bluuebunny/crossref_metadata_2025 huggingface dataset:
Analyzing Competition Between a Living Mulch and a Vegetable Crop in an Interplanting System
Authors: Wiles L.J. , William R.D. , Crabtree G.D. , Radosevich S.R.
Published: August 2022

Development of interplanting systems for vegetables has been impeded due to concerns about yield reductions and use of systematic experimental designs that limit analysis of fundamental competitive processes. This study employed an addition series and growth analysis combined with management strategies aimed at minimizing competition between the crop and the interplant. Pak choi [Brassica rapa L. (Chinensis Group)] was interplanted with strips of ryegrass (Lolium perenne L.) that covered 67% of the soil. Pak Choi was a weak competitor compared to perennial ryegrass. Mulch suppression using a sublethal rate of fluazifop provided the most promising management strategy to reduce competition from the ryegrass interplant. Timing of suppression and reduction of mulch root growth were critical elements of successful management. Chemical names used: (±)-2-[4-[[5-(trifluoromethyl)-2-pyrindinyI]oxy]phenoxy]propanoic acid (fluazifop).
Sod Proximity Influences the Growth and Yield of Young Peach Trees
Authors: Welker W.V. , Glenn D.M.
Published: August 2022

Peach [Prunus persica (L.) Batsch] trees were grown for four growing seasons within a tall fescue (Festuca arundinacea Schreb.) sod in vegetation-free squares ranging in size from 0.36 to 13.0 m2. Tree growth, leaf nitrogen, and fruit yield increased as the size of the vegetation-free area increased. A growth and field response plateau was reached at 9.0 m2. Tree growth was proportional to the size of the vegetation-free area throughout the length of the study. The magnitude of leaf nitrogen response declined with years. The fescue sod apparently restricted the effective root zone of the trees, thus controlling growth by limiting the volume of soil the tree could use.
Grass Living Mulch for Strawberries
Authors: Newenhouse Astrid C. , Dana Malcolm N.
Published: August 2022

‘Sparkle’ and ‘Honeoye’ strawberries (Fragaria × ananassa Duchesne) were planted into plots of newly seeded perennial ryegrass (Lolium perenne L.), Kentucky bluegrass (Poa pratensis L.), winter wheat (Triticum aestivum L.), or no grass. After a 1985 windstorm during the green fruit stage, yield was higher in living mulch plots than in control plots and fruit from control plots were small and dark relative to those from the ryegrass plots. In 1986, all plots had similar yields. All plants grew at similar rates during the establishment year. Later, strawberry plants in living mulch plots had smaller leaves than plants in control plots. Plants in all treatments contained above the critical concentrations of leaf N on most sampling dates. Soil under grass was less compacted and was cooler than cultivated soil. Living mulch prevented annual weed establishment after the first and improved winter survival of flower buds. A tillering type of ryegrass was the best living mulch of the three species tested. It quickly covered the ground but did not spread into the crop rows, and grew tall enough to afford wind protection.
Influence of Orchard Management Systems on Spur Quality, Light, and Fruit within the Canopy of ‘Golden Delicious’ Apple Trees
Authors: Ferree David C.
Published: August 2022

Trees of ‘Golden Delicious’ apple (Malus domestica Borkh.) were established in 1973 in the following orchard management systems: slender spindle (SS), trellis (TR), interstem hedgerow (IH), and pyramid hedgerow (PH). Spur quality and percent photosynthetic photon flux (PPF) transmission declined from the top to the bottom of the canopy of all systems. The three conical central leader type trees (SS, IH, PH) produced a quarter of their fruit on or close to the central leader, while the palmette-shaped TR produced 60% in the center sections along the wire trellis. There was no difference between vertical fruit distribution in trees in the more intensive systems (SS, TR), but the larger trees (IH, PH) produced twice as much fruit in the top half of the canopy as in the bottom half. Trees in the SS had a lower percentage of PPF transmission values within the canopy than trees in the TR systems. Trees in IH generally had higher PPF transmission values within the canopy than the larger PH trees. The number of leaves per spur and specific leaf weight of spur leaves generally followed the light distribution pattern, and trees in the TR and IH systems had higher-quality spurs than the SS and PH systems. The SS and TR systems appeared more responsive to the orientation of the sun, having higher light transmission values on the east side of the canopy in the morning and west side in the afternoon, than the IH or PH systems.
Growth and Yield of Crisphead Lettuce under Various Shade Conditions
Authors: Sanchez Charles A. , Allen Robert J. , Schaffer Bruce
Published: August 2022

Studies were conducted during five winter cropping periods in the Everglades, near Belle Glade, Fla., to determine effects of shade applied at various times throughout the growing period on the growth and yield of lettuce (Lactuca sativa L.). Ancillary studies also were conducted in a greenhouse to determine effects of shade on the light response of lettuce with respect to net CO2 assimilation. The maximum net CO2 assimilation rate (Pn) for lettuce decreased as the irradiance at which the plants were grown decreased. Continuous shading from thinning to harvest reduced crop growth approximately in direct proportion to the reduction in irradiance. Lettuce was most sensitive to reductions in radiation when growth and development were most rapid. These data suggest that lettuce growth from planting through the eight-leaf stage is not affected by small reductions in radiation that might occur in nature, but appears to be largely influenced by temperature. This observation is consistent with data collected during greenhouse experiments that showed that Pn at this early growth stage was low regardless of the shade treatment. Lettuce growth from the eight-leaf through the preheading stage was reduced by low shade levels (75% of prevailing solar radiation). Lettuce yield, however, generally was not affected by low shade levels through the preheading stage. Shading, regardless of the degree, reduced growth and yield during the heading stage of development. Results from greenhouse experiments indicated that the light saturation point of lettuce for photosynthesis during this latter growth stage could reach 800 μmol·s−1·m−2. This light level is higher than prevailing light that often exists during fall and winter growing seasons in southern Florida.
Yield and Quality of Processing Tomatoes in Response to Irrigation Rate and Schedule
Authors: Sanders D.C. , Howell T.A. , Hile M.M.S. , Hodges L. , Meek D. , Phene C.J.
Published: August 2022

