bluuebunny/crossref_metadata_2025 huggingface dataset:
Stockplant Etiolation and Blanching of Woody Plants Prior to Cutting Propagation
Authors: Maynard Brian K. , Bassuk Nina L.
Published: August 2022

A modification of the traditional technique of etiolation and blanching, using Velcro adhesive fabric strips as the blanching material, was used with success in improving cutting propagation of a wide range of difficult-to-root woody species. Stockplants were etiolated under black cloth at budbreak, followed by banding for a period of 4 weeks, to produce a cutting with an etiolated base. Rooting of softwood cuttings from 18 of 21 species tested was improved significantly by these stockplant pretreatments. The use of Velcro as the banding material facilitated blanching, permitted the application of rooting hormone as a part of the blanching procedure, wounded underlying stem tissues, and resulted occasionally in the formation of adventitious roots on intact shoots.
Growth of Bedding Plants in Response to Root-zone Heating and Night Temperature Regimes
Authors: Shedlosky M.E. , White J.W.
Published: August 2022

Nine bedding plant vegetable and flower cultivars were grown in each of 10 night air and root media temperature regimes. Generally, fresh and dry weights were greater at 16°C than at 7° night air temperature when root-zone (RZ) heating was not used. Soil warming increased fresh and dry weights of all cultivars grown at 16° night air temperatures. When air temperatures were below 16°, soil warming maintained fresh and dry weights equivalent to or better than plants grown at 16° without soil warming. Two split-night (SN) air temperature regimes were as effective as a constant 16° night temperature, ranking first and 3rd in fresh and dry weight per unit of energy consumption. All soil warming treatments had higher energy productivity than the 16° air temperature treatment with no RZ heating.
Variation in Glucosinolates in Oriental Brassica Vegetables
Authors: Hill Curtis B. , Williams Paul H. , Carlson Diana G. , Tookey H. L.
Published: August 2022

The glucosinolates (GSs) were estimated in the normally eaten portions of 72 cultivars of Oriental brassica vegetables including mustard greens (Brassica juncea L.), Chinese kale (B. oleracea L. Alboglabra Group Bail.), Chinese cabbage (B. rapa L. Pekinensis Group Bail.), pak choy (B. rapa Chinensis Group Bail.), tendergreen (B. rapa Perviridis Group Bail.), turnip (B. rapa L. Rapifera Group Bail., B. narinosa Bail., and B. nipposinica Bail.). Variation in GS profiles was complex. There was variation in percentages of major GSs and total GS among B. juncea, B. oleracea, and the combination B. rapa plus narinosa and nipposinica and among four subspecific groups of rapa plus the two species closely related to rapa: narinosa and nipposinica. B. juncea had distinctively high proportions of allyl-GS, ranging from 81% to 94%, whereas B. oleracea had distinctively high proportions of 4-methylsulfinylbutyl-GS, ranging from 9% to 68%. Differences in GS profiles among the rapa groups, narinosa and nipposinica, were less distinctive. Cultivars of pak choy from China differed in percentages of three minor GSs from cultivars from Japan and elsewhere. There was also variation among cultivars of Chinese kale and between turnip foliage and roots.
High Temperature Stress Affects Pollen Viability in Bottle Gourd
Authors: Iapichino G. F. , Loy J. B.
Published: August 2022

The effect of high temperature on pollen viability and fruit set was studied in a Sicilian landrace of Lagenaria siceraria (Mol.) Standi. In vitro germination of pollen from flowers of plants exposed for 7 hr to either 28° or 33°C was not significantly different from that of pollen from untreated, greenhouse-grown plants. A single 7-hr exposure of plants to 38° completely inhibited germination of pollen from flowers reaching anthesis either immediately following the treatment or 24 hr later, and substantially reduced germination of pollen from flowers reaching anthesis at 48 or 72 hr after treatment. Pollen from flowers subjected to 38° for 7 hr failed to germinate and grow into styles of untreated female flowers and failed to induce fruit set. Exposure of plants to 38° for 4 hr reduced in vitro pollen germination by 55% to 75%, but a 2-hr treatment at 38° had no detectable effect on pollen viability.
Isozyme Analysis of Mature Avocado Embryos to Determine Outcrossing Rate in a ‘Hass’ Plot
Authors: Goldring Anat , Gazit Shmuel , Degani Chemda
Published: August 2022

Outcrossing rate in a solid block of ‘Hass’ avocado (Persea americana Mill) was determined using the isozyme systems of malate dehydrogenase (MDH) (EC 1.1.1.37), leucine aminopeptidase (LAP) (EC 3.4.11.1), and triosephosphate isomerase (TPI) (EC 5.3.1.1), for which evidence concerning the genetic control of the latter is presented. Almost all ‘Hass’ mature fruits were found to have resulted from cross-pollination. Among the potential pollen donors—‘Hass’, ‘Ettinger’, and ‘Reed’—‘Ettinger’ excelled, producing almost all of the hybrid fruits.
Mineral Nutrient Balance and Impairment of the Nitrate-reducing System in Alternate-bearing ‘Wilking’ Mandarin Trees
Authors: Golomb Avinoam , Goldschmidt Eliezer E.
Published: August 2022

