bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth and Cropping of ‘Redhaven’ Peach Trees Following Foliar Applications of Flurprimidol and Paclobutrazol
Authors: Marini Richard P.
Published: August 2022

Flurprimidol (FP) and paclobutrazol (PB) were applied foliarly to 5-year-old ‘Redhaven’ peach [Prunus persica (L. Batsch)] trees 3 weeks after full bloom, at 0, 500, 1000, 2000, and 3000 ppm. The 2 growth retardants generally affected growth similarly at any given concentration. Shoot growth was suppressed in a linear manner as concentration was increased for both materials the year of application. Only FP suppressed shoot growth the 2nd season following treatment, while both materials enhanced shoot growth the 3rd season following treatment. Both materials suppressed trunk growth for 2 seasons. Yield and fruit size were not significantly influenced by treatments. Yield efficiency was greatest for trees treated at the highest rates of both materials 3 seasons after application. Vegetative and floral bud break on treated trees was advanced the 3rd season after application. Chemical names used: β-[(4-chlorophenyl)methy]-2-(l,l-dimethylethyl)-l-H,2,4-triazole-l-ethanol (paclobutrazol); α-(l-methylethyl)-α-[4-(trifluoromethoxy)phenyl]-5-pyrimidinemethanol (flurprimidol).
The Use of Initial Withholding of Irrigation and Tree Spacing to Enhance the Effect of Regulated Deficit Irrigation on Pear Trees
Authors: Mitchell P.D. , Chalmers D.J. , Jerie P.H. , Burge G.
Published: August 2022

Withholding irrigation (WI), followed by regulated deficit irrigation (RDI) at 2 levels, were compared with conventionally scheduled irrigation during rapid vegetative growth on ‘Bartlett’ pear (Pyrus communis L.) trees. All trees were irrigated at an increased common level during subsequent rapid fruit growth, by which time most vegetative growth had ceased. Irrigation effects were studied at 3 tree spacings (4 × 1 m, 4 × 0.75 m, and 4 × 0.5 m). Shoot and frame growth was related directly to early irrigation treatment before summer pruning. However, significant shoot growth that was reinitiated following summer pruning during one year increased on RDI treatments. The improved tree water status gained by changing from RDI to full irrigation in both years and from WI to RDI in the first year stimulated the growth rate of the total crop on the RDI treatments. Gross yield was increased significantly by WI and RDI in both years. Blossom density also was increased. Preliminary WI increased the control of vegetative growth by RDI when the soil was wet at flowering.
Changes in Membrane Properties and Abscisic Acid During Senescence of Harvested Bell Pepper Fruit
Authors: Lurie Susan , Ben-Yehoshua S.
Published: August 2022

This work describes changes in abscisic acid (ABA) content, membrane permeability, microviscosity, and lipid composition during storage of green and red bell pepper fruit (Capsicum annuum L. cv. Maor). Membrane permeability increased as measured by leakage of electrolytes and ninhydrin-reacting substances, sucb as amino acids. Membrane microviscosity increased initially and then showed a slow decrease. In red peppers, the increase in microviscosity occurred sooner than in green peppers, and the membrane leakage was higher. Examination of the composition of sterol and phospholipid in microsomal membranes revealed a connection between sterol level and membrane microviscosity. Sterol levels increased and then slightly decreased, while phospholipid levels showed no significant change. Abscisic acid levels showed an increase during senescence, followed by a decrease that was more dramatic in green pepper.
Weight Loss in Sweet Potatoes During Curing and Storage: Contribution of Transpiration and Respiration
Authors: Picha David H.
Published: August 2022

Cured sweet potatoes [Ipomoea batatas (L.) Lam] were stored successfully at 15.6°C and 90% RH for up to a year without sprouting. Contribution of respiration and transpiration to total weight loss was determined during curing and storage in 6 cultivars. Respiration rate was highest the day of harvest, decreased during curing, and continued to decrease at a slower rate during the first several months of storage, whereafter it remained constant (except for slight increases during the last several months in 2 cultivars). Respiration contributed more to total weight loss during the latter periods of storage than during curing or the first months in storage. Transpiration, however, was the major source of weight loss. The highest rate of weight loss occurred during curing, followed by a gradual rate of loss during storage. Total weight loss of cured roots after 50 weeks of storage ranged from 6.7% (‘Rojo Blanco’) to 16.1% (‘Travis’).
Cut Flower Longevity of Peony
Authors: Heuser Charles W. , Evensen Kathleen B.
Published: August 2022

Flower longevity (as influenced by stage of maturity at harvest), dry weight, and flower preservative were studied using cut flowers of herbaceous peony (Paeonia spp.) cultivars Felix Crousse, Festiva Maxima, John C. Lee, Mons. Jules Elie, and Richard Carvel. Flowers harvested in the tight calyx stage frequently failed to open or opening was delayed. No substantial difference in longevity between flowers harvested at the loose calyx stage or first loose petal stage was found. Those cut at the loose calyx stage maintained quality well during dry storage at 0°C for up to 4 weeks. Vase-life and days to opening differed significantly with cultivar, length of storage, and their interaction. Fresh weight increased before or during flower opening, and the increase was greater after storage than for unstored flowers. Inclusion of a floral preservative in the vase solution increased gain in fresh weight upon hydration after storage and weight throughout vase-life.
Nitrate Concentration and Reduction in Different Genotypes of Lettuce
Authors: Blom-Zandstra Margaretha , Eenink Albert H.
Published: August 2022