Field studies were conducted on a Typic Xerorthents Entiosols soil (Hanford sandy loam) to determine the response of two cultivars of processing tomatoes (Lycopersicon esculentum Mill.) to trickle irrigation applied at three percentages of evapotranspiration (ET) to either the top of the plant row or between the beds using a traveling irrigation system. Irrigation was terminated when fruits were either 30% or 70% red (14 or 7 days before harvest). Yields of red tomatoes and total tomatoes increased with increasing trickle irrigation water. The concentrations of soluble solids (SSC) and total solids (TS) and pH decreased with increasing trickle irrigation rates, while color, fruit size, and acidity increased, as did the yield of SSC and TS per hectare. Placement of trickle irrigation on the plant row was more favorable than placement in the furrow between the beds for yield and quality characteristics. Trickle irrigation to 70% ET terminated 7 days before harvest produced responses similar to conventional furrow irrigation. Although statistically these treatments could not be compared directly to conventional furrow, all traveling trickle irrigation rates were superior in water use efficiency to that of the conventional furrow irrigation. Trickle irrigation rates of 35% ET, 70% ET, and 105% ET did not differ in water use efficiency. Chemical names used: 2(a-naphthoxy)-N,N-diethyl propionamide (napropamide); S-propyl butylethiocarbamate (pebulate).
Uniconazole Affects Vegetative Growth, Flowering, and Stem Anatomy of Hibiscus
Authors: Wang Yin-Tung , Gregg Lori L.
Published: August 2022

Eight-month-old ‘Jane Cowl’ hibiscus (Hibiscus rosa-sinensis L.) in 2.8-liter pots received 0, 0.1, 0.2, or 0.4 mg of uniconazole/pot as a soil drench. Plants were pruned 35 days after treatment and then grown for an additional 65 days. Plant height, number of leaves and flower buds per shoot, shoot length, stem diameter, and leaf size decreased with increasing rates of uniconazole. Flower number was greater at the two low rates; however, days to first bloom and leaf dark respiration rate were unaffected. Leaf chlorophyll concentration increased with increasing rates of uniconazole. Development of secondary xylem tissue, transverse diameter of vessels, and number and size of phloem fibers were suppressed by uniconazole, resulting in a cascading growth habit. Plants grown from cuttings taken from plants 35 days after treatment were shorter, with fewer lateral shoots and total leaves than cuttings from untreated plants. Uniconazole had no effect on growth of shoot tip cuttings taken from the new lateral shoots of treated plants 110 days after pruning. Soil drenches of uniconazole at 0.025 to 0.2 mg/pot to young plants in 1.5-liter pots resulted in shorter plants, delayed flowering, and fewer flowers with smaller diameter and shorter pedicels. Results from foliar application of uniconazole at 0.05 to 0.2 mg/plant (10 to 40 mg·liter−1) were similar to the soil drench, except that the reduction in shoot growth was less at low rates than with drench application. Chemical name used: (E)-1-(p-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol (uniconazole).
Waxing and Plastic Wraps Influence Water Loss from Papaya Fruit during Storage and Ripening
Authors: Paull Robert E. , Chen Nancy J.
Published: August 2022

The effect of waxes and plastic shrink wraps on weight loss from papaya (Carica papaya L.) fruit during ripening was determined. Loss of ≈8% of initial weight from mature-green papaya produced “rubbery”, low-gloss, unsalable fruit. The rate of weight loss from ripening papaya was ≈0.1% initial weight/day per mbar. The highest rate of weight loss occurred via the stem scar (nearly 3500 mg·cm−2·day−1) while 4.4 mg·cm−2·day−1 was lost through the skin. The major mode of weight loss was the skin because of its larger surface area. The stomata did not appear to function in ripening fruit. The skin's resistance to water movement increased at the start of ripening, then declined with no apparent change in the rate of total water loss. Part of the decline in resistance was associated with the disruption of the cuticle with latex, especially after the 50% ripe stage. These results suggest that the major site of resistance to weight loss changed late in ripening. Fruit waxing reduced weight loss by 14% to 40%, while plastic shrink wraps reduced loss by ≈90%. The loss of water was the major component of weight loss. Some waxes and one wrap delayed ripening by 1 to 2 days at ambient temperatures, after storage for up to 2 weeks at 10C. Occasionally, off-flavors occurred in waxed and wrapped fruit when the fruit cavity CO2 level exceeded ≈7% at the full-ripe stage.
Correlation of Reduced Softening and Increased Polyamine Levels during Low-oxygen Storage of ‘McIntosh’ Apples
Authors: Kramer George F. , Wang Chien Yi , Conway William S.
Published: August 2022

