bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Temperature Regime and Nitrogen Fertilizer Level on Vegetative and Reproductive Bud Development in Cymbidium Orchids
Authors: Powell Conway LI. , Caldwell Kate I. , Littler Ray A. , Warrington Ian
Published: August 2022

Clonally produced plants of Cymbidium Astronaut ‘Rajah’ (3.5 years exflask) were assigned to three day/night temperature regimes (20°C day/12° night, 26°/12°, and 26°/18°) at two nitrogen fertilizer rates (17 and 170 ppm N in the daily nutrient feed) in controlled environment rooms in Oct. 1984. Plants were removed at seven regular intervals between 29 Oct. 1984 and 15 Apr. 1985 and destructively harvested for assessment of bud development. There were, on average, 4.4 renewal vegetative buds (≥25 mm long) per plant produced over the 6-month experimental period with no apparent effect of temperature or nitrogen treatments on this cultivar. Of all vegetative renewal buds, 73% occurred on the bottom two nodes of the pseudobulb, whereas only 36% of reproductive buds grew from the bottom two nodes. Reproductive buds occurred up to the eighth node. By harvest 7, the 26°/12° temperature regime resulted in 5.9 reproductive buds per plant, with only 0.8 and 1.7 reproductive buds per plant, respectively, observed for the 20°/12° and 26°/18° temperature treatments. There was no effect of nitrogen fertilizer on floral bud numbers.
Inheritance of a Narrow Leaf Shape in Zinnia elegans
Authors: Cowen R.K. Duffy , Ewart L.C.
Published: August 2022

Two narrow-leaf (N1 and N2) and two wide-leaf (W1 and W2) Zinnia elegans Jacq. lines were developed. Three crosses were made: N2 × W2, W1 × N2, and W2 × N1. Six generations (P1, P2, F1, F2, BC-P1, and BC-P2) for each of the three crosses were evaluated on the basis of leaf width. A generation means analysis indicated that additive gene effects were of significant importance in the control of leaf width, while both dominance and epistatic effects were nonsignificant. High gains from selection on the basis of leaf shape are, therefore, indicated.
Water-soluble Cation Contents of ‘Jonathan’ Apple Fruit Pulp as an Estimation of Total Content
Authors: Saks Yolanta , Sonego Lilian , Ben-Arie Ruth
Published: August 2022

A method was developed to determine the total Ca, Mg, and K content of apple (Malus domestica Borkh.) pulp based on an assay in the water-extractable fraction. Water-soluble and total levels of each of the three elements in the fruit correlated significantly (P < 0.001) at harvest. The method is accurate (cv = 4.1%, 4.1%, and 2.5% for Ca, Mg, and K, respectively) and time-saving. The total level of minerals determined by the method proposed correlated well (P < 0.001) with that obtained by acid digestion of freeze-dried apple pulp.
Comparison of Fluid Drilling with Conventional Planting Methods for Stand Establishment and Yield of Spring and Fall Broccoli Crops
Authors: Kahn Brian A. , Motes James E.
Published: August 2022

Fluid drilling was compared with dry seeding and transplanting for stand establishment and effects on crop yields in spring and fall crops of broccoli [Brassica oleracea L. (Italica Group)]. Two cultivars, at least two seeding dates, and one transplanting date were used in each experiment. Fluid drilling and dry seeding produced the desired post-thinning stand with March seeding dates. Yields were variable for spring crops due to interactions with planting date. Fluid drilling usually was inferior to dry seeding for stand establishment with August seeding dates. Thus, fluid drilling was not superior to dry seeding or transplanting for earliness and uniformity of harvest and total marketable yields in fall broccoli crops. With timely planting, dry seeding or transplanting could be used for successful stand establishment and satisfactory yields of spring and fall broccoli crops. Fluid drilling did not seem advantageous, especially for fall crops. Cultivar and planting date effects often were more important than effects of stand establishment methods in these studies.
Stand Deficiencies and Replanting Effects on Tomato Fruit Yields and Size
Authors: Stoffella Peter J. , Maynard Donald N.
Published: August 2022

The effects of replanting stand-deficient plots on marketable tomato (Lycopersicon esculentum Mill.) fruit size and yields were investigated at Bradenton, Fla. during the 1986 spring and fall seasons. Treatments consisted of a control (10-plant plot) and plots with 9, 8, and 7 (10%, 20%, and 30%) missing plants. Other plots with the same stand deficiency were replanted to attain a complete stand 2 or 3 weeks and 1, 2, or 3 weeks after initial transplanting in the spring and fall experiments, respectively. Plots with 30% stand reduction produced a lower weight and number of marketable fruit per hectare than control plots in both seasons. In spring, replanting stand-deficient plots did not increase marketable fruit yields relative to plots not replanted, regardless of the time of replanting or percentage of stand reduction. In fall, under an unfavorable environment due to a late infestation of bacterial spot, replanting plots with 30% stand reduction increased marketable fruit yields over similar plots that were not replanted, when the replanting occurred 1 or 2 weeks after initial transplanting, but not when replanting was delayed 3 weeks. Small, medium, or extra-large marketable fruit weight per hectare were similar in both seasons for plots with 30% stand reduction, whether replanted or not. Mean fruit size (g/fruit) did not differ significantly among treatments in either experiment. These results suggest that replanting improved marketable tomato yields only when the level of stand deficiency reached 30% and only in a stressed environment.
Final Irrigation Timing for Spring Pea Seed Production
Authors: Raymond Michael A. , Stark Jeffrey C. , Murray Glen A.
Published: August 2022