Two alternate-bearing ‘Wilking’ mandarin (Citrus reticulata Blanco) trees, an “on” and an “off” tree, were uprooted and dissected into 11 organ types during the time of fruit maturation (February). Total or water-soluble N, P, K, Ca, and Mg (nitrate for soluble N) content were determined for each organ. Calcium was separated further into water-soluble, exchangeable, insoluble, and oxalate fractions. Leaves and twigs of on trees had reduced N, P, and particularly K levels. Organs of on trees, including minor roots and fruit, contained increased nitrate levels. Leaves, twigs, and minor roots of on trees accumulated Ca, mainly as Ca oxalate. The amounts of N, P, and K present in the fruit represented 32.2%, 43.7%, and 57.8%, respectively, of the total for an on tree. Fruit were very low in Ca, containing only 6% of the tree total. A 15-month follow-up of seasonal fluctuations in minerals of on and off ‘Wilking’ trees showed that the mineral composition of leaves and twigs was rapidly changed by the presence or absence of fruit. Defruiting in July prevented mineral depletion and permitted reasonable flower-bud differentiation on subsequent year. Leaf disks of on trees had low initial nitrate–reductase activity but responded weakly to nitrate induction. Leaves of overloaded on trees appear to suffer from a metabolic disorder involving relatively high nitrate levels, Ca accumulation, and loss of the nitrate–reductase induction response.
Gelling Agent and Growth Regulator Effects on Shoot Vitrification of ‘Gala’ Apple in Vitro
Authors: Pasqualetto P.-L. , Zimmerman R.H. , Fordham I.
Published: August 2022

In the article “Gelling Agent and Growth Regulator Effects on Shoot Vitrification of ‘Gala’ Apple in Vitro”, by P.-L. Pasqualetto, R.H. Zimmerman, and I. Fordham (J. Amer. Soc. Hort. Sci. 111:976–980, November 1986), two corrections should be noted: 1) On p. 979, the 11th line in the discussion, Fig. 1 should read Fig. 2. 2) The correct version of Table 1 is printed below.
Foliar-applied Boron Increases Fruit Set in ‘Barcelona’ Hazelnut
Authors: Shrestha G.K. , Thompson M.M. , Righetti T.L.
Published: August 2022

Boron (B) sprays applied to ‘Barcelona’ hazelnut orchards induced fruit set increases over controls, averaging 23% in 1984 and 17% in 1985. Leaves from B-sprayed trees had higher B contents than controls throughout the season. Amounts of B in young fruits increased two-fold with B sprays, but, unlike leaf values, differences between treated and control fruits disappeared by mid-summer. In the orchards studied, the B content of developing fruits from unsprayed trees was similar even though leaf B content varied widely. Because fruit set increases were obtained in both seasons with B sprays on trees whose leaf values currently are considered excessive, as well as those considered optimal or deficient, guidelines for B recommendation need revision. Boron content in May fruit from unsprayed trees might be universally low for optimum nut development, indicating that annual B sprays may be required. Foliar sprays in April damaged young leaves and shoot tips; thus, delaying sprays until the 2nd week of May is recommended.
Floral and Foliar Quality of Potted Easter Lilies after STS or Phenidone Application, Refrigerated Storage, and Simulated Shipment
Authors: Prince Timothy A. , Cunningham Maria S , Peary James S.
Published: August 2022

The poststorage and post-shipping quality of Lilium longiflorum Thunb. ‘Nellie White’ plants sprayed with silver thiosulfate (STS) complex or phenidone was observed in a simulated interior environment. Bud abortion and foliar chlorosis increased while floral longevity declined with increasing storage period from 0 to 4 weeks in the dark at 2°C. One to 3 days of simulated, boxed shipment at 23° subsequent to 3 weeks storage at 2° further increased foliar chlorosis but did not influence bud abortion or floral longevity. Whole plant STS sprays (0.5 to 2.0 mM Ag) prior to harvest reduced storage-induced bud abortion and increased floral longevity, but did not reduce foliar chlorosis. Ethephon application to plants that had been stored for 3 weeks at 2° induced bud abortion and abnormal floral development. STS application (1.0 mM Ag) prior to storage reduced ethephon-induced disorders. Preharvest whole plant sprays of phenidone decreased bud abortion on stored and nonstored plants but did not influence floral longevity. Uptake of phenidone and STS through cut petioles enhanced ethylene production during opening of excised lily buds. Ethylene production increased while respiration declined during senescence of excised buds. STS did not reduce but did delay the peak of ethylene production during senescence of lily flowers. Chemical names used: 1-phenyl-3-pyrazolidone (phenidone); (2-chlorethyl)phosphonic acid (ethephon).
Relationship of Plant Development to Nodulation in Determinate and Indeterminate Beans
Authors: Morrison Steven L. , Baird Lisa M.
Published: August 2022

The relationship of plant growth habit to establishment of a successful symbiosis between Phaseolus vulgaris L. and Rhizobium phaseoli was examined. A determinate and an indeterminate cultivar of bean were inoculated with a pure culture of R. phaseoli 127K44, and plant development was measured using the plastochron index. Time required to nodulate as determined by nodule count did not vary between plant types. The timing, duration, and overall success of the symbiosis as measured by increased acetylene reduction, dry weight, and transport of ureides and amino acids were related to the period of exponential leaf expansion in both the determinate and indeterminate cultivar.
Nucleotide Metabolism in ‘Washington’ Navel Orange Fruit: II. Pathway Capacities During Development
Authors: Tomlinson Patricia Tolson , Lovatt Carol J.
Published: August 2022

