bluuebunny/crossref_metadata_2025 huggingface dataset:
Stomatal Mechanisms Determining Genetic Resistance to Ozone in Phaseolus vulgaris L.1
Authors: Butler L. Knudson , Tibbitts T. W.
Published: August 2022

The ozone-sensitive bean cultivars ‘Spurt’ and ‘Blue Lake Stringless’ and the ozone-resistant cultivars ‘Black Turtle Soup’ and ‘French’s Horticultural’ were grown from seed in a growth chamber. The resistant cultivars had 25% fewer stomata per mm2 leaf area than the sensitive cultivars and exhibited partial stomatal closure following exposure to 134 pphm ozone for 1 hr, while the sensitive cultivars did not. Stomatal closure was determined to be more important than reduced stomatal frequency in providing resistance to ozone. On the basis of previously established ozone dose-response data for P. vulgaris, the stomatal mechanisms appeared to account for the difference in ozone sensitivity between the sensitive and resistant cultivars. Neither leaf area nor leaf expansion rate were correlated with genetic resistance to ozone in these cultivars.
Tomato Root Development as Related to Potassium Nutrition 1
Authors: Widder I. E. , Lorenz O. A.
Published: August 2022

Determinant cultivars ‘VF 145B-7879’ and ‘VF 109’ of processing tomato (Lycopersicon esculentum Mill.) develop smaller root systems under field conditions with less root proliferation particularly below 60 cm than semideterminant fresh market cultivars, ‘Early Pak’ and ‘Pearson’. Following fruit set, K concentration in shoots of ‘VF 145’ and ‘VF 109’ decreased from about 4% to below 2% resulting in K deficiency symptoms, whereas no deficiency symptoms were observed in ‘Early Pak’ and ‘Pearson’. The data suggest that the K deficiency condition is due to the inability of the relatively small root systems of the determinant tomato cultivars to absorb K at a rate sufficient to meet the demands of the concentrated fruit set. ‘VF 145’ and ‘VF 109’ compensate for the stress condition by translocating K out of leaves and stems and into fruit as evidenced by a negative rate of accumulation of K in the shoots. They also partition a higher percentage of absorbed K into fruit rather than into continued vegetative growth than ‘Early Pak’ and ‘Pearson’.
Absence of Acidless Progeny from Crosses of Acidless × Acidless Citrus Cultivars 1
Authors: Cameron James W. , Soost Robert K.
Published: August 2022

Titratable acidity and total soluble solids were measured in F1 populations from crosses of an acidless pummelo [Citrus grandis (L.) Osbeck] with an acidless orange [C. sinensis (L.) Osbeck], an acidless mandarin-lime (C. limonia Osbeck), and an acidless sweet lime (C. limettioides Tan.). No acidless individuals were found among a total of 291 hybrids. Acidity ranges were those which might be expected if acid forms of the orange and the limes had been crossed with the acidless pummelo. In each cross, however, acidities averaged lower than the acidities of some acid cultivars which were compared to the acidless parents. This effect is attributed largely to the influence of the acidless pummelo. Two bud-propagation trees from another acidless orange accession have regularly produced acid fruit at Riverside; this may be the result of cell substitution between histogenic layers. The acidless orange and acidless lime parents may all be chimeral for the acidless factor. Alternatively, the factor in these parents may be different from that in the acidless pummelo. Levels of total soluble solids in the hybrids were mostly within the ranges of the parents, and showed no appreciable relationship to acidity levels.
Flavonoid Chemical Markers in Poinsettia Bracts1
Authors: Asen S.
Published: August 2022

High-performance liquid chromatographic (HPLC) procedures for the separation of flavonoids in poinsettia bracts are described. Anthocyanins present were cyanidin 3-galactoside, and the 3-glucosides and 3-rutinosides of cyanidin and pelargonidin. Flavonols present were 3-rhamnosylgalactosides, 3-rhamnosylgluco-sides, 3-galactosides, 3-glucosides, and 3-rhamnosides of quercetin and kaempferol. The use of these chemical markers along with the classical methods for plant identification should help resolve the difficulties of describing new cultivars protected by the plant patent law.
Effect of Photoperiod on Growth Responses of Citrus Rootstocks1
Authors: Warner Robert M. , Worku Zemedu , Silva James A.
Published: August 2022

Trifoliate orange [Poncirus trifoliata (L.) Raf.] and various other commonly-used rootstocks, submitted to long-day (LD) of 16 hours, (normal day + 4 hr incandescent light break), normal day (ND) of 12 hours ± 1 hr 10 min and short-day (SD) of 8 hour photoperiods fell into 2 groups—those which responded to LD tratment and those which did not. Rootstocks in the first group, Christianson, Beneke, Pomeroy, Rubidoux and Yamaguchi, trifoliate orange cultivars; Carrizo and Savage citranges [P. trifoliata × C. sinensis (L.) Osbeck.]; Sacaton citrumelo [P. trifoliata × C. paradisi Macf.]. Hawaiian sweet orange (C. sinensis) and Milam lemon (C. jambhiri Lush.), responded strongly to LD treatments in shoot growth and stem diameter. Rootstocks less responsive to photoperiod include Cleopatra mandarin (C. reshi Hort. ex Tan.), Estes lemon, (C. jambhiri), Troyer citrange, Swingle citrumelo, C. macrophylla Webster, C. taiwanica Tan. and Shin and C. volkameriana Pasq. This second group was considered better adapted to tropical conditions because they made better growth under SD conditions.
The Effects of Fresh and Aged Bark Growing Media and Zinc Nutrition on the Growth, Zinc Uptake, and N Content of Tomato1
Authors: Cotter D. J. , McGregor C. R.
Published: August 2022