Field studies were conducted in 1985 and 1986 to evaluate the effects of final irrigation timing on spring pea (Pisum sativum L. cv. Mars) seed yield, percent germination, and distribution of yield within the canopy. Final irrigations were applied on 10 dates during the period from 10% bloom to early senescence. Total seed yield did not increase with irrigations applied past 237 degree-days (base 4.5°C) after bloom (DDAB) in 1985 or 366 DDAB in 1986. However, the highest germination percentages and viable seed yields in 1985 and 1986 were obtained when final irrigations were applied at 487 and 450 DDAB, respectively. In 1986, total seed yield, percent germination, and viable seed yield throughout the canopy increased when the final irrigation was applied at 366 or 588 DDAB compared to earlier final irrigations. Viable seed yield reductions for the early irrigation cut-off dates resulted primarily from reduced numbers of pods per plant, and seeds per pod in the upper canopy (nodes 14 to 17) and decreased germination of seed produced throughout the canopy. We conclude that application of the final irrigation at ≈450 to 500 DDAB (usually 2 weeks after final pod set) should produce viable seed yields similar to those obtained with continued irrigation through early senescence.
Quantification of the Impact of Environment on the Susceptibility of Rosa hybrida Flowers to Botrytis cinerea
Authors: Marois James J. , Redmond Judith C. , MacDonald James D.
Published: August 2022

The relationship between Botrytis cinerea inoculum concentration and Botrytis blight on Rosa hybrida flowers from production greenhouses was monitored in the fall of 1985 and 1986 and winter of 1986 and 1987 under laboratory conditions. ‘Golden Wave’ rose flowers were inoculated with 0 to 104 conidia per milliliter and stored in incubation chambers at ≥95% RH and 21°C. Disease severity was quantified by the number of lesions per flower 48 hr after inoculation. The relationship between inoculum concentration and disease severity was linear; the coefficient of determination ranged from 0.87 to 0.99. The slope of the inoculum concentration–disease severity relationship was used to quantify susceptibility, which ranged from 0.006 to 0.035. Slopes were significantly greater with roses produced in December, January, and February (0.018 to 0.035) than those produced in October or November (0.006 to 0.013). Susceptibility of the flowers to B. cinerea was correlated linearly (r = 0.98) and inversely to the overall mean vapor pressure deficit from 0800 to 1900 hr for the 5-week growth period before harvest.
Inheritance of Resistance to Foliar Bacterial Spot of Tomato Incited by Xanthomonas campestris pv. vesicatoria
Authors: Scott J.W. , Jones J.B.
Published: August 2022

Hawaii 7998 (foliage resistant to bacterial spot) was crossed with ‘Walter’ (susceptible) and F1, backcross, and F2 generations were derived. These genotypes were grown in the field at Bradenton, Fla. in the summers of 1984 and 1985 and inoculated with Xanthomonas campestris pv. vesicatoria, the incitant of bacterial spot. Disease severity for respective genotypes was similar both years, although somewhat greater in 1985. Disease severity in the F1 was intermediate to the parents, but slightly skewed toward resistance both years. The percentage of F2 plants with resistance comparable to Hawaii 7988 was 9.6% in 1984 and 4.6% in 1985. There was no evidence of cytoplasmic inheritance from three sets of reciprocal crosses tested in 1985. The data fit an additive-dominance genetic model, but dominance variance was negative both years, which indicates a small or negligible dominance effect. The negative dominance variance resulted in biased estimates of additive variance, narrow-sense heritability, and the number of effective factors. Nevertheless, narrow-sense heritability was moderate to high. When incorporating this resistance into new genetic backgrounds, we suggest that a modified backcrossing scheme with rigorous disease screening be used to obtain plants from homozygous resistant BCF3 lines before crossing.
Olive Organ Abscission: Fruit and Leaf Response to Applied Ethylene
Authors: Lang Gregory A. , Martin George C.
Published: August 2022

Fruit-bearing olive (Olea europaea L.) shoots were exposed to more than 100 ethylene (C2H4) treatments to determine if C2H4-induced abscission varied between leaves and fruits in response to manipulation of treatment concentration, duration, and total amount of exogenous C2H4. Nearly three-quarters of the treatments induced greater fruit abscission than leaf abscission on a percentage basis. The potential for optimization of C2H4-induced fruit abscission relative to leaf abscission was examined by calculating the fruit-to-Ieaf (F:L) abscission ratio. Of the treatments inducing at least 75% fruit abscission, the dose range of 150 to 370 μmol C2H4 gave ratios up to 13.3; however, results were highly variable and closely dependent on the interaction of concentration and duration. Response surfaces were created to depict this interaction. Desirable levels of fruit abscission occurred at durations > 30 hr and concentrations > 2 to 3 μl·liter−1. However, excessive leaf abscission occurred at durations of 24 to 48 hr, depending on concentration. Acceptable F:L ratios were found for about 30% of the surface, with the highest ratios occurring for treatments of 3 to 5 μl·liter−1 for 28 to 34 hr.
Evaluation of Benzyladenine as a Chemical Thinner on ‘McIntosh’ Apples
Authors: Greene Duane W. , Autio Wesley R.
Published: August 2022

Five chemical thinning trials, conducted over 4 years, indicated that BA is an effective thinner for ‘McIntosh’ apples (Malus domestica Borkh.). Although it can thin at concentrations as low as 25 mg·liter−1, in most years a higher concentration was required to thin adequately. It appeared that 14 to 18 days after full bloom, when fruit size was about 10 mm, may be the period when maximum thinning was achieved. Greater thinning occurred when BA and carbaryl were combined than when they were used individually. BA increased fruit weight, flesh firmness, and soluble solids content at harvest relative to no thinning. The storage life of fruit treated with BA was less than that of fruit from nonthinned trees, but this effect may have been an indirect response related to the larger fruit size rather than a direct response to the chemical. BA caused thinning and induced lateral branching simultaneously on young ‘Macspur McIntosh’ trees. Therefore, crop load on trees just coming into production may be significantly reduced when BA is used to induce lateral branching. Chemical names used: N-(phenylmethyl)-IH-purine-6-amine [benzyladenine (BA)], 1-napthaleneacetic acid [NAA], 1-naphthalenyl methylcarbamate [carbaryl].
Temperature and Photoperiod Influence Reproductive Development of Reduced-photoperiod-sensitive Mungbean Genotypes
Authors: Fernandez George C. J. , Chen H. K.
Published: August 2022