Changes in the capacity of ‘Washington’ navel orange [Citrus sinensis (L.) Osbeck] fruit to synthesize (de novo or by salvage) pyrimidine nucleotides, but not purine nucleotides, appears to be related to the stage of fruit development. De novo pyrimidine synthesis in whole-fruit tissue increased 6-fold during Stage I of development (cell division phase), from 10 nmol [14C]bicarbonate incorporated into uridine nucleotides during 5 hr per g dry weight whole-fruit tissue from ovaries harvested at flower petal drop to 57 nmol for 2-month-old fruit. Capacity of peel tissue to synthesize pyrimidine nucleotides de novo decreased following completion of Stage I, from 43 nmol [14C]bicarbonate incorporated into uridine nucleotides during 5 hr per g dry weight of peel tissue from 2-month-old fruit to 11 nmol for 5-month-old (Stage II) fruit. This decrease was not offset by increased salvage of uridine. Capacity of whole-fruit tissue to synthesize purines de novo increased 3-fold during Stage I. Synthetic capacity of peel tissue from Stage I fruit was half that observed for whole-fruit tissue and did not decrease significantly during Stages II (cell enlargement phase) and III (maturation phase). These observations suggest purine synthetic capacity may not be related to stage of development. Changes in protein or glucose contents, or respiratory activity of peel tissue, could not account for the observed reduction in pyrimidine synthetic capacity. Thus, the reduction observed in synthetic activity was specific for pyrimidine nucleotides. The capacity of fast-growing, 1-month-old fruit (high potential to set) to synthesize or catabolize either pyrimidine or purine nucleotides did not differ from that of slow-growing fruit (low potential to set), suggesting that nucleotide synthesis is not limiting to growth.
Diurnal Changes in Fixation, Transport, and Allocation of Carbon in the Sweet Potato Using 11C Tracer
Authors: Kays S.J. , Goeschl J.D. , Magnuson C.E. , Fares Y.
Published: August 2022

Fully expanded apical leaves of Ipomoea batatas (L.) Lam. cv. Jewel were exposed three times during the day to a square wave of 11CO2 for sufficient duration to approach steady-state isotope equilibrium in the plant. This procedure allowed monitoring of changes in the storage of photosynthate within the treated leaf and the transport and allocation of this carbon throughout the plant during the day. Early in the day, export of photosynthate from the treated leaf predominated over storage (57:43%). By mid-day, export had declined to a point that storage was favored (44:56%). Toward late afternoon, export again increased (54:46%). These changes in the allocation of carbon within the leaf were reflected by alterations in the size and turn-over time of the export pool of photosynthates within the labeled leaf. The latter increased progressively from early morning (19 min) until late afternoon (27 min). The speed of photosynthate transport within the plant varied with position along the main stem. Speeds up to 6 cm·min−1 were found between short segments of the stem (i.e. ≈10 cm). As the distance between sites increased, slow and fast rates were averaged, giving mean speeds of 2.0 to 2.5 cm·min−1. The speed of transport also changed during the day and depended, in part, on the position of the transport path along the main stem. Virtually no carbon was translocated acropetally from labeled fully expanded apical leaves during the day. Although some photosynthate was translocated into lateral branches developing at the base of the plant, the predominate sink was the root system.
Effect of Surfactants on Foliar Penetration of NAA and NAA-induced Ethylene Evolution in Cowpea
Authors: Lownds N.K. , Leon J.M. , Bukovac M.J.
Published: August 2022

Effects of the surfactants Pace, Regulaid and Tween 20 were determined on foliar penetration of NAA and on NAA-induced ethylene production by cowpea [Vigna unguiculata (L.) Walp. subsp. unguiculata cv. Dixielee]. All three surfactants decreased surface tension of NAA solutions, causing a marked increase in wetting and in droplet : leaf interface area. The greatest increase in NAA penetration was obtained with Regulaid followed by Pace and Tween 20. The surfactant effect was most pronounced during the droplet drying phase, but penetration continued to take place from the deposit after drying. The mode of action of surfactants in enhancing NAA penetration is complex. Regulaid-enhanced penetration closely paralleled the increase in interface area, but similar relationships were not found for Pace or Tween 20, particularly at concentrations above the critical micelle concentration. Surfactant-enhanced NAA penetration caused an increase in NAA-induced ethylene production. There was a strong correlation (r = 0.82) between NAA penetration and ethylene production for doses of 0.5 to 2.5 μg/disk. Above 2.5 μg/disk, ethylene production increased at a decreasing rate. The potential for using auxin-induced ethylene production as an index for quantifying auxin penetration is discussed. Chemical names used: l-naphthaleneacetic acid (NAA), polyoxyethylene polypropoxypropanol dihydroxypropane (Regulaid), polyoxyethylene (20) sorbitan monolaurate (Tween 20), surfactant blend in paraffin base petroleum oil (Pace).
Storage of Germinated Tomato and Pepper Seeds
Authors: Ghate Suhas R. , Chinnan Manjeet S.
Published: August 2022

Germinated seeds of tomato (Lycopersicon esculentum Mill.) and pepper (Capsicum annum L.) were placed in bags of different polyethylene films and stored in various environmental conditions for up to 63 days. Performance of the stored seeds was evaluated both in the greenhouse and field. Tomato seed placed in 100 μm polyethylene film bags packaged either in vacuum or nitrogen and stored at 7°C produced excellent plant stand up to 63 days. Radicle elongation in nitrogen environment was minimal. The same environments, in addition to hand-sealing in Ziploc bags and storing at 7°, kept the germinated pepper seed in a viable condition. Radicle elongation was the least in vacuum and nitrogen environments.
Soluble Carbohydrate Concentration of Fraser Fir Foliage and Its Relationship to Postharvest Needle Retention
Authors: Mitcham-Butler Elizabeth J. , Hinesley L. Eric , Pharr David M.
Published: August 2022

