bluuebunny/crossref_metadata_2025 huggingface dataset:
Response of Tomato to Defoliation
Authors: Wolk J.O. , Kretchman D.W. , Ortega D.G.
Published: August 2022

Defoliation of transplants of tomato (Lycopersicon esculentum Mill.) at planting delayed plant development (including fruit maturity), but leaf areas of defoliated and nondefoliated plants were equal at fruit maturity. Defoliation at first bloom, full bloom, or 2.5-cm fruit diameter resulted in progressively less leaf area at harvest as the degree of defoliation increased. Defoliation of 80% at the above 3 stages of flower/fruit development resulted in reduced yield. Defoliation of 25% or 50% prior to or at full bloom had no apparent influence on yield. However, 25% or 50% defoliation when fruits were near 2.5-cm diameter resulted in yield reduction. Defoliation had no apparent influence on fruit size at harvest. Soluble solids in the fruit were reduced progressively with each successive increase in defoliation, while titratable acidity and pH were not affected. Defoliation increased photosynthesis in remaining leaves 4 and 14 days after treatment but had no effect on transpiration.
Evaluations of Herbicides in Slow-release Formulations for Container-grown Landscape Crops
Authors: Ruizzo M.A. , Smith E.M. , Gorske S.F.
Published: August 2022

Alachlor (2-chloro-2',6'-diethyl-N-(methoxyinethyl) acetanilide), chloramben (3-amino-2,5-dichlorobenzoic acid), naptalam (N-1-napthylphthalamic acid (2-N-1-naphthy) aminocarbaryl benzoic acid), and propachlor (2-chlor-N-isopropylacetanilide) incorporated into dicalcium phosphate and plaster of paris slow-release tablet formulations successfully controlled weeds for 16 weeks with no significant injury to cotoneaster (Cotoneaster dammeri C.K. Schneid. ‘Royal Beauty’), euonymus [Euonymus fortunei (Tarcz.) Hand Mazz. ‘Emerald ’N Gold’], forsythia (Forsythia X intermedia Zab. ‘Spring Glory’), ind privet (Ligustrum X vicaryi, a hybrid between L. ovalifolium Hasst. ‘Aureum’ and L. vulgare L.). One tablet per container was applied, delivering 20 or 40 kg/ha active ingredient. Metolachlor (2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamide) was incorporated in the tablet formulations to deliver a rate of 40 kg/ha active ingredient per tablet to evaluate area of weed control. Weed density was significantly reduced in containers treated with metolachlor tablets. An essentially weed-free area (7- to 8-cm radius) encompassing a single herbicide tablet was observed. Tablet formulations did not significantly differ in reduction of weed density in nursery containers.
Effects of Film Thickness and Storage Temperature on Water Loss and Internal Quality of Seal-packaged Grapefruit
Authors: Purvis A.C.
Published: August 2022

‘Marsh’ grapefruit (Citrus paradisi Macf.) were seal-packaged in low-density, polyethylene films ranging from 20 to 40 µm in thickness and stored at temperatures from 5 to 28°C for periods up to 109 days. Film thickness had a negligible effect on transpiration, respiratory gas exchange, and juice quality. Storage temperature had a negligible effect on transpiration of seal-packaged fruit. However, 28° storage temperature significantly affected acid concentration in both seal-packaged and unwaxed fruit, probably as a result of increased respiratory activity at high storage temperatures. Quality of both seal-packaged fruit and unwaxed fruit deteriorated in storage at 28°.
Ion Regulation and Response of Tomato to Sodium Chloride: A Homeostatic System
Authors: Sacher R.F. , Staples R.C. , Robinson R.W.
Published: August 2022

Lycopersicon esculentum Mill. cv. New Yorker, Solanum pennellii Corr. PI 246502, and 16 stable breeding lines of horticultural type derived from this cross were evaluated under saline (0.1 m NaCl) and control conditions. The breeding line population exhibited a much wider range of salt tolerance than that found in the cultivated species. Relative ability to regulate sodium accumulation in the leaves was significantly correlated with growth under saline irrigation. Absolute levels of foliar sodium or chloride accumulated under saline irrigation were not significantly correlated with plant growth. Regulation of ion accumulation was assessed as the ratio of foliar ionic content in saltgrown plants to foliar content in control plants, a value which we define as ion regulation index (IRI). A low index indicated regulation of accumulation of a particular ion. Regulation of ion uptake is interpreted as reflecting an effective homeostatic system. The homeostasis was attributed to tomato, and salt tolerance improvement occurred only if the requisite homeostasis was combined with other factors conferred by S. pennelli. Information regarding occurrence and possible mechanisms of this type of salt tolerance is reviewed.
Effects of Dormant Pruning, Summer Pruning, Scoring, and Growth Regulators on Growth, Yield, and Fruit Quality of ‘Delicious’ and ‘Cortland’ Apple Trees
Authors: Greene Duane W. , Lord William J.
Published: August 2022