Using the 9th and 10th International Mungbean Nursery (IMN) data, quadratic response surface models were developed to predict days to flowering (DF) of mungbean [Vigna radiata (L.) Wilczek] genotypes grown at 11-hr and 30 min and 13-hr and 30-min preflowering mean photoperiod (P) and 22 to 30C mean diurnal temperature (T) regimes. Both linear and quadratic effects were significant on DF and on the rate of progress towards flowering (1/DF); however, only the linear effect was significant in days to maturity (DM). The effect of T was more pronounced than that of P on DF of reduced-photoperiod-sensitive (RPS) genotypes. The earliest DF (flowering tendency) was estimated at 34 days after planting at the optimum mean diurnal temperature (T0) of 28C and the optimum mean photoperiod (P0) of 12 hr. At the suboptimal temperature (T < T0), the estimates of the base temperature Tb and the thermal time θr were 10C and 555 degree-days, respectively. Thus, flowering dates of these RPS mungbean lines can be predicted, which in turn will assist in the selection of proper planting dates.
Photoperiodic Inhibition of Stem Elongation and Flowering in Rudbeckia hirta ‘Marmalade’
Authors: Orvos Andrea R. , Lyons Robert E.
Published: August 2022

Rudbeckia hirta ‘Marmalade’, a long-day (LD) plant, required a minimum of 4 LD for flower initiation. Continuation of LD photoperiods beyond the minimum cycle number was essential for normal growth and development. Plants that received only enough LD for floral initiation were half as tall and flowered significantly later than plants held in LD for the entire experiment. Limited periods of LD were much more effective than soil applications of up to 50 ppm ancymidol for height control, and 50 ppm ancymidol delayed flowering. Chemical name used: α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidinemethanol (ancymidol).
Salvia splendens Seed Pregermination and Priming for Rapid and Uniform Plant Emergence
Authors: Carpenter William J.
Published: August 2022

Salvia (Salvia spendens, F. Sellow ex Roem & Schult.) seeds imbibed in distilled water at 6C for 6 days germinated earlier and with fewer days to 50% of total germination (T50) than non-imbibed seeds. Drying imbibed seeds for 1 to 5 days at 5C and 45% RH before sowing signficiantly reduced seed viability. Priming seeds in a hypertonic osmotic solution of aerated polyethylene glycol 8000 (PEG) at —0.8 MPa for 10 days at 15C improved germination of the three cultivars tested. In laboratory and plant growth chamber trials, seeds primed with PEG 8000 and nonprimed seeds had similar total germination at 20 and 25C, but primed seeds had significantly higher germination at 10, 15, and 30C. At 35C, PEG-primed seeds had 44% to 65% germination, while nonprimed seeds failed to germinate. Alternating 10 and 20C or 20 and 30C diurnally at 12-hr cycles did not increase total germination regardless of seed treatment. Seeds primed with PEG had lower T50 than nonprimed seeds at 10, 15, 20, 25, and 30C, with the largest difference at the most unfavorable temperatures for germination. Primed seeds stored at 5C for 1 to 16 weeks reduced total germination and the potential capacity for rapid germination.
Allocation of Nutrients in Huckleberries
Authors: Stark Nellie , Baker Stephen , Essig Don
Published: August 2022

Plant nutrient content and major organic components were determined in 35 clones of huckleberry (Vaccinium globulare Rydb.) growing in seven major berry-producing areas of western Montana. Roots were sinks for Al, Cu, and Fe, while leaves concentrated B, Mg, and Si. Flowers were high in K, P, Zn, and total N. Berries had a high Na content. Leaves of young plants contained different nutrient concentrations than those of older plants without berries. Mature plants that produced berries differed in nutrient concentrations from those that did not. Productivity of wild plants under moderate climatic stress can be predicted using the concentrations of Ca and Mg in the old stems, Cu and calories in the rhizomes, Fe in the new stems, and from the total plant ash content. Large high-producing plants had significantly greater concentrations of nearly all nutrients than large low-producing plants. Plant size and age appear to be related to berry production, which was highest in soils with high organic content and high available elemental content.
Effect of Cold Storage on Changes in the Contents of Total and Individual Free Amino Acids in Corollas from Cut ‘Sonia’ Roses
Authors: Lukaszewska A. J. , Dreise G. R. , Pérez-Zúniga F. J. , Gorin N.
Published: August 2022

There was an accumulation of total free amino acids (calculated as the sum of the individual amino acids) in corollas from cut ‘Sonia’ roses (Rosa hybrida) stored at 2C (cold-stored flowers) but not in those kept at 20C (control flowers). In cold-stored flowers, senescence was retarded, as indicated by only a slight opening of the corolla and no subsequent petal abscission. Hence, there appeared to be no direct correlation between senescence of cut roses and accumulation of total amino acids in corollas; neither was there a relationship between individual or total free amino acids and protease activity in the corollas from either cold-stored or control flowers. Changes in the contents of all free amino acids, except alanine and lysine, were affected by cold storage. The effect on aspartic acid was statistically significant, but not spectacular. Cold storage delayed the decrease in contents of glutamic acid, asparagine, tyrosine, glycine, leucine, isoleucine and valine, and prevented accumulation of phenylalanine, proline, and histidine. We detected only one theoretically expected interconversion between two amino acids; i.e., glutamic acid to proline, that occurred in corollas from control flowers during the first 6 days of storage. We suggest that the patterns of changes in the contents of tyrosine, valine, isoleucine (or isoleucine plus leucine), and phenylalanine are not restricted to the cultivar Sonia.
Manganese and Rates of Growth and Mineral Accumulation in Cucumber
Authors: Crawford T. W. , Stroehlein J. L. , Kuehl R. O.
Published: August 2022