Plant dry weight of tomato (Lycopersicon esculentum Mill.) grown in aged bark media was equal to or greater than that of those cultured in a control medium of perlite-sand. Plant growth in fresh bark was inhibited initially and then recovered. Zn concentration and total content per plant were high for plants cultured in bark media even when little or no Zn was applied. The intereaction between media and applied Zn was significant. Plant Zn increased with increasing amount of applied soluble Zn when cultured in perlite-sand, but did not normally change for plants cultured in bark. High Zn concentration of plants cultured in fresh bark was too low to account for the initial growth inhibition. N concentration and content per plant were normally lower for plants grown in fresh bark. N of plants in aged bark was similar to plants in the standard medium. Growth inhibition of plants in fresh bark did not appear to be due to N deficiency.
Water-stress-induced Cold Hardening of Young Citrus Trees1
Authors: Yelenosky George
Published: August 2022

Water-stressed young, potted citrus seedlings and budded trees on different rootstocks were tested for freeze avoidance and tolerance. Water stress increased the supercooling of cold-sensitive citrus seedlings in freezeavoidance tests and increased the cold hardiness of grapefruit and orange trees in freeze-tolerance tests. Water stress was most effective in reducing injury during freezes above −6.7°C. Temperatures below −6.7° resulted in complete kill regardless of −25 bars water stress in the leaves. Tissue analyses showed increased in proline accompanying increases in sugars during forced dehydration of citrus leaves.
The Influence of Ethylene Treatment of Immature Fruit of Prune (Prunus domestica L.) on the Enzyme-mediated Isolation of Mesocarp Cells and Protoplasts1
Authors: Weinbaum S. A. , Labavitch J. M. , Weinbaum Z.
Published: August 2022

Immature fruit of ‘French’ prune were treated in air or ethylene and mesocarp tissues incubated with crude cell wall degrading enzymes to release cells and protoplasts. Ethylene treatment substantially reduced the release of cells and protoplasts and increased the proportion of pectic polymers in the cell walls.
Storage Behavior of Pelleted, Tableted, and Taped Lettuce Seed1
Authors: Roos Eric E.
Published: August 2022

Coated and raw (uncoated) lettuce (Lactuca sativa L.) seed obtained from commercial sources were subjected to 6 storage conditions (ranging from 21° C, 90% relative humidity (RH) to 5°, 40% RH) for a period of 3 years. Four types of packaging material differing in moisture-barrier properties were used. Samples were removed periodically for moisture and germination tests. Under poor storage conditions, coated seed deteriorated more rapidly than the raw seed controls. Under favorable storage conditions, both coated and raw seed retained full viability for the 3 years.
Consumer Demand Analysis for Roses1
Authors: Hutchison N. R. , Robertson J. L.
Published: August 2022

Conjoint analysis was used to evaluate the effect of form, composition, flower type, flower color, and price on the marketability of roses. Form was the most important floral product attribute influencing the consumers’ impulse rose purchasing. Mixed rose arrangements with carnations and pompon chrysanthemums were more marketable in an impulse purchasing environment than was the traditional all-rose package. Trade-off analysis of product form, composition and price indicated that as consumer impulse purchasing increased, the red Hybrid Tea rose lost its competitive position at the expense of non-red Floribunda and Sweetheart roses. Male and female subjects were shown to have differing priorities concerning desirable characteristics of the rose product. Price variation was relatively unimportant in the purchase selection of roses.
Boron Tolerance of Twenty-five Ornamental Shrub Species1
Authors: Francois L. E. , Clark R. A.
Published: August 2022

Boron (B) tolerance of 25 ornamental shrub species was determined in large, outdoor sand cultures. Tolerant species such as Natal plum (Carissa grandiflora (E. H. Mey.) A. D. C.), Indian hawthorn (Raphiolepis indica (L.) Lindl.), Chinese hibiscus (Hibiscus rosa-sinensis L.), oleander (Nerium oleander L.), Japanese boxwood (Buxus microphylla Siebold and Zucc.), bottlebrush (Callistemon citrinus (Curtis) Stapf), ceniza (Leucophyllum frutescens (Berland.) I. M. Johnst.), and blue dracaena (Cordyline indivisa (G. Forst) Steud.) were affected little, if at all, by 7.5 mg B/liter in the irrigation water. Sensitive species like yellow sage (Lantana camara L.), juniper (Juniperus chinensis L.), Chinese holly (Ilex cornuta Lindl. and Paxt.), Wax-leaf privet (Ligustrum japonicum Thunb.), laurustinus (Viburnum tinus L.), thorny elaeagnus (Elaeagnus pungens Thunb.), xylosma (Xylosma congestum (Lour.) Merrill), photinia (Photinia ☓ Fraseri Dress.), and Oregon grape (Mahonia aquifolium (Pursh) Nutt.) were severely damaged or killed by 7.5 mg B/liter and moderately damaged by 2.5 mg B/liter in the irrigation water. B tolerance and B accumulation in the leaves were not correlated and no correlation was found between B tolerance and salinity tolerance.
Captan Deposition in Peach Orchard Hedgerows1
Authors: Gaynor J. D. , Layne R. E. C.
Published: August 2022