The rate of postharvest softening of ‘McIntosh’ apples (Malus domestica Borkh.) was reduced by storage in a 1% O2 atmosphere at 1 or 3.5C. Apples stored in controlled atmosphere (CA) also maintained higher levels of the polyamines putrescine (PUT), spermidine (SPD), and spermine (SPN) in both skin and flesh tissues than those stored in air. The levels of putrescine and spermidine increased by 2- to 6-fold in CA-stored apples, while spermine decreased, but remained 2- to 5-fold higher than in air-stored fruit at both temperatures. Polyamines were also found to inhibit the in vitro activity of the cell wall-degrading enzyme polygalacturonase (PG). SPD and SPN were more effective than PUT, with SPN possessing the greatest inhibitory activity. These results are consistent with a hypothesis that increased polyamine levels are involved in the beneficial effects of CA storage and that polyamine activity could include the inhibition of cell wall degradation.
Nonstructural Carbohydrate Partitioning in Perennial Parts of Sweet Cherry
Authors: Keller John D. , Loescher Wayne H.
Published: August 2022

Nonstructural carbohydrates of sweet cherry (Prunus avium L. ‘Bing’) changed dramatically both qualitatively and quantitatively during the year. In perennial tissues, total nonstructural carbohydrates (TNC) were highest at leaf abscission. TNC increased sharply in spurs at budbreak, but, in other perennial tissues, reserves decreased with or before budbreak. TNC in all but spurs were least, e.g., 2% to 4% of fall levels, shortly after full bloom, but then immediately began to increase. Accumulations slowed during the last 4 to 6 weeks of fruit growth and then increased after harvest. Prebloom decreases and postbloom increases occurred earlier in 1- and 2-year-old shoots when compared to trunk or root tissues. Starch was the most common storage material. During winter, interconversion of starch and soluble carbohydrates in wood of the trunk and 1- and 2-year-old shoots was apparent. Sucrose was the predominant soluble carbohydrate during dormancy, but sorbitol dominated during active growth. Raffinose was present only during dormancy, and inositol only when leaves were present. Because sweet cherry flowers and fruits early, carbohydrate reserves could critically affect productivity.
Differential Flood Stress Resistance of Two Tomato Genotypes
Authors: McNamara Steven T. , Mitchell Cary A.
Published: August 2022

Tomato accessions PI 128644 (Lycopersicon peruvianum var. dentatum Mill.) and PI 406966 (L. esculentum Mill.) were identified in preliminary screening trials as being relatively nonresistant and resistant to root-zone flooding, respectively. A comparative study of these accessions was undertaken to examine adaptive responses to inundation. Root and shoot growth of both accessions were inhibited by 120 hr of flooding. Aerobic respiratory capacity of secondary roots of both accessions decreased to a similar extent after 24 hr of inundation. Flooding did not significantly affect anaerobic root respiration rate of either accession. Stomatal conductance decreased after 24 hr of flooding for both accessions, with some recovery by PI 406966 after 168 hr of treatment, coinciding with development of adventitious roots on lower stems. Few adventitious roots formed on flooded PI 128644 plants. Leaf water potential of both accessions initially increased as a result of flooding, but declined to near control level by 120 hr of treatment. Total phenol content of PI 128644 roots decreased with 72 hr of flooding, while that of PI 406966 roots was not significantly affected. Factors underlying the greater resistance of PI 406966 to flooding remain unclear, but may include a lower root respiratory requirement for O2 and greater ability to sequester or eliminate toxic substances during inundation.
Pollen Source Influences Fruiting of ‘Sharpblue’ Blueberry
Authors: Lyrene P.M.
Published: August 2022

The effects of cross-pollination, self-pollination, and mixed (self plus cross) pollination of ‘Sharpblue’ blueberry (primarily V. corymbosum) were studied. The pollen for cross-pollination came from V. corymbosum clones ‘O’Neal’ and ‘FL 2-1’. Self-pollination resulted in 37% fruit set, compared to 74% to 91% set for the other pollination treatments. The number of well-developed seeds per matured berry averaged 3.5 for self-pollination, 13.0 for mixed pollination, and 24.4 for cross-pollination. The number of days from pollination to ripe fruit was highly and negatively correlated with berry seed number, regardless of the pollen source. Mixed pollinations delayed ripening an average of 7 days compared to cross-pollination, and self-pollination delayed ripening by an additional 13 days over mixed pollination.
Protein and Nonprotein Amino Acids in Citrus Leaves as Affected by Phytophthora spp., Root Infestation and Soil Oxygen Content1
Authors: Labanauskas C. K. , Stolzy L. H. , Handy M. F.
Published: August 2022

Protein amino acids in leaves of Phytophthora spp.-infested or noninfested plants were not affected measurably. Leaves from plants supplied with low soil oxygen levels contained significantly less protein amino acids: lysine, histidine, aspartic acid, threonine, serine, glutamic acid, glycine, alanine, valine, isoleucine, leucine, tyrosine, and phenylalanine but more arginine than analogous leaves of plants supplied with normal soil oxygen concn.

The leaves of Phytophthora-infested plants contained significantly lower concn of nonprotein amino acids: threonine, glycine, alanine, cystine, valine, methionine, isoleucine, leucine, tyrosine, and phenylalanine but higher concn of arginine and aspartic and glutamic acids. The nonprotein amino acids: lysine, arginine, aspartic acid, and pro line were higher, while threonine and glutamic acid were lower, in seedling leaves supplied with low soil oxygen than those in leaves on plants supplied with normal soil oxygen.

The protein and nonprotein proline, and the sum of nonprotein amino acids increased in leaves of noninfested plants, while decreasing in leaves of infested plants, with a decreasing level of soil oxygen to roots.

