bluuebunny/crossref_metadata_2025 huggingface dataset:
Conserving Water in Sprinkling for Frost Protection by Intermittent Application1
Authors: Perry Katharine B. , Martsolf J. David , Morrow C. Terry
Published: August 2022

Adjustment of the sprinkling application rate to existing atmospheric conditions to conserve water may be accomplished by turning systems on and off. The maximum off period that is tolerable is calculated. It is the sum of time required to freeze the applied water plus time during which the ice coated plant parts cool to the critical temperature. Values of the off period for typical frost conditions are proportional to wind speed and wet bulb temperature. Field test results indicate intermittent sprinkling provides a method to reduce water consumption in sprinkling for frost protection.
Inheritance of Root-knot Resistance in the Cowpea (Vigna unguiculata (L.) Walp.)1
Authors: Fery R. L. , Dukes P. D.
Published: August 2022

The inheritance of resistance in cowpea to root knot incited by the root-knot nematodes Meloidogyne incognita (Kofoid & White) Chitwood, M. javanica (Treub.) Chitwood, and M. hapla Chitwood was determined in 3 separate greenhouse experiments. Each seed was inoculated at planting with about 2,000 eggs of the appropriate Meloidogyne species. In Experiment I, plants of parental, F1, F2, and F1 × P1 and F1 × P2 backcross generations of a cross between the resistant cultivar ‘Mississippi Silver’ and the susceptible breeding line CR 18-13-1 were tested for reaction to M. incognita. In Experiment II, plants of parental, some F1, and all F2 generations of a series of crosses involving CR 18-13-1 and the resistant lines ‘Colossus’, ‘Mississippi Silver’, ‘Iron’, and PI 353383 were evaluated for resistance to M. incognita. In Experiment III, plants of parental, F1, and 30 randomly chosen F3 lines of the ‘Mississippi Silver’ × CR 18-13-1 cross were evaluated in separate tests for reaction to M. incognita, M. javanica, and M. hapla. A single dominant gene determined resistance to M. incognita, M. javanica, and M. hapla; the same gene governed resistance in ‘Colossus’, ‘Mississippi Silver’, ‘Iron’, and PI 353383. The gene conditioned a high level of resistance, but it did not confer immunity. Roots of many resistant plants exhibited limited galling and supported some egg production by the parasites. We propose that this gene be designated Root-knot resistance and symbolized Rk.
The Influence of Tree Population and Summer Pruning on Productivity, Growth, and Quality of Peaches1
Authors: Leuty S. J. , Pree D. J.
Published: August 2022

Three cultivars of peach (Prunus persica (L.) Batsch) were grown for 9 years at 3 different densities under 3 training systems. Those spaced at 1157 and 868 trees/ha were mechanically summer pruned annually to predetermined forms; trees spaced at 397 trees/ha were pruned conventionally. While yields during the first few years reflected tree density, the cumulative yield gap among treatments narrowed annually beginning in the 6th growing season. The usually lower production from mature trees spaced at 1157 and 868 trees/ha was attributed in part to non-selective, summer hedging. The effectiveness of various pest control chemicals did not differ among treatments.
Effect of Daminozide and Ethephon on Transplant Quality, Plant Growth and Development, and Yield of Processing Tomatoes1
Authors: Taha A. A. , Kretchman D. W. , Jaworski C. A.
Published: August 2022

Treatment of tomato transplants (Lycopersicon esculentum Mill.) with (2-chloroethyl)phosphonic acid (ethephon) at 100 to 500 ppm when flower buds were visible but not open resulted in flower abscission of the first fruiting cluster, adventitious root formation on the plant stem, increased dry-matter content and more rapid plant recovery following transplanting than untreated and/or clipped plants. Fruit maturity was earlier and more uniform on treated than untreated plants. Treatment of transplants with ethephon at 0.28 kg per ha, combined with a fruit-ripening ethephon treatment at 0.9 kg per ha, increased ripe-fruit yield from a once-over harvest compared with untreated or either treatment alone. Flower abscission on transplants was erratic from treatment with 2,500 or 5,000 ppm of butanedioic acid mono-(2,2-dimethylhydrazide) (daminozide), dry matter was increased, no adventitious roots developed, and transplant recovery was similar to that observed with untreated and/or clipped plants. Daminozide treatment had no influence on fruit maturity and yield.
Glucosinolates: Potential Toxicants in Cabbage Cultivars1
Authors: VanEtten C. H. , Daxenbichler M. E. , Tookey H. L. , Kwolek W. F. , Williams P. H. , Yoder O. C.
Published: August 2022

Seventy-nine cultivars and lines of cabbage Brassica oleracea L. (Capitata group) were analyzed for 11 glucosinolates to provide a data base of the levels of these potential toxicants. Aglucon hydrolytic products of glucosinolates from fresh cabbage (mean of 79 cultivars) include 24 ppm allyl isothiocyanate, 45 ppm 3-methylsulfinylpropyl isothiocyanate, 18 ppm SCN ion, 17 ppm 4-methylsulfinylbutyl isothiocyanate, and 4 ppm goitrin. Composition of the cultivars are summarized by type (red, white, savoy) and by end use (market, storage, kraut). Glucosinolates with a 3-carbon aglucon (excluding the sinolate carbon) predominate over 4-carbon glucosinolates in white and savoy types. Four-carbon glucosinolates (including goitrin precursor) predominate in red cabbages. Savoy cabbages are high in glucosinolates yielding SCN ion. Distinctions between market, storage, and kraut cultivars are less well defined. No differences could be seen between open pollinated and hybrid cultivars. Year-to-year variation for 12 cultivars is discussed.
Effect of Silver Nitrate, Aminoethoxyvinylglycine, and Gibberellins A4+7 plus 6-Benzylamino purine on Fruit Set and Development of ‘Delicious’ Apples1
Authors: Greene Duane W.
Published: August 2022