Four hedgerow types: oblique fan, canted oblique fan, modified central leader, and open center, in a peach (Prunus persica (L.) Batsch cv. Olinda) orchard were evaluated in 1975 and 1977 for their effect on deposition of captan (N-trichloromethyl-4-cyclohexene-l,2,dicarboximide). Within hedgerows captan residues on leaves were generally higher on bottoms than tops of trees but among hedgerows, leaf residues were higher on oblique fan. The higher leaf residues resulted in 10.8% more of the captan applied per tree retained by oblique fan compared to 31.7% intercepted by the other hedgerows. Ground deposits for oblique fan and open center averaged 11.7% but were 6.3% higher for canted oblique fan and modified central leader. Ground deposits did not relate to area below trees or hedgerow type but leaf residues and that unaccounted for related to tree canopy volume. Compared to the standard open center, oblique fan was 41% more efficient at intercepting captan, modified central leader 20% more efficient and canted oblique fan showed no improvement in efficiency. Hedgerows with smaller tree canopy volumes increased captan interception, reduced spray drift and thereby provided economic and environmental gains through more efficient captan use.
Light Compensation Point and Leaf Distribution of Ficus benjamina as Affected by Light Intensity and Nitrogen—Potassium Nutrition1
Authors: Johnson C. R. , Krantz J. K. , Joiner J. N. , Conover C. A.
Published: August 2022

Plants of Ficus benjamina L. had less leaves in the upper half of sun and shade-grown plants with higher N rates. Potassium affected leaf distribution only in bottom portion of canopy and had no effects on LCP. High N levels increased light compensation point (LCP) of sun-grown plants, but reduced LCP of shadegrown plants. Increased number of leaves in upper half of sun-grown plants reduced LCP but shade-grown plants showed an opposite effect.
Physiological, Morphological, and Anatomical Studies of Tomato Genotypes Varying in Carboxylation Efficiency1
Authors: Augustine J. J. , Stevens M. Allen , Breidenbach R. W.
Published: August 2022

The relative growth rates for tomato (Lycopersicon esculentum Mill.) genotypes differing in carboxylation efficiency (CE) were similar. Manapal (dg), which had a high CE, had a more rapid vegetative phase growth rate and LA 1098 (low CE) was slower growing. Specific leaf dry weight was greater in high CE genotypes indicating that it may be a useful selection criterion. Leaf thickness was greater in the high CE genotypes (Manapal (dg) and 067) than in the intermediate CE cultivars. Manapal (dg) and 067 (high CE) has much greater percent air space in the palisade tissue and much longer palisade cells than 7879 and VF 36 (intermediate CE). Conversely the number of palisade cells cm−2 was much less in the high CE genotypes. These results indicate that differences in gaseous diffusion potential may in part account for genotypic differences in CE. Differences in CE at 21 and 2% O2 indicated that genotypic differences for photorespiration rate was not an important contributor to the variation in CE.
Differential Response of Lycoperiscon and Solanum Species to Salinity1
Authors: Phills B. R. , Peck N. H. , MacDonald G. E. , Robinson R. W.
Published: August 2022

Lycopersicon and Solanum species and an F1 hybrid of L. esculentum × S. lycopersicoides differed in growth and concentration of elements in leaves in response to levels of NaCl in outdoor sand culture. S. lycopersicoides and its hybrid with the tomato were more sensitive to NaCl on the basis of reduction in dry matter accumulation than L. esculentum, L. peruvianum, or S. pennellii. The dry weights of S. lycopersicoides and the F1 grown without NaCl in the rooting medium were 6 times greater than the average of L. esculentum, L. peruvianum, and S. pennellii, but only 2 times greater when the plants were grown with 294 meq NaCl/liter of rooting medium nutrient solution. S. lycopersicoides and the F1 were fruitless. The average tops without fruit of all species had 10.9% dry weight when grown without NaCl while tops of plants grown with 294 meq NaCl/liter nutrient solution had 14.0% dry wight. NaCl in the rooting medium increased the concentration of Na less in the leaves of S. lycopersicoides and the F1 than the other species and increased the Cl concentration in the leaves of all species. S. lycopersicoides and the F1 had higher concentration of K, and lower Ca in the leaves than the other species. S. pennellii had higher concentrations of Fe and Mn in the leaves than other species.
Effect of Soil Temperature and Photoperiod on Vegetative and Reproductive Growth of Alstroemeria ‘Regina’1
Authors: Heins R. D. , Wilkins H. F.
Published: August 2022