Seasonal changes in soluble carbohydrates of Fraser fir [Abies fraseri (Pursh) Poir.] needles were monitored in Fall 1984, Spring 1985, and Fall 1985 through Spring 1986. Raffinose concentration increased in the fall and decreased in the spring. There was a 23-fold increase in raffinose concentration from Aug. 1985 to Jan. 1986. Sucrose concentration varied from fall to spring with the lowest concentration occurring in February. Postharvest needle abscission from harvested branches held 6 weeks without water was inversely correlated with raffinose concentration at the time of harvest. Diurnal fluctuations in soluble carbohydrates were monitored on 12 July and 26 Oct. 1985. Raffinose concentration fluctuated slightly on both dates with a decrease during the dark period. On 12 July, sucrose increased during the day and decreased at night, whereas hexoses decreased in the day and increased at night. No significant diurnal changes in sucrose or hexose were evident on 26 Oct. Controlled-environment studies at 24° (day)/18°C (night), 18°/12°, and 12°/6° showed that most of the raffinose accumulation was due to low temperature; the remainder to short days. Postharvest needle loss was lowest in plants with high needle raffinose concentrations resulting from the 12°/6° temperature. Storage without water resulted in significant postharvest needle loss for shoots from plants preconditioned with 24°/18° and 18°/12°, but not for those exposed to 12°/76°. Compared to long days, plants preconditioned with short days lost fewer needles following harvest.
Characterization of the Influence of Moderate Temperatures on Rest Completion in Peach
Authors: Erez A. , Couvillon G.A.
Published: August 2022

The chilling enhancement effect of moderate temperature (15°C) on rest completion in ‘Redhaven’ peach was verified and observed only when the moderate temperature occurred followed exposure to chilling temperatures. Chilling efficiency rose with temperatures between 0° and 8° if no moderate temperatures were interspersed. Although 0° was an inefficient chilling temperature, cycling between 0° and 15° resulted in as efficient bud rest release as 6°. The most efficient moderate temperature level was 13°, and the effect of moderate temperatures on rest completion seemed to increase when received during the latter stages of rest. Leaf and flower buds reacted similarly, although the reaction of the former was more prominent. A two-step scheme is proposed for the effect of temperature on bud rest. The first step involves the conversion from the unchilled to the chilled state by chilling temperatures. This stage can be reversed by high temperatures. The second stage is not reversible and involves the conversion by moderate temperatures of the unstable intermediate formed by step 1 to a stable material, which, when accumulated to a certain level, will result in rest completion.
Mathematical Characterization of Seed Mortality in Storage
Authors: Moore Frank D. , Jolliffe Peter A.
Published: August 2022

Currently, median seed survival period (P50) is a seed storage index estimated from a probit model Y = a + bX, where Y = probit transformed viability proportions and X = in effect seed lifetimes; therefore, P50 = (5 − a)/−b, where 5 is the probit of 50% germination. Since use of the probit model is based on the assumption of normally distributed seed “lifetimes,” our purpose was to eliminate this restriction by means of a new substitute model. Pearl millet [Pennisetum americanum (L.) Schum.] seeds were stored under constant conditions at 21°C and seed moisture contents of 18% or 14%. The seeds stored at 14% moisture content exhibited a statistically normal distribution of lifetimes, while those stored at 18% moisture content underwent rapid viability loss concomitant with a statistically non-normal, positively skewed distribution. Several empirical models other than the probit were used to describe deterioration of both populations; however, we propose a nonlinear four-parameter Weibull distribution for seed lifetimes. A useful property of the function is flexibility in modeling data, which may be normally distributed or positively skewed. Parameter initialization is facilitated by plotting the data on paper with transformed scales. Weibull parameters were used to generate seed mortality rate curves, P50, and a new storage index, M/MV, where M is mode and MV is modal value. Inaccuracy in estimating initial seed mortality (Y intercept) is a negative feature we found associated with most of the empirical models investigated, including the Weibull. Evidence is presented to show the extreme dynamics of the system in the vicinity of the Y intercept, particularly in the case of seeds with 18% moisture content, which had deteriorated after 4 months of storage at 21°C and 90% RH.
Variation Among Highbush Blueberry Cultivars in Susceptibility to Spring Frost
Authors: Hancock J.F. , Nelson J.W. , Bittenbender H.C. , Callow P.W. , Cameron J.S. , Krebs S.L. , Pritts M.P. , Schumann C.M.
Published: August 2022

Flower bud injury was assessed in 18 cultivars of highbush blueberry (Vaccinium corymbosum L.) after two spring frosts. Bud position on shoots was significantly correlated (P < 0.05) with percent brown ovaries. Significant differences in proportion of brown ovaries were noted among cultivars, but most of the variation was associated with stage of bud development. The least-developed buds were the most hardy. Bloom date was significantly correlated with harvest date across cultivars, although ‘Spartan’ flowered much later than other early ripening cultivars.
Generation Means Analysis of Plant Characters in Crosses Between Two Determinate Cucumber Lines and Cucumis sativus var. hardwickii
Authors: Delaney D.E. , Lower R.L.
Published: August 2022

In an effort to develop a high-yielding, determinate plant type with multiple lateral branches, crosses were made between two determinate Cucumis sativus var. sativus lines (‘Spacemaster’ and NCSU M27) and a C. sativus var. hardwickii (R.) Alef. line, LJ 90430. Individual plant data from six generations (P1, P2, F1, F2, BC1P1, BC1P2) were subjected to an analysis of generation means to determine the importance of gene effects for number of nodes, number of primary lateral branches, average internode length, main stem length, and number of fruit per plant at maturity. A simple additive-dominance model adequately explained variation for number of primary laterals in both crosses, and average internode length in the ‘Spacemaster’ × LJ 90340 cross. For all other traits, it was necessary to add one or more digenic epistatic effects to the model. Heterosis of the F1 over the mid-parent was highly significant for all traits in both crosses. Heterosis above the high-parent was observed for average internode length and main stem length. Dominance for number of primary laterals was in the direction of the parent with higher lateral number.
Growth, Yield, and Nutrient Uptake of Transplanted Fresh-market Tomatoes as Affected by Plastic Mulch and Initial Nitrogen Rate
Authors: Wien H.C. , Minotti P.L.
Published: August 2022