Several genotypes of lettuce (Lactuca sativa L.), significantly differing in NO3 accumulation, were used to study the relationship between NO3-N concentration and NO3 reduction. Reduction of NO3 was investigated by measuring the in vivo nitrate reductase activity and the production of organic N. When NO3 was supplied to the in vivo assay, no relationship was found between the enzyme activity and the NO3-N concentration of the tissue, whereas this activity was positively correlated to the NO3-N concentration when NO3 was omitted during the incubation. As an indicator for the in situ NO3 reduction, organic N was determined. No relationship between NO3-N concentration and production of organic N occurred when different genotypes were compared. Nitrate-N, nitrate reductase activity, and organic N decreased with increasing age of the plants. The results suggest that accumulation of NO3 is not solely a result of a variation in reduction capacity between cultivars. Breeding for low NO3 accumulation should not be focused only on the increase of either nitrate reductase activity or production of organic N.
Levels of ACC in Various Floral Portions During Aging of Cut Carnations
Authors: Hsieh Yi-Chi , Sacalis John
Published: August 2022

Studies were conducted to determine the involvement of ACC movement from extrapetal portions with initiation of petal senescence. During early senescence, ACC in all portions except the calyx displayed transient increases in levels of ACC. The largest increase in ACC specific concentration occurred in the receptacle. Removal of petals at harvest resulted in accumulation of ACC in the ovary and receptacle. [14C]ACC applied to the styles moved to the petals within 24 hr, but during this time, very little 14C was found in the receptacle. Although the major rise in ACC occurred in styles, ovary, receptacle, and petals between days 6 and 10 of aging, a secondary transient peak of ACC was always observed between days 2 and 4 only in the receptacle. It is suggested that the receptacle may contribute significantly to the initiation of petal senescence by acting as a source of ACC. Chemical names used: 1-aminocyclopropane-1-carboxylic acid (ACC).
The Influence of Explant Origin on Tissue Browning and Shoot Production in Shoot Tip Cultures of Grapevine
Authors: Yu Dan-hua , Meredith Carole P.
Published: August 2022

We investigated the effect of explant origin on survival and adventitious shoot production from field-grown shoot tips of 8 Vitis vinifera L. cultivars. Survival and shoot production were greater in explants from axillary shoot tips than those from terminal positions. Similarly, explants from shaded shoot tips exceeded those that had grown in full sun. Explants from weak shoot tips had a higher survival rate than those from vigorous shoot tips. The effects of position, light, and vigor were independent. There was a strong negative correlation between survival in vitro and the preexisting phenolic content of the explants. Similar effects were observed with greenhouse-grown explants. Our findings may be applicable to other woody species with high phenolic contents.
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

Shoot tips of ‘Gala’ apple (Malus domestica Borkh.) were grown on proliferation medium containing Murashige and Skoog salts, supplemented with 0.56 mm myo-inositol; 1.2 μm thiamine-HCl; 2.2 or 4.4 μm BA; 0.005, 0.05, or 0.5 μm IBA; and 1.3 μm GA3. The media were solidified with Gelrite at concentrations from 0.5 to 1.5 g·liter−1 plus agar (Sigma) from 0.5 to 4.0 g·liter−1. Vitrification was influenced both by gelling agent and BA concentration, whereas the IBA concentration had little effect. Increasing either agar or Gelrite concentration resulted in a decreasing percentage of vitrified explants. The higher BA level generally increased vitrification, but increasing the agar concentration tended to reduce the difference in effect of the 2 BA levels. Certain combinations of gelling agents produced no vitrification with no reduction in shoot proliferation, and with a clarity of the medium approaching that of Gelrite alone. Chemical names used: N-(phenylmethyl)-lH-purin-6-amine [benzyladenine (BA)]; lH-indole-3-butanoic acid (IBA); and gibberellic acid (GA3).
Sample Size Estimates for Avocado Yield Experiments
Authors: Schaffer Bruce , Baranowski R.M.
Published: August 2022

Fruit number and weight per tree were recorded for 3 years for 2 avocado (Persea americana M.) cultivars—‘Booth 8’ and ‘Peterson’. Sample variances were used to determine the number of years per experiment and trees per treatment required to detect differences in yield among treatments at the 5% and 10% significance levels for each cultivar. Yearly variability was greater than variability among trees for both cultivars. Yearly variability for total fruit weight was greater for ‘Booth 8’ than for ‘Peterson’. Fifteen trees per treatment were required to detect a 10–20% difference in total fruit weight per treatment at the 5% level of significance. Each additional tree per treatment decreased the percentage of detectable difference only slightly. Increasing the number of years per experiment decreased the percentage of detectable difference. However, after 3 years, additional years decreased the percentage of detectable difference only slightly for both an alternate- and a nonalternate-bearing cultivar. Efficient designs for avocado yield experiments for the cultivars tested should consist of 10 to 15 trees per treatment and should be conducted for at least 3 years.
Identification of Anthurium andraeanum Cultivars by Gel Electrophoresis
Authors: Kobayashi R.S. , Brewbaker J.L. , Kamemoto H.
Published: August 2022

The use of gel electrophoresis of different isozyme systems was investigated as a possible tool to identify Anthurium andraeanum cultivars. Procedures were developed to extract active enzymes from anthurium leaves. Clear zymograms were obtained from only one of three extraction methods examined. This method consisted of grinding the leaf tissue in liquid nitrogen and then adding to the ground tissue a buffer containing a phenoloxidase inhibitor, reducing agents, and polyvinylpolypyrrolidone (PVPP). The identification of seven anthurium cultivars was undertaken using seven enzyme systems. Bands were observed in four of these systems; glutamate-oxaloacetate transaminase (GOT), malate dehydrogenase (MDH), peroxidase (Px), and phosphoglucose isomerase (PGI). All seven cultivars were characterized by the combined data of Px, MDH, and PGI.
Effect of Deficit Irrigation on Yield and Quality of Sweet Corn
Authors: Braunworth William S. , Mack Harry J.
Published: August 2022