Alstroemeria ‘Regina’ plants produced more vegetative shoots when the soil temperature alternated between 15°C (40 days) and 21° (20 days) as compared to a constant 15° soil temperature. However, a higher percentage of the shoots flowered from plants grown at the constant 15° soil temperature. Short days (8 hours light) inhibited flowering irrespective of soil temperature. Plants given a long-day treatment by exposing them to a night break with incandescent light flowered 6 weeks earlier than plants grown under normal day photoperiods during winter and spring and produced 30% more flowering stems. Treatments favoring flower development produced shorter flowering stems with fewer leaves. Maximum flower production resulted from plants grown at a constant 15° soil temperature and irradiated with incandescent lights as a night interruption.
Seasonal Changes in the Physiology of Vegetative Buds of Normal and Bud-failure Affected ‘Nonpareil’ Almond Trees1
Authors: Hellali Rachid , Kester D. E. , Martin G. C.
Published: August 2022

Vegetative buds from ‘Nonpareil’ almond trees affected by noninfectious bud-failure with (BF) and without (non-BF) symptoms were compared to plants without noninfectious bud-failure (normal). Samples were collected every 2 weeks from June until the following March to establish seasonal trends in weight and abscisic acid (ABA) and gibberellins (GA). Increases in bud fresh and dry weight occurred during July and August, followed by progressive dehydration up to the end of September. These changes were accompanied first by an increase in ABA and GA-like activity, and then a decrease in both hormones. During the remainder of the year (October to January) bud weight increased gradually and ABA and GA were low. Buds from BF and non-BF plants increased in weight in July and August, but much less than the normal. ABA levels were much less than from the normal, but the GA activity was comparable to normal. BF symptom development is characterized by lower production of ABA during the critical July-Aug. period. A disruption of the normal rest induction and recovery pattern was also hypothesized.
Bolting Control by Ethephon in Fall-planted, Short-day Onions1
Authors: Corgan J. N. , Izquierdo Juan
Published: August 2022

Fall and late-winter treatments of (2-chloroethyl)phosphonic acid (ethephon) at 2500 or 5000 ppm reduced bolting of fall-planted, short-day cultivars of onion (Allium cepa L.). Ethephon inhibited plant growth and reduced bulb size. Ethephon reduced yields when bolting in control plots was low or when cool spring weather restricted growth. With warm spring weather and 18% bolting in control plots, ethephon reduced bolting to 3% with no effect on yield. Ethephon caused some winter plant loss in 1 of the 3 years. Loss was greatest when higher rates of ethephon were applied in the fall to very young plants.
Some Effects of Gibberellins A4+7 plus Benzyladenine on Fruit Weight, Shape, Quality, Ca Content, and Storage Behavior of ‘Spartan’ Apple1
Authors: Looney Norman E.
Published: August 2022

Fruits on individual spurs, on branch units, and on whole ‘Spartan’ apple (Malus domestica Borkh.) trees treated with a proprietary mixture of gibberellins A4 + A7 plus benzyladenine (GA4+7 plus BA) were generally heavier and longer than untreated fruits in 2 seasons. The principle effect of treatments applied at first petal fall (FPF) was an increase in the fruit length/diameter (L/D) ratio. Treatments applied 3 days to 5 weeks after FPF increased fruit weight and enhanced the L/D ratio. Ca concentration was reduced by the treatments which enhanced fruit weight and the incidence of ‘Spartan’ breakdown was increased. Fruit firmness and soluble solids were unaltered by the GA4+7 plus BA treatments. Fruit acidity was reduced in one experiment.
Water Stress Responses of Apple Trees. I. Effects of Light and Soil Preconditioning Treatments on Tree Physiology1
Authors: Davies Frederick S. , Lakso Alan N.
Published: August 2022

Potted apple trees (Malus domestica Borkh. cv Empire) were grown either in the greenhouse at 40% of available photosynthetically active radiation (PAR), or outdoors for 9 weeks. Although greenhouse trees displayed much lower specific leaf weights than outdoor trees, net photosynthetic (Pn) rates were comparable at light saturation. Half the trees in each group were subjected to 3 successive soil preconditioning treatments. Preconditioning the trees by withholding water did not affect Pn, transpiration (E), or stomatal conductance (ks) during a subsequent drought period in outdoor trees; however, preconditioning increased ks in greenhouse trees. Water-use efficiency increased for both greenhouse and outdoor trees as stomata closed and soil water potential decreased. Total growth and root:shoot ratios were unaffected by either light or soil preconditioning, indicating that potted apple trees are adaptable to different environmental conditions.
Water Stress Responses of Apple Trees. II. Resistance and Capacitance as Affected by Greenhouse and Field Conditions1
Authors: Davies Frederick S. , Lakso Alan N.
Published: August 2022