Substantive amounts of protein amino acids found in citrus seedling leaves were glutamic acid, aspartic acid, proline, leucine, and arginine; those of nonprotein amino acids were proline, arginine, serine, lysine, and aspartic acid. These amounts represent, respectively, 50 and 90% of the sum.
Effects of N, P, and K Fertilization on Fruit Yield, Macro- and Micronutrient Levels, and Nitrate Accumulation in Okra [Abelmoschus esculentus (L) Moench]1
Authors: Asif Mir I. , Greig J. K.
Published: August 2022

Maximum yield was obtained from 120 lb. N/A; while, P and K had no favorable influence on yield. Fruit yield varied between years, probably because of rainfall variation.

Nitrogen and Cu levels of plants increased but P, Ca, and Zn levels decreased with N application. Applied P-K increased only P and K levels of the plants. Levels of N, Mg, and Cu were higher in 1969 than in 1968, but Fe showed a reverse trend. Nitrogen applications increased NO3- accumulation in the fruit. Phosphorus and K concn were max in fruits; N, Zn, and Mn were high in leaves; and Ca and Mg concn were higher in green stems than in other tissues. Copper content was equally high in fruits and green stems. Roots contained max Fe, suggesting that okra plants tend to accumulate Fe in roots without translocating much to above-ground plant parts.
Nitrogen and Potassium Rate Effects on Growth, Leaf Nitrogen and Winter Hardiness of Pyracantha coccinea ‘Lalandi’ and Ilex crenata ‘Rotundifolia’1
Authors: Kelley James D.
Published: August 2022

Pyracantha coccinea Dipp. ‘Lalandi’ and Ilex crenata Maxim, ex Matsum. ‘Rotundifolia’ were grown in 1-gal containers for 1 growing season at 6 rates of N and 6 rates of K with treatments arranged in a factorial design. Nitrogen at moderate rates (1.32 and 1.98 lb. of NH4NO3 per 100 gal water) produced the best growth response as determined by number of laterals and total growth per plant. Higher rates produced little or no additional growth. Optimum concn of leaf N was about 2.32% for P. coccinea and 2.65% for I. crenata. Potassium rate had no significant effect on growth or leaf N. Interactions between N and K were not significant. High correlation coefficients (r = .95) were found between leaf N and total growth per plant for both species. The N status and total growth response of these species can be best determined by leaf analysis. Nitrogen concn in leaves of P. coccinea and ability to overwinter were negatively correlated.
Sampling Procedures and Optimum Sample Size for Estimating Yield Components in Peas (Pisum sativum L.)1
Authors: Gritton E. T. , Pi-yeong Chi
Published: August 2022

Yield of fresh shelled peas and number of pods per plant, number of peas per pod, and wt per ovule were determined on plant samples collected by 2 different methods. There was no significant difference between means of the samples pulled “at random” by samplers as they walked through the plot and the samples made up of plants previously specified by randomization. A test of homogeneity of variances showed that taking samples by randomization gave a significantly lower variance for yield of shelled fresh peas, but not for the individual yield components. There was no overall significant difference in sampling methods, probably because of the difficulty of exercising bias in traits such as those studied. Weight of shelled fresh peas was the most variable character, followed by number of pods per plant, number of peas per pod, and wt per ovule.

Estimates of precision obtained from various combinations of number of plants sampled per replication and number of replications, with a cost ratio of replication to plant of 18:1, yielded 16 as the optimum number of plants to sample per replicate for wt of shelled fresh peas, with 3, 5, and 8 replications required for C.V.’s of 13, 10, and 8%, respectively. Other yield characters were less variable and would be estimated with even greater precision.
Effects of Succinic Acid-2,2-Dimethylhydrazide on the Color, Firmness, and Uniformity of Processing Peaches1
Authors: Baumgardner R. A. , Stembridge G. E. , Van Blaricom L. O. , Gambrell C. E.
Published: August 2022

Application of succinic acid,2,2-dimethylhydrazide (SADH) to peaches at the onset of pit hardening advanced maturity and caused more rapid softening during ripening on the tree.

Flesh color at a given firmness was improved by SADH over a wide maturity range. The color difference was maintained after processing; canned halves from SADH trees had a higher USDA color grade than control fruit of comparable firmness.

Uniformity of firmness and flesh color among fruit within trees varied with crop maturity, but uniformity was not substantially affected by SADH. However, enhancement of flesh color by SADH improved the quality of fruit obtained by once-over harvest and tended to concentrate the grade distribution of canned halves in USDA color grades A and B.
Staking and Pruning Influence Trunk Development of Young Trees1
Authors: Leiser Andrew T. , Harris Richard W. , Neel P. Lanny , Long Dwight , Stice Norman W. , Maire Richard G.
Published: August 2022

Trunk development of young container-grown trees was influenced by pruning and staking practices. The conventional nursery practice of staking and severely pruning laterals of container-grown trees produces plants which usually cannot stand without support when planted in the landscape. However trees were produced that were able to stand erect without staking by eliminating stakes during production, leaving lateral branches on the trunk, and spacing plants so their tops were free to move. Even though rigidly staked trees with lower limbs removed grew taller, they developed less caliper at the trunk base, much less taper to the trunk, and a smaller root system. Most of the trees staked during production, regardless of whether they were lightly or severely pruned, were not able to stand upright when planted out, while the unstaked trees needed no support.
A Cytogenetic Study of a Radiation-Induced Male Sterile Mutant of Cucumber1
Authors: Whelan Ernest D. P.
Published: August 2022