Two field experiments were conducted with two cultivars of transplanted tomatoes (Lycopersicon esculentum Mill.) with and without plastic mulch, varying the initial rate of N fertilizer, but maintaining the total N rate at 168 kg·ha–1 by sidedressing. In 1982, 0 and 112 kg·ha–1 initial N rates, and bare ground, black mulch, and clear plastic mulch were compared on a gravelly loam soil. In 1983, initial N rates used were 34, 67, 101, or 134 kg·ha–1, with bare ground and clear mulch on a silt loam soil. Effects of the plastic mulch dominated both experiments. Mulching increased rate of basal branch appearance and led to early flowering on branches. Total plant growth, as measured by vine weights at final harvest, was increased by mulch in both years. Mulching increased early yield only in 1983, but increased total yields by 13% and 79% in 1982 and 1983, respectively. Initial N fertilizer rates did not influence total yields significantly in either experiment, although high initial N rate, combined with clear plastic mulch, led to a significant decrease in percent marketable fruit in 1982. In 1983, mulching increased shoot concentrations of N, NO3-N, P, K, Ca, Mg, Cu, and Β (P = < 0.01) in spite of the fact that mulched plants were larger than unmulched plants at sampling time, 24 days after transplanting. Nitrogen fertilizer increased only the N and P concentrations and to a lesser extent than did the mulch.
Absorption, Translocation, and Metabolism of Et-IAA in Relation to Fruit Set and Growth of Day-neutral Strawberry
Authors: Darnell Rebecca L. , Martin George C.
Published: August 2022

Single applications of auxins that normally induce parthenocarpic fruit set in June-bearing and everbearing strawberries (Fragaria × ananassa Duch) (e.g., NAA, 2-NOA, and IAA) do not induce set in the day-neutral cultivar Fern. The only auxin found to date that induces set in day-neutrals with a single application is Et-IAA. The translocation and metabolism of [14C]Et-IAA applied to receptacles was followed in order to gain insight into mechanisms involved in set. Ninety to ninety five percent of the recovered 14C activity remained in the receptacles throughout set and initial development (0 to 6 days) after Et-IAA application. Growth of treated receptacles followed the rapid metabolism of [14C]Et-IAA. Twelve hours after application, 16% of the radioactivity remained in the Et-IAA fraction. This level decreased to <5% by 144 hr after application. The majority of the radioactivity (55–60%) was contained in highly polar compounds. Little activity was recovered in the free IAA fraction. Chemical names used: 1-naphthaleneacetic acid (NAA); 2-naphthoxyacetic acid (2-NOA); 1H-indole-3-acetic acid (IAA); IAA ethyl ester (Et-IAA).
Morphological Characteristics of Tannin Cells in Japanese Persimmon Fruit
Authors: Yonemori Keizo , Matsushima Jiro
Published: August 2022

Tannin cells from fruit of Japanese persimmon (Diospyros kaki L.) cvs. Fuyu [pollination-constant and nonastringent (PCNA)], Chokenji [pollination-variant and nonastringent (PVNA)], Hiratanenashi [pollination-variant and astringent (PVA)], and Kuramitsu [pollination-constant and astringent (PCA)], were observed by florescence microscope (FM) and scanning electron microscope (SEM) on 4 July, when all cultivars were very astringent, and on 5 Sept., when ‘Fuyu’ and ‘Chokenji’ fruit had completely lost their astringency. ‘Hiratanenashi’ and ‘Kuramitsu’ fruit, however, were still quite astringent on the latter date. FM observations on 4 July indicated that tannin cells of all fruit possessed some discontinuous portions in the cell walls. SEM observations of fractured surfaces of fruit flesh verified the existence of pores in the tannin cell walls. Moreover, coagulated internal contents of tannin cells (caused by the fixatives) had protruded through the pores. On 5 Sept., however, the pores in tannin cell walls of ‘Fuyu’ and ‘Chokenji’ were not present, and the surface of coagulated internal contents had become smooth. ‘Hiratanenashi’ and ‘Kuramitsu’ fruit on 5 Sept. showed little change in the structure from that observed on 4 July. Pore occlusion occurred in ‘Hiratanenashi’ fruit that were treated on the tree with ethanol fumes to remove astringency, which indicates that loss of astringency induces structural changes in tannin cell walls.
Acclimatization of ex Vitro Strawberry Plantlets in CO2-enriched Environments and Supplementary Lighting
Authors: Desjardins Y. , Gosselin Α. , Yelle S.
Published: August 2022

The effect of CO2 enrichment (CE) and supplemental lighting (SL) on the growth of ex vitro strawberry (Fragaria × ananassa Duch.) plantlets was studied during acclimatization. Three different concentrations of CO2 [330, 900, and 1500 ppm (v/v)] and two SL treatments (0 and 150 μmol·s–1·m–2) were applied. There was no significant interaction between light and CO2 for root and leaf dry weight and leaf area. CE had no effect on these parameters in the early period following transfer but resulted in significant increases at days 20 and 30. CE had no significant influence on leaf and root relative growth rate (RGR) over the three sampling periods, but had a significant effect on net assimilation rate at a 20- to 30-day period. At the end of the experiment, 900- and 1500-ppm treatments had a significantly higher root and shoot dry weight than the 300-ppm treatment. SL resulted in increased dry weight at 10 days and even greater increases at days 20 and 30. CE was more effective than SL in stimulating root growth, whereas SL increased shoot growth significantly. There was a synergistic effect between CE and SL. The period needed to obtain plants of a similar size to an acclimatized plantlet was shortened by 15 days with 900 ppm CO2 and SL. At the end of the experiment, SL and CE at 1500 and 900 ppm increased leaf and root dry weight by a factor of 3 and 5 for ‘Honeyoye’ and ‘Kent’, respectively. These increases were less important for SL or CE used alone.
Genetic Analysis of 2-Tridecanone Concentration, Leaf Trichome Characteristics, and Tobacco Hornworm Resistance in Tomato
Authors: Fery Richard L. , Kennedy George G.
Published: August 2022