Summer pruning 6-year-old trees of ‘Cortland’ apple (Malus domestica Borkh.) for 3 consecutive years in either early July or early August reduced trunk circumference increase the year of pruning and increased terminal growth the following year. Terminal growth on 8-year-old ‘Red Prince Delicious’ trees summer-pruned in August for 3 consecutive years was similar to dormant-pruned trees, and trunk circumference increase was reduced the last 2 years. Fruit size and soluble solids were reduced the last 2 years. Fruit size and soluble solids were reduced by summer pruning ‘Cortland’ but not ‘Red Prince’. Flowering, fruit set, yield, flesh firmness, flesh calcium, and storage disorders were not affected by summer pruning of either cultivar. Terminal growth of ‘Cortland’ trees was reduced the year of scoring and the following year. Bloom was increased the year following scoring. Scoring ‘Red Prince’ for 3 consecutive years consistently reduced terminal growth and increased yield the second and third years. Corrective dormant pruning (CDP) on ‘Red Prince’ reduced bloom but not yield the first year. In the 2 subsequent years, bloom, fruit set, and yield were not affected by CDP and the practice alleviated the problem of tree crowding. Summer pruning on ‘Cortland’ trees followed by a postbloom spray of butanedioic acid mono(2,2-dimethyl hydrazide) (daminozide) of 1500 ppm showed promise as a way to control tree growth, increase flower bud formation, and fruit set.
Relationship between Galactinol Synthase Activity and Sugar Composition of Leaves and Seeds of Several Crop Species
Authors: Handley Levis W. , Pharr David M. , McFeeters Roger F.
Published: August 2022

Galactinol synthase was assayed from leaves of 24 different accessions (20 species), maturing seeds of soybean, and cotyledons of germinating cucumber seeds. Leaf tissue contained concentrations of raffinose ranging from not detectable to 0.36 mg/g fresh weight (gfw) and stachyose ranging from not detectable to 1.39 mg/gfw. Galactinol synthase activity from leaves was correlated with the proportion of total sugar present as raffinose saccharides. In maturing soybean seeds, the appearance of galactinol synthase coincided with the biosynthesis of the galactosyl-sugars. Cucumber seeds contained high levels of raffinose and stachyose which decreased in the cotyledon during germination to a steady-state level coincident with the appearance of galactinol synthase.
Nutrient Changes in Apple Leaves due to the Spotted Tentiform Leafminer
Authors: Bodnar J.M. , Proctor J.T.A. , Laing J.E. , Cline R.A.
Published: August 2022

Leaves of apple (Malus domestica Borkh.) containing up to 8 mines per leaf produced by the spotted tentiform leafminer (STLM), Phyllonorycter blancardella (Fabr.), were analyzed for N, K, Ca, Mg, Mn, and Zn. Nutrient imbalance due to leafmining depended upon leaf type, location of the leaf, and the relative concentration of an element in the leaf types. Leafmining had the greatest effect on interior spur leaves, and particularly on concentration reduction of Ca and Mg which are major constituents of the insect hemolymph.
Griseofulvin-induced Chromosome Instability and Reduction in a Petunia Somatic Hybrid
Authors: Griesbach Robert J. , Schnabelrauch Linda S. , Sink Kenneth C.
Published: August 2022

Leaf sections of a Petunia paradii x P. inflata somatic hybrid treated with griseofulvin (7-chloro-2’,4,6-trimethoxy-6’-methyl-spiro(benzofuran-2(3H), 1’-2 cyclohexene)-3, 4’dione) have been regenerated into whole plants. Of the regenerates, 5% expressed various degrees of leaf and flower abnormalities. About 80% of these abnormal types had chromosome numbers reduced from the pentaploid control level. It appears that the griseofulvin-induced chromosome instability may activate a type of position effect-variegation which causes both leaf and flower variegation.
Relationship between Environment during Seed Development and Seed Vigor of Two Endosperm Mutants of Corn
Authors: Styer Roger C. , Cantliffe Daniel J.
Published: August 2022

Seeds of 2 corn (Zea mays L.) endosperm mutants, shrunken-2 (sh2) and sugary (su), were produced in the field and greenhouse and harvested 18 to 46 days postpollination (dpp). Seeds of su accumulated dry weight rapidly after 26 dpp, while sh2 seeds had nearly attained their final weight by this stage. This resulted in a larger endosperm in su. Greenhouse-grown sh2 seeds weighed more than field-grown sh2 throughout development. Germination and seedling growth of greenhouse-grown sh2 seeds under optimum conditions were greater than that of field-grown sh2 when seeds were older than 26 days. Greenhouse-grown sh2 seeds 26 days and older germinated as well as field- and greenhouse-grown su with comparable seedling growth. Germination of field-grown sh2 seeds was much higher throughout development in the cold rolled-towel test compared to the cold soil test. Viability and vigor differences between immature seeds of both genotypes were not distinguishable by the cold, rolled-towel test, but were very noticeable in the cold soil test. Under cold soil test conditions, greenhouse-grown sh2 seeds had significantly greater emergence than did field-grown sh2 38 dpp and older. Mature greenhouse-grown sh2 and su seeds were of equal viability and vigor in the cold soil test.
Influence of Soil Acidity on Watermelon Leaf Tissue Mineral Concentration and Yield
Authors: Sundstrom F.J. , Edwards R.L. , Constantin R.J. , Wells D.W.
Published: August 2022

Application of limestone to a Cahaba sandy loam increased exchangeable soil Ca and decreased extractable soil Al and Mn. Leaf tissue composition of ‘Calhoun Gray’ and ‘Dixielee’ watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] was significantly influenced by soil pH. Increased levels of limestone significantly increased tissue Ca and reduced tissue Al and Mn concentrations. High soil acidity was closely associated with high tissue Mn in both cultivars. Tissue Al levels were not as sharply reduced by increasing soil pH as were tissue Mn levels. Tissue Al influences on yield were not significant in either cultivar at any soil pH. In nonlimed plots, ‘Calhoun Gray’ tissue Mn was highly correlated with depressed crop yield, while ‘Dixielee’ produced no marketable fruit at soil pH 5.0. Foliar Mn toxicity symptoms were observed on the 2 cultivars at soil pH 5.0. Maximum watermelon yield was obtained at soil pH 6.0 on plots that received 112 kg N/ha.
Effects of PEG-induced Water Stress on Calcium Uptake in Peach Seedlings
Authors: Haber Melanie F. , Young Eric , Faust M.
Published: August 2022