The yield and quality response of sweet corn (Zea mays L.) to variable water supply was evaluated in 1984 and 1985. Irrigation depths were established with sprinklers at five intervals from 0% to 100%, with the 100% treatment intended to refill the root zone to field capacity. The other treatments were considered as deficit irrigation. Irrigations were scheduled when 47–57% of the available water was depleted in the root zone of the 100% treatment level plots. Yields were similar when irrigation depths were 50% or greater in 1984 and 1985, although water application depths varied between years. Water balance measurements indicated very little deep percolation. Deficit irrigations of about 50% and 70% saved water and maintained yield. Yield, ear weight, and kernel weight decreased in the nonirrigated treatments or when water application depths were about 25%. Nonirrigated sweet corn tended to be more mature at harvest then irrigated corn.
Effects of Nitrogen Applications on Direct-seeded Broccoli from a Single Harvest Adjusted for Maturity
Authors: Kowalenko C.G. , Hall J.W.
Published: August 2022

A single harvest method using horticultural maturity rating data was tested in 2 years of Ν application field trials with broccoli. Using analysis of variance with the maturity data as covariates, it was possible to evaluate how broccoli yield response to Ν was influenced through the effect of Ν on maturity. This single harvest method simplified field operations and facilitated interpretation of Ν uptake data. Nitrogen treatments did not significantly alter maturity of broccoli in either year. Broccoli yield increased with up to 250 kg·ha–1 of Ν in both years. Sweet corn, which was grown adjacent to the broccoli in the first year, did not respond to similar applications. Nitrogen did not preferentially increase vegetative growth of broccoli, but in one year increased head yield. Nitrogen accumulated in the head of broccoli. The corn crop accumulated extra Ν in the vegetation and this was assumed to be luxury uptake. The difference in response to Ν of corn and broccoli was assumed to be the result of a difference in Ν use or uptake efficiency rather than overall demand, since the total above-ground uptake by corn and broccoli was quite similar.
Table Beet Plant and Canned Root Responses to Na, K, and Cl From Soils and From Applications of NaCl and KCl
Authors: Peck Nathan H. , VanBuren Jerome P. , MacDonald George E. , Hemmat Minou , Becker Robert F.
Published: August 2022

The concentrations of elements in the portions of vegetable plants used for human consumption as well as the yield should be evaluated. Applications of NaCl and KCl to loam soils (Glossoboric Hapludalf, loamy, mixed mesic) have consistently increased the growth of table beet (Beta vulgaris L.) plants and the yield of the enlarged portion of the roots. The concentrations of Na, K, and Cl in the roots were also increased. The objective of this study was to develop a method of predicting the concentration of Na in canned table beet roots. Sodium, K, and Cl from the soils and from preplant soil applications of Na at 0, 250, and 500 kg·ha−1 and KCI at 300 kg·ha−1 were monitored systematically as continua through the soil tests and the chemical analyses of leaf blade and petioles at midseason, in the raw roots at harvest, and in the solid and liquid portions of the canned roots. Sodium from the soils and from increasing the rate of NaCl linearly increased the concentration of Na in all components. The concentrations of Na in the leaf blades and the leaf petioles at midseason were excellent predictors of the content of Na in the canned beet roots. Application of equivalent ionic rates of NaCl and KCI produced the same yields of roots.
Yield Components in ‘Montmorency’ and ‘Meteor’ Sour Cherry
Authors: Chang L.S. , Iezzoni A.F. , Flore J.A.
Published: August 2022

Two sour cherry (Prunus cerasus L.) cultivars ‘Montmorency’ and ‘Meteor’ were evaluated over two seasons to determine the relative importance of different components of yield. A path coefficient analysis was performed to determine the direct and indirect effects of primary, secondary, and tertiary components on limb yield. Fruit number, fruit weight, the number of lateral buds and spurs, and fruit set were found to be the most important components affecting limb yield in both cultivars. However, the fruiting habits of the two cultivars were significantly different. ‘Montmorency’ produced 68% of its fruit on lateral buds on 1-year-old wood, while ‘Meteor’ had 70% of its fruit on 2-year-old spurs. When the data were standardized by dividing by limb cross-sectional area, ‘Meteor’ had a higher flower bud density (number of flowers/cm2) and yield efficiency (grams of fruits/cm2) than ‘Montmorency’. Although ‘Meteor’ had higher limb yields than ‘Montmorency’, the ‘Montmorency’ trees sampled had about four times more limbs than ‘Meteor’, and, therefore, higher tree yields.
Enhanced Degradation of Pesticides in Aqueous Formulations Due to Addition of Calcium Chloride
Authors: Marshall Clark J. , Brooks M.W. , Woods S.A. , Coli W.M.
Published: August 2022

Addition of technical flake CaCl2 to spray mixtures resulted in substantial alkalinization of all solutions. The pH values of CaCl2 solutions returned to neutral levels over time (e.g., usually in 24 hr) or could be returned rapidly to neutrality by the addition of CO2. These data indicate that the causative agent for alkalinization is Ca(OH)2, a byproduct in the Solvay process used to produce technical flake CaCl2. Under the alkaline conditions produced by the addition of technical flake CaCl2, enhanced degradation of formetanate (Carzol SP), benomyl (Benlate-50WP) and methomyl/(Lannate) was observed to be related directly to CaCl2 concentration. Azinphos-methyl (Guthion- 50WP) was found to be the most persistent pesticide under these experimental conditions. Chemical names used: (0,0-dimethyl-S-[(4-oxo-1,2,3-benzotriazin- 3(4H)-yl)methyl]phosphorodithioate (azinphos-methyl); methyl[1-[(bu-tylamino)carbonyl]-1H-benzimidazol-2-yl]carbamate (benomyl); N,N dimethyl-N’-[3-[[(methylamino)carbonyl]oxy] phenyljmethanimidamide (formetanate); methyl N-[[(methylamino)carbonyl]oxy] ethanimidothioate(methomyl).
Rooting and Subsequent Growth of Woody Ornamental Softwood Cuttings Treated with Endomycorrhizal Inoculum
Authors: Nelson Sherman D.
Published: August 2022