‘Sumter’ cucumber (Cucumis sativus L.) plants were grown in the vegetative state with nutritionally sufficient solution followed by a 2-week period with Mn deficiency (no Mn), sufficiency (0.1 mg Mn/liter), or toxicity (10 mg Mn/liter). Beginning 34 days after germination, or about 2 weeks before imposition of Mn deficiency and toxicity treatments, plants were harvested every 3 days. With Mn deficiency and toxicity, rates of accumulation of dry weight (DW), fresh weight (FW), N, P, and K were lower than with Mn sufficiency. In contrast, rates of accumulation for Cu, Fe, and Zn were generally higher with Mn deficiency, compared to these fluxes in Mn-sufficient plants. Anomalously high accumulation rates for DW, FW, Cu, and Mn were estimated for the 3-day period following the beginning of the toxic Mn treatment.
Chilling Requirement of Post-rest Heat Accumulation as Related to Difference in Time of Bloom Between Peach and Western Sand Cherry
Authors: Werner Dennis J. , Mowrey Bruce D. , Young Eric
Published: August 2022

In the article “Chilling Requirement of Post-rest Heat Accumulation as Related to Difference in Time of Bloom Between Peach and Western Sand Cherry,” by Dennis J. Werner, Bruce D. Mowrey, and Eric Young [J. Amer. Soc. Hort. Sci. 113(5):775-778, September 1988], in the legend of Fig. 2, second line, “14 hr” should read “1400 hr”.
Nitrate and Ammonium Uptake by Nitrogen-deficient Perennial Ryegrass and Kentucky Bluegrass Turf
Authors: Bowman D. C. , Paul J. L. , Davis W. B.
Published: August 2022

Nitrogen uptake by two N-deficient turfgrass species was characterized by measuring N depletion from a complete nutrient solution. The uptake rate of both and was enhanced up to 6-fold in N-deficient perennial ryegrass (Lolium perenne L.) compared to N-sufficient controls, reaching a maximum of about 0.3 and 0.4 g N/m2 per hr for and , respectively. Deficiency-enhanced uptake exceeded uptake by controls for about 72 hr following resupply of N. Nitrogen uptake was enhanced to a similar degree by N deprivation in Kentucky bluegrass (Poa pratensis L.). Mowing had no effect on uptake by N-deficient perennial ryegrass turf, whereas mowing inhibited uptake by N-sufficient turf by ≈60%. Deficiency-enhanced uptake was found to be the result of an increased capacity for N absorption (Imax) rather than an increased affinity for N (Km). Imax values increased from 0.24 and 0.73 mg N/g dry weight per hr for N-sufficient ryegrass turf for and , respectively, to 1.44 and 2.68 mg N/g dry weight per hr for N-deficient turf. Km values increased slightly, from 14 μm for both N forms for N-sufficient turf to 24 and 39 μm for and , respectively, for N-deficient turf.
Characterization of Ancymidol Effects on Growth and Pigments of Helianthus annuus Cultivars
Authors: Starman T. W. , Kelly J. W. , Pemberton H. B.
Published: August 2022

Ancymidol foliar spray at 66 and 132 mg·liter−1 a.i. significantly decreased height, node number, leaf area, fresh weight, and dry weight of four sunflower cultivars. Ancymidol resulted in darker green leaves and increased chlorophyll content per unit area, as measured spectrophotometrically, when compared with controls. However, chlorophyll a, b, and total chlorophyll were increased in only two cultivars when measured on a weight basis using high-performance liquid chromatography (HPLC). Ancymidol increased three xanthophyll levels (neoxanthin, vio-laxanthin, and lutein) in the four cultivars, but had no effect on β-carotene when measured on a weight basis by HPLC. Chemical name used: a-cyclopropyl-a-(4-methoxyphenyl)-5-pyrimidine methanol (ancymidol).
Recovery of γ-Linolenic Acid from Somatic Embryos of Borage
Authors: Quinn James , Simon James E. , Janick Jules
Published: August 2022

Somatic embryos of borage (Borago officinalis L., Boraginaceae) were induced directly from immature zygotic embryos and indirectly from callus. Embryogenic callus maintained on liquid basal medium supplemented with 4.5 μm 2,4-D and 10% (v/v) coconut water (CW) produced globular structures that became rhizogenic upon transfer to 2,4-D-free basal medium. Embryogenic callus maintained on semisolid basal medium supplemented with 4.5 μm 2,4-D and 10% CW continued to produce somatic embryos, but development was abnormal. Globular structures often failed to develop cotyledons, and those that developed were small and fused; hypocotyls tended to be large and elongated. Root meristems appeared normal, but shoot meristems were not formed. Carbon source (sucrose, glucose, or maltose) and ABA did not normalize somatic embryogenesis. A highly embryogenic, non-browning clone produced various tissue types when 2,4-D was withdrawn that varied in total fatty acids: white nodular structures (12.6%), cotyledonary structures (22.5%), white callus (5.0%), green leafy growth (3.1%), and translucent globular growth (5.1%). γ-Linolenic acid, as a percentage of total fatty acids, was highest in cotyledonary structures (19.9%) and lowest in white callus (10.2%). Chemical names used: abscisic acid (ABA); 2,4-dichlorophenoxyacetic acid (2,4-D); coconut water (CW).
Salinity Influences Cucumber Growth and Yield
Authors: Jones R. W. , Pike L. M. , Yourman L. F.
Published: August 2022