Two male sterile lines of cucumber (Cucumis sativus L.) were obtained from the inbred progeny of a single seed of the cv. Burpless Hybrid exposed to 16.000 rads from a cobalt-60 gamma source. The male steriles were characterized by abortion of the staminate blossoms. In rare instances where the flowers matured to anthesis, only rudimentary anthers, which contained no pollen, were present. Genetic studies showed that male sterility was due to a single, recessive allele common to both lines. This gene is designated ms2 - Cytological examination revealed that pollen abortion did not occur until after the mitotic division of the pollen grain nucleus. Sometime following this stage of development, the pollen grains and tissues of the anther degenerated and the staminate flowers aborted. One male sterile line also contained a reciprocal translocation induced by radiation, which was not linked with the male sterile character
Inheritance of Resistance in Phaseolus vulgaris to Uromyces phaseoli typica Brazilian Rust Race B11 and of Plant Habit1
Authors: Augustin Eliane , Coyne D. P. , Schuster M. L.
Published: August 2022

A new method of inoculation of bean seedlings with urediospores of Uromyces phaseoli typica Arth. produced an even distribution of numerous pustules on the leaves. A suspension of urediospores in Freon-113 was sprayed on both surfaces of the primary leaves. The plants were then placed in a moist chamber for 18 hr under a low light intensity of 2 × 10-5µ einsteins cm2 sec-1, before being transferred to the greenhouse. In screening tests the cvs. Great Northern 1140 and Kentucky Wonder Wax No. 765 were resistant to Brazilian race B11; ‘GN 1140’ showed the highest grade of resistance. Segregation for the reaction to rust race B11 in the F2 generation in crosses between the resistant cv. GN 1140 and 4 susceptible lines indicated that a major gene controlled the reaction with the resistant reaction dominant. The symbol RB11 was assigned to the dominant allele. Linkage was not detected between genes controlling plant habit and disease reaction.
Combining Ability of Two Degenerative Sweet Corn Mutants II
Authors: Lachman W. H.
Published: August 2022

Two degenerative sweet corn mutants, C30, a mutant of P39, ‘Pee Wee’ a mutant of C30 and P39 were crossed with sweet corn inbred C15 to determine their relative abilities to promote heterosis in hybrids. Of the 3 inbreds, C30 had the greatest ability to promote heterosis when in combination with C l5; ‘Pee Wee’ was least effective. Evidently, not all degenerative mutants are capable of promoting marked heterotic effects.
Acidic Root-Promoting Growth Inhibitor(s) Found in Picea and Chamaecyparis1
Authors: Tognoni Franco , Lorenzi Roberto
Published: August 2022

The acid phase of methanolic extracts of Picea glauca var. albertiana cv. Conica tissue, a difficult-to-root cultivar, had a high content of substances, at Rf 0.9 – 1.0, which inhibited the growth of Avena first internode. Chamaecyparis lawsoniana var. fletcheri, an easy-to-root variety, had a lower content of these substances. The substances stimulated root formation in mung bean cuttings, but no synergistic root-promoting effect was found when they were supplied to mung bean cuttings in the presence of 5 × 10−6M indoleacetic acid (IAA).

The substances at Rf 0.9 – 1.0 showed a dose-response effect over a concn range of 0 to 1.106 g fresh wt. Concn higher than 1.106 g did not further increase the number of roots in either species. An additive effect between extract and IAA was found in Picea at concn below 0.276 g and in Chamaecyparis at concn lower than 0.110 g and higher than 1.106 g fresh wt. The possibility that root initiation may be determined by hormone balance rather than a single substance is discussed.
Influence of Day/Night Temperature Under Controlled Environments on the Growth and Flowering of Limonium ‘Midnight Blue’1
Authors: Krizek Donald T. , Semeniuk Peter
Published: August 2022

The effects of 3 day/night temp (16/13, 21/18, and 27/24°C) on the growth and flowering of annual statice (Limonium ‘Midnight Blue’)3 were determined after 14, 28, and 42 days of controlled-environment treatment. A day/night temp of 16/13° severely limited seedling growth as measured by leaf number and fresh and dry wt of tops. Vegetative growth at 21/18°C was markedly greater than at 16/13°. Increasing the day/night temp further to 27/24° had no appreciable effect on leaf number but did produce additional increases in fresh and dry wt of tops. Despite the minimum amount of vegetative growth produced at 16/13°C after 42 days, this treatment resulted in the greatest number of plants flowering in the shortest time, suggesting a cool temp requirement for flower initiation in this cultivar. The stimulatory effects of a cool temp or inhibitory effects of a high temp on flower initiation persisted after the seedlings were removed from the growth chambers and placed in the greenhouse on natural long photoperiods. The feasibility of using cool-temp treatment at the seedling stage to promote flowering in this cultivar was, thereby, demonstrated.
Effects of Preharvest Application of Ethephon on ‘Early Black’ Cranberries1
Authors: Bramlage W. J. , Devlin R. M. , Smagula J. M.
Published: August 2022

Application of (2-chloroethyl) phosphonic acid (ethephon) at a rate of 0.92 kg/ha stimulated preharvest anthocyanin accumulation in ‘Early Black’ cranberries. A 10-fold increase in ethylene production followed application; however, within 10 days there was little difference in ethylene production between control and treated fruit. The increase in pigment that occurred during this time persisted well beyond this period. Ethephon did not affect the rate of CO2 production from the fruit. Whether or not anthocyanin stimulation occurred via accelerated ripening was not resolved.
Influence of Controlled Atmosphere Storage on Quality of Canned Apricots1
Authors: Claypool L. L. , Pangborn R. M.
Published: August 2022