Selected woody ornamentals were inoculated with Glomus intraradices Schenck & Smith to form endomycorrhizae during vegetative propagation. Inoculation of rooting media with chopped marigold root inoculum, before cuttings were stuck, was an effective method for colonizing developing roots. In some plants, the presence of endomycorrhizal inoculum delayed early root development but subsequent root and shoot growth approached or surpassed that of nonmycorrhizal plants.
Effect of Fertilizer, Temperature, and Light Level on Growth of Syngonium podophyllum ‘White Butterfly’
Authors: Chase A.R. , Poole R.T.
Published: August 2022

The effect of fertilizer level (1.2-41.3 g Osmocote 19N-2.6P-10K per 15-cm pot) was tested in factorial experiments with air temperature [13.5° to 21°C (winter) or 32° to 41° (summer)] and light level (47-80% shade) on Syngonium podophyllum Schott ‘White Butterfly’. Optimal shoot growth was obtained for plants fertilized with 4.9 to 19.5 g Osmocote per 15-cm pot for 3 months under greenhouse conditions during the summer and winter (recommended rate is about 5.0 g). Slight reductions in plant growth occurred at higher rates. Interactions between fertilizer level and air temperature were rarely significant. Optimal shoot growth was obtained for plants with a maximum air temperature between 32° and 41° during the summer and a minimum air temperature of 18.5° and 21° during the winter. High-quality plants were produced with fertilizer rates from 4.9 to 34.0 g per 15-cm pot for 3 months under shadehouse conditions. Plants grown with 200 μmol·s-1·m-2 (80% shade) had fewer leaves, were taller, whiter (color), had lower-quality grades, lower fresh weight of shoots, higher percentage of pots with healthy-appearing roots, and produced larger leaves than those grown with 700 μmol·s-1·m-2 light (47% shade). Interactions between fertilizer and light levels were not significant.
Linear Programming Models for Wholesale Nursery Product Mix Planning
Authors: Sabota C.M. , Williams David J. , Westgren Randall E.
Published: August 2022

Operation management techniques, such as linear programming (LP), can provide producers and managers with greater quantities of information and, from this, more informed, up-to-date decisions can be made. Linear programming techniques were applied to data from ten container plant nurseries to determine possible production systems, their inputs, and to maximize profit. Models were developed for large (average, 27 ha) and small (average, 5 ha) container nurseries. Plant type and container size were used interactively as decision variables (activities) in the models. The small nursery model had 44 plant type alternatives and the large nursery model had 87. Resources included in the constraints were equipment, materials, and labor used to produce each plant type. The actual constraint values determined from survey information are provided, as well as a multiperiod model and a theoretical model.
Distribution, Storage, and Remobilization of 14C-labeled Assimilate in Easter Lily
Authors: Wang Yin-Tung , Breen Patrick J.
Published: August 2022

Whole shoots of Easter lily (Lilium longiflorum Thunb. cv. Nellie White) were exposed to 14CO2 at 25, 37, and 51 days after full bloom of the commercial crop. Seven days after each exposure, 20% of the total recovered 14C remained in the shoot, which included stem roots, 10-25% in stem bulblets, 11-20% in mother scales, and 34-44% in daughter scales. Sink activity increased sharply from the outer mother scales to the inner daughter scales. The fraction of total 14C in the main bulb decreased, while that in the stem bulblets increased at successive exposures. Another group of plants was labeled repeatedly by dosing with 14CO2 on the three previous occasions and, also, at 65 days after full bloom. Bulbs were harvested 7 days after the final exposure, stored at 18°C for 14 weeks, and then replanted, At bulb digging, 50%, 30%, and 20% of the total 14C recovered were in the main bulb, stem bulblets, and shoot, respectively. Mother scales lost dry weight and 14C during storage and were nearly depleted when flower buds were visible the next season. Specific 14C activity in the emerging flowering shoot was high but decreased dramatically as the leaf number rapidly increased. The shoot and new daughter scales were the principal recipients of mobilized scale reserves, although only 28% of the 14C lost from mother scales were recovered in other plant parts. A majority of the carbon originally in mother scales was likely lost in respiration between fall harvest and 3 weeks after anthesis the following year. The daughter bulb contained 64% of the 14C in the bulb at fall harvest, and lost very little 14C during regrowth the following year.
Effects of Soil-applied Elemental Sulfur, Aluminum Sulfate, and Sawdust on Growth of Rabbiteye Blueberries
Authors: Peterson D.V. , Mullins C.A. , Lietzke D.A. , Deyton D.E.
Published: August 2022

Elemental sulfur (S) and aluminum sulfate (AS), each at four rates, were used to acidify a Lily sandy loam soil of pH 6.2 and to assess effects on early growth of rabbiteye blueberry (Vaccinium ashei Reade) transplants. In addition, sawdust was incorporated into the soil at rates of 0%, 20%, 40%, and 60% by volume. Soils treated with AS had higher levels of extractable A1 and plants had less growth compared to plants grown in soils treated with elemental S. Plants grown in soils not amended with sawdust exhibited poor growth, regardless of the rate of either S or AS. Percent weight gain generally increased with increasing rate of sawdust addition.
Postharvest Curing at High Temperatures Reduces Decay of Individually Sealed Lemons, Pomelos, and Other Citrus Fruit
Authors: Ben-Yehoshua S. , Barak E. , Shapiro B.
Published: August 2022