Germination and radicle elongation experiments were performed with six cultivars of cucumber (Cucumis sativus L.) at seven salinity concentrations (0, 0.8, 4.0, 6.0, 9.0, 12, and 15 dS·m−1). Increasing salinity has no effect on final germination percentage after 5 days, but did decrease radicle elongation. In seedling growth studies with salinity levels ranging from 0.8 to 12 dS·m−1, increasing salt levels decreased shoot length and shoot dry weight. Analysis of shoot tissue from these seedlings indicated that higher salinity levels increased concentrations of Ca and Na, while Mg and K concentrations decreased. Yield and fruit quality were measured in a greenhouse study at two salinity levels (1.6 and 4.0 dS· m−1). Salinity significantly decreased fruit yield in five of six cultivars, but had no effect on fruit quality. Seedling shoot length of a cultivar grown at 9.0 dS· m−1 was correlated with relative yield at 4.0 dS· m−1. A salinity screening technique based on this relationship is proposed.
Calcium Deficiency Reduces Cucumber Fruit and Seed Quality
Authors: Frost David J. , Kretchman Dale W.
Published: August 2022

‘Sumter’ cucumber plants (Cucumis sativus L.) were grown in an acid-washed sand with a modified Hoagland's solution containing calcium (Ca) at 160 (control), 80, or 40 mg·liter−1. Fruits grown under low Ca levels developed water-soaked and necrotic lesions on the epidermis and pericarp of the distal end of the fruits. Some Ca-stressed fruits also developed a placental disruption near the stem-end forming a cylindrical air pocket. Fruit fresh and dry weights from 40 mg Ca/liter were lower than those of the control between weeks 4 to 7 of development. The Ca content of the fruit pericarp sections decreased with increased Ca stress. Regardless of treatment, the proximal peduncle portion contained the highest level of Ca, while the distal section contained the lowest. Seed quality was also reduced from Ca stress. Almost all dry seeds from the control but only 70% of those from 40 mg Ca/liter germinated with the standard germination test. Drying seed at 25C for 5 days reduced the viability of Ca-stressed seeds, when compared to undried seed (72% vs. 99% germination). The vigor of the control seeds was significantly higher when dried. Seeds from the 40 mg Ca/liter treatment produced a significantly higher proportion of abnormal seedlings than the control seeds (58% vs. 4%).
Modeling Row Cover Effects on Microclimate and Yield: I. Growth Response of Tomato and Cucumber
Authors: Wolfe David W. , Albright Louis D. , Wyland Jonathan
Published: August 2022

Several polyethylene and fabric row cover materials, and clear and black polyethylene mulch, were evaluated in a 2-year field study. For cucumbers [Cucumis sativus (L.)], visible wilting and slowed growth rates of young transplants exposed to cold nights were minimized when grown under row covers that maintained high humidities and higher air and soil temperatures than in the exposed controls. Early cucumber yields were increased 2- to 6-fold by the use of covers. In contrast, tomatoes [Lycopersicon esculentum (Mill.)] showed no significant early yield increases, but a 63% reduction in early yield in 1985 under a perforated clear polyethylene cover. The frequency and duration of daytime air temperatures exceeding 35C had a negative impact on tomato fruit size, quality, and percentage marketable. For cucumber, the relationship between cumulative degree days (during the covered interval) and biomass, early, and total yields was linear (r2 between 0.70 and 0.82) with positive slope. Tomato yields could not be accurately predicted using this approach, but correlations were improved (for the 1985 data set) by using modified degree-day formulas incorporating a negative high-temperature factor.
Asparagus Aphid Feeding and Freezing Damage Asparagus Plants
Authors: Valenzuela Hector R. , Bienz Darrel R.
Published: August 2022

Asparagus aphid [Brachycorynella asparagi (Mordvilko)] feeding without freezing reduced vigor of asparagus (Asparagus officinalis L.), as measured by crown size, fern growth, root necrosis, and bud number, but did not greatly reduce short-term survival. Freezing dormant crowns for 24 hr at −4.5C killed some crowns and reduced vigor of survivors. Aphid feeding and freezing were synergistic; they reduced survival and vigor of survivors to a much greater extent than either aphid feeding or freezing alone. Aphid feeding resulted in early budbreak and precocious growth. A method for counting aphids per plant was developed.
Boron Tolerance of Snap Bean and Cowpea
Authors: Francois L. E.
Published: August 2022

The effect of excess B in the soil solution on snap bean (Phaseolus vulgaris L.) and cowpea [Vigna unguiculata (L.) Walp.] was determined in large, outdoor sand tanks. Boron treatments were imposed by irrigation with culture solutions that contained 0.5, 1.0, 3.0, 6.0, 9.0, or 12.0 mg B/liter for snap bean; and 1.0, 2.0, 3.0, 4.0, 6.0, or 8.0 mg B/liter for cowpea. Relative pod yield of snap bean was reduced 12.1% and cowpea seed yield was reduced 11.5% with each unit (mg·liter−1) increase in soil solution B (Bsw) >1.0 and 2.5 mg B/liter, respectively. Reduced yield of snap bean pods and cowpea seeds was attributed primarily to a reduction in pod number. Increasing Bsw significantly reduced plant size of both species.
Tolerances of California Nectarine Cultivars to Methyl Bromide Quarantine Treatments
Authors: Harvey John M. , Harris C. Max , Hartsell Preston L.
Published: August 2022