Sprays of silver nitrate (AgNO3), aminoethoxyvinylglycine (AVG) and gibberellins A4+7 (GA4+7) plus 6-benzylamino purine (BA) were applied with 0.1% Triton B-1956 at bloom to ‘Richared Delicious’ apple trees (Malus domestica Borkh.). AVG at 200 ppm alone or when applied with 50 ppm each of GA4+7 and BA increased fruit set whereas GA4+7 plus BA applied alone at 50 ppm caused fruit thinning. AVG reduced endogenous ethylene production and overcame the increased ethylene production brought about by GA4+7 plus BA application. AVG applied alone at 200 ppm or when combined with GA4+7 plus BA reduced fruit size and increased the L/D ratio at harvest.
Turnover of Tritiated Water in Calamondin Plants1
Authors: Mantell A. , Goldschmidt E. E. , Monselise S. P.
Published: August 2022

The turnover of water in small fruit-bearing plants of calamondin (Citrus madurensis Loureiro) was studied by following the uptake of tritium-labelled nutrient solution. The turnover was much greater in vegetative tissue than in the fruit. Even after 3 days, the radioactivity of water in the fruit, relative to that in the solution, did not reach 20%, compared with about 60% in the leaf tissue. The radioactivity of water in the pedicel reached 60%, similar to that in leaf tissue. Decay of radioactivity in fruit was considerably slower than in other organs when the plant was transferred from a labelled to a non-labelled solution. The turnover of water in fruit was extremely slow even when transpiration was increased by exposing the entire plant or fruit alone to a stream of dry air. Defoliation of fruit-bearing branches decreased the entry of water into fruit tissues. The availability of water for fruit growth in view of the competition offered by the leaves is discussed.
Influence of Certain Citrus Interstocks on β-Carotene and Lycopene Levels in 10-year-old ‘Redbush’ Grapefruit1
Authors: Issa Jami , Mielke Eugene A.
Published: August 2022

Interstocks significantly affected β-carotene and lycopene in the pulp and peel of ‘Redblush’ grapefruit (Citrus paradisi Macf.) on Cleopatra mandarin (C. reshni Hort. ex. Tan.) rootstocks. Fruit from non-interstocked trees consistently had the lowest levels of both pigments. Trees wit Nasnaran (C. amblycarpa Ochse.) interstocks had consistently high levels of both pigments, particularly late in the harvest season.
Tomato Plant Development and Elemental Accumulation1
Authors: Halbrooks Mary C. , Wilcox G. E.
Published: August 2022

Growth and elemental uptake patterns in field-grown plants of tomato (Lycopersicon esculentum mill.) were determined from 21 days after emergence to harvest. Dry weight accumulation was linear after 56 days at 5.55 g/day-plant. Dry weight accumulation after 70 days was mainly as fruit, which accumulated at 4.9 g/day-plant. Nutrient accumulation per day after 70 days was 20 mg N, 2 mg P, 25 mg K, 120 mg Ca and 10 mg Mg in the vines, and 150 mg N, 21 mg P, 231 mg K, 6 mg CA and 10 mg Mg in the fruit. Thus, after 70 days about 90% of the N, P and K, 5% of the Ca and 32% of the Mg uptake was in the fruit.
Response of Selected Tree Species to Sodium Chloride1
Authors: Townsend Alden M.
Published: August 2022

Six tree species were subjected to 0, 2000, 4500, and 7000 ppm NaCl in a hydroponics system. Flowering dogwood (Cornus florida L.) and American sycamore (Platanus occidentalis L.) showed the most foliar injury, followed by pin oak (Quercus palustris Muenchh.), honeylocust (Gleditsia triacanthos L.), eastern white pine (Pinus strobus L.), and Japanese pagoda tree (Sophora japonica L.). Height growth and dry weight increase of sycamore and dogwood, and dry weight of eastern white pine were significantly reduced by salt treatment. Dry weights of pin oak, Japanese pagoda tree, and honeylocust were unaffected. Chloride generally accumulated in higher concentrations in the leaves than in the stems, whereas Na showed the opposite pattern. Concentration of Cl in the stem was better correlated with species’ sensitivity to salt than were Cl and Na in the leaves, or Na in the stem. Although stem concentrations of N, P, Mn, Fe, B, and Zn did not change significantly with salt treatment in any of the 6 species, leaf concentrations of all of these elements did change significantly in one or more species. Manganese and Cu increased with salt in the leaves or stems of several sensitive species, but stayed stable in the tolerant species. Frequency of changes in concentrations of essential elements in response to salt occurred as often in the salt-tolerant as in the salt-sensitive species.
Role of Auxin in Root Primordium Formation in Etiolated ‘Red Kidney’ Bean Stems1
Authors: Kawase Makoto , Matsui Hitoshi
Published: August 2022

When hypocotyls of intact ‘Red Kidney’ beans (Phaseolus vulgaris L.) were wrapped with black plastic sheets, visible root primordia appeared within 12 days. No root primordium appeared in hypocotyls wrapped with clear plastic sheets. Etiolation did not stimulate formation of root primordium when shoots above the cotyledons were removed, but stimulated formation when shoots were replaced with lanolin containing indoleacetic acid (IAA), indolebutyric acid (IBA), or naphthaleneacetic acid (NAA). Even non-etiolated hypocotyls produced root primordia when auxin concentration in the lanolin was high. Etiolation treatment was more effective in root primordium formation when auxin supply was low. Pretreatment of hypocotyls with etiolation with shoots above the cotyledons removed did not stimulate the formation of root primordium in subsequently detached hypocotyl cuttings. Etiolation treatment did not significantly change the auxin concentration in the etiolated parts. These results suggest that etiolation stimulated root initiation by increasing the sensitivity of the stem to auxin.
Seasonal Trends in Net Photosynthetic Potential, Dark Respiration, and Specific Leaf Weight of Apple Leaves as Affected by Canopy Position1
Authors: Porpiglia Peter J. , Barden John A.
Published: August 2022