‘Blenheim’ and ‘Tilton’ apricots were stored under several CA conditions at 0°C and in air storage at −1°C. Loss in acidity with time in storage was more rapid in air than in CA. Oxygen level seemed more important than CO2 in influencing rate of acid loss. Taste panels evaluating the canned fruit were able to differentiate between fruits of different harvest maturities and ascribed better flavor to the more mature fruits. Fruits canned the day of harvest were of better quality than those canned after storage. Flavor deteriorated progressively as storage time increased. The rate of flavor deterioration was less in CA than in air, although the air lots had been held at a slightly more favorable storage temp. ‘Blenheim’ apricots stored in atmospheres containing 2.5 to 3.5% CO2 had better flavor than those stored in atmospheres higher in CO2. Approximately equal flavor deterioration of ‘Blenheim’ apricots occurred in 3 weeks in air, 5 weeks in low O2 atmospheres with 5 and 10% CO2, and 7 weeks in low O2 atmospheres containing 2.5 to 3.5% CO2. ‘Blenheim’ apricots were greatly preferred over ‘Tilton’. The potential storage life of ‘Tilton’ in relation to acceptable flavor was much less than that of ‘Blenheim’.
Effect of Plot Size and Number of Replications Upon the Efficiency of Muscadine Grape Cultivar Trials1
Authors: Nesbitt William B. , Kirk Herbert J.
Published: August 2022

A rearrangement of the Harris et al. equation was used to determine a precise and economical field plan for conducting a randomized complete block muscadine grape cv. and selection trial. An increase in the number of replications decreased the magnitude of the yield differences that are detectable as being significant to a greater extent than did an increase in plot size or number of clones being tested. Relatively little precision was gained by increasing the plot size from 1 to 2 vines and almost nothing was gained by increasing the plot size further to 3 or 4 vines. Muscadine grape yield trials can be conducted most efficiently by using 1-vine plots and 5 or more replications.
Three Years’ Results with Chemical Thinning of Peaches with (2-chloroethyl)phosphonic Acid1
Authors: Thompson A. H. , Rogers B. L.
Published: August 2022

Three years’ investigations of ethephon sprays for thinning of ‘Redskin’ and ‘Redhaven’ cvs. are summarized. In screening, thinning without foliage injury was achieved up to about 3 weeks after full bloom at concn up to 300 ppm. Field experiments tended to confirm screening results. Within timing used, satisfactory thinning was accomplished most often during blossoming. Foliage injury generally increased as application was delayed and as concn increased. Fruit size at harvest was increased more by blossom treatments than later application. Fruit abscission occurred quickly after spraying. Ethephon is most promising as a peach thinning chemical, but time-dosage curves within acceptable injury Emits are not yet established.
Vascular Blockage in Cut Roses1
Authors: Gilman Karen Frenzel , Steponkus Peter L.
Published: August 2022

A gravity system was developed for measuring xylem conductivity in excised stem sections from ‘Red American Beauty’ roses. The system was reliable for measurement of the potential xylem conductivity which closely corresponded to actual water uptake in cut roses. Distilled water, sucrose, 8-hydroxy quinoline sulfate (8-HQS), and a modified Cornell solution (2% sucrose + 200 mg/liter 8-HQS) were tested for their effects on xylem conductivity and vascular blockage in excised stem sections. The modified Cornell solution showed the most favorable effects on conductivity, vase life, and appearance. The browning of stem tissue with 8-HQS was associated with a depressed rate of metabolism as measured by a modified triphenyl tetrazolium chloride test. Good xylem conductivity and a low incidence of vascular blockage was associated with the 8-HQS-depressed metabolic rate indicating an active process, attributed to a wound response triggered by excision of the cut flower, in the stem is responsible for vascular blockage. However, microscopic observations of fresh, frozen, and permanent tissue sections of rose xylem showed no evidence of lignin, tannins, or tyloses which are reputed to accompany wound response in plants.
Control of Annual Weeds in Container Grown Nursery Stock1
Authors: Fretz Thomas A.
Published: August 2022

Seven herbicides were evaluated for their safety and efficacy on 5 species of container grown nursery stock. During both growing seasons all materials except isopropyl-m-chlorocarbanilate [chlorpropham] at 2.2 and 8.9 kg/ha, chlorpropham at 2.2 and 8.9 kg/ha + P-chlorophenyl-N-methylcarbamate [PPG-124] at 0.4 and 1.7 kg/ha, resp., and N,N-dimethyl 2,2-diphenylacetamide [diphenamid] at 5.6 kg/ha gave satisfactory long season (163 days) broadleaf weed control. Long season grass weed control in nursery containers was achieved both years with 2,6-dichlorobenzonitrile (dichlobenil) at 13.4 kg/ha, α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin) at 2.2 and 8.9 kg/ha, S-ethyl dipropylthiocarbamate (EPTC) at 5.6 and 22.4 kg/ha, chlorpropham + PPG-124 at 8.9 + 1.7 kg/ha and diphenamid at 22.4 kg/ha. Both azalea species employed in the test exhibited severe chlorosis, necrosis, and stunting when dichlobenil at 13.4 kg/ha and EPTC at 22.4 kg/ha were employed. Japanese holly and ‘Sasanqua’ camellias were severely injured by dichlobenil at 13.4 kg/ha, while ‘Hetzi’ juniper was tolerant to all herbicides at all rates employed.
Influence of Preharvest Sprays of Calcium Salts and Wax on Fruit Quality of Red Raspberry
Authors: Eaves C. A. , Lockhart C. L. , Stark R. , Craig D. L.
Published: August 2022

Preharvest sprays of CaCl2, Ca(NO3)2, or water soluble wax increased berry size (by wt) and decreased the rate of softening during storage for 48 hr at 21°C. In a split plot experiment, with 4 cvs. and 3 dates of harvest, preharvest sprays of wax increased firmness but had no effect on total acidity, acid loss, water loss, or fungal decay. There were, however, significant interactions between cvs. and harvest dates in relation to firmness, acidity, and rot development.
Organic and Mineral Fertilizers Compared by Yield, Quality, and Composition of Spinach1
Authors: Peavy William S. , Greig J. K.
Published: August 2022