The tolerance of six cultivars of nectarine [Prunus persica (L.) Batsch var. nectarina (Ait.) Maxim.] to methyl bromide (MB) quarantine treatments was determined. A treatment, 48 g MB/m3 for 2 hr at 21C, which controlled codling moth [Cydia pomonella (L.)], caused no significant phytotoxic response in any of the cultivars. The threshold for injury at the above time and temperature was ≈64 g MB/m3 in ‘Summer Grand’, ‘May Grand’, ‘Fantasia’, and ‘Firebrite’; between 48 and 64 g MB/m3 in ‘Red Diamond’; and between 80 and 96 g MB/m3 in ‘Spring Red’. All fumigated nectarines were significantly firmer than the control fruit after storage for 7 days at 2.5C, but subsequently ripened satisfactorily; soluble solids content of the fruit was not affected by the fumigations used in this study. Inorganic bromide residues in fruit treated with the 48 g·m−3 dosage at 21C or above ranged from 3.5 to 7.2 ppm, well below the U.S. tolerance of 20 ppm. Organic bromide residues were <0.01 ppm within 48 hr after treatment.
Regulation of Russet Spotting, Phenolic Metabolism, and IAA Oxidase by Low Oxygen in Iceberg Lettuce
Authors: Ke Dangyang , Saltveit Mikal E.
Published: August 2022

A 1.5% O2 atmosphere, relative to normal air, dramatically inhibited ethylene-induced russet spot development, PAL, and ionically bound POD, and ionicaliy bound IAA oxidase activities and reduced soluble phenolic content in stored iceberg lettuce (Lactuca sativa L.). Low O2 also inhibited eythylene production and respiration. Polyphenol oxidase activity was slightly inhibited by low O2. The results suggest that low O2 inhibition of ethylene action and attendant effects on phenolic metabolism and IAA oxidase activity may be responsible for inhibition of russet spotting by 1.5% O2. Chemical names used: indole-3-acetic acid (IAA); phenylalanine ammonia-lyase (PAL); peroxidase (POD); polyphenol oxidase (PPO).
Steryl Lipid Content and Composition in Bell Pepper Fruit at Three Stages of Ripening
Authors: Whitaker Bruce D. , Lusby William R.
Published: August 2022

The content and sterol composition of free sterols (FS), steryl esters (SE), acylated steryl glycosides (ASG), and steryl glycosides (SG) in pericarp tissue of bell pepper fruit from three cultivars (Capsicum annuum L. cv Gator Bell, Bell Tower, and Lady Bell) were determined at three stages of ripening (mature-green, turning, and red-ripe). In each cultivar, FS were predominant at all stages of ripening, with ≈5- to 20-fold lesser amounts of SE, ASG, and SG. The proportions of the sterol conjugates (SE, ASG, and SG) varied somewhat between cultivars, but there was a consistent increase in the ratio of SG to ASG with ripening. The sterol composition of steryl lipids was quite similar in the three cultivars, and only minor changes occurred with ripening. Sitosterol was always the major sterol, followed by campesterol. Sitosterol plus campesterol comprised 89% to 95% of the total sterols in FS, ASG, and SG, and 74% to 91% in SE. Cholesterol and stigmasterol were always present as minor (1% to 4%) constituents. In general, small increases in stigmasterol and several minor, unidentified sterols occurred with ripening, at the expense of sitosterol and campesterol. These changes were greatest in SE.
Zygotic Polyembryony in Interspecific Hybrids of Carica papaya and C. cauliflora
Authors: Manshardt Richard M. , Wenslaff Timothy F.
Published: August 2022

A study of reproductive barriers limiting interspecific hybridization between Carica papaya L. and C. cauliflora Jacq. was undertaken in four reciprocal interspecific crosses using two different lines of each species. Particular attention was focused on determining whether polyembryonic clusters produced in these crosses were of maternal or zygotic origin. Prezygotic barriers were unimportant; pollen tube penetration and zygote formation were similar in intra- and interspecific crosses. Substantial postzygotic disruptions were observed, including disorganized growth and abortion of hybrid embryos and lack of normal endosperm development. In most crosses, disorganized embryos aborted before differentiating into polyembryonic structures. However, crosses employing UH345 (C. cauliflora) as female parent produced some embryos that developed to maturity (6 months), and, in these crosses, embryogenic proliferation from zygotic tissue became evident as early as the beginning of the 3rd month. There was no evidence of somatic embryogenesis from maternal tissues in any cross. Embryos rescued 3 to 6 months after pollination continued embryogenic growth in vitro on basal Murashige and Skoog (MS) medium and germinated on medium containing 0.2 mg BA/liter and 0.5 mg NAA/liter. Zymograms assayed for isocitrate dehydrogenase, malate dehydrogenase, and phosphoglucomutase activity confirmed the zygotic origin of tissues taken from in vitro cultures and recovered plantlets. Vigor, viability, and fertility (< 1% stainable pollen) of hybrids recovered from embryo culture were low. Chemical names used: 6-benzylaminopurine (BA); 1-napthaleneacetic acid (NAA).
Growth and Yield of Rabbiteye Blueberry as Affected by Orchard Floor Management Practices and Irrigation Geometry
Authors: Patten Kim D. , Neuendorff Elizabeth W. , Nimr Gary H. , Peters Stan C. , Cawthon Don L.
Published: August 2022

‘Tifblue’ and ‘Delite’ rabbiteye blueberry (Vaccinium ashei Reade) plants were grown for 4 years with or without mulch, with cultivated or sodded row middles, and under various irrigation treatments [one drip emitter at the base of the plant, two drip emitters 46 cm on either side of the plant, or a 40° or 360° low-volume spray emitter (LVSE) placed midway between plants]. Plant establishment and growth were optimal with 360° LVSE. Differences between irrigation treatments were minimized with mulch. Mulch increased growth of drip-irrigated but not of LVSE-irrigated plants and increased the yield of two-emitter and 360° LVSE-irrigated plants but not of one-emitter or 40° LVSE-irrigated plants. Treatment effects on growth were more apparent in the early establishment phase than in the 4th year of growth and with ‘Tifblue’ than ‘Delite’. Frost damage on ‘Delite’ was reduced by mulch. Vegetative bud development in the spring and fruit maturity were usually delayed on plants grown between sodded alleys or with mulch. Leaf drop in the fall was also delayed by mulch.
Heritability, Phenotypic Correlations, and Associations of the Common Blight Disease Reactions in Beans
Authors: Aggour Ahmed R. , Coyne Dermot P.
Published: August 2022