Polyethylene glycol (PEG-4000)-induced water stress (—0.5 to —7.5 bars) reduced shoot and root growth, water use, and stem 45Ca in seedlings of peach (Prunus persica (L.) Batsch). Sucrose feeding through a leaf did not affect stem 45Ca with or without osmotic stress. 45Calcium uptake per milligram water used was not different at different solution osmotic potentials. A split-root study, with half the root system receiving 45Ca and/or PEG, showed that if 45Ca was supplied only to the water-stressed root half, 45Ca uptake into stems was low regardless of whether the other root half was stressed or not. Results indicate that reduced stem Ca during water stress is probably not a direct result of decreased root energy needed for active uptake or reduced translocation out of the root. Calcium absorption appeared to be related to the amount of unsuberized root surface available for Ca uptake.
Anatomical and Morphological Development of ‘Manzanillo’ Olive Seed in Relation to Germination
Authors: Lagarda A. , Martin G.C. , Polito V.S.
Published: August 2022

Microscopic examination of sectioned germinating olive seed (Olea europaea L.) did not reveal differences from many other seed types. No seedcoat-imposed mechanical restrictions were found during germination. The seed was 4% and the embryo 1% of the mature, whole fruit dry weight. Maximum embryo dry weight was achieved by early October. Germination was 90% when the embryo had gained 60% of its final dry weight. No dormancy factors were evident in the excised embryos.
Enhancement of Lettuce Yield by Manipulation of Light and Nitrogen Nutrition
Authors: Knight Sharon L. , Mitchell Cary A.
Published: August 2022

Several levels of photosynthetic photon flux density (PPFD) were tested for effects on growth of 4 cultivars of lettuce (Lactuca sativa L.) under controlled-environment conditions. Growth of ‘Salad Bowl’, ‘Bibb’, and ‘Ruby’ was greater at 932 µmol s -1m-2 than at ≤ 644 µmol s-1m-2 under a 16-hour photoperiod. Thirty mM NO3- or 5 mM NH4+ + 25 mM NO3- increased leaf dry weight while reducing leaf chlorosis in ‘Salad Bowl’ and ‘Grand Rapids’ relative to that with 15 mM NO3-, and reduced leaf purpling in ‘Bibb’ and ‘Ruby’ with little or no effect on yield. Continuous illumination with 455 or 918 µmol s-1 m-2 stimulated yield of ‘Salad Bowl’ and ‘Bibb’ when 30 mM N as NH4+ + NO3- was used relative to that with 15 mM NO3-.
Influence of Liming Rate on Holly, Azalea, and Juniper Growth in Pine Bark
Authors: Chrustic Grace A. , Wright Robert D.
Published: August 2022

Rooted cuttings of Ilex crenata Thunb. ‘Helleri’, Rhododendron obtusum Planch. ‘Rosebud’, and Juniperus chinensis L. ‘San Jose’ were grown in a 100% pine-bark medium amended with dolomitic limestone at 0 to 8 kg m-3 with resulting pH from 3.4 to 7.2. Except for juniper at 2 kg m-3, growth was not increased by liming, and 8 kg m-3 tended to reduce shoot and root growth. This reduced growth was attributed in part to greater NH4 adsorption by the bark, reducing the amount available for plant uptake, and a higher nitrification rate, leading to an elevated NO3 to NH4 ratio in the medium. Liming pine bark to improve growth of these woody plants may be unnecessary.
Strengthening of Tomato Shoots by Gyratory Shaking
Authors: Heuchert Joan C. , Marks Jay S. , Mitchell Cary A.
Published: August 2022

Seedlings of tomato (Lycopersicon esculentum Mill cv. Rutgers) grown in a greenhouse under conditions of limiting light intensity developed weak stems. Periodic gyratory shaking retarded axial and lateral growth of stems and petioles while strengthening these tissues. Hypocotyls and first internodes excised from shaken plants had greater moduli of elasticity and of rupture and ultimate shear strength than did similar sections cut from undisturbed controls. Threshold of deformation (rigidity) was greatest for stems of shaken plants. The cellulose fraction of stem fiber increased concomitant with elastic strength of shaken tomato seedlings.
Root and Air Temperature Effects on the Flowering and Yield of Tomato
Authors: Papadopoulos Athanasios P. , Tiessen Herman
Published: August 2022

Cultivars of greenhouse tomato (Lycopersicon esculentum Mill.) were grown in the greenhouse and in growth chambers to study the effects of root and air temperature on flowering and yield. A low air temperature of 19° (day)/14°C (night), during the fall crop, caused no reduction in yield when compared with the commonly used 22°/17° air temperature. A 13°/8° air temperature during the spring crop drastically reduced yield compared with the 19°/14°C air temperature. Flowering of ‘Ohio MR-13’ in growth chambers was delayed significantly at air temperatures of 24°/8° compared to 24°/17°, but the flowering of ‘Vendor’ was unaffected by air temperature treatments. Marketable yield of ‘Vendor’ was significantly higher at 24°/8° compared to the 24°/17° treatment, while the marketable yield of ‘Ohio MR-13’ was unaffected. At a constant, day air temperature of 24°, the amount of small fruit decreased as night air temperature was lowered from 17° to 8° and maturity was delayed as night air temperature was lowered from 14° to 8°. The effect of low air temperature on flowering and yield of tomatoes was large and could not be offset by increasing root temperatures. At air temperatures of 24°/17°, 24°/14°, and 24°/8°, marketable yields were affected adversely by the absence of root thermoperiodicity (day to night root temperature variation).
Influence of Air and Soil Temperatures on the Growth and Development of Lilium longiflorum Thunb. during Different Growth Phases
Authors: Wang Y.T. , Roberts A.N.
Published: August 2022

