the irrigation reservoir when the leachate from Osmocote 14N-6.1P-11.6K or constant liquid fertilization (CLF) was utilized. No accumulation of salts occurred whether ‘Scarlet Sophia’ marigolds (Tagetes patula L.) were irrigated by capillary mat or trickle tube. With one exception, plants fertilized with Osmocote 14N-6.1P-11.6K at the recommended rate (lx) or twice (2x) the recommended rate produced plants equal to or better than CLF at 100 ppm N. Except for recycled CLF, macronutrient content of plant tissues was within acceptable ranges. Fertilizer treatments did not affect the number of days to flower. The combination of Osmocote fertilization and capillary mat irrigation was more effective in producing high-quality plants than Osmocote fertilization and trickle-tube irrigation. Tap-water utilization was reduced substantially by using recycled water.
Ground Color Measurements of Peach
Authors: Delwiche Michael J. , Baumgardner Reginald A.
Published: August 2022

The relationship of ground color to maturity was examined for 13 cultivars of peach [Prunus persica (L.) Batsch]. Samples representing a range in maturity for each cultivar were tested for flesh firmness and surface ground color at harvest. After ripening, the same lots of peaches were measured for ground color, soluble solids, titratable acid, taste, and visual appearance. Color was measured with a colorimeter in Hunter “L”, “a”, and “b” color coordinates and compared with a series of color references. Peaches selected as being of threshold maturity at harvest, based on taste ratings and firmness, showed average ground color readings of L = 61.2, a = −5.4, and b = 26.8, with results for individual cultivars narrowly distributed in this region of color space. Differences in ground color for varying maturities occurred primarily in the “a” coordinate, which increased as maturity advanced. On average, ground color was a better at-harvest indicator of edible quality after ripening than flesh firmness. Color references used for grading in California did not match actual ground color measurements for peaches grown in South Carolina.
Effect of Nitrogen Rate and Water Stress on Growth and Water Relations of Young Sweet Corn Plants
Authors: Tesha Andrew J. , Eck Paul
Published: August 2022

Seedlings of sweet corn (Zea mays L. cv. Iochief) were grown in sand with 3 rates of N at a moderate and severe water-stress rate produced by adding polyethylene glycol (PEG 6000) to the nutrient solution. As water stress increased, dry-matter production decreased. Increasing N rate compensated in part for the loss in dry-matter production that resulted from the water stress. Leaf chlorophyll levels and stomatal density on the abaxial leaf surface increased with an increase in N, and a faster recovery of the relative water content of leaf tissue following waterstress treatment occurred. All 3 responses could have contributed to the N response in dry-matter production observed at the 2 water-stress levels. A low N rate may aid young sweet corn seedlings under severe water stress to resist drought, as indicated by a stabilization in dry-matter production in plants receiving only 8 mm N in the nutrient solution when moving from moderate to severe water stress. These plants had a higher relative water content and leaf water potential under severe water stress than plants receiving higher rates of N, which may have contributed to the ability of plants receiving a low-N rate to cope with the severe water stress.
Responses of ‘Zucchini’ Squash to Storage in Low-O2 Atmospheres at Chilling and Nonchilling Temperatures
Authors: Mencarelli Fabio , Lipton Werner J. , Peterson Sharon J.
Published: August 2022

Zucchini squash (Cucurbita pepo L.) was stored 2 weeks at 2.5°, 5°, or 10°C and with 1%, 2%, 4%, 8%, or 21% O2 and then was aerated 2 days at 10°. Low O2 levels inhibited the rates of CO2 and ethylene production, particularly at 5° and 10°. Both rates increased during aeration, but much more in samples held previously at 2.5° or 5° than in those from 10°. About 75% and 55%, respectively, of the burst in CO2 production in samples from 2.5° and 5° was due to exposure to low temperature; the remainder was attributed to the effect of exposure to low O2 levels. For ethylene production, the corresponding values were about 95% and 70%. Zucchini squash stored at 5° for 2 weeks was virtually free of chilling injury (Cl), surface mold, decay, or off-flavors; almost all of the fruit still was rated good to excellent in appearance. About ¾ of the squash was still in this category after 2 additional days at 10°. At 5°, squash did not benefit from storage in low-O2 atmospheres. Storage at 2.5° induced severe Cl, which was ameliorated by holding the squash in 4%, 2%, or 1% O2 instead of in 21% or 8% O2. However, amelioration was no longer evident after 2 days of aeration at 10°. Defects not related to Cl—especially off-flavors—developed most noticeably in squash held at 10°; the benefit from low O2 levels was slight. Storing zucchini squash at 6° ± 2° likely would be optimal if it must be held longer than a few days.
Developmental and Anatomical Changes in Leaves of Yellow Birch and Red Kidney Bean Exposed to Simulated Acid Precipitation
Authors: Paparozzi Ellen T. , Tukey H.B.
Published: August 2022