Changes in photosynthetic parameters in ‘Stayman’/Malling Merton (MM) 111 apple (Malus domestica Borkh.) trees measuring 5 m wide and 4 m high were studied for an entire growing season. Parameters investigated included penetration of photosynthetically active radiation (PAR), changes in spur leaf net photosynthetic (Pn) potential, dark respiration (Rd) and specific leaf weight (SLW). As measured by changes in PAR penetration, canopy development was generally complete by mid-May. Pn, Rd, and SLW were modified by canopy position. SLW was influenced by the previous light environment as peripheral canopy leaves had higher SLW’s than interior leaves.
Efficacy of Resistance to Root-knot Nematode in Snap Beans1
Authors: Wyatt J. E. , Fassuliotis George , Johnson A. W.
Published: August 2022

Four snap bean (Phaseolus vulgaris L.) breeding lines, resistant PI 165426, and 2 susceptible commercial cultivars were tested for resistance to root galling and root-knot nematode (Meloidogyne incognita (Kofoid & White) Chitwood) reproduction under greenhouse and field conditions. Root gall indices, reproduction indices, and numbers of eggs/g of root were significantly less on resistant lines than on ‘White Seeded Provider’ in 2 greenhouse tests. In field tests, soil treatment with the nematicide DBCP resulted in significant control. In nontreated plots, resistant bean lines had less root galls than ‘Early Gallatin’. Plots planted with resistant lines had fewer M. incognita larvae than those with ‘Early Gallatin’. Mean yield of pods from resistant lines in nontreated soil was about 3 times the yield of ‘Early Gallatin’. Yield of pods from treated and nontreated subplots were not significantly different. These results indicate that resistance is equivalent to soil fumigation for root-knot nematode control in snap beans.
Seasonal Trends in Concentration of Nitrogen, Phosphorus, Potassium, Calcium, and Magnesium in Leaf Portions of Apple, Blueberry, Grape, and Peach1
Authors: Chuntanaparb Nilprapai , Cummings George
Published: August 2022

Concentration of N, P, K, Ca and Mg in foliage samples every 3 weeks starting in mid May was determined. Prior to analysis, leaf blades were separated into margin and midrib portions and the petioles of apple (Malus domestica Borkh) and muscadine grapes (Vitis rotundifolia Michx) were removed and analyzed separately. Differences were evident in the concentration of N, K, and Mg between portions of the leaf blade in each of the plants analyzed. Leaf blade portions of highbush blueberry (Vaccinium corymbosum L.) or grape did not differ in P concentration. Changes in the concentration of an element within a portion of the leaf were normally accompanied by similar changes in the other portion or portions. Notable exceptions were the marked increases in grape petiole Ca and Mg during mid and late season with much less change in leaf blade content. Ca appeared to accumulate in the midrib portion to a much greater extent than the leaf margin portion of peach (Prunus perisca (L.) Batsch). The only indication of a late season mobilization of an element from the leaf margin was the decrease in N in the margin and a concurrent increase in themidrib portion of peach leaves.
Differences in Salt Tolerance within ‘Empire’ Lettuce1
Authors: Shannon Michael C.
Published: August 2022

Selections were made within ‘Empire’ lettuce (Lactuca sativa L.) to determine whether observed salt tolerance differences were due to microenvironmental influences in salt distribution or to genotypic variation. In a 3-year study conducted in small field plots, selections from ‘Empire’ were tested under high and low salinity conditions. First cycle, pure-line selections for high plant fresh weight (frame) and high head/frame ratios under high salinity were significantly improved in their respective selected characters over the parental line. Further selection within these lines did not substantially improve their respective phenotypes and led to the conclusion that the selected characters were homozygous within the ‘Empire’ cultivar.
Temperature-stress-induced Production of Abscisic Acid and Dihydrophaseic Acid in Warm- and Coolseason Crops1
Authors: Daie J. , Campbell W. F. , Seeley S. D.
Published: August 2022

Abscisic acid (ABA) metabolism of 6-week-old seedlings of cool- and warm-season crops was determined after a 24-hr exposure to supra- and sub-optimal temperatures. Plants were grown at 25°C and then exposed to 10, 25, or 40°C. After a 24-hr exposure, free (FABA) and hydrolyzable (HABA) abscisic acid and dihydrophaseic acid (DPA) were measured in the plant tops by gas chromatography. Warm-season crops, exposed to 10°C exhibited elevated levels of FABA, HABA and DP A compared to those plants exposed to 25 or 40°C. Among cool-season crops, only peas had higher FABA and HABA levels at 40°C than at 10 or 25°C, while beets had lower levels of HABA at 25°C than at 10 or 40°C. DPA existed at much higher concentrations than FABA and HABA in all plants. The increases in ABA and DPA in warm-season crops exposed to 10°C are attributed to low temperature stress.
Sweet Corn Growth, Yield, and Nutrient Uptake Responses to Tillage Systems1,2
Authors: Smittle D. A. , Threadgill E. D. , Seigler W. E.
Published: August 2022