Yearling ‘Nellie White’ Easter lily plants were subjected to various air and soil temperature combinations to determine temperature requirements for 6 growth phases, each of one-month duration. An air and soil temperature of 24°C favored rapid leaf unfolding, stem elongation, and flower expansion with concomitant depletion of primary scales. After flower buds were visible, soil temperature had no appreciable effect on their rate of expansion; air temperature was the controlling factor. Leaf unfolding rate, stem length, and flower bud size were of equal value in monitoring crop development. Secondary scale initiation and development during the prebloom period was positively related to soil temperature rather than air temperature and was maximum at 24°. The rate of scale initiation progressively decreased from first appearance of the secondary meristem until anthesis of the primary axis. High soil temperature decreased the diameter of the secondary (daughter) axis apical meristem at any time prior to appearance of flower buds on primary axis (buds visible).
Use of Canopy-air Temperature Differentials as a Method for Scheduling Irrigations in Snap Beans
Authors: Bonanno A. Richard , Mack Harry J.
Published: August 2022

Two field experiments were conducted during 1981-1982 to determine the feasibility of using midday canopy temperatures, measured with an infrared radiation thermometer, for irrigation scheduling in ‘Oregon 1604’ and ‘Galamor’ snap beans (Phaseolus vulgaris L.) Treatments which allowed various levels of positive canopy minus air temperature differences [stress-degree-days (SDD)] to accumulate between irrigations were evaluated along with a treatment irrigated at 4 growth stages, a dry treatment, and a control treatment which was irrigated at -0.06 MPa soil water potential (SWP). Diurnal measurement of canopy and air temperatures indicated that the greatest differences between canopy and air temperature occurred near solar noon. In 1981, all treatments irrigated by an accumulation of positive SDD had reduced yields compared to the control SWP treatment. In 1982, under higher rainfall and lower air saturation vapor pressure deficits (VPD) than in 1981, yields of the SDD irrigated treatments were comparable to those obtained with the SWP treatment. Accumulation of positive SDD values to schedule irrigations was adequate when midday VPD values were low. However, when high VPD occurred, SDD values were always negative. A model is presented in which SDD values can be adjusted for environmental variability to more accurately schedule irrigations. Measurements of air temperatures within the canopy were made and compared to surface canopy temperatures measured with an infrared thermometer. Regression analysis showed that canopy temperature could be predicted using the air temperature within the canopy (R2 = 0.89). The sum of SDD values for the season was used to estimate canning maturity pod yield (R2 = 0.65).
Water Relations and Growth of Snap Beans as Influenced by Differential Irrigation
Authors: Bonanno A. Richard , Mack Harry J.
Published: August 2022

Two field experiments were conducted to evaluate the effects of differential irrigation on plant growth, development, and water status of 2 snap bean cultivars, ‘Oregon 1604’ and ‘Galamor’ (Phaseolus vulgaris L.). Plants were grown at various irrigation levels ranging from a well-watered control to a dry treatment which received only one irrigation to establish plants. Measurements on plants sampled weekly at 6 times during the growing season showed that total plant dry weight, total leaf dry weight, total leaf area, average area per leaf, and number of leaves per plant were reduced by water deficits in both cultivars. Also, for both cultivars, total leaf area per plant was reduced more by a decrease in area per leaf than by a reduction in leaf number. Specific dry leaf weight was higher in the drier treatments. During each year, a significant difference between treatments occurred earlier in the season for total leaf area per plant than for total plant weight. At predawn, leaf water potential (ψ) always was more negative in the dry treatment than in the control. Early in the season, there was no significant difference in midday ψ between the control and dry treatment. Later, as soil water became limiting, the dry treatment had a more negative ψ than the control. Near the end of the season, after the dry treatment had been subjected to a long period of water stress, midday ψ was more negative in the control than in the dry treatment. Although some osmotic adjustment occurred in the dry treatment, leaf turgor potential (ψp) was generally lower than in the control throughout the day. As ψ decreased from early morning through midday, transpiration rates increased due to an increase in evaporative demand on the leaves. Leaf diffusive resistance also increased with decreasing ψ but a “threshold value” for stomatal closure was not demonstrated.
Effect of Light Environment and Spur Age on ‘Delicious’ Apple Fruit Size and Quality
Authors: Robinson Terence L. , Seeley Earl J. , Barritt Bruce H.
Published: August 2022

Limbs of ‘Miller Sturdeespur Delicious’ apple trees (Malus domestica Borkh.) with bearing spurs ranging in age from 2 to 11 years were provided with differing solar exposure levels ranging from 5% to 95% of full sunlight (400 to 700 nm) from 55 days postbloom until harvest. As the exposure level of the limb canopy was reduced, fruit length, width, weight, soluble solids, starch content, and total solids were reduced while fruit firmness and total acidity were increased. Visual fruit red color of this high-coloring strain was not affected. As spur age increased, fruit length, width, weight, and soluble solids decreased while fruit firmness and total acidity increased. Spur age did not influence fruit red color, starch content, or total solids. Light exposure level accounted for a relatively large portion of the variation in fruit size and quality between limbs while spur age accounted for only a small portion of the variation within each limb.
Growth and Fruiting Responses of ‘Redspur Delicious’ Apple Trees to Pruning Treatments
Authors: Lord William J. , Damon Richard A.
Published: August 2022