Experiments were developed to study the mechanism and genetic nature of the tobacco hornworm [Manduca sexta (L.)] resistance factor in the wild tomato (Lycopersicon hirsutum f. glabratum C. H. Mull. L hirsutum f. glabratum PI 134417 was crossed with the susceptible tomato (L. esculentum Mill. cv. Walter) (cross A) and the susceptible L. hirsutum Humb. & Bonpl. PI 127826 (cross B). Excised leaflets from individual plants of the parental, F1, F2, and backcross populations of each cross were bioassayed for M. sexta resistance, assayed for 2-tridecanone concentration using gas chromatography, and evaluated for density of the type VI trichome. Additionally, plants in the cross A populations were scored for morphological traits of the type VI trichome. Results of genetic analyses suggest that M. sexta resistance is conditioned by at least three recessive genes; high 2-tridecanone concentration was found to be inherited in a similar manner. No associations were found between type VI trichome morphology and the variables 2-tridecanone, type VI trichrome density, and tobacco hornworm resistance. Polynomial regression analysis showed that there is a semilogarithmic relationship between 2-tridecanone concentration and resistance ratings. Multiple linear regression analysis indicated that 2-tridecanone is principally responsible for the high degree of M. sexta resistance exhibited by PI 134417. Type VI trichome density, however, did account for a significant, although small, amount of the total variation in resistance in several of the segregating populations. We conclude that the genetic system that conditions high 2-tridecanone concentration (i.e., at least three recessive genes) is the same genetic system responsible for the high level of M. sexta resistance exhibited by PI 134417.
Root Branching in Zamia floridana: Effect of Growth Regulators and Anatomical Features
Authors: Dehgan Bijan , Johnson Charles R.
Published: August 2022

To determine the potential for root branching, the primary root of Zamia floridana L. seedlings was excised near the root–shoot junction and the cut ends were dipped in 2000 ppm IBA, 2000 ppm BA, or combination of the two, each for 5 sec. Whereas excised control plants produced only one root, those treated with IBA, BA, and IBA–BA averaged 2.1, 3.2, and 2.3 roots, respectively. In all instances, the number of secondary roots increased significantly compared with intact seedlings. Since seedling roots are diarch throughout, new primordia must be initiated in the interfascicular parenchyma tissue for more than two roots to be produced. Treatment with IBA probably disrupted apical control of roots by the shoot meristem and stimulated development of the two possible secondary roots associated with xylem poles, while BA caused new primordia to be formed in the interfascicular parenchyma region. Chemical names used: 1H-indole-3-butyric acid (IBA); N-(phenylmethyl)-1H-purin-6-amine (BA).
Early Performance and Economic Value of Feathered Apple Trees on Semi-standard Rootstocks
Authors: Ferree David C. , Rhodus W. Timothy
Published: August 2022

Apple (Malus domestica Borkh.) cultivars Lawspur Rome Beauty (a terminal bearer), Smoothee Golden Delicious, and Redchief Delicious (a spur-type) on MM. 106 or MM.111 were planted as whips or feathered trees (branched during their initial year of growth in the nursery) with the feathers pruned or unpruned. During the first year of growth, feathered trees of ‘Lawspur’ made more new growth than trees planted as whips, and pruning the feathered trees further increased new growth. The branching status of trees at planting had no influence on the first year growth of ‘Redchief’ and ‘Smoothee’. Following the second growing season, feathered trees of ‘Lawspur’ and ‘Smoothee’ had increased trunk cross-sectional areas, but those of ‘Redchief’ were not significantly increased. In the third season, feathered trees of ‘Lawspur’ and ‘Smoothee’ produced higher yields than trees planted as whips. Feathered trees of ‘Smoothee’, left unpruned at planting, had higher yields than trees with the feathers pruned; however, the opposite was true with ‘Lawspur’. Average shoot growth of trees on MM. 106, planted as whips, was longer than on MM.111; however, the opposite was true with feathered trees. Total growth/tree on MM.111 was increased for feathered trees, but there was no effect of initial branching status on growth of trees on MM. 106. Calculation of present values indicated positive economic benefits resulting from planting feathered trees of both ‘Lawspur’ and ‘Smoothee’. There was no positive economic return generated by any of the treatments on ‘Redchief’ or ‘Smoothee’ planted as whips after 4 years of growth.
Effects of Daminozide and Paclobutrazol Treatments on Fruit Ripening and Storage Behavior of ‘McIntosh’ Apple
Authors: Elfving D.C. , Chu C.L. , Lougheed E.C. , Cline R.A.
Published: August 2022

Foliar daminozide (DZ) and paclobutrazol (PBZ) applications delayed apple (Malus domestica Borkh.) fruit maturation and ripening at harvest the year of treatment. There was little effect on juice soluble solids or mean fruit weight. Following 24 weeks of air storage, treated fruit were firmer and displayed less core browning than those untreated. Trunk-drench or soil-spray applications of PBZ had little or no effect on any of these quality or physiological parameters of the fruit. In the year after treatment there were no residual effects of either DZ or PBZ on any fruit physiological parameters, despite significant PBZ-induced reductions in shoot growth, fruit size, seed number, pedicel length, and alterations in fruit shape. Chemical names used: butanedioic acid mono(2,2-dimethylhydrazide) (daminozide); β-[(4-chlorophenyl)methyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).
Sampling Considerations for Nitrate Quick Tests of Greenhouse-grown Tomatoes
Authors: Coltman Robert R.
Published: August 2022