Response of sweet corn (Zea mays L.) to tillage methods on a Tifton loamy sand was investigated during 1976 and 1977. The greatest volume of soil having a strength of less than 100 N/cm2 core index resulted from moldboard plowing to a depth of 28-30 cm. The smallest volume of low-strength soil resulted from disk harrowing to a depth of 10-13 cm. Soil strength patterns produced by these tillage methods were relatively uniform across the seedbed. A subsoil-bed system produced a channel of low-strength soil under the row to a depth of 40 cm; however, soil strengths 15 cm to the side of the row were similar to the disk harrow method. Soil strength patterns resulting from subsoil-plant systems were similar to subsoil-bed. Soil strength increased during the growing seasons with tillage differences evident near harvest. Root growth, plant growth, yield, and nutrient uptake efficiency responses of sweet corn were proportional to the volumes of low-strength soil at planting.
Compositional Changes in the Developing ‘Hayward’ Kiwi Fruit in California1
Authors: Okuse Ichiro , Ryugo Kay
Published: August 2022

‘Hayward’ kiwi fruit (Actinidia chinensis Planch.) samples collected at 20-day intervals after full bloom, May 18, until harvest in late October, were analyzed for carbohydrates, protein, organic acids including ascorbic and dehydroascorbic acids, tannins and polyphenolic substances, and cytokinin-like compounds. Starch is a predominant carbohydrate stored in the carpellary tissue which becomes hydrolyzed as the fruit approach maturity. Quinic acid was the main organic acid in young fruit which disappeared concurrently with the appearance of ascorbic acid. Mature fruit has low concentrations of tannins and polyphenolic substances but many raphides. Types of cytokinins changed as the fruit developed.
Control of Strawberry Fruit Set and Development with Auxins1
Authors: Mudge K. W. , Narayanan K. R. , Poovaiah B. W.
Published: August 2022

The control of fruit set and development in strawberries (Fragaria X ananassa Duch.) was investigated by exogenous application of auxins to unpollinated flowers or receptacles from which achenes had been removed. Addition of 2% dimethylsulfoxide (DMSO) to aqueous naphthaleneacetic acid (NAA) sprays or dips increased fruit set from ca. 50% to 100%, thus providing a simple and dependable method to induce parthenocarpic fruit set in strawberries. Strawberry fruits were found to be less sensitive to auxin than coleoptiles when auxin-induced strawberry receptacle growth was compared with corn or oat coleoptile elongation. Suboptimal NAA concentrations induced parthenocarpic fruit set with limited fruit growth. Such fruits remained auxin-responsive and viable for 30-45 days when a second NAA treatment resumed their normal growth and development, thus doubling the life span of strawberry fruit from 30 to 60 days. In contrast, unpollinated flowers treated with optimal NAA concentrations in DMSO behaved like pollinated flowers and ripened within 25-30 days. Fifteen auxin analogs and structurally related non-auxins were tested for their ability to stimulate growth of strawberry receptacles following achene removal. The relative effectiveness of these compounds in inducing receptacle growth was very similar, with a few exceptions, to their relative effectiveness in stimulating corn coleoptile elongation.
Relationship of Vegetative Maturity in Salix purpurea as Influenced by Mineral Fertilization1
Authors: Fuchigami L. H. , Weiser C. J.
Published: August 2022

Rooted cuttings of a clonal selection of Salix purpurea L. were grown in perlite, in a warm greenhouse at natural daylengths and irrigated daily with one of 10 different mineral nutrient solutions. Plants from each of the nutrient treatments were hand defoliated at weekly intervals beginning in August to assess the effects of mineral nutrients on vegetative maturity development. Vegetative maturity was quantified the following spring by measuring stem dieback. Plants in some nutrient treatments ceased growing 9 weeks earlier in the autumn, and became vegetatively mature several weeks sooner than plants in other treatments. Specifically, treatments such as the distilled water control and Hoagland solution -N,-P, and -S induced early growth cessation, resulted in less stem growth, and induced early onset of vegetative maturity as evidenced by reduced stem dieback the following spring. Development of vegetative maturity was slower in plants irrigated with complete Hoagland solution or Hoagland solution -Ca, -Mg, and -K, which continued growing until October when natural defoliation and growth cessation occurred on control plants treated with complete Hoagland solution. The study demonstrates that vegetative maturity in S. purpurea can be hastened by witholding N, P, and S.
Estimation of Leaflet, Leaf, and Total Leaf Area of Panax quinquefolius L. Using Linear Measurements1
Authors: Hughes Becky R. , Proctor J. T. A.
Published: August 2022

Leaflet length and width were used to calculate leaflet area, leaf area and total leaf area per plant for 3-year-old American ginseng, Panax quinquefolius L. grown in growth chambers. On the basis of correlation and regression analyses the product of leaflet length and width (LW) was chosen as the independent variable, but leaflet width squared (W2) also proved satisfactory. Although leaflet shape varied somewhat with position, one regression equation was found suitable. Assuming that the Y-intercept was equal to zero had little effect on the coefficient of determination (R2) or the standard error of estimation so the following equations were chosen to determine leaflet, leaf and total leaf area, respectively: A = 0.66 LW (R2 = 98.92%, ± 0.75 cm2); A = Σ0.67 LW (R2 = 98.36%, ± 2.49 cm2); A = Σ0 .67 LW (R2 = 97.36%, ± 7.83 cm2). The relationship between leaflet LW and total leaf area per plant was used to determine leaf area per plant and LAI for commercial ginseng crops 1, 2, 3, and 4 years old.
Fate of 14C-Gibberellic Acid in Senescing On-tree ‘Valencia’ Orange Fruit1
Authors: Goldschmidt Eliezer E. , Galili David
Published: August 2022