Curing of sealed lemons of normal and decay-prone types [Citrus limon (L.) Burm.f] and of sealed Goliath pomelo [Citrus grandis (L.) Osbeck] inhibited postharvest decay without deleterious effects on fruit quality and prevented the development of Penicillium digitatum on inoculated fruit. Curing of nonsealed fruit was less effective in reducing decay than curing sealed fruit and caused prohibitive weight loss, shrinkage, and softening. Curing of sealed and waxed ‘Shamouti’ and ‘Valencia’ oranges (C. sinensis), in comparison to only sealed fruit, resulted in some CO2 injury of the peel and off-flavor.
Genotype × Environment Interaction Bias in Heritability Estimates for Cut-flower Yield of Greenhouse Gerberas
Authors: Byrne Thomas , Drennan Dana , Harding James
Published: August 2022

Statistics were developed to measure the relative importance of genotype × environmental (GE) interactions. Estimates indicate that as much as half of the genetic variance for cut-flower yield in the Davis Population of Gerbera may be attributable to GE interactions. The bias this causes in broad-sense heritability estimates averaged 10.3% ± 2.97% for single-factor interactions; 15.6% ± 3.52% for 2-factor interactions, and 26.8% ± 3.45% for 3-factor interactions. The mean unadjusted broad-sense heritability for cut-flower yield in the same experiments was 37.1% ± 6.54%. Therefore, response equations that do not take interaction bias into account will overestimate selection potential.
Effect of Fertilizer, Paclobutrazol, and Chlormequat on Strawberry
Authors: McArthur D.A.J. , Eaton G.W.
Published: August 2022

In the article “Effect of Fertilizer, Paclobutrazol, and Chlormequat on Strawberry”, by D.A.J. McArthur and G.W. Eaton (J. Amer. Soc. Hort. Sci. 112:241–246, March 1987), the authors note that the fertilizer ratio that reads “20N–4.3P–8.3K” throughout the text and tables should read “20N–8.7P–16.6K”.
Influence of Rootstock and Pruning on Productivity, Growth, and Fruit Size of European Plum Cultivars
Authors: Tehrani G. , Leuty S.J.
Published: August 2022

Effects of annual mechanical summer shearing on growth and productivity of six European plum cultivars (Prunus domestica L.) were studied. The cultivars were grown for 15 years on three clonal plum rootstocks and trained to modified leader system. The annual summer shearing reduced growth, yield, and yield efficiency index but did not affect mean fruit weight compared to the trees dormant-pruned annually and trained to modified leader system. Trees that were annually dormant-pruned from 1974 to 1984 yielded similarly when grown on ‘Brompton’ (P. domestica L.) and ‘St. Julien A’ (P. insititia Bailey) and ‘Myrobalan B’ (P. cerasifera Ehrh.). Yields of ‘Verity’ and ‘Valor’ were higher than ‘Iroquois’ and ‘Italian’, which had the lowest cumulative yield. ‘Bluebell’, ‘Stanley’, and ‘Valor’ had intermediate yields. Mean fruit weight was the same for all rootstocks trained to modified leader systems, but, after 7 consecutive years of shearing, pooled mean fruit weight from trees on ‘Myrobalan B’ was smaller than that of other roots. Trees with ‘Myrobalan B’ root were larger than trees grown on ‘Brompton’ and ‘St. Julien A’.
Sources of Photosynthate for Fruit Growth in ‘Bing’ Sweet Cherry
Authors: Roper Teryl R. , Loescher Wayne H. , Keller John , Rom Curt R.
Published: August 2022

Source–sink relationships in sweet cherry were altered by girdling limbs both above and below fruiting spurs. Spurs isolated by girdling both above and below had lower total fruit weight per spur and lower weight per fruit then those above or below girdles. Fruit number per spur was not altered, but soluble solids and fruit color were lower in fruits from isolated spurs than fruit from spurs either above or below girdles. Fruit on spurs above girdles were generally highest in soluble solids and fruit color. These factors indicate fruit on isolated spurs also were delayed in maturity. Spurs below girdles were unaffected by girdling. Girdling had no effect on spur leaf net photosynthesis, stomatal conductance, or fruit water loss rate. The results indicate that spur leaves alone do not have the capacity to support fruit growth in sweet cherry and must, therefore, be supplemented by photosynthates from other sources.
Variation in Growth and Flowering Habits of Junebearing and Everbearing Strawberries
Authors: Nicoli Marion F. , Galletta Gene J.
Published: August 2022

Variation in vegetative and reproductive growth patterns leading to summer flowering and fruiting was evaluated in everbearing and in representative Junebearing strawberry (Fragaria × ananassa Duch) clones under simulated summer conditions in the greenhouse and in growth chambers. Summer flowering intensity, periodicity, fruit set, and maturation were related to plant architectural parameters such as crown, leaf and runner production, number of meristems produced and differentiated, leaf areas and petiole length, plant volume, and dry weight allocation patterns. A continuum of growth habits and flowering behavior precluded rigid classification of summer flowering response, but useful arbitrary distinctions were made on the bases of: photoperiod reaction into short-day (Junebearing) vs. weak, intermediate, or strong day-neutrals; or summer fruit expectation into essentially none (Junebearing) vs. sporadic or consistent everbearers. Critical criteria for separating Junebearers from everbearers include degree of summer flowering and fruiting (fresh or dry weight basis), plant volume (and its components, petiole length, and average leaf area), and the dry weight allocation ratios—root : shoot and reproductive : vegetative. Everbearing (or day-neutral) types could be distinguished by plant volume and composition differences (size, number, and percentage of developed meristems, leaf area ratio, reproductive dry weight, etc.) and continuity of individual plant flowering. Three basic models of shoot growth and inflorescence positioning are proposed from evidence for alternative modes of flowering site generation in everbearing strawberries.
Genetic Variation and Inheritance of Resistance of Leaf Iron-deficiency Chlorosis in Dry Beans
Authors: Zaiter Haytham Z. , Coyne Dermot P. , Clark Ralph B.
Published: August 2022