Greenhouse-grown potted apple trees (Malus domestica Borkh. cv. Empire) on Malling-Merton (MM) 111 rootstocks displayed much lower water potentials at the end of the season than did similar trees grown outdoors when measured under the same soil moisture and evaporative demand conditions. Differences in water potentials over a wide range of soil moistures were due to the much higher plant and root resistances and the lower leaf capacitances of the greenhouse-grown trees as calculated by using electric analogue circuits. Root resistance differences could not be explained by changes in feeder root percentages or root:shoot ratios.
Effects of Defoliation and Root Height Above a Water Table on Some Red Oak Root Metabolites1
Authors: Parker Johnson
Published: August 2022

Seedlings of Quercus rubra L. were subjected to moisture stress and defoliation. Root growth and starch content declined as moisture stress and defoliation severity increased. Fructose and glucose, as well as several amino acids, were sharply higher with increasing moisture stress and these sugars were higher in defoliated than in undefoliated seedlings. Sucrose decreased with increasing severity of defoliation and tended to decrease with increasing moisture stress among defoliated seedlings.
Stunting of Peach Seedlings Following Soil Fumigation1
Authors: Lambert D. H. , Stouffer R. F. , Cole H.
Published: August 2022

A study of peach (Prunus persica (L.) Batsch) seedlings which became stunted in soil fumigated with methyl bromide-chloropicrin indicated that poor growth was associated with a major deficiency of P aggravated by marginal levels of Cu and Zn. The concentrations of K, Ca, and Mg were also lower in stunted plants. Where stunting occurred, mycorrhizal root colonization was very poor and viable inoculum was low. These results indicate that elimination of mycorrhizal fungi is the primary factor in fumigation-induced stunting of peach, and also suggest that a reduction in Cu uptake in combination with previously recognized P and Zn deficiencies may contribute to poor growth.
Mechanical Stress Induces Ethylene Production and Epinasty in Poinsettia Cultivars1
Authors: Saltveit Mikal E. , Pharr D. M. , Larson Roy A.
Published: August 2022

Mechanically bent petioles of potted poinsettia plants (Euphorbia pulcherrima Klotzsch ex. Willd., cvs. V-14, Eckespoint C-1 Red, Annette Hegg Diva, Annette Hegg White, and Annette Hegg Hot Pink) produced 3 to 70 times as much ethylene as petioles from unstressed plants. The Annette Hegg cultivars which were most susceptible to leaf epinasty after being sleeved for 24 hours showed the greatest enhancement of ethylene evolution after being mechanically stressed for 24 hours. Exposure to 10 ppm ethylene in air produced the same cultivar dependent pattern of epinasty in 4 hours as was produced by 24 hours of mechanical stress. Spraying with 250 ppm AgNO3, an antagonist of ethylene synthesis and action, reduced the severity of epinasty in ‘Annette Hegg Diva’ plants sleeved for 24 hours. The less susceptible ‘Eckespoint C-1 Red’ and ‘V-14’, produced less stress ethylene and were less susceptible to ethylene-induced epinasty.
The Influence of Storage Temperature and Warming During Storage on Peach and Nectarine Fruit Quality1
Authors: Anderson R. E.
Published: August 2022

Peaches and nectarines (Prunus persica (L.) Batsch) ripened after storage for 4 weeks at 0°C retained a significantly better internal appearance and had less internal breakdown than those ripened after storage at 5°. Shifting fruit to 5° after storage for 1 or 2 weeks at 0° resulted in fruit with very severe internal breakdown. Breakdown in these fruit was as severe as in fruit stored continually at 5°. However, fruit shifted to 0° after storage for 1 or 2 weeks at 5° developed significantly less breakdown than those shifted from 0° to 5°. Fruit that were warmed (2 days at about 18.3°) during low temperature storage developed significantly less internal breakdown than comparable fruit that were not warmed. Peaches and nectarines that were warmed during storage also tended to have lower respiration rates than those that were not warmed. Acidity was significantly higher after storage in fruit stored at 0° than it was in fruit stored at 5° and acidity tended to remain higher in warmed than in nonwarmed fruit.
Comparative Sensitivity of Cultivars of Coleus to Increased UV-B Radiation1
Authors: Semeniuk Peter , Stewart Robert N.
Published: August 2022

Coleus cultivars differed in their response to enhanced levels of UV-B. With 80% or greater increase in biologically effective radiation, some distorted leaves developed, anthocyanin pigmentation was decreased, and absorbance at several peaks in the UV region increased. Coleus was less sensitive during seasons of high ambient photosynthetically active radiation (PAR) than during low PAR suggesting photorepair was a factor in the response. None showed a response in height, number of nodes, fresh weight, or dry weight.
Role of the Various Seed Parts in Peach Seed Dormancy and Initial Seedling Growth
Authors: Toit du H. J. , Jacobs G. , Strydom D. K.
Published: August 2022