Mature green ‘Valencia’ orange (Citrus sinensis (L.) Osbeck) fruit were painted with solutions of 25 ppm 14C-gibberellic acid and harvested from the tree 1, 3, 10, 30, and 100 days after application. Radioactivity recovered from the flavedo after 1 day amounted to 2% of that applied and more than 1% could still be recovered after 100 days. About 50% of the radioactivity partitioned at pH 3.0 into ethylacetate in all flavedo samples (day 1 to 100). Migration of the ethylacetate radioactivity in thin layer chromatography (TLC) indicated that it may still be in the form of gibberellic acid.
Effect of the n Gene on Pea Pod Characteristics1
Authors: Wehner T. C. , Gritton E. T.
Published: August 2022

Fifteen pod characteristics were measured on parents and on F1 and F2 progeny of 14 crosses involving 9 cultivars or experimental lines of peas segregating for the n gene. In the F2 generation, pods of nn plants were 17% shorter, 32% narrower, and 17% lighter in weight than normal (N-) pods. Pod walls of nn plants were 54% thicker, primarily the result of an increase in the number of parenchyma cells, though cell size also tended to be greater. Variation among F2 progeny indicated that plants with thicker and heavier pod walls can be developed.
Pesticide Effects on the Plant Cuticle: IV. The Effect of EPTC on the Permeability of Cabbage, Bean, and Sugar Beet Cuticle1
Authors: Flore J. A. , Bukovac M. J.
Published: August 2022

S-ethyl dipropylthiocarbamate (EPTC, 2.24 kg×ha) inhibited epicuticular wax production on developing leaves of cabbage (Brassica oleracea L. Capitata group cv. Market Prize), resulting in an increase in cuticular permeability. This increased penetration of 14C-I-naphthaleneacetic acid (14C-NAA) and increased cuticular transpiration. EPTC-enhanced penetration was a consequence of increased diffusion across the cuticle, and not of active uptake. Application of EPTC increased penetration of NAA 200% in bean (Phaseolus vulgaris L.)and 121% in sugar beet (Beta vulgaris L.). For cabbage, the percent increase in penetration due to EPTC inhibition of cuticle development 7 days after treatment (141 %) was similar to that at 42 days (112%). The effect of EPTC declined until full leaf expansion (28 days after application). Silver nitrate was preferentially taken up by the cuticular ledges of guard cells and the anticlinal walls of epidermal cells, and was greater in leaves from EPTC-treated plants than in those from non-treated plants.
Water Stress and Cold Hardiness in Field-grown Citrus1
Authors: Davies Frederick S. , Buchanan David W. , Anderson Jeffrey A.
Published: August 2022

‘Orlando’ tangelo (Citrus reticulata Blanco × Citrus paradisi Macf.) trees not irrigated in the fall, but protected by under-tree sprinkling during a frost, sustained the lowest percentage of leaf and fruit damage as determined 6 weeks after the frost. Trees irrigated both in the fall and during a frost, or those receiving no fall irrigation or under-tree sprinkling, were intermediate in fruit damage. Fall irrigation without sprinkling the night of a frost contributed to the most severe damage to leaves and fruit. Soil moisture content of irrigated blocks was significantly greater than for non-irrigated blocks during the fall, yet afternoon leaf xylem water potential and stem water content were comparable. Leaf freezing point of detached leaves of ‘Orlando’ and navel orange (Citrus sinensis (L.) Osbeck) was poorly correlated with leaf xylem water potential, abaxial diffusion resistance, and relative water content. Leaf freezing and killing temperature was unaffected by fall irrigation and ranged from -5.8 to -6.8°C from October until December in 1978 and 1979.
High Temperature Effects on Leaf Resistance, Leaf Water Potential, and Photosynthesis of Non-bearing Prune Trees1
Authors: Even-Chen Z. , Weinbaum S. A. , Pearcy R. W.
Published: August 2022

The effects of ambient temperatures between 15° and 43°C were determined on net photosynthesis of ‘French’ prune (Prunus domestica L. cv. Agen) trees maintained under a non-limiting soil water supply. The temperature optimum for photosynthesis was about 30° and net CO2 assimilation decreased rapidly above 35° even when water vapor pressure differences (VPD) were only 5 to 10 mb. Leaf resistance (r1) remained very low (2 to 3 sec cm-1) although leaf temperature reached 47° and the leaf water potential (ψ) decreased to -25 bars. Thus, non-stomatal photosynthetic inhibition was responsible for the 80% decline in net CO2 assimilation. Canopy wetting prevented the decline in net CO2 assimilation by reducing leaf temperature 8° (vs. control) and maintaining the ψ 14 bars higher than the non-misted control.
Estimates of Genetic Variances for Yield in Pickling Cucumber1
Authors: Ghaderi Ardeshir , Lower R. L.
Published: August 2022

Between and within F3, family variances were used to estimate the genetic variances for 3 yield characters in 6 crosses of pickling cucumber (Cucumis sativus L.). Significant additive and/or dominance variances were obtained for all characters in certain crosses. Significant additive variances suggested the effectiveness of selection for development of superior inbred lines, and significant dominance variances could be utilized in the production of hybrids. Fruit number contributes most to the commercial value of pickling cucumber, but selection for this trait will probably be effective if parthenocarpic gynoecious materials are used.
The Influence of Temperature on Regreening and Carotenoid Content of the ‘Valencia’ Orange Rind1
Authors: Coggins Charles W. , Hall Anthony E. , Jones Winston W.
Published: August 2022