Dry bean (Phaseolus vulgaris L.) cultivars/lines differed in their iron-deficiency leaf chlorosis response when grown in field trials on a calcareous soil in western Nebraska. The genetic basis of this response was determined. Crosses were made between three susceptible (PI 165078, Navy ‘Tuscola’, and Light Red Kidney ‘Redkloud’) and seven resistant parents (G.N. ‘Valley’, G.N. 1140, G.N. ‘UI 59’, G.N. ‘Emerson’, Pinto EP-1, Pinto ‘Olathe’, and Black Neb-WM1-83-10). The parents, F2, and several F3 progenies were evaluated visually in replicated field trials for leaf iron-deficiency chlorosis. Based on F2 and F3 segregation patterns, it was hypothesized that resistance was controlled by two major complementary dominant genes. The environment also influenced considerably the range in expression of the leaf chlorosis, particularly in the susceptible parents and progenies.
Effect of Atmospheric CO2 Concentration and Root-zone Temperature on Growth, Mineral Nutrition, and Nitrate Reductase Activity of Greenhouse Tomato
Authors: Yelle Serge , Gosselin André , Trudel Marc-J.
Published: August 2022

Tomato plants (Lycopersicon esculentum Mill. cvs. Vendor and Carmelo) were exposed to two CO2 levels (330 or 800 µl·liter−1) and five root-zone temperatures (12°, 18°, 24°, 30°, or 36°C). The enhancement of shoot growth from CO2 enrichment increased with root-zone temperature (RZT) to 30°. Enhancement of root growth decreased. The response to high CO2 level was larger with ‘Vendor’ than ‘Carmelo’. A concentration of 800 µl·liter−1 of CO2 increased N and K uptake by 58% and 45%, respectively. The largest P uptake was obtained with plants grown at 800 µl·liter−1 CO2 and 36° RZT. Leaf concentration decreased at 800 µl·liter−1 of CO2 and at a RZT of 12°. At low RZT, CO2 enrichment increased growth but did not increase the translocation of to the leaf. There was no significant relationship between nitrate reductase activity (NRA) and leaf content, implying that the “inactive ” (which does not affect NRA) was at higher levels in leaves exposed to 330 µl·liter−1 CO2 than in those exposed to 800 µl·liter−1 CO2. There was also a decrease in N concentration of leaves subjected to 800 µl·liter−1 CO2, possibly caused by a reduction in transport toward leaves rather than a decrease in reduction within leaves. Therefore, the best response to CO2 enrichment at 30° appears to be related to increased translocation.
Comparative Morphology of Fatsia japonica, Hedera helix, and Their Hybrid, × Fatshedera lizei
Authors: Dehgan Bijan
Published: August 2022

Micromorphology and chromosome number of Fatsia japonica Decne et Planch. ‘Moseri’, Hedera helix var. hibernica Kirchn., and their putative intergeneric hybrid, × Fatshedera lizei are surveyed. × Fatshedera lizei is intermediate in most characteristics of leaf surface morphology. Both H. helix and F. japonica have 2n = 48 chromosomes; a range of counts from 72-98 for × F. lizei suggests that it may be an unstable tetraploid. Comparisons of chromosome size suggest that both parental genomes are represented in the the karyotype of × F. lizei. Certain novel characteristics of the hybrid (inflorescence morphology, petiole morphology and anatomy, leaf vascular anatomy) are possibly the result of phenotypic expression of the hybrid genome or polyploid effects. Micromorphological characteristics can provide evidence of hybrid intermediacy when gross morphological features do not clearly identify hybrid origin.
Germination and Priming of Tomato, Carrot, Onion, and Sorghum Seeds in a Range of Osmotica
Authors: Haigh M. , Barlow E.W.R.
Published: August 2022

In the article “Germination and Priming of Tomato, Carrot, Onion, and Sorghum Seeds in a Range of Osmotica”, by Anthony M. Haigh and E.W.R. Barlow (J. Amer. Soc. Hort. Sci. 112:202–208, March 1987), the term “ionic strength” has been inadvertently used throughout the paper where “ionic concentration” was meant.
Response of Snap Beans to Tillage and Cover Crop Combinations
Authors: Skarphol Brenda J. , Corey Kenneth A. , Meisinger John J.
Published: August 2022

Field experiments were conducted on a Norfolk loamy sand (fine-loamy, siliceous, thermic Typic Paleudult) from 1983 through 1985 to determine the effects of tillage method, cover crop, and N fertilization on inorganic soil N and yield, yield components, and N content of snap bean (Phaseolus vulgaris L.). Hairy vetch (Vicia villosa Roth), hairy vetch plus wheat (Triticum aestivum L.), Austrian winter pea (Pisum sativum ssp. arvense L. Poir), Austrian winter pea plus wheat, wheat, crimson clover (Trifolium incarnatum L.) and no cover were the cover crop treatments. Inorganic N concentrations generally were greater in soil with cover crop treatments containing legumes than in soil with no cover and wheat treatments. The use of Austrian winter pea, hairy vetch, and crimson clover as cover crops without supplemental N resulted in snap bean yields comparable to those obtained when 90 kg·ha−1 additional N was supplied. Supplemental N decreased the amount of dry matter partitioned into pods. Inorganic N profiles in the soil indicated that conventional tillage (CT) practices resulted in greater mineralization of N fixed by the legume cover crops than no-tillage (NT) practices. However, snap bean yields for NT were comparable to or greater than those obtained with CT, suggesting that N released from legume residues provided sufficient supplemental N for optimum growth and yield.
Photon Flux and Leaf Temperature Effects on Flower Initiation and Early Development of ‘Red Elite’ Geraniums
Authors: White J.W. , Polys S.M.
Published: August 2022