Tomato plants were grown in two greenhouse experiments to determine sampling guidelines for using semiquantitative quick tests of petiole sap nitrate to monitor crop N status. In Expt. 1, a 40-µg NO3-N/ml liquid feed rate produced maximum marketable yields of ‘Celebrity’ tomatoes (Lycopersicon esculentum Mill.) (3.4 kg/plant) with estimated petiole sap concentrations of 2138, 1091, and 636 µg NO3-N/ml at early bloom, small fruit, and full-ripe fruit stages, respectively. In Expt. 2, a stable minimum level of petiole sap NO3-N of about 800 µg·ml−1 was found during fruit production in maximally yielding (3.1 kg/plant) ‘Tropic’ tomato plants. These plants received 60 µg NO3− N/ml in liquid feed solutions during fruit production. Liquid NO3-N feed rates producing maximum yields in these experiments were about five times lower than those typically used for growing tomatoes. Sap nitrate content did not fluctuate greatly between 0803 hr and 1430 hr. Sap nitrate levels rose sharply in response to increased N feed concentrations and as a result of lower leaf pruning. Because of high day-to-day and plant-to-plant variation in petiole sap nitrate readings, strategies for obtaining results with sufficient diagnostic value would appear to involve at least weekly samplings of five to 15 plants, and restricting diagnoses of deficient crop N to instances where readings < 800 µg NO3-N/ml for two or more consecutive samplings have been obtained.
Influence of Light- and Dark-period Air Temperatures and Root Temperature on Growth of Lettuce in Nutrient Flow Systems
Authors: Hicklenton Peter R. , Wolynetz Mark S.
Published: August 2022

Butterhead lettuce (Lactuca sativa L. ‘Montana’) plants were grown in recirculating solution culture in growth chambers under various combinations of day temperatures (TD; 12°, 15°, 19.5°, or 22.5°C) and night temperatures (TN; 5° or 14°) and root-zone temperature (TR; 20°, 23°, 26°, or 29°) Photosynthetic photon flux (PPF) was 3.8 mol·day−1·m−2. Leaf area and weight were determined at 7-day intervals. The final harvest followed 28 days of treatments. There were no significant interaction effects between TD and TN. An increase of TD from 12° to 19.5° increased fresh and dry leaf weight and leaf area at final harvest, but increasing TN from 5° to 14° had little effect. Specific leaf area and leaf area ratio increased with increasing TD and TN. Leaf weight ratio increased with TD but remained constant with TN. The overall effect of TR on plant size was minor. Dry weight of roots decreased with increasing TR at the 14- and 21-day harvests, but fresh and dry leaf weights were not affected. Leaf area increased with TR up to 26°. Increases in TR resulted in increased values for specific leaf area, leaf area ratio, and leaf weight ratio at final harvest. The results suggest that some butterhead lettuce cultivars may be grown satisfactorily under low daily PPF by allowing TN to decline to 5° while maintaining TD at ≈ 19°C. In ‘Montana’, increasing TR above 20° under those conditions had little beneficial effect on plant size at harvest.
Deleterious Effects of White Seed due to p Gene in Beans
Authors: Dickson M.H. , Petzoldt R.
Published: August 2022

Isogenic white-seeded (WS) lines of common bean (Phaseolus vulgaris L.) were developed from colored seeded (CS) lines by backcrossing and mutagenesis. Each CS line was selected for its specific resistance to Pythium, Fusarium, Rhizoctonia, seed corn maggot, mechanical damage, or cold tolerance. In all instances, the WS lines, with the p gene, were inferior to the CS lines with P.
Yield Component Analysis of Strawberry Genotypes Differing in Productivity
Authors: Strik Bernadine C. , Proctor John T.A.
Published: August 2022

Strawberry genotypes (Fragaria × ananassa Duchesne) varying in yield per plant were studied. In 1985, genotypes were grown in matted rows and in 1986 as individual plants. Yield per plant within genotypes was mainly dependent on the number of berries per plant, regardless of cultural system. Other variables were correlated with yield, including crown dry weight and leaf area after harvest, and number of inflorescences, which indirectly affected berry number. Potential differences in yield within genotypes apparently were established prior to flower bud differentiation. Variables associated with yield among genotypes differed with cultural conditions. When genotypes were grown in matted rows, vegetative variables were highly correlated with yield. With less interplant competition, reproductive variables were correlated with yield among genotypes. Data suggested that, in some genotypes, runnering and fruiting may have competed for assimilates. Genotypic variability in yield components suggests that genotypes with similar yield can have different routes to yield.
Effect of Pre-bloom Sprays and Soil Drenches of Paclobutrazol on Growth, Yield, and Fruit Composition of ‘Roumi Red’ Grapes
Authors: Shaltout Assem D. , Salem Ahmed T. , Kilany Ahmed S.
Published: August 2022

Trials were conducted using paclobutrazol (PP333) either as a foliar application or a soil drench to improve berry set and yield of ‘Roumi Red’ grapes (Vitis vinifera L.). Concentrations of 100 and 250 ppm (foliar applications) and 2 ml/vine as a ground application had no effect on either chlorophyll and carotenoid leaf content or physical and chemical properties of berries, other than cluster weight and number of berries/cluster, which increased significantly. Concentrations of 1000, 1500, and 2000 ppm and 4 ml/vine reduced shoot and internode length as well as °Brix, whereas physical and chemical properties of berries, bud fertility, chlorophyll, and carotenoid leaf content were increased. A carry-over effect was noticed the year following the year of application with concentrations of 750 ppm and 3 ml/vine or higher. Chemical name used: β[(4-chlorophenyl)methyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).
Micropropagation of Cherry Rootstocks: III. Correlations Between Anatomical and Physiological Parameters and Root Initiation
Authors: Ranjit Makunda , Kester D.E. , Polito V.S.
Published: August 2022