Mineral fertilizers increased yield and concn of N in leaf tissue more than organic fertilizers when nutrients were applied to make mineral and organic rates identical. All 3 types of fertilizer treatments increased N concn in plant tissues over the control plots. Organic fertilizer resulted in significantly higher P concn in plant tissue than did MF or MFSN for every crop. Mineral fertilizer increased Ca uptake the 1st and 3rd crops, but significantly reversed those results in the 2nd (overwintered) crop. Organic fertilizers increased Fe uptake significantly over MF the 2nd and 3rd crops and significantly increased Na uptake more than either MF or MFSN every crop. Of the 13 variables studied, concn of 10 variables was greater in the overwintered crop than in the spring planted crops.
Effect of Plant Growth Regulators on Apple Fruit and Pedicel Abscission1
Authors: Stahly E. A. , Williams M. W.
Published: August 2022

Lanolin bands containing 2, 3, 5-triiodobenzoic acid (TIBA) applied to the pedicel of apple fruits 2 to 3 weeks after bloom caused the fruits to drop. Naphthaleneacetic acid (NAA) applied to the cut end of defruited pedicels prevented pedicel abscission, but a band of lanolin containing TIBA at mid-pedicel caused most of them to abscise. Cytokinins did not prevent pedicel abscission. Indole-3-acetic acid (IAA) and gibberellins A3 and A4,7 more effectively prevented pedicel abscission of ‘Delicious’ than ‘Golden Delicious’.
Climatic Effects on Fruit Shape and Peel Thickness in ‘Marsh Seedless’ Grapefruit1
Authors: Cohen A. , Lomas J. , Rassis A.
Published: August 2022

The relations between peel thickness and fruit shape of ‘Marsh Seedless’ grapefruit and various climatic factors were studied at 8 locations in Israel. Peel thickness was affected greatest by winter temp. Low winter temp resulted in fruits with thick peel in the following year. Fruit shape was affected to a similar degree by low winter temp, summer air humidity, and rate of evaporation. Summer temp and the differences between maximum and minimum temp in the spring and fall, had little effect on fruit shape and peel thickness.
Performance of 13 Citrus Cultivars as Rootstocks for Grapefruit1
Authors: Wutscher Heinz K. , Shull A. V.
Published: August 2022

Yield, fruit quality, growth, and the levels of 12 elements in the leaves of 14-year old nucellar ‘Redblush’ grapefruit on 13 rootstocks showed that trees on Citrumelo C.P.B. 4475, ‘Morton’ citrange, and ‘Bittersweet’ sour orange were the most productive; those on ‘Ponkan’ mandarin, seedlings on their own roots, and sour orange were the least productive3. Two-year means of total soluble solids ranged from 10.3% for fruit from trees on ‘Bittersweet’ sour orange, ‘Carrizo’ citrange, and ‘Ponkan’ mandarin to 11.3% on sour orange. Fruit size was best on ‘Bittersweet’ sour orange and on Citrumelo C.P.B. 4475. Effects of rootstock on the levels of N, K, Mg, Mn, Zn, Na, and Cl and B in the leaves were statistically significant.
Association of Plant Density, Cowpea Curculio Damage and Choanephora Pod Rot in Southern Peas1
Authors: Fery Richard L. , Cuthbert Frank P.
Published: August 2022

Cowpea curculio damage in southern peas was found to be highly correlated with plant density. A mean increase in curculio damage of over 300% was associated with the increase in density from 37.5 to 600 plants/100 ft row. The incidence of Choanephora pot rot also Increased with increased plant density. This association, however, was the result of the density effect on curculio damage. The insect damage apparently provided points of entry for the pathogen.
Effects of Low Oxygen Atmosphere Storage on Ripening and Associated Biochemical Changes of Tomato Fruits1
Authors: Salunkhe D. K. , Wu M. T.
Published: August 2022

Low O2 atmospheres inhibited ripening and thus increased the storage life at 12.78°C (55°F) of tomato fruits. At 10% O2 and 90% N2, the storage life was 62 days; at 3% O2 and 97% N2, 76 days. The maximum life of tomato fruits in this study was 87 days (1% O2 and 99% N2). Low O2 atmospheres inhibited degradation of chlorophyll and starch, and syntheses of lycopene, β-carotene, and soluble sugars of tomato fruits.
Manganese Enrichment of Tomato and Onion Seed1
Authors: Traverse Ross J. , Riekels Jerald W.
Published: August 2022

Soaking tomato seeds in MnS04 solutions of concentrations greater than 0.5 and 1 M MnS04 inhibited germination during treatment without affecting the viability of the seeds. The emergence and early growth of tomato seedlings and the emergence of onion seedlings in soil was greater using seeds previously treated with 1 M MnS04 than with untreated seeds or with seeds treated with 2 and 2.5 M MnS04. These treatments had no effect on onion seedling growth. Soaking seeds in 1 M MnS04 was effective in supplying the Mn requirements of tomato plants grown in Mn deficient solutions for Approx 40 days. Shorter periods of normal growth were obtained by treating the seeds with less than 1 M concn of MnS04.