Geranium (Pelargonium × hortorum Bailey ‘Red Elite’) seedlings were grown with five daily mean temperature (DMT) and daily light integral (DLI) treatment combinations: DMT of 23°C/day at DLI of 8.64 mol·day−1·m−2 (TI), DMT of 25° at 8.64 mol (T2), DMT of 23° at DLI of 17.28 mol, (T3) DMT of 25° at DLI 17.28 mol (T4), and DMT of 21° at 17.28 mol (C1). Using infrared thermometry to control leaf temperature, DMT had a greater influence on flower initiation at the transition stage and on flower bud development to macrobud stage than DLI. Seedlings in T4 reached transition stage 24 days after sowing with a cumulative irradiance of 415 mol. Transition occurred in T1 at 27 days from sowing, with a cumulative irradiance of only 233 mol. Some time after 27 days from sowing, transition occurred in T2, T3, and C1. With a DLI of 17.28 mol, a DMT reduction from 25° to 23° to 21° effected macrobuds in 42, 56, or 62 days after sowing, respectively; whereas with a DLI of 8.64 mol, a decrease from 25° to 23° effected macrobuds in 54 or 51 days.
Particle Size and Container Size Effects on Growth of Three Ornamental Species
Authors: Tilt Kenneth M. , Bilderback T.E. , Fonteno W.C.
Published: August 2022

Composted hardwood bark and aged pine bark were combined to produce two media with different particle size fractions. Media were combined with 3.8-, 5.7-, and 11.4-liter containers to produce six air and water capacities. Rooted cuttings of Ilex × ‘Nellie R. Stevens’ Van Lennep holly, × Cupressocyparis leylandii Jacks and Dall. ‘Ηaggerston Grey’ leyland cypress and Rhododendron × sp. ‘Sunglow’ azalea were potted in the resulting media–container combinations to determine the effects of particle size distribution, moisture and air content, and volume of containers on plant growth. Manipulating the particle size decreased the water held by ≈9%, but increased air space by ≈8% between the control and the coarse medium. The control medium yielded greatest top dry weight for all three species. Root dry weight and root ball volume were similar in coarse and control medium. Plant growth also was related to container size. A 2-fold increase in top dry weight occurred as container volume of the medium increased from 3.8 to 11.4 liters. Increasing container water content had a significant effect on top dry weight of all three species. Aeration was not as limiting to root growth as water content was to top growth.
Drought and Salinity Stress Effects on Guayule Seedling Emergence
Authors: Tipton Jimmy L.
Published: August 2022

The effect of drought and salinity stress on emergence of six Guayule (Parthenium argentatum Gray) cultivars was investigated. Final percent emergence declined an average of 62% from optimum conditions to those of moderate stress. Whereas the effect of either stress was nearly equivalent on final percent emergence, drought had a slightly greater effect on maximum emergence rate and salinity a greater effect on inflection time (time to maximum emergence rate) in most cultivars. Cultivars had no effect on final percent emergence, but they did affect maximum emergence rate and inflection time. Germination of cultivar 11619 was more stress-tolerant than others, since it had a higher maximum emergence rate and lower inflection time under stress. Within cultivars, variability was high for final percent emergence and maximum emergence rate and low for inflection time.
Differential Cucurbita spp. Tolerance to the Herbicide Trifluralin
Authors: Poe Renee R. , Coyne Dermot P. , Swisher Beth A. , Clegg Max D.
Published: August 2022

A germination test of seven Cucurbita entries in a dark growth chamber indicated no effects of trifluralin on germination. Increasing the plant population/pot of butternut type squash (C. moschata Poir, cv. Ponca) did not improve trifluralin tolerance. A factorial arrangement of three treatments (six Cucurbita entries × five trifluralin doses × three herbicide incorporation zone placements in pots) with a randomized complete block design was used in two greenhouse experiments. The incorporation zone treatments included surface layering (above seed), subsurface layering (below seed), and full-pot incorporation of the herbicide dose. The layering treatments increased concentration (ppm) of the herbicide due to the concentrated dose in a small volume of sand medium (200 vs. 500 g quartz sand). Total plant dry weight differences were detected between zoning treatments. After an initial stimulating effect, plant dry weight decreased over the dose range. The C. maxima Duch, PI 182202, and C. pepo L., PI 234252, showed the highest tolerance. Adventitious roots developed and senescence of the primary root occurred above the subsurface treated layer that had been treated at high trifluralin concentrations. The root zone was the primary site of herbicide action. C. moschata, C. pepo, and C. maxima spp. (21 entries) were screened in two tests for tolerance to trifluralin over a range of 0 to 0.4 ppm incorporated in quartz sand. Entry, herbicide dose, and entry × dose interaction effects were significant. C. maxima PI lines 368567 and 179264 exhibited the highest tolerance regardless of dose. Chemical name used: α,α,α-trifluoro-2,6-dinitro-N, N-dipropyl-p-toluidine (trifluralin).
Planting Methods to Improve Stand Establishment, Uniformity, and Earliness to Flower in Bell Pepper
Authors: Schultheis J.R. , Cantliffe D.J. , Bryan H.H. , Stoffella P.J.
Published: August 2022