A 7-year pruning trial with ‘Redspur Delicious’ trees (Malus domestica Borkh.) compared growth and fruiting responses to 3 pruning systems: 1) trees pruned with structural limbs spaced around a central leader and 20 cm apart vertically (regularly pruned); 2) central leader trees with structural limbs in tiers and one-year-old wood headed annually (tiers and heading); and 3) trees trained as slender spindles. Heading increased shoot growth from one-year-old wood but not every year. Generally, the growth response was limited to the first 6 subapical buds behind the heading cuts. Heading reduced the number of nodes on one-year-old wood, forced some lateral buds to produce vigorous shoots, and removed the apical section of wood which was shown to be more productive than the subapical sections. Cumulative yields of the slender spindle and regularly pruned trees were comparable, and both were higher than those of trees pruned by the tiers and heading system.
Seed Transmission of Gamma Radiation-induced Morphological Changes in Geranium
Authors: Grossman Herbert H. , Craig Richard
Published: August 2022

M2 progenies from geranium (Pelargorium X hortorum L.H. Bailey), which had been irradiated with 1, 2, and 3 krads of acute gamma radiation, were evaluated for stem and branch length and number of leaves and branches. After several weeks, the progenies from plants irradiated with 2 and 3 krads were significantly shorter than the controls. Progenies treated with 3 krads were 21% shorter and exhibited a 30% reduction in branch length compared to the controls at the termination of the experiment. These effects were similar to those observed in the M1 generation. Leaf and branch number did not differ significantly among progenies of the irradiated plants. It is suggested that gamma radiation induced changes in endogenous levels of GA in the M1 plants, and these changes were transmitted to the M2 progenies.
Influence of Flower Maturity and Environment on Hybrid and Selfed Seed Production of Several Tomato Genotypes
Authors: Shakya S.M. , Scott J.W.
Published: August 2022

Male-sterile, male-fertile, exserted stigma, and exserted stigma with positional sterile (ps) genotypes of tomato (Lycopersicon esculentum Mill.) were pollinated at daily intervals from one day before to 2 days after anthesis (A-1, A0, A+1, A+2, respectively) in 2 field experiments and one greenhouse experiment. A male-sterile with gene ms-1035 had greater seeds per pollination than other genotypes in all 3 experiments. Seeds per pollination produced in the greenhouse was greater than that of a similar field experiment at all pollination stages except A-1, where seed production was similar. Seeds per pollination was less at A-1 than at later pollination stages. This was due to significant differences in seeds per fruit in all experiments and percentage of fruit set in 2 of 3 experiments. There was no selfing in the 2 male-sterile genotypes in any experiment and no selfing for exserted stigma with ps in the field experiments. There was about 2% selfing with ps at A+2 in the greenhouse. Selfing with stigma exsertion alone ranged from 2% to 22% in the field and from less than 1% to about 5% in the greenhouse. The relationship of selfing with pollination stage was not clear for the exserted stigma genotype.
Influence of K and Ca on Quality and Yield of Watermelon
Authors: Sundstrom F.J. , Carter S.J.
Published: August 2022

Fertilizer K supplied as KC1, and Ca supplied as gypsum, interacted in their effect on yield and tissue composition of ‘Calhoun Gray’ watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai]. Increased rates of K significantly affected yield in a curvilinear manner. Response for K at varying levels of Ca had linear and either cubic and/or quadratic relationships. Increased rates of Ca reduced K uptake and yield. There was a highly significant inverse relationship between tissue K and tissue Ca. Although there was a significant K x Ca interaction on yield, individual element correlation coefficients with yield also were significant. Increased rates of fertilizer K increased rind thickness at watermelon equator, which was found to be related to watermelon rupture pressure. Ca and blossomend rind thickness had no influence on rupture pressure. K and Ca did not influence blossom-end rot, redness of flesh, or soluble solids of watermelon.
Characteristics of Four Sets of Reciprocal Crosses in Dendrobium (Orchidaceae)
Authors: McConnel James , Kamemoto H.
Published: August 2022

Progenies of 4 sets of reciprocal crosses in Dendrobium were compared including an intraspecific cross, 2 interspecific crosses, and an amphidiploid cross. With the reciprocal crosses involving 2 accessions of D. canaliculatum (D173-2 and D129), offspring with cytoplasm of D173-2 (Papua, New Guinea accession) were taller, produced more pseudobulbs, and gave a higher flower yield than with D129. Offspring with the same D. canaliculatum cytoplasm also produced taller plants and more pseudobulbs in reciprocal crosses between D. canaliculatum and D. strebloceras. Reciprocal crosses of D. schulleri × D. × Sunset differed in chromosome number and flower quality. D. schulleri × D. × Sunset produced triploid offspring, while the reciprocal produced diploid offspring. Reciprocal matings of 2 amphidiploid D. × Jaquelyn Thomas selections did not differ in height, yield, number of pseudobulbs, or floral characteristics.
Effects of Preplant Phosphorus Fertilization Rate and of Nitrate and Ammonium Liquid Feeds on Tomato Grown in Peat–Vermiculite
Authors: Gibson Carol J. , Pill Wallace G.
Published: August 2022

The effects of 0.02, 0.06, 0.18, and 0.54 kg P/m3 incorporation as superphosphate (0-9-0) in peat–vermiculite and of NO3-N and NH4-H liquid feeds were investigated with tomato (Lycopersicon esculentum Mill. cv. Marglobe). Increasing P rate decreased shoot and root dry weights but increased total fruit fresh weight. NH4-N, relative to NO3-N nutrition, decreased shoot growth but had no effect on fruit yield. Decreased vegetative growth with increasing P rate and NH4-N nutrition was associated with decreased leaflet xylem pressure potential, increased transpiration rate, and increased leaf NH4-N concentration. Leaf P and medium water-soluble P concentrations increased with increasing P rate but were unaffected by N form. During time of fruit development, leaf P content decreased at the 2 lowest P rates but increased at higher P rates. Net P export from leaves ceased and luxury P consumption began between 0.06 and 0.18 kg P/m3.
Inheritance and Heritability of Resistance to Tomato Anthracnose Caused by Colletotrichum dematium
Authors: Miller Anita N. , Ng Timothy J , Barksdale Thomas H.
Published: August 2022