Leaves of Betula alleghaniensis Britt. (yellow birch) and Phaseolus vulgaris L cv. Red Kidney (bean) were examined microscopically during development and after exposure to simulated rain of pH 5.5, 4.3, 3.2, and 2.8. Yellow birch leaves attained maximal leaf area, midvein length, and cuticle thickness at 21 days. Trichomes were either long, unicellular, or multicellular with caplike head and stalk. Epicuticular wax was a bumpy and amorphous layer. The 2nd trifoliolate leaf of red kidney bean attained maximal leaf area, midvein length, and cuticle thickness when the 3rd trifoliolate leaf was expanding. Trichomes present were long, with a unicellular head and a multicellular base; long, unicellular, and terminally hooked; and small and multicellular. Epicuticular wax was present as small irregular flakes. After 2 days of pH 2.8 and 4 days of pH 3.2 simulated acid rain, round yellow and small tan lesions appeared on birch and bean leaves, respectively. Most injury occurred on or between small veins. Most trichome types were uninjured. Lesions formed as a result of collapsed epidermal and highly plasmolyzed palisade cells. The cuticle was still present over injured epidermal cells and epicuticular waxes were unchanged. There was no statistical difference in mean cuticle thickness due to pH of simulated rain.
In Vitro Culture and Plant Formation from Grape Cultivars with Abortive Ovules and Seeds
Authors: Spiegel-Roy P. , Sahar N. , Baron J. , Lavi U.
Published: August 2022

Normal embryos and seedling plants were obtained from abortive ovules and seeds of seedless grape cultivars ‘Perlette’, ‘Flame Seedless’ and ‘Sultanina’. Plant development was accompanied by callus formation only in ‘Perlette’. The best medium was Nitsch’s with the addition of 10-5m IAA and 10-6m GA3. Excision and culturing of ‘Flame Seedless’ ovules 49 days after anthesis gave higher germination percentages and more viable plants than excision and culturing at anthesis plus 28. Selfed ‘Perlette’ and ‘Perlette’ × ‘Flame Seedless’ ovules cultured at 52 days gave 11%, and the reciprocal cross over 16% well developed seedlings. The significance of the findings for breeding stenospermocarpic grapes is discussed.
Effects of Hedging and Selective Limb Pruning of Elliott, Desirable, and Farley Pecan Trees under Three Irrigation Regimes
Authors: Worley Ray E.
Published: August 2022

Twenty-year-old ‘Elliott’, ‘Desirable’, and ‘Farley’ trees were pruned over, an 8-year period using: 1) pruning on only low and broken limbs, 2) removal of competing wood from alternating temporary trees, 3) top and side hedging, and 4) selective limb pruning. Wood removal from temporary trees was low, except for the last two years of the study, and little difference in yield and quality from the control was obtained. Top and side hedging reduced overall yield of ‘Desirable’ and ‘Farley’ and it changed the alternate bearing phase of ‘Elliott’ so that yields were increased and decreased in alternating years. Selective limb pruning increased yield of ‘Desirable’ in one year but, overall, gave no significant yield changes from the control. Selective limb pruning increased ‘Elliott’ yield in some years and reduced it in others to give an overall reduction in yield. Selective limb pruning did not reduce yield of ‘Farley’ significantly. Selective limb pruning usually increased nut size, and pruning effects on quality were erratic. Both hedging and selective limb pruning usually increased terminal growth. Most parameters measured showed significant cultivar × year × irrigation × pruning interactions.
Effect of Relative Humidity Prior to and during Exposure on Response of Peas to Ozone and Sulfur Dioxide
Authors: Kobriger Janice M. , Tibbitts Theodore W.
Published: August 2022

Pea (Pisum sativum L. ‘Alsweet’) plants were grown in a controlled environment and exposed to ozone, sulfur dioxide, or a mixture of the 2 pollutants. Plants were preconditioned with low (36%) or high (77%) relative humidity (RH) for 6 days and then exposed to the pollutants for 2 hr in low (31%) or high (67%) RH. Injury was evaluated as both necrosis and chlorophyll concentrations. A high RH prior to exposure to air pollutants greatly increased subsequent plant injury from pollutants. The increased injury with high RH prior to exposure to pollutants was associated with increased stomatal conductance. Relative humidity during exposure to air pollutants had little effect on plant injury.
Correlative Bud Inhibition and Growth Habit of the Strawberry as Influenced by Application of Gibberellic Acid, Cytokinin, and Chilling during Short Daylength
Authors: Braun Joseph W. , Render Walter J.
Published: August 2022

In axillary meristems laid down just prior or subsequent to commencement of growth regulator applications, exogenous gibberellic acid (GA) alone promoted runner formation. Strongly-inhibited axillary buds with leaf primordia responded to GA + BA (benzyladenine) with runner formation in the June-bearer ‘Fortune’. Few of the inhibited buds of the everbearer ‘Geneva’ responded to GA or GA + BA. Following application of BA alone, inhibited buds of June-bearing cultivars formed lateral crowns (‘Fortune’) or runners (‘Earlidawn’). Runner formation following chilling of June-bearing ‘Fortune’ plants exposed to short days (SDs) occurred from meristems initiated after satisfaction of the cold requirement. Comparable buds on plants receiving no chilling during SDs remained inhibited, as did axillary meristems present during SDs. In contrast, runners formed by chilled, everbearing ‘Geneva’ plants originated from axillary meristems initiated prior to chilling but not from subsequent meristems. Chilling ‘Geneva’ plants during exposure to SDs removed the inhibition from existing axillary meristems and promoted runner formation. Runnering did not occur in activley growing ‘Geneva’ plants maintained under long days (LDs).
Delayed Light Emission for Early Detection of Chilling in Cucumber and Bell Pepper Fruit
Authors: Abbott Judith A. , Massie David R.
Published: August 2022