‘Frost Valencia’ [Citrus sinensis (L.) Osbeck] budded to trifoliate orange rootstock [Poncirus trifoliata (L.) Raf. 1, with orange-colored fruit, were subjected to 4 temperature regimes consisting of 2 day-night shoot environments and 2 constant soil temperatures in 2 glasshouses. In the cool shoot environment (20×15°C, day×night air temperature), carotenoid content of fruit increased substantially, whereas, in the warm glasshouses (30×15°), carotenoid content either changed little (apical and equatorial regions) or decreased slightly (basal region). Chlorophyll content of fruit increased to detectable levels only in the warm glasshouse. Soil temperatures of 15 and 25° had little or no influence on carotenoid or chlorophyll content of fruit in either glasshouse. Thus, regreening occurred only in the warm shoot environment and at both root temperatures. These temperature effects did not appear to operate through a redistribution of nitrogen to the rind.
Influence of Trickle and Sprinkle Irrigation on ‘Golden Delicious’ Apple Quality1
Authors: Drake S. R. , Proebsting E. L. , Mahan M. O. , Thompson J. B.
Published: August 2022

‘Golden Delicious’ apples (Malus domestica Borkh.) from trickle-irrigated plots were more mature than sprinkle-irrigated apples. Trickle-irrigated apples were higher in yellow color, soluble solids, and pH. Titratable acidity and moisture were less in fresh and stored apples that were grown with trickle irrigation. Applesauce from trickle-irrigated apples was superior in consistency and developed less free liquor (weep) than sauce from sprinkle-irrigated apples. Drip losses were greater in frozen apple slices from sprinkle-irrigated apples. Canned or frozen apple slices were firmer when produced from apples that were sprinkle-irrigated. The color of apple products from trickle-irrigated apples was superior to the products from sprinkle-irrigated apples. These differences resulted from treatments where leaf water potential differed by only 1 to 2 bars, –14 and –12 bars with trickle and –12 and –11 bars with sprinklers in 1978 and 1979.
Influence of Light Quality during Seed Development and Drying on Germination in Watermelon1
Authors: Fritts Susan K. , Brent Loy J.
Published: August 2022

The effect of light quality during seed development and drying on subsequent germination was investigated in watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] with ‘Sugar Baby’ and 2 dwarf strains, WB-2 and ‘Sugar Baby’ (dw-2). The light treatments during seed drying, fluorescent (F), incandescent (Inc), red (R), and far-red (FR), did not consistently affect percent germination. Seeds dried under R or F light usually germinated faster than those dried in darkness or under FR light, but the effect was too small to justify application in commercial seed processing. Seeds from fruit covered with black polyethylene during development germinated faster and were less sensitive to light treatments during drying than seeds from uncovered fruit.
Vegetative and Reproductive Growth Responses of Three Strawberry Cultivars to Nitrogen1
Authors: Breen Patrick J. , Martin Lloyd W.
Published: August 2022

Abundant (‘Hood’ and ‘Benton’) and poor (‘Olympus’) runnering cultivars of strawberry (Fragaria × ananassa Duch.) were grown in a milled-bark medium over an 8- or 16-fold range of slow-release ureaform N. Growth was poor or normal at low and intermediated rates of N, but inhibited at high rates. Number of leaves, crowns, and runners and subsequent inflorescence and flower production were frequently less than maximum at the highest level of N (4.8 gN/liter bark medium). Applied N had a significant effect on the number of crowns/plant, inflorescences/crown and flowers/inflorescence. In all cultivars, percent N in leaves in August, or in the entire shoot in November, showed a significant linear relationship with applied N. ‘Hood’ accumulated a higher concentration of N in both parts than ‘Olympus’ or ‘Benton’. Flower production in all cultivars was significantly correlated with the percent N in the shoot in November. Although the optimum range of applied N was similar for all cultivars, ‘Olympus’ was the most responsive to N in terms of increased leaf and flower production. When maximum values are compared, ‘Olympus’ in one year produced over 40% more leaves and 75% more flowers but at least 74% fewer runners than ‘Hood’ or ‘Benton’. ‘Benton’ was the only cultivar that at low and intermediate rates of applied N averaged less than one inflorescence/crown. Crown production by the 3 cultivars was not significantly different and high levels of applied N failed to increase the number of crowns available for flower initiation above those obtained at intermediate rates.
Effect of Nitrapyrin and Nitrate Level on Growth, Elemental Composition, and Water Relations of Tomato Grown in Peat-Vermiculite1
Authors: Pill Wallace G.
Published: August 2022

Nitrapyrin (NI) incorporation into a peat-vermiculite medium reduced shoot growth of tomato (Lycopersicon esculentum Mill. cv. Marglobe) but this reduction was less pronounced at higher NO3-N fertilization levels. An initial 50 ppm NI application caused less growth reduction than 7, weekly 7.14 ppm applications. While increasing NO3 level had little effect on shoot ion concentration, with the exception of increasing shoot K and NO3 concentration, the increased shoot total N, Mg, and K concentrations with NI were attributed to the concentrating effect of reduced growth. Single and multiple NI applications decreased and increased, respectively, both plant water stress and medium NO3 retention. Nitrapyrin consistently increased medium NO3 concentration at the 2 highest NO3 fertilization levels. With time, however, medium NO3 concentration decreased and increased with single and multiple NI applications, respectively, relative to each other. Nitrapyrin initially decreased leaf xylem pressure potential (ψp), but with time, water stress decreased below that of the control plants with the single NI application but remained consistently high with multiple applications. Since leaf diffusive resistance and ψp were lower and transpiration rate was initially higher with the single NI application relative to the control, and since plants given the multiple NI applications had the lowest ψp and transpiration rate values throughout the study, it is hypothesized that NI reduced water uptake. That NI decreased both NO3 assimilation and uptake was evidenced by decreased shoot total N content, increased shoot NO3 content, and increased medium NO3 concentration.
Effect of Poultry Manure on Strawberry Fruiting Response, Soil Nutrient Changes, and Leaching1
Authors: Albregts E. E. , Howard C. M.
Published: August 2022