Cold requirement for germination of excised ‘Kakamas’ peach (Prunus persica (L.) Batsch) embryos was satisfied after 2 weeks at 4.4°C; embryos with testas intact required 4 weeks, while seeds with intact endocarps required 12 weeks stratification. Leaching of unstratified excised embryos stimulated germination. The endocarp affected germination by delaying water uptake. Supplying additional O2 during stratification or germination of seeds with intact endocarps did not improve germination. Cracking the endocarps stimulated germination of stratified seeds, but sealing the cracks with lanolin paste prevented this effect. The endocarps may interfere with the leaching of inhibitors from the testa and embryo. Initial seedling growth of embryos with or without testas increased linearly with increasing time of stratification in terms of shoot length, dry weight of shoots and leaves, dry weight of roots and leaf area, length and width. Seedlings arising from embryos with intact testas were taller and had a greater dry mass of shoots, leaves and roots compared to seedlings arising from embryos without testas.
Stomatal and Leaf Surface Features as Related to the Ozone Sensitivity of Petunia Cultivars1
Authors: Elkiey T. , Ormrod D. P. , Pelletier R. L.
Published: August 2022

Under the light microscope the stomata of 3 cultivars of Petunia hybrida Vilm. were similar in shape and type. However, scanning electron microscopic examination of ‘White Cascade’ petunia (O3 sensitive) revealed guard cell cuticle was not raised above the epidermal surface. ‘Capri’ (O3 insensitive) had the greatest number of stomata/mm2 and the shortest pore length whereas ‘White Cascade’ had the lowest number but the longest pore length. The cultivar with intermediate O3 sensitivity, ‘White Magic’, had an intermediate stomatal density and pore size. The stomatal pore area (mm2/mm2 leaf surface area) was found to be about equal in all 3 cultivars. ‘Capri’ had many more trichomes per unit area than ‘White Cascade’ while ‘White Magic’ had intermediate numbers. No major differences existed in leaf diffusive resistance among the cvs. in either light or dark. The O3 insensitivity of ‘Capri’ was not explained by inherently fewer stomata and/or smaller stomatal size and/or greater leaf diffusive resistance than those of the sensitive ‘White Cascade’. Number of trichomes, sizes of epidermal cells and configuration of guard cell cuticle in relation to epidermal cells may be related to sensitivity.
Growth and Tissue Composition of Sweet Corn as Affected by Nitrogen Source, Nitrapyrin, and Season1
Authors: Rudert B. D. , Locascio S. J.
Published: August 2022

Sweet corn (Zea mays L.) was grown to evaluate the effect of N source, N rate, time of N application, and the nitrification inhibitor, 2-chloro-6-(trichloromethyl) pyridine (nitrapyrin), on crop efficiency and movement of applied N on a Kanapaha fine sand. Sweet corn yield was not affected by nitrapyrin rates of 0, 0.56, and 1.12 kg/ha, during 2 seasons. During a wet 1976 summer season, total yield was 65% higher with N applied as (NH4)2 SO4 than as Ca(NO3)2. Total yield increased linearly from 6. 1 to 9.8 MT/ha with an increase in N rate from 56 to 224 kg/ha as (NH4)SO4. With Ca(NO3)2, total yield averaged 4.9 MT/ha and was not influenced by N rate. During the drier 1977 spring season, marketable yield was not influenced by N source. Total yield increased linearly from 9.1 to 14.6 MT/ha with an increase in N rate. In the wetter season, the application of N in split rather than single applications as Ca(NO3)2 increased yield. During the dry season, timing of N application had no effect on yield with either N source. The suppressing action of NH4-N absorption on the absorption of other cations was evident but was not consistent throughout the study. The application of (NH4)2SO4 as compared to Ca(NO3)2 resulted in higher plant dry weights at an early sampling stage in the wet season but not during the dry season. Higher soil N (NH4-N + NO3-N) levels were maintained above a 20-cm soil depth with (NH4)2SO4 than with Ca(NO3)2 during the wet season.
Anthocyanins of Fruits of Vaccinium, Sub-genera Cyanococcus and Polycodium1
Authors: Ballinger Walter E. , Galletta G. J. , Maness E. P.
Published: August 2022

Anthocyanins of ripe fruits of 13 species of Vaccinium (12 species of the Cyanococcus and 1 species of the Polycodium sub-genera) collected in the eastern United States and grown together near Castle Hayne, North Carolina were hydrolyzed to yield aglycones and sugars. TLC separation and identification of these hydrolysates indicated that anthocyanins of the 12 species of the sub-genus Cyanococcus (true blueberries; Camp) contained 5 aglycones (> means “in greater quantity than”) (delphinidin > cyanidin > malvidin > petunidin > peonidin) and 2 sugars (galactose > arabinose). Anthocyanins of Polycodium representative V. stamineum (deerberries) differed from those of representatives of Cyanococcus in that they yielded only large amounts of the aglycone cyanidin and trace amounts of peonidin. Hydrolysis of anthocyanins of fruits of V. stamineum and 7 species of Cyanococcus yielded glucose. Thus, species of Cyanococcus appeared to have a similar anthocyanin content. Anthocyanin contents of Polycodium (V. stamineum) were different than those of Cyanococcus but generally the same as those reported for cranberries (V. macrocarpon, sub-genus Oxycoccus). Reports in the literature indicate that anthocyanins of other sub-genera of Vaccinium contain xylose (V. myrtillis; bilberry; cyanidin-3-xylosylglycoside) and rhamnose (V. vitis-idaea; cowberry; delphinidin-3-glycoside, 5-glycoside, and 3-rhamno-glycoside). Thus, as indicated from this initial study, fruits of the genus Vaccinium appear to vary in anthocyanin content with sub-generic classification.
Normalized Electrical Impedance Evaluates Cold Injury to Stem Sections of ‘Delicious’ Apple1
Authors: Cooley D. R. , Evert D. R.
Published: August 2022