Successive plantings were made from August through October in southeastern Florida to compare plant establishment methods and their effects on stand establishment, plant growth, and maturation (time to anthesis) of bell pepper (Capsicum annuum L.). Direct-seeding treatments were germinated seeds planted in potassium starch acrylamide (PSA) gel, magnesium silicate clay (MSC) gel, plug-mix, MSC gel mix, PSA gel mix. Nongerminated seeds were covered with soil or plug-mix. Three types of containerized transplants were used for comparison of earliness to flowering. Regardless of planting date, the PSA gel mix treatment generally led to earlier emergence and more uniform plant stands compared with the other direct-seeding techniques tested. Fluid drilling with PSA (without plug-mix) typically led to reduced plant stands, whereas all other direct-seeding methods did not differ in stands. Plant dry weights were increased as much as 100% when seeds were sown in PSA gel mix rather than with other seeding treatments. Plants established by transplanting began flowering at least 16 days earlier than plants established via direct seeding. Direct-seeding germinated seeds in PSA gel mix or plug-mix led to earlier, more uniform anthesis than sowing nongerminated seeds in soil.
Temperature and Light Integral Effects on Growth and Flowering of Hybrid Geraniums
Authors: White J.W. , Warrington I.J.
Published: August 2022

‘Red Elite’ hybrid geraniums were grown in controlled environment rooms and greenhouses with 109 combinations of daily light integrals (DLI) ranging from 9 to 25 mol·day−1·m−2 and daily mean temperatures (DMT) from 13.5° to 22.5°C. The time between seedling emergence and macrobud did not change significantly until the DLI was < 13 mol·day−1·m−2 (at 18° DMT). Flowering will not occur below a DLI of 3.3 mol·day−1·m−2. The time between emergence and macrobud progressively decreases as DLI increases until a DLI of close to 13 mol·day−1·m−2 is reached, and with increases in DLI above ≈17 mol·day−1·m−2 there is virtually no increase in the developmental rate of flower buds to the macrobud stage. Rate of development response of ‘Red Elite’ to temperature over the 9° to 27° range was curvilinear. DMT had more influence that DLI between 14 and 25 mol·day−1·m−2 on the time of flower development from macrobud to anthesis. The rate of development response over the 13° to 27° range was linear, and a heat sum relationship could be used to predict flowering. Increased DMT reduced the time between sowing and flowering with consequent reduction in dry weight and flower and bud numbers.
Net CO2 Assimilation and Plant Water Relations Characteristics of Pecan Growth Flushes
Authors: Andersen P.C. , Brodbeck B.V.
Published: August 2022

Spring- and summer-flush pecan [Carya illinoensis (Wangenh.) C. Koch] leaves were evaluated to determine climatological factors affecting leaf gas exchange, biophysical factors affecting growth, and to investigate the potential impact of a summer growth flush on alternate bearing. Expanding leaves had a higher osmotic potential, lower turgor pressure (ψp), poorer stomatal control, higher cuticular conductance, and a lower bulk modulus of elasticity than expanded leaves. Stomatal closure occurred at a progressively lower leaf water potential (ψw) as leaves aged. Net CO2 assimilation rate and leaf conductance to water vapor (g1) of pecan in the field did not decline in response to high atmospheric water stress and minimum midday ψw of −1.4 to −1.9 MPa when trees were supplied with adequate soil moisture. Leaf elongation rate was exponentially related to with marked reductions in growth occurring at ψp below 0.6 MPa and a complete cessation in growth below ψp = 0.3 MPa. Net CO2 assimilation rates of expanded leaves were up to 22 μmol·s−1m−2, several times higher than previously reported. Net CO2 assimilation rate was not inhibited by 41.5°C leaf temperature, 2000 μmol·s−1m−2 photosynthetic photon flux, and 3 kPa vapor pressure deficits (VPD). Transpiration rate (E) increased greatly with increasing VPD. Values of gl and E were generally higher than those reported for woody C3 perennials. The efficient water transport system of pecans under conditions of nonlimiting soil moisture may be a consequence of evolution in a floodplain ecosystem.
Field Evaluations of Frost Injury to Deciduous Fruit Trees as Influenced by Ice Nucleation-active Pseudomonas syringae
Authors: Proebsting E.L. , Gross D.C.
Published: August 2022

The influence of ice nucleation-active (INA) bacteria on the susceptibility of flower buds (flowers or fruitlets) to frost injury in the field was determined during 6 years for five species of deciduous fruit trees. Frost analyses compared trees supporting either low [usually undetectable to 102 colony-forming units (CFU)/g] or high (104 to 108 CFU/g) populations of INA Pseudomonas syringae. Frequent sprays of streptomycin and oxytetracycline maintained low INA bacterial populations throughout the frost-tolerant prebloom and frost-sensitive postbloom stages. Despite contrasting INA bacterial populations of up to 106 CFU/g between the two treatments, there were no differences in mortality of flowers and fruitlets exposed to frosts with minimum air temperatures between −2.5° and −4°C. Measurements of yield and assessments of fruit quality, moreover, showed no effect of INA bacteria, corroborating springtime evaluations of mortality due to frosts. Mean ice nucleation temperatures (MNT) for flowers or fruitlets attached to 50-mm woody stems reflected their tendency to freeze at about −2°, regardless of the size of the INA bacterial population. In contrast, excised flowers or fruitlets carrying high populations of INA bacteria consistently exhibited an MNT 1° to 2° lower, demonstrating the governing influence of the intrinsic wood-associated ice nuclei during orchard frosts. Sources of ice nuclei associated with fruit trees and factors modifying their activity in orchards are discussed in relation to the feasibility of frost protection by controlling INA bacteria.