Strawberries (Fragaria × ananassa Duch.) were grown for 3 seasons on a well-drained fine sand which received 0, 4.5, 9, 18, and 36 metric tons (MT)/ha of poultry manure annually. Fruit yields increased each season with increased rates of manure up to 18 MT/ha. The 36 MT/ha rate caused a foliage burn during the first 3 seasons which may have reduced yields. Considerable leaching of the soluble nutrients from manure to and below the 60-cm soil depth occurred from season to season. Analyses of saturated soil extracts indicated that concentrations of soluble salts, K, and NO3–N increased with increasing rates of manure at all 4 depths to 60 cm. The Ca, K, and Mg concentrations at all 4 soil depths increased with increased manure rates and generally decreased with depth. Organic matter content of the surface 15 cm of the soil increased with increased manure rate. Soil pH was only slightly affected by the manure treatments.
Nutrient Composition, Sensory Characteristics, and Texture Measurements of Seven Cultivars of Dry Beans1
Authors: Koehler H. H. , Burke D. W.
Published: August 2022

Seven cultivars representing 5 principal types of dry beans (Phaseolus vulgaris L.) produced commercially in the state of Washington were analyzed chemically for content of moisture, fat, ash, total protein, calcium, iron, potassium, zinc, thiamin, riboflavin, and amino acids when raw or when freeze-dried following cooking. Samples of cooked beans were subjected to sensory evaluation and shear-force measurement. Protein quality was evaluated using Tetrahymena pyriformis W. Results are being used for comparison with values for new cultivars produced later in the breeding program. The 7 cultivars contained significant percentages of the United States Recommended Daily Allowances (US-RDA) for iron, calcium, potassium, thiamin, and riboflavin. The nutritional quality of their protein was half to two-thirds that of casein. All cultivars were judged to be acceptable in flavor and texture. ‘Pinto UI-114’ was outstanding for both nutritional content and sensory quality.
Effect of Soil Depth and In-row Vine Spacing on Yield and Juice Quality in a Mature ‘Concord’ Vineyard1
Authors: Morris J. R. , Cawthon D. L.
Published: August 2022

A site was prepared with 2 distinctly different soil depths and a vineyard of ‘Concord’ grapes (Vitis labrusca L.) was established with in-row spacings of 1.52, 1.83, 2.13, 2.44, and 3.05 m. Wider in-row vine spacings resulted in increased vine yields on deeper soils to the point that yields per meter of cordon and per hectare were not reduced; but yield per meter of cordon and per hectare was reduced on the shallow soil when in row vine spacings exceeded 2.44 m. There were few effects on juice quality from either soil depths or in-row vine spacings.
Sugars in Developing and Mature Fruits of Several Watermelon Cultivars1,2
Authors: Elmstrom G. W. , Davis Paul L.
Published: August 2022

Sugars in watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] cultivars grown at Leesburg, Florida, were determined by liquid chromatography in 1976, 1977, and 1979. There was a wide variation among cultivars in the ratio of total reducing sugars, fructose plus glucose, to the nonreducing sugar, sucrose. This ratio was dependent upon cultivar and stage of maturity. In 1979, sugars in developing fruit of 8 watermelon cultivars were determined at 7 intervals from 12 to 36 days after anthesis. Initial development of sugar was more rapid in the cultivars ‘Sugarlee’, ‘Crimson Sweet’, ‘Dixielee’, and ‘Yellow Baby’ than in ‘Charleston Gray’ and ‘Jubilee’. Early development of sugar is especially important for production of high quality fruit when melons are harvested before full maturity for the commercial trade. In general, fructose and glucose increased until the 24th day and declined thereafter, whereas sucrose was not detected until the 20th day and increased thereafter. The relative sweetness at all stages was calculated.
Inheritance of Parthenocarpic Yield in Gynoecious Pickling Cucumber for Once-over Mechanical Harvest by Diallel Analysis of Six Gynoecious Lines1
Authors: El-Shawaf I. I. S. , Baker L. R.
Published: August 2022

Six gynoecious inbred lines of cucumber (Cucumis sativus L.) were evaluated for parthenocarpic yield by using 2 diallel analysis programs. A complete diallel of F1 and half-diallel of F2 generations, including parents, was used to study the genetics of parthenocarpic yield. Highly significant differences for GCA and SCA effects were found for all yield characters, suggesting that both additive and non-additive gene action were important. Reciprocal differences or maternal effects were not significant for any of the yield characters. Diallel analysis suggested that recessive genes were acting in the direction of higher yields. Accordingly, the development of a parthenocarpic hybrid cultivar with high yield potential would require that both parents possess genotypes with high yield potentials. Heritability estimates varied from nearly 0 to 32% for 3 different yield measurements with number of fruits on the main stem most heritable. Significant ratios for heterosis and heterobeltiosis were obtained for all yield measurements. However, only fruit number on the main stem was affected by an inbreeding depression. Breeding improvement programs for parthenocarpy might include recurrent selection for fruit number on the main stem of gynoecious seed parent lines combined with backcrossing of the gene for hermaphroditic expression into gynoecious parthenocarpic lines for pollen parents.
Comparison of Single and Three-way Crosses of Pickling Cucumber Hybrids for Femaleness and Yield by Once-over Harvest1
Authors: Tasdighi M. , Baker L. R.
Published: August 2022