Refreshed (repetitively stimulated) delayed light emission (DLE) of cucumber and bell pepper fruit was strongly related to temperature and duration of exposure to chilling temperatures. At the 10th measurement cycle (about 150 ms), DLE of cucumbers exposed to 2.5°C for ≥12 hr or 5.0° for ≥24 hr was greater than that of cucumbers held at higher temperatures (7.5° to 12.5°) for 12 to 264 hr. Similarly, DLE of bell peppers exposed to 2.5° for ≥48 hr was greater than that of peppers held at higher temperatures. For both cucumbers and peppers, however, there was a greater difference in DLE between fruit held at 2.5° or 5.0° and those held at higher temperatures around measurement cycles 400 to 500 (at 6.0–7.5 sec) and this difference increased with increasing duration of exposure. Amount of refreshed DLE around measurement cycles 400 to 500 or the rate of change in DLE around cycles 180 to 300 is proposed as an indicator of chilling exposure for cucumber and bell pepper fruit.
Zoysiagrass Establishment in Kentucky Bluegrass Using Growth Retardants
Authors: Hubbell G. P. , Dunn J. H.
Published: August 2022

Zoysia japonica ‘Meyer’, is frequently used as lawn and golf turf in the upper South because of its excellent summer qualities and superior winter hardiness compared to other warm-season grasses. Planting is mostly by vegetative methods to obtain uniform turf. Planting in existing turf slows spread of zoysiagrass because of plant competition. The objective of this study was to selectively inhibit growth, with growth retardants, of competing Kentucky bluegrass, Poa pratensis L. ‘Baron’, turf into which ‘Meyer’ zoysia had been planted. Mefluidide, at a rate of 0.028 kg/ha, enhanced the spread of zoysiagrass in bluegrass by 20% compared with untreated plots during the 1st year, without serious injury to the bluegrass turf. Fertilizing zoysiagrass plugs with UF (38N-0-0) also increased zoysiagrass cover by 10-20% during the 1st 2 years compared with control plots or those fertilized with urea after zoysiagrass had been transplanted. Irrigation location had no effect on zoysiagrass spread, possibly because of the relatively mild and wet summers of 1981-82 when minimal irrigation was needed to maintain good quality turf. Results of this study show that growth retardants in combination with certain N fertilization techniques can enhance the spread of transplanted zoysiagrass without serious injury to the existing bluegrass sward. This is attributed to selectively decreased growth of bluegrass and, therefore, partial elimination of bluegrass competition from the bluegrass or, to possible stimulation of zoysiagrass by mefluidide.
Gibberellic Acid Stimulated Degradation of Endosperm in Pepper
Authors: Watkins J. T. , Cantliffe D. J. , Huber D. J. , Nell T. A.
Published: August 2022

Capsicum annuum (‘Early Calwonder’) seeds germinated (radicle protrusion) in 8 days at 15°C and 4 days at 25°. The seeds have an endosperm 7 to 9 cells in thickness which lies directly in front of the radicle. The external appearance of the endosperm did not change until one day before radicle emergence, when the endosperm in front of the radicle enlarged and protruded outward. This change was accompanied by breakdown and loss of endosperm cellular integrity and reduction in endosperm thickness directly in front of the radicle, but not in other regions of the endosperm. Gibberellic acid (GA4+7) decreased the time for appearance of the protruding endosperm and radicle protrusion through the seed coat by one day. Cell wall degrading activity was detectable during the early stages of germination and became extremely high after radicle emergence. Seeds treated with 100 ppm GA4+7 showed slightly increased enzyme activity during early germination and differences became more pronounced as germination progressed. Cellulase activity was not found in the extracts, but seed enzyme preparations degraded a galactomannan substrate. The enzyme exhibited only endohydrolytic activity, indicating an enzyme which may participate in the weakening of cell wall. It was postulated that an endomannanase is needed for endosperm breakdown in front of the radicle in order for rapid germination of pepper to occur. A reduction in germination temperature from 25° to 15° reduced the rate of radicle movement through the seed coat by one half.
Fruit Temperature Effects on Mechanical Damage of Sweet Cherries
Authors: Patten K. D. , Patterson M. E.
Published: August 2022

The resistance of sweet cherries to compression damage as measured by the fruit firmness variables, [force to bioyield (FBY), slope of a compression curve, and maximum and residual forces of a compression-relaxation curve] decreased linearly with increasing fruit temperture. The incidence of impact-induced surface pitting decreased linearly as fruit temperature increased. The rate of decrease in impact damage per degree increase in fruit temperature was a function of the cultivar, contact surface, and drop height.