Common blight in beans (Phaseolus vulgaris L.) incited by Xanthomonas campestris pv. phaseoli (Smith) Dye (X c p) reduces crop yield and seed quality. The objective of this experiment was to study heritability and phenotypic correlations of the disease reaction to various strains of X c p at several plant developmental stages in specific bean crosses using diverse methods of inoculation. Leaf and pod disease reactions to strains of X c p were inherited quantitatively and narrow-sense heritability estimates were low in the following crosses between Phaseolus vulgaris cultivars/lines: Bac-6 (moderately resistant = MR) × NE-EP1 (MR); Bat-862 (MR) × ‘Pompadour Checa’ (susceptible = S); ‘Pompadour Checa’ (S) × Bac-6 (MR); ‘Venezuela 44’ (S) × Bat-862 (MR). Pod disease reaction was not correlated with leaf disease reaction at any growth stage. Low or nonsignificant phenotypic correlations were detected between disease reactions of leaves at the seedling and flowering stages with the several methods of inoculation. Intermediate phenotypic correlations were found for disease reactions with three methods of inoculation at the seedling stage, but only with two methods in the flowering stage. Negative or nonsignificant phenotypic correlations were observed between leaf disease reaction and number of days to first flower. Different duplicate recessive genes were found to control two foliar abnormality traits: crippled growth and variegated leaves. No plants with a combination of both traits were observed. An association was found between crippled growth and a high level of resistance to strain V3S8 of X c p in the cross Bat-862 × ‘Pompadour Checa’.
Heat Tolerance and Pod Set in Green Beans
Authors: Dickson M. H. , Petzoldt R.
Published: August 2022

Heat at any growth stage can damage green beans (Phaseolus vulgaris L.), but plants are most susceptible at or near bloom. The effect of heat during the bloom period resulted in reduction of a yield in proportion to the duration of the heat period. The most critical growth stage was found to be 2 to 3 days before anthesis, rather than at anthesis itself. By subjecting F1 plants to heat during the bloom period, genetic selection for heat tolerance was moderately effective. The heritability for heat tolerance was quite low. Broad-sense heritability was 19% to 79% and narrow-sense heritability 0% to 14%. These values are probably conservative, since during the genetic study the heat period was initiated on the first day of bloom, which resulted in some escapes and excess variability.
Thinning Response of Early, Mid-, and Late-season Peaches
Authors: Johnson R.S. , Handley D.F.
Published: August 2022

The response of fruit size and fruit size distribution was studied in four peach (Prunus persica L. Batsch.) cultivars (May Crest, June Lady, Elegant Lady, O’Henry) ranging in maturity date from late May to early August (75 to 150 days after bloom). Mature, open-vase trees were thinned to fruit levels ranging from 150 to 2200 fruit per tree. The slopes of the linear relationships between fruit weight and fruit number per tree were consistent among cultivars, but their y-intercepts increased proportionate to maturity date. The standard deviation of individual fruit weights tended to decrease with increasing fruit number per tree and increased with later-maturing cultivars. However, the coefficient of variation remained nearly constant among cultivars. Mean fruit weight generally dropped off with successive harvests, especially on trees with heavy fruit loads. Heavy fruit loads also delayed maturity in all four cultivars. This study measured the variation of fruit weight response to thinning, information that is needed for a detailed economic analysis of thinning to different fruit loads.
Paclobutrazol and Root Zone Water Content Influence Peach Seedling Behavior
Authors: Biasi Rita , Costa Guglielmo , Succi Flavia , Nishijima Chic , Martin George C.
Published: August 2022

Containerized peach [Prunus persica (L.) Batsch.] seedlings were grown in the greenhouse at three water levels [25%, and 100% field capacity (FC)] with experiments duplicated in Bologna, Italy and Davis, Calif. One group of the seedlings was treated with 0.1 g active ingredient (a.i.) paclobutrazol (PBZ) applied as a soil drench, whereas the second group received water only. Addition of PBZ suppressed shoot growth and leaf area more than reduced water content alone. PBZ reduced root fresh and dry weights and total water consumption. At 0600 and 1200 hr, PBZ increased stomatal conductance at 100% FC; later that same day stomatal conductance decreased. At 50% and 25% FC, PBZ decreased stomatal conductance compared to controls at all times measured. Chemical name used: (2RS, 3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)pentan-3-ol (paclobutrazol).
Stability Differences among Fresh-market Tomato Genotypes: II. Fruit Quality
Authors: Gull Dwain D. , Stoffella Peter J. , Locascio Salvador J. , Olson Steve M. , Bryan Herbert H. , Everett Paul H. , Howe Teresa K. , Scott John W.
Published: August 2022

Ten fresh-market tomato (Lycopersicon esculentum Mill.) genotypes were evaluated for stability of fruit firmness, citric acid, soluble solids, β-carotene and ascorbic acid concentrations, sugar : acid ratio, color, N content, and dry weight when grown in nine environments. Linear relationships between the genotype means for a given trait and the mean for the trait in each environment were used as an indicator of stability. A stable genotype for a given trait was considered to possess a regression coefficient (b1) ⩽ a coefficient of linear determination (r2) > 0.50, a genotype mean above the grand mean (mean of all genotypes), and a nonsignificant deviation from regression mean square (S2d). Using these criteria, stability in the nine environments was shown by the fruits of the various cultivars as follows: ‘Flora-Dade’, ‘FTE-12’, and D76I27 for firmness; ‘Castlehy 1035’ and ‘Sunny’ for citric acid; ‘Walter’ for soluble solids concentration; ‘FTE-12’ for ascorbic acid concentration; ‘Hayslip’, ‘Walter’, and ‘Burgis’ for sugar : acid ratio; ‘FTE-12’ and ‘Hayslip’ for β-carotene concentration: ‘Flora-Dade’ and 827115-IBK for color a/b; ‘Castlehy 1035’ and ‘Hayslip’ for dry weight; and ‘Walter’ for N content. Stable genotypes are less sensitive to environmental changes and are more adapted to favorable and unfavorable conditions than unstable genotypes. No genotype was found to be stable for every fruit quality trait in the nine environments. Stability of fruit quality characteristics should be considered in tomato breeding programs to develop genotypes adapted to diverse environmental and management conditions.
Regulation of Ethylene Biosynthesis in Broccoli Flower Buds in Controlled Atmospheres
Authors: Makhlouf Joseph , Willemot Claude , Arul Joseph , Castaigne François , Emond Jean-Pierre
Published: August 2022