Normalized electrical impedance measured cold injury to stem sections of ‘Delicious’ apple (Malus domestica Borkh). The measurements did not alter later visual ratings of browning on the same sample. Normalized electrical impedance estimates of injury and visual ratings of browning agreed in 87% of the samples in the first year and 95% of the samples in the second year. In 29 of the 30 adjacent sampling temperatures that produced intermediate injury, as determined by visual browning, normalized impedance values had a higher probability of distinguishing between temperatures than did visual browning. Linear interpolation of the temperatures, which were needed to produce equal injury for the two methods, yielded a mean difference of 0.8°C.
Effect of Apple Cultivar on Foraging Behavior and Pollen Transfer by Honey Bees1
Authors: Robinson Willard Scott
Published: August 2022

The flower structure of the ‘Delicious’ apple (Malus domestica Borkh) differs from that of most apple cultivars by having gaps at the base of stamens. Honey bees (Apis mellifera L.) learn to collect nectar through these gaps and avoid the flowers’ sexual parts; consequently, visits to ‘Delicious’ are less than half as effective in pollination as are visits to other cultivars.
Peach Leaf Surfaces: Changes in Wettability, Retention, Cuticular Permeability, and Epicuticular Wax Chemistry during Expansion with Special Reference to Spray Application1
Authors: Bukovac Martin J. , Flore James A. , Baker Edward A.
Published: August 2022

Changes in surface characteristics of the adaxial and abaxial cuticular membranes of expanding ‘Red-haven’ peach [Prunus persica (L.) Batsch] leaves were followed and related to wettability and to retention and penetration of foliar-applied compounds. Epicuticular wax deposition increased with leaf development until full expansion, the maximum being 50 to 65 μg cm−2. Although wax fine-structure was not prominent on expanding leaves, localized areas of crystalline wax occurred on both surfaces of fully expanded leaves. The 2 surfaces differed markedly in the composition of the epicuticular wax. Although triterpenoid acids, alkanes and primary alcohols were present on both surfaces, sterols and esters were predominant on the adaxial surface. Marked changes in composition occurred with leaf age. The contact angles formed by aqueous droplets on the adaxial surface increased with leaf development and attained the highest value only after full leaf expansion; on the abaxial surface the contact angle increased sharply and approached a maximum at 70 to 80% full expansion. Retention of aqueous solutions decreased with leaf expansion. Permeability of the cuticular membrane, as indexed by transpirational loss and penetration of 14C-NAA (naphthaleneacetic acid), decreased progressively with increasing leaf age. These findings are discussed in relation to spray application and penetration of foliar-applied chemicals.
Translocation and Metabolism of Carbohydrate Fraction of 14C-photosynthates in ‘French’ Prune, Prunus domestica L.1
Authors: Hansen Poul , Ryugo Kay
Published: August 2022

When 14CO2 was administered to leaves on girdled ‘French’ prune spurs, the label was incorporated into sorbitol, sucrose, glucose, fructose, starch, and amylase-insoluble assimilates. The rates of export of soluble sugars and sorbitol and mobilization of starch from leaves were proportional to the rate of fruit growth. The deposition of amylase-inert assimilates in leaves exceeded that of starch, which may account for the gradual increase in specific leaf weight in prunes. The proportion of sorbitol to total sugars in leaf blades and petioles, stem, and peduncle was nearly constant during the 22-day experim ental period but changed abruptly in the fruit. 14C-sorbitol fed to fruits via their peduncles was metabolized to 14C-sucrose, but the reverse reaction was barely detectable.
Genetics of High-temperature Fruit Set in the Tomato1
Authors: El Ahmadi A. Beshir , Allen Stevens M.
Published: August 2022

The genetics of high-temperature fruit set was studied with a complete diallel cross using 5 cultivars with excellent high temperature tolerance and a California cultivar lacking stigma exsertion. The cultivars differed genetically for number of flowers per cluster, percent fruit set, number of seeds per fruit and stigma exsertion. At normal and high temperatures recessive genes are associated with greater flower number and heritability for this character was high. Percent fruit set is under the control of a largely additive system with a moderate heritability at high temperature. Nonallelic gene interaction was involved in seed set and dominance components exceeded additive at both temperatures. Heritability for seed set was low at high temperature. Stigma exsertion at high temperature is controlled by partially dominant genes with a high diallel additive component and heritability. The results suggest that a scheme of selection for specific combining ability would be useful to combine the strengths of the high temperature tolerant lines with needed characters from a successful cultivar.
Crop Response in a Greenhouse Environmentally Controlled with Air Drawn from a Coal Mine1
Authors: Buxton J. W. , Walker J. N. , Collins L. D. , Knavel Dean E. , Hartman J. R.
Published: August 2022