The amount of Mn retained after desorption and washing was greater with each increase in the soaking temp (0, 10, 20, and 30°C). A substantial amount of the Mn retained by the tomato and onion seeds after soaking appeared to be located on the seed coat or in the “outer space” of the tissue. With onion seeds, an additional portion of the Mn retained after soaking was located on the exchange sites of the seeds.
Inheritance of Resistance to Cowpea Chlorotic Mottle Virus in Southern Pea, Vigna sinensis1
Authors: Rogers Kenneth M. , Norton J. D. , Chambliss O. L.
Published: August 2022

The inheritance of resistance to cowpea chlorotic mottle virus (CCMV) in southern pea, Vigna sinensis (L.) Savi., Plant Introduction 255811, was determined in crosses with the susceptible cvs. Knuckle Purple Hull, Mississippi Silver, and Princess Anne. Segregation of F2 and backcross populations indicated that resistance to CCMV in P.I. 255811 is governed by 1 major recessive gene pair.
Participation of Phytochrome in Regulating Internode Elongation of Chrysanthemum morifolium (Ramat.) Hemsl.1
Authors: Cathey H. M.
Published: August 2022

Chrysanthemum plants complete flower initiation and development processes by the 12th hr of the daily long night. Artificial light after the 12-hr dark period and continued until sunrise or sunlight promotes internode extension and increased fresh and dry wt without delaying flower initiation and development. Light from incandescent-filament lamps (equal-red and far-red) was the most effective source of morning-lighting effects. Light from fluorescent lamps (red) did not promote internode elongation. Use of photographic safety lamps (BCJ) (far-red) permitted flowers to be initiated, but delayed flower development. Intermittent light (0.5 to 120 ft-c) from incandescent lamps was much less effective than continuous light in promoting stem elongation. Results indicate that 2 phytochrome-mediated systems act sequentially to regulate flowering and stem elongation in chrysanthemum. The first, which responds to light in the middle of the night, delays flowering and promotes internode elongation. The second, which acts after a 12-hr dark period, does not alter the time to flowering but promotes internode elongation. The physiological action of this system permits continued synthesis and/or effectiveness of increased levels of endogenous growth-promoting substances.
Influence of Nitrate on Tomato Growth1,2
Authors: Gomez-Lepe B. E. , Ulrich Albert
Published: August 2022

Tomato plants (Lycopersicon esculentum L. cv. VF 145-21-4) in the greenhouse developed over a 5-week period from seedling to early bloom stage, increased in fresh and dry weight of shoots and roots, in plant height, and internal NO3-N concentration in relation to the NO3 supply of the culture solution. Increases in NO3-N varied among plant parts: roots < stem < petiole > blade. Growth of shoots was related to NO3-N concentration in plant parts. A petiole from a young mature leaf, leaf 2, was the best indicator of N status of the plant. Its critical value for N deficiency was 275 ppm of NO3-N (dry wt) when estimated at a 10% reduction in growth. A tentative critical value for use under field conditions was set at 500 ppm. Movement of NO3 was primarily unidirectional from the petiole to the blade, with little return movement to the stem and upward to younger petioles.
Persistent-Green Color Snap Beans (Phaseolus vulgaris L.): Color-related Constituents and Quality of Cooked Fresh Beans1
Authors: Zaehringer M. V. , Davis K. R. , Dean L. L.
Published: August 2022

Evaluations of cooked fresh beans showed that the persistent-green color (PC) cv., Custer, was darker, greener, and less yellow than the normal-green cv., Canyon. Persistent-green color lines Xlda 71-2081 and Xlda 267-4 were intermediate between the 2. Chlorophyll concentrations were higher in all PC lines than in the normal-green cultivar but the ratio of chlorophyll a/b was lower. Chlorophyll content was significantly correlated with Gardner color values and with visual color scores. No color values correlated with pheophytin or carotene content.

Xlda 71-2081 had the highest work-to-shear values, % seed, % fiber, and highest panel scores for fibrousness. Whether the higher values were attributable to genetic controls or to a difference in maturity was not determined in this study. Little sloughing was observed. All cultivars had a slightly to moderately full, natural flavor. The PC beans were equal or superior to the normal-green cultivar in all measured quality characteristics with ‘Custer’ showing the most promise.
Solar Radiation and Water Loss from Glasshouse Roses1
Authors: Stanhill G. , Scholte Albers J.
Published: August 2022

Measurements of global radiation above, and net solar radiation below, the roof of a glasshouse were both highly correlated on a daily and hourly basis with the water loss from a flowering rose crop as measured with a weighing lysimeter. The relationship can be used for an automatic system of irrigation control. Under local glasshouse, soil, and crop response conditions such a system would require an application of 6 liters of water per square meter of bed for every 730 cal cm2 global radiation above the glasshouse. Alternatively, a foliage spray irrigation system to ensure that the upper part of the canopy is kept continuously moist, would require applications of at least 0.4 liters per square meter at radiation intervals between 15 and 4 cal cm2 of global radiation outside the greenhouse, the exact figure depending mainly on the rate of air movement around the foliage. The latent heat equivalent of the crop water loss was 87% of the global radiation incident on the canopy, a figure similar to those listed for other, tall glasshouse crops.
Studies on Lettuce Seed Quality: III. Relationships between Flowering Pattern, Seed Yield, and Seed Quality1
Authors: Soffer Hillel , Smith O. E.
Published: August 2022

Lettuce plants (Lactuca sativa L.) showed definite flowering peaks over a 70-day period. Over 90% of the seed yield was from flowers which opened during the first 35 days, and seed produced from flowers opening during the first 2 flowering peaks were heavier than those produced later in the season. Seed size was not correlated with number of seeds per flower head. Seed yield and quality were not affected by early harvest or by withholding water and nutrients during the last half of the flowering period. Flowering rate, seed yield, and seed quality were not related to air temperature in the range 67 to 94°F.