An array of 102 single and 3-way cross hybrids of pickling cucumbers (Cucumis sativus L.) were evaluated for yield over 2 years under field conditions. Hybrids were produced by crossing lines with gynoecious, monoecious, hermaphroditic, and androecious expression. The significant correlations between femaleness (percent pistillate nodes) and marketable yield were 0.34 for single cross and 0.45 for 3-way cross hybrids. Highest yields were obtained from the single crosses of gynoecious × androecious, and gynoecious × hermaphrodite, followed by the 3-way cross of (gynoecious × hermaphrodite) × androecious, on the basis of either total or marketable fruits per plant. Hybrids having androecious pollen parents exhibited more femaleness and produced higher yields than those with monoecious pollen parents. The possible use of these high yielding parental sex combinations as hybrid cultivars in place of conventional single crosses (gynoecious × monoecious) might improve the production of pickling cucumbers for once-over mechanical harvest.
Germination Studies of Clay-coated Sweet Pepper Seeds1
Authors: Sachs M. , Cantliffe D. J. , Nell T. A.
Published: August 2022

Seed germination of sweet pepper (Capsicum annuum L.) is inhibited after the seed is coated. The inhibitory effect of pellet-coating of ‘Early Calwonder’ pepper seed was caused by the physical properties of the coating materials. Clay coating limited part of the oxygen (O2) from reaching the germinating seed and provided a mechanical barrier to protrusion of the radicle. Clay-coated pepper seed germinated satisfactorily on filter paper in a high O2 environment or with minimum moisture on agar. Pellet coating formulations which would provide more O2 to the imbibing seed would assure comparable germination of raw and coated sweet pepper seed.
The Influence of Summer Pruning on Photosynthesis, Transpiration, Leaf Abscission, and Dry Weight Accumulation of Young Apple Trees1
Authors: Taylor B. H. , Ferree D. C.
Published: August 2022

Young, container-grown ‘Topred Delicious’/Malling (M) 9 apple trees (Malus domestica Borkh.) trained to a single shoot out-of-doors were summer pruned to remove 0, 25, 50 or 75% of 78 cm shoots. Net photosynthesis (Pn) and transpiration (Tr) were as much as 36% greater on older, basal leaves of trees with 50 and 75% shoot removal than on unpruned trees. These differences were present for 39 days after pruning. Basal leaves did not abscise in the 11-week period after pruning on trees with 75% shoot removal and remained longer on trees with 50% shoot removal than on unpruned trees. Leaf area removed by pruning was partially compensated by leaves on subsequent regrowth. All summer pruning treatments suppressed the area of individual leaves on regrowth by about 50% of the size of similar aged leaves on unpruned trees. Summer pruning suppressed the dry weight of basal stem sections and roots roughly in proportion to shoot removal amounts, while dry weight of shoot regrowth was less influenced. Eleven weeks after pruning, dry weight of roots on summer pruned trees with 25, 50 and 75% shoot removal was 20, 39 and 50% less, respectively, than root dry weight of unpruned trees.
Inheritance of Resistance to Blackeye Cowpea Mosaic Virus in Vigna unguiculata (L.) Walp.1
Authors: Walker Charles A. , Chambliss Oyette L.
Published: August 2022

A single recessive gene, blc, controls resistance to blackeye cowpea mosaic virus (B1CMV) in progeny from a cross between southernpea (cowpea) cultivars ‘Worthmore’ (homozygous resistant) and ‘California Blackeye No. 5’ (homozygous susceptible). All F1 plants and backcrosses to the susceptible parent were susceptible, indicating that resistance is recessive to susceptibility. Backcrosses to the resistant parent segregated 1 susceptible: 1 resistant and F2 plants segregated 3 susceptible:1 resistant.
Winter Injury to Apple Cultivars as Affected by Growth Regulators, Weed Control Method, and Rootstocks1
Authors: Westwood M. N. , Bjornstad H. O.
Published: August 2022

Effects of cultivars, rootstock, and long-term growth regulator and herbicide treatments on above-ground tree damage from a December 1972 freeze were recorded soon after the freeze and again 7 years later. Ultimate injury was greatest with ‘Jonared’ and least with ‘Golden Delicious’ apple (Malus domestica Borkh.) in the growth regulator plot, while in the herbicide plot it was opposite for the 2 cultivars. There was not a good relationship between injury to specific plant parts (flower buds, spurs, leaders, and lower trunks) observed soon after the freeze, and ultimate tree mortality. Growth regulator treatments significantly increased freeze damage to flowers and spurs, but ultimate tree mortality was reduced by daminozide sprays. Clean cultivation increased flower and spur mortality but did not reduce yield or increase tree mortality compared to the sod treatment. Trees on Mailing (M) 5, M 7 and M 9 rootstocks showed greater initial trunk injury than those on seedling roots, but only those on M 9 showed significantly greater ultimate mortality.
Distribution of 14C Photosynthetic Assimilates in ‘Valencia’ Orange Seedlings at 10° and 25°C1,2
Authors: Guy C. L. , Yelenosky G. , Sweet H. C.
Published: August 2022

The distribution of 14C-photosynthate was determined in 8-month-old potted ‘Valencia’ orange seedlings [Citrus sinensis (L.) Osbeck] during 25° and 10°C temperature regimes. Seedlings were pulse-labeled with 14CO2 for 3 hr after equilibration with ambient air. Radioactive assimilates were extracted at selected intervals, from leaves, stems, and roots and separated into several biochemical fractions. Low-temperature (10°) exposure resulted in a greater retention of 14C in the sugar fraction of leaves and a lower rate of 14C incorporation into organic and amino acid fractions. Data indicate a lower rate of metabolism of photosynthate and a reduced distribution of 14C in citrus seedlings at 10° than at 25°C.