Easy-to-root ‘Colt’ showed cell divisions leading to root initials beginning within 2 days after exposure to auxin. By contrast, juvenile (i.e., 2-year-old seedling) rooting Mazzard (P. avium) and invigorated (i.e., by co-culture) rooting ‘46-1 Mazzard’ required 4 and 5 days. Root initials appeared in the phloem parenchyma in ‘Colt’ and in the cambium region in both seedling Mazzard and invigorated ‘46-1 Mazzard’. Peroxidase activity (PA) was low in shoot tips of ‘Colt’, intermediate in juvenile Mazzard, and high in adult non-rooting ‘46-1 Mazzard’. In basal shoot tissue, PA activity was low in both ‘Colt’ and invigorated ‘46-1 Mazzard’ prior to root initiation, but increased sharply when root initiation started. The appearance of root initials was associated with an increase in intensity of anodic band A for isoperoxidase.
Differential Responses of Four Bean Cultivars to Chronic Doses of Ozone
Authors: Heck W.W. , Dunning J.A. , Reinert R.A. , Prior S.A. , Rangappa M. , Benepal P.S.
Published: August 2022

Four cultivars of bean (Phaseolus vulgaris L.), with different sensitivities to ozone (O3), were exposed to chronic doses of O3 for 7 hr/day in early and late-season studies. Plants were pot-cultured in open-top field chambers. Greater than ambient O3 doses were applied by supplementing the O3 present in nonfiltered air with additional O3 at a constant rate for 7 hr/day. Cultivar sensitivity, as determined using an acute exposure screening protocol, was maintained in both studies. Regression of yield against O3 concentrations showed that ‘BBL-254’ and ‘BBL-290’ were more sensitive to O3 than were ‘BBL-274’ and ‘Dwarf Horticultural’. Results suggest that the acute screen used can predict the relative yield response of cultivars grown under field conditions when very sensitive and very resistant cultivars are compared. The results support the contention that bean germplasm has traits for resistance to O3 at current levels of O3, but that resistance is lost with increasing O3 concentration. Predicted relative yield suppression at a 7 hr/day seasonal mean of 0.04 to 0.06 ppm (the common ambient range in eastern United States) was 2% to 4% for the two resistant cultivars and 10% to 26% for the two sensitive cultivars.
Effects of Petiole Calcium Status, Petiole Location, and Plant Age on the Incidence and Progression of Soft Rot in Chinese Cabbage
Authors: Fritz Vincent A. , Honma Shigemi , Widders Irvin
Published: August 2022

Sand nutrient cultures (containing different Ca2+ compositions) were used to modify the petiole Ca2+ concentrations in Chinese cabbage (Brassica campestris Group pekinensis). Petiole sections (6.5 cm2) from inner and outer leaves, 30 and 60 days after transplanting, were inoculated with Erwinia carotovora ssp. carotovora to evaluate resistance to soft rot incidence and disease progression. Xylem exudates collected from the plants in the sand nutrient culture were analyzed for Ca2+ concentration. Elevated petiole Ca2+ concentrations were not correlated with the development of soft rot in inoculated petiole sections. Plant age and petiole position (inner and outer) did not consistently affect soft rot development. There was a trend of reduced soft rot in inoculated petiole (inner) sections of ‘Hakuran’ plants as the xylem exudate Ca2+ levels increased.
Response of Fresh-market Tomatoes to Nitrogen Fertilizer and Plastic Mulch in a Short Growing Season
Authors: Wien H.C. , Minotti P.L.
Published: August 2022

Two experiments were conducted on a gravelly loam soil of low N status to determine the amounts and timing of N fertilizer needed for high early and total yields of fresh-market tomatoes grown with or without clear plastic mulch. In both years, the mulch slightly increased early flower number, hastened flower production, and increased early yield. Hastening of maturity of plants on mulch resulted in a 22% increase in ripe fruit in the short (118-day) season of 1984 and a decrease in percent green fruit at final harvest. A N rate of 84 kg·ha−1 increased total yields compared to 0 N, whereas 168 kg·ha−1 of N decreased early yield in 1984 but not 1985. Applying one-half of the N at planting and sidedressing the remaining half was just as effective in increasing yields as applying all the N at planting, even with mulched plants. Low tissue NO3-N concentration (< 0.2%) 3 weeks after transplanting reflected insufficient N application for optimum yield but also resulted from limited soil moisture when applied N was adequate. The mulch has increased P consistently and, to a lesser extent, the K concentration in young tomato plants, whereas the effects of mulch on mineral concentration of other elements have varied with year, soil type, and climatic factors.
Salt Tolerance of Azalea Cultivars
Authors: Milbocker D.C.
Published: August 2022

Conventional leafburn evaluations were compared with a new root cell plasmolysis technique to test azalea cultivars (Rhododendron sp.) for salt tolerance. Plasmolysis was a more rapid indicator of salt tolerance than leafburn evaluation, and the technique was an acceptable method of evaluating azalea salt tolerance. Results of this research indicated that the salt-tolerant group contained those species and cultivars considered sun-tolerant, which are characterized by large leaves, coarse stems, and rapid growth. Kurume azaleas were among those determined to be salt-sensitive.