A 6-parent diallel was used to study combining ability and type of gene action contributing to resistance in tomato (Lycopersicon esculentum Mill.) to anthracnose caused by Colletotrichum dematium (Pers. ex Fr.). The 6 parents, one set of F1, hybrids, and 5 selected reciprocal crosses were grown at 2 locations. Ripe fruit were harvested, puncture-inoculated with the pathogen, and subsequently evaluated for resultant lesion diameter. No reciprocal effects were found at either location for the 5 crosses studied. The analysis of variance for parent and F1 hybrid performance revealed a genotype × location interaction. Combining ability analysis based on the F1 hybrids alone indicated a significant general combining ability (GCA) effect. The specific combining ability (SCA) and GCA × location interaction mean squares were smaller than the GCA value but were still significant. Differential performance over locations of the hybrids of one line was primarily responsible for the GCA × location interaction. Analysis of variance and covariance of parental arrays indicated partial dominance in the direction of susceptibility. Narrow sense heritability for the trait was 70% over both locations.
Ice Nucleation Active (INA) Agents in Freezing of Young Citrus Trees
Authors: Yelenosky G.
Published: August 2022

Aqueous suspensions of ice nucleation active (INA) bacteria [Pseudomonas syringae van Hall and Erwinia herbicola (Löhnis) Dye] and suspensions of nonbacterial agents, silver iodide, phenazine, and flurophlogopite, were used to induce freezing in young citrus trees, ‘Valencia’ orange [Citrus sinensis (L.) Osbeck] on sour orange (C. aurantium L.) rootstock. Trees sprayed with INA agents froze at higher temperatures than unsprayed trees. INA bacteria-induced freezing was significant only when leaf surfaces were allowed to dry prior to freeze tests. Leaves with dry surfaces supercooled 1° to 3°C more than wet leaves, which started to freeze, and about 1° sooner with than without INA agents. Differences between INA bacteria and nonbacterial agents were not significant in the moment of freeze of wet leaves. INA agents induced freezing in citrus leaves usually before −5°, and in water drops, before −4°. Freezing was easier to induce on the underside (abaxial) than top (adaxial) surfaces of leaves. Sucrose, proline, and expressed sap were nonINA on citrus leaves and in drops of water.
Breeding for Resistance to Aphanomyces euteiches Root Rot and Rhizoctonia solani Stem Rot in Peas
Authors: Shehata Mando A. , Davis D.W. , Pfleger F.L.
Published: August 2022

A modified Environmental Shift Technique based on use of a disease index (scoring) gave consistent separation between susceptible and moderately resistant pea (Pisum sativum L.) genotypes to Aphanomyces euteiches Drech. root rot in 3 tests. A moderately high association (r = −0.63 to −0.83) between disease index and percentage of plant survival was found in segregating populations. Minnesota 108, moderately resistant to A. euteiches, produced adventitious roots readily at an early stage. Root rot resistance and number of adventitious roots were inherited independently. Broad sense heritability (BSH) ranging between 0.45 and 0.57 for resistance to A. euteiches root rot, and between 0.39 and 0.44 for resistance to Rhizoctonia solani Kuehn stem rot, varied by parental combination, experiment, and method of estimation. However, heritability based on gain by selection in the F3 ranged from 0.28 to 0.46 and from 0.21 to 0.44 for resistance to A. euteiches and R. solani, respectively. Frequency distribution of resistant and susceptible plants suggested quantitative inheritance of resistance to both diseases. Recurrent selection, in which each cycle includes one intermating, selfing, and testing generation, is suggested to improve and transfer resistance.
Effect of Photoperiod and High Intensity Supplementary Lighting on Flowering of Alstroemeria ‘Orchid’ and ‘Regina’
Authors: Lin W.C. , Molnar J.M.
Published: August 2022

Alstroemeria plants were grown under 10, 12, 14, 16, 18, and 24 hour photoperiods by employing an 8-hour natural day and low intensity incandescent lighting as a daylength extension. The production of flower stems was increased to a maximal level by extending the photoperiod to 16 hours in ‘Orchid’ and in ‘Regina’. Under 16 hours high-intensity supplementary lighting with high-pressure sodium (HPS) lamps, the production of flower stems in ‘Orchid’ increased by 49% in the first year and 36% in the 2nd year. ‘Regina’ flower stems increased by 26% in the first year and 16% in the 2nd year. HPS lighting increased the number of flowering shoots per square meter from 166 (control) to 262 in ‘Orchid’ and from 10 to 21 in ‘Regina’ during the period November to February.
Changes in Organic Acids, Sugars, and Headspace Volatiles during Fruit Ripening of Soursop (Annona muricata L.)
Authors: Paull Robert E. , Deputy James , Chen Nancy Jung
Published: August 2022