The effect of controlled atmospheres on the regulation of ethylene biosynthesis during the senescence of broccoli flower buds (Brassica oleracea, L. Italica group cv. Green Valiant) was assessed. The broccoli buds wee stored in the dark at 25C under a continuous stream of nitrogen containing the following percentages of CO2-O2 : 0-20 (air), 0-2.5, 6-20, and 10-20. Generally, respiration, ethylene production, and ethylene-forming enzyme (EFE) activity followed a climacteric like pattern in all atmospheres. The ACC content changed little during the “climacteric”, but increased dramatically during the “post-climacteric” period, when ethylene production and EFE activity decreased. Under high CO2, respiration was reduced, but ethylene production and EFE activity were temporarily stimulated early during treatment. Under low O2, respiration, ethylene production, EFE activity, and ACC content were reduced, and the “climacteric” and chlorophyll losses were delayed to a greater extent than under high CO2. Whatever the treatment, ACC level was not the limiting factor in ethylene biosynthesis in broccoli; the reduction in ethylene production during senescence resulted from the degradation of the system that converts ACC to ethylene. Chemical name used: 1-aminocyclopropane-1-carboxylic acid (ACC).
Utilization of Hardwood Bark in Media for Growing Woody Ornamental Plants in Containers1
Authors: Klett J. E. , Gartner J. B. , Hughes T. D.
Published: August 2022

Hardwood bark was used in combination with other materials as media for forsythia and juniper plants in containers with various growing procedures, bark sources, and fertility practices. Based on dry wt, the most rapid growth of forsythia was obtained in a bark and fine sand medium; whereas, the least growth was obtained in soil, peat, and perlite. However, pfitzer juniper plants under 2 different fertility regimes grew most rapidly in a bark, soil, and peat medium, slowest in a bark and torpedo #2 sand medium, and at an intermediate growth rate in soil, peat, and perlite. The standard mix (soil, peat, and perlite) was more acidic than the experimental mixes containing bark and sand. Chlorotic plants were more numerous in acidic mixes. Leaf tissue analyses from the plants grown in the peat amended bark and standard mix had higher Fe and Mn concn than plants grown in a bark-sand mix.
Movement of 14C in Cut Roses and Carnations After Uptake of 14C-Sucrose1
Authors: Sacalis John N. , Durkin Dominic
Published: August 2022

Movement of 14C was studied in cut roses and carnations using a pulse of 14C-sucrose and a distilled water chase. The label moved selectively to leaves and stems, but not to flower heads during the pulse. During the chase, however, 14C moved from leaves and stems into the flower heads. Age had no effect on this movement into rose flower heads, but movement of 14C into carnation flower heads diminished as cut carnations aged.

It was established by girdling cut rose stems that assimilates are translocated from leaves and stems to flower heads via the phloem.
Effect of Irrigation Treatments for Apple Trees on Water Uptake from Different Soil Layers1
Authors: Levin I. , Assaf R. , Bravdo B.
Published: August 2022

Six irrigation treatments consisting of replenishing the water extracted from the 0-60 cm or 0-120 cm layer, were applied to a 10-year-old apple orchard. The highest yield and fruit size were obtained by irrigating to 60 cm depth when soil moisture to this depth dropped to 40% available water during the 2 months of intensive fruit growth. During the rest of the season this treatment was irrigated to 60 cm whenever the 0-60 cm layer dropped to wilting point and to 120 cm whenever the 60-120 cm layer dropped to 60% available water. The relative water extraction from the 60-90 cm layer was the highest in this treatment. Increasing water uptake from layers below 120 cm by watering them was not effective. Climatic conditions favoring high rates of evaporation increased the relative contribution of layers deeper than 90 cm in all plots. The proportion of water loss from the 0-30 cm layer increased with the number of irrigations.
Salt Tolerance of Ornamental Shrubs and Ground Covers1
Authors: Bernstein L. , Francois L. E. , Clark R. A.
Published: August 2022

The salt tolerance of 25 shrub and ground-cover species was determined in plots artificially salinized with NaCl + CaCl2. Chloride and Na injury was observed in sand cultures of the same species with 4 different salt treatments. Tolerant species, like bougainvillea, Natal plum, and rosemary were affected little, if at all, by soil salinities of 8 mmho/cm (electrical conductivity of the saturation extract: ECe), whereas sensitive species like star jasmine, guava, holly, and rose were severely damaged or killed at ECe’s of 4 mmho/cm. Salt tolerance was not well correlated with injury by Cl or Na, although many species exhibited leaf burn; nor was survival under highly saline conditions necessarily a good index of salt tolerance. Five-gallon specimens of sensitive, slow-growing species such as pittosporum were more tolerant than 1-gal specimens and delaying salination of such species increased salt tolerance somewhat. Leaves with symptoms like those of Cl or of Na injury but containing very little of these ions were frequently observed in landscape plantings of a number of shrub species. The injury was attributed to inadequate watering. It is suggested that Cl or Na accumulation in leaves of shrubs may cause injury by interfering with normal stomatal closure, causing excessive water loss and leaf injury symptoms like those of drought.