Sequential changes in starch, sugars, organic acids, and headspace volatiles were determined on single soursop fruits from harvest to fruit breakdown. Sucrose increased 4-fold; maximum concentration occurred 3 days after harvest, then declined to 40% of the peak value. Fructose and glucose increased slowly to a peak 5 days after harvest. The ratio of sucrose, glucose, and fructose, respectively, at the edible ripe stage was 4.3:3.0:3.2. There was a 7-fold increase in malic acid and a 3-fold increase in citric acid. Both acids peaked 3 to 4 days after harvest, then declined. About half of the organic acids were present as salts. Headspace volatile production paralleled ethylene evolution. Volatile production began to increase 3 days after harvest and peaked 2 days later. This peak corresponded with the peaks in total sugars, organic acids, and the edible ripe stage when individual fruit results were compared on the basis of the start of the climacteric respiratory increase. After the peak in volatile production, there was a dramatic drop over the next 3 days in major fruity esters produced, with a gradual increase in volatiles, which probably imparted the off-odor of the overripe fruit. The activities of amylase, polygalacturonase, and cellulase increased during ripening. Starch breakdown leading to sugar and organic acid production occurred before any rise in ethylene production. This breakdown of starch may be an important initiating event in the ripening of soursop fruit.
Effects of Picloram and Other Auxins on Onion Tissue Cultures
Authors: Phillips Gregory C. , Luteyn Kent J.
Published: August 2022

Seedling shoot meristem-tip explants of ‘Yellow Grano’ and ‘Yellow Sweet Spanish’ onions (Allium cepa L.) were cultured in vitro on media varying in auxin and cytokinin composition. 4-Amino-3,5,6-trichloropicolinic acid (picloram) as an auxin source was superior to α-naphthaleneacetic acid (NAA) used as a control for shoot multiplication cultures maintained for 6 months or longer. A combination of 0.03 mg/liter picloram and 0.5 mg/liter 6-benzylamino purine (BA) was optimal. Picloram was comparable or superior to the 2,4-dichlorophenoxyacetic acid (2,4-D) control for induction, continued maintenance and friability of callus, and subsequent regeneration of plants. Somatic embryos developed at high frequency in some lines of both cultivars on media containing 0.75 mg/liter picloram and 1.5 to 2.0 mg/liter BA. The most promising scheme for plant regeneration from 6- to 12-month-old callus cultures involved transfer from somatic embryo induction media to modified shoot multiplication media. These techniques also were successful using mature bulb basal plate-scale explants.
Effect of Container Plant Growth Medium and Fertilizer Phosphorus on Establishment and Host Growth Response to Vesicular–Arbuscular Mycorrhizae
Authors: Biermann Brenda , Linderman R.G.
Published: August 2022

The establishment and performance of vesicular–arbuscular mycorrhizae (VAM) formed by Glomus fasciculatum (Thaxter) Gerd. & Trappe were studied on geranium (Pelargonium × hortorum L.H. Bailey) and subterranean clover (Trifolium subterraneum L.) in various growth media at 2 P fertility levels. Colonization by G. fasciculatum was not extensive and shoot dry weight and P uptake consequently were not increased by VAM in soilless media such as peat, bark, perlite, and vermiculite. In media containing soil and fertilized at the low P level, roots were colonized extensively by G. fasciculatum, and host shoot growth and P concentrations were increased by VAM. Host growth enhancement by VAM was not observed at the higher P fertility level. Differences in colonization and mycorrhizal response in different fertilized growth media were correlated negatively with the logarithm of the equilibrium solution P concentration. Colonization, growth response, and P uptake by geranium inoculated with G. mosseae (Nic. & Gerd.) Gerd. & Trappe or Acaulospora spinosa Walker & Trappe were affected by growth medium and P fertilizer in the same way as plants inoculated with G. fasciculatum. Peat mosses from different sources varied considerably in their effects on mycorrhiza formation by G. fasciculatum, and on growth response of geranium when the peat was diluted with different amounts of soil. These differences appeared to be related to the equilibrium solution P concentration of the fertilized peats, and not to extractable P of the unfertilized peats. Use of rock phosphate or bonemeal instead of NaH2PO4 as a source of P did not improve the establishment of VAM and host growth response in soil, peat, or vermiculite. Addition of 5–10% Turface, bentonite, silt loam soil, or clay subsoil to peat or vermiculite resulted in increased colonization of host roots and significant mycorrhizal growth response, whereas amendment with liquid sludge inhibited formation of mycorrhizae.
Sensitivity of Satsuma Mandarin to Ozone as Related to Stomatal Function Indicated by Transpiration Rate, Change of Stem Diameter, and Leaf Temperature
Authors: Matsushima Jiro , Yonemori Keizo , Iwao Kenzo
Published: August 2022

Transpiration rate, stem diameter, and leaf temperature of satsuma mandarin (Citrus unshiu Marc.) were found to be sensitive indicators of stomatal response to ozone exposure. Time of reaction of each to 1.2 ppm ozone was 3 min. Stem diameter showed marked oscillation and leaf temperature slight oscillation, when ozone was applied. Correlation coefficiennt between ozone concentration and transpiration rate at the equilibrium status after the beginning of exposure was r = 0.718, and increasing the concentration of ozone decreased stomata size. Thus, it was determined that low sensitivity of satsuma mandarin to ozone is due to rapid stomatal closure by ozone.
Characterizing the Germination Inhibitor from Asexual Embryo Leachate of Theobroma cacao
Authors: Wang Yi-Chang , Janick Jules
Published: August 2022

Leachates from asexual embryos of cacao (Theobroma cacao L.) inhibited seed germination of lettuce (Lactuca sativa L. ‘Ruby’), and inhibitor activity increased with concentration and duration of soaking. The amount of inhibitor was greatest in very small asexual embryos and was detected in immature but not mature zygotic embryos. The capability of cacao embryo leachate to inhibit lettuce seed germination was destroyed by heat (100°C for 20 min). When the leachate was separated into 15 fractions with high pressure liquid chromatography (HPLC), 5 significantly promoted and 2 significantly inhibited lettuce seed germination. Abscisic acid was not detected in the leachate. Fraction 10 co-chromatographed with p-coumaric acid, but p-coumaric acid is heat stable and its presence was not confirmed by mass spectrometry.
Simplified Method for Rooting Apple Cultivars in Vitro
Authors: Zimmerman Richard H. , Fordham Ingrid
Published: August 2022

Apple cultivar cuttings, prepared from shoots proliferated in vitro, initiated roots readily when placed for 3–7 days in the dark in a liquid medium containing only 43.8 mm sucrose and 1.5 μM indolebutyric acid (IBA). Raising the temperature during dark treatment from 25° to 30°C improved rooting for several cultivars. The addition of half-strength Murashige and Skoog (MS) salts or of phloroglucinol (PG) to the rooting medium did not improve rooting. IBA was the most effective auxin tried and indoleacetic acid (IAA) the least effective. Maintaining the cultures in the dark for more than 6 days improved rooting of only 1 cultivar and after 9 days rooting percentages sometimes decreased. More than 80% rooting was obtained with ‘McIntosh’ and ‘Mutsu’ after only 4 subcultures (4–5 months in culture), whereas some other cultivars in culture for a much longer time rooted no better or not as well. Roots that were initiated in liquid medium elongated after cuttings were inserted into preformed peat plugs. The resulting plantlets acclimated easily for transfer to greenhouse conditions.
Functional Growth Analysis of Field Grown Strawberry
Authors: Olsen Jeffery L. , Martin Lloyd W. , Pelofske Peter J. , Breen Patrick J. , Forney Charles F.
Published: August 2022

Field grown strawberry plants (Fragaria × ananassa Duch.) of an advanced breeding selection (OR-US 4681) were harvested every 3–4 days during establishment and through fruiting the next spring. Plant dry weight and leaf area increased rapidly during mid-summer, then slowed and finally ceased in October. Absolute growth rate (AGR) peaked at 1 g dry matter/day near 1 Sept., then fell to zero by early October. Over this period, there was a decrease in weekly mean temperature (37%), solar radiation (47%), and daylength (35%). Maximum values of relative growth rate (RGR) (0.044 g/g/day) and unit leaf rate (ULR) (9 g/m2/day) were determined at the start of sampling at the end of June; both rates declined steadily thereafter. The following April through June, both plant dry weight and leaf area increased exponentially, whereas RGR remained constant at 0.02 g/g/day, and ULR rose from 5.5 to 6.5 g/m2/day. The rate of dry matter accumulation in fruit was exponential, whereas it was linear in leaf lamina and stems (crowns plus petioles). A much smaller proportion of dry matter was partitioned to leaves during fruiting than during plant establishment.
The Relationship of Apple Embryos and Their Cotyledons to Maturity, Dormancy, and the Potential to Form Shoots in Vitro
Authors: Kouider M. , Korban S. S. , Skirvin R. M. , Joung H.
Published: August 2022

Embryos extracted from developing apple fruit were cultured in vitro. Immature embryos (up to 4 weeks post anthesis), cultured without their testa and endosperm, produced only callus tissue. Six and a half-week-old embryos produced multiple shoots and the percentage of embryos producing shoots rather than callus tissue increased with time. Ten and a half-week-old embryos produced the highest number of shoots per embryo, after which a decrease in multiple shoot formation was observed with mature (14 weeks post anthesis) embryos producing 1 shoot and 1 root per embryo. Simultaneously, embryonic-axis free cotyledon cultures were established from embryos of various ages. Adventitious shoots developed from cotyledon explants, and the number of multiple shoots formed, increased with time (June-September). Cotyledons extracted periodically from mature fruit stored at 3°C continued to produce multiple shoots in culture, but this gradually decreased with time (15-120 days). After 6 months in cold storage, cotyledon explants failed to develop any shoots.
Vegetative Growth, Yield, and Fruit Quality of Peach as Influenced by Dormant Pruning, Summer Pruning, and Summer Topping
Authors: Marini Richard P.
Published: August 2022

Three peach [Prunus persica (L.) Batsch] cultivars varying in age and vigor were dormant pruned, summer pruned, or summer topped for 2 or 3 years, depending on the cultivar. Pruning treatments had little effect on trunk enlargement and shoot growth of mature 4 Sun queen’ and ‘Loring’ trees. Pruning or topping in June and/or July improved light penetration in tree centers. Pruning or topping in July or June and July stimulated shoot growth of young ‘Cresthaven’ trees more than dormant pruning the season following treatment. Pruning treatment had no consistent effects on yield, fruit size, or date of maturity. Red color and soluble solids of ‘Loring’ fruit were not effected by pruning treatment, but flesh firmness was increased for fruit from summer topped trees. ‘Sunqueen’ fruit quality was effected less by pruning treatment than by crop load, canopy position, or harvest date. Red color and soluble solids were greater for fruit from the tree top and on moderately cropping trees than those from the tree interior or trees with a heavy crop. Harvest date influenced all aspects of fruit quality, but the effects were not consistent for both years.
Low Temperature Germination of Celery Seeds for Fluid Drilling
Authors: Furutani Sheldon C. , Zandstra Bernard H. , Price Hugh C.
Published: August 2022

Celery (Apium graveolens L.) seeds germinated at 10°C for 14 days produced shorter and more uniform radicles (0– mm) than seeds germinated for 8 days at 24° (0–10 mm). Removal of seed leachates improved the germination of celery seeds in the light. Celery seeds germinated at 10° prior to sowing emerged faster, and produced more uniform plants than those not pregermihated, and were not thermodormant when incubated at 32°.