The environment created by ventilating a greenhouse with mine-air was suitable for the production of high quality spray chrysanthemums (Chrysanthemum morifolium Ramat.) and snapdragons (Antirrhinum majus L.) from mid-February through November without any additional energy requirement. The environment created in the greenhouse from December to February was extremely humid and favored botrytis development and physiological problems which reduced crop quality.
Losses in Fresh Tomatoes at the Retail and Consumer Levels in the Greater New York Area1
Authors: Ceponis M. J. , Butterfield J. E.
Published: August 2022

Parasitic diseases were the main cause of losses at retail and consumer levels in fresh tomatoes (Lycopersicon esculentum Mill.) marketed in Greater New York in 1974-1977. Losses at the retail level (LRL) were 6.3 and 6.7% in prepackaged and loose fruits, respectively, and losses in consumer samples (LCL) were 7.9 and 4.7%, respectively. More than 60% of the LRL and 80% of the LCL resulted from diseases, principally alternaria, rhizopus, and gray mold rots and bacterial soft rot. Physical injuries and physiological disorders caused the remaining losses, the former being considerably more damaging.
Reflective Film Mulches Influences Insect Control and Yield in Vegetables1
Authors: Schalk J. M. , Creighton C. S. , Fery R. L. , Sitterly W. R. , Davis B. W. , McFadden T. L. , Day Augustine
Published: August 2022

In field tests, the most effective film mulch in deterring insects and reducing insect damage to fruits was aluminum. The insects affected were aphids, brown stink bugs, aphid parasites, and Diabrotica spp. Mosaic virus diseases were reduced among aluminum-mulched squash (Cucurbita pepo L.) and cucumber (Cucumis sativus L.) plants. Plant growth, flowering, and fruiting were delayed in tomatoes (Lycopersicon esculentum Mill.) and southernpeas (Vigna unguiculata (L.) Walp.).
Chemical Stimulation of Branching in Deciduous Tree Fruit Nursery Stock with Ethyl 5-(4-chlorophenyl)-2H-tetrazole-2-acetate1
Authors: Larsen Fenton E
Published: August 2022

Ethyl 5-(4-chlorophenyl)-2H-tetrazole-2-acetate (PP528) applied in early summer to apple (Malus domestica Borkh.) and pear (Pyrus communis L.) trees stimulated lateral branching the first year in the nursery. Concentrations of 25 to 50 ppm were effective, while 100 ppm or more sometimes killed shoot terminals and stopped or retarded further vertical growth for the season. Branch angles were not measured, but when terminal meristems were not killed, branch angles were wide. If terminal meristems were killed, the uppermost branch angles were narrow. Double applications 2 weeks apart of 25 or 50 ppm were sometimes more effective than single applications. Timing, uniformity of growth, and application during active growth were important to produce maximum branching effect and branching in suitable locations. PP528 caused more branching in 2 nonspurred ‘Delicious’ apple cultivars (up to 9 times control values) than in ‘Oregon Spur Delicious’ (up to 3 times the control). Treatments with up to 200 ppm were largely ineffective on sweet cherry (Prunus avium L.). Use of 100 or 250 ppm GA was of little benefit in overcoming the stunting effect of high concentrations of PP528.
The Effects of Node Position, Shoot Vigor, and Strain on ‘Delicious’ Apple Spur Development1
Authors: Walsh Christopher S.
Published: August 2022

Bud weight, and spur number, length, and fruitfulness were measured in shoots of ‘Delicious’ apple (Malus domestica Borkh.). In 2-, 3-, and 4-year-old wood, spur number, length, and fruitfulness were greater at the subapical nodes than at the basal nodes of the shoot. In dormant 1-year-old shoots, bud weight was affected by strain, node, position, and vigor. Axillary buds were largest in the apical portion of standard ‘Delicious’ shoots and in the basal portion of spur-types. In extremely vigorous shoots of ‘Gardner Delicious’ basal buds did not grow at the beginning of the second growing season unless treated with 6-benzylamino purine (BA), which induced normal spurs.
Relationships between Growth of Bell Peppers (Capsicum annuum L.) and Nutrient Accumulation during Ontogeny in Field Environments1
Authors: Miller C. H. , McCollum R. E. , Claimon Sootin
Published: August 2022

‘Keystone Resistant Giant’ pepper plants, grown at a population of 48,000/ha, were sampled, fractionated, dried, weighed and analyzed for macroelement content every 14 days between 28 and 112 days after transplanting. The highest specific accumulation rate for N, P, K, Ca and Mg occurred 28 to 42 days after transplanting, but the highest absolute nutrient uptake rate was during 56 to 70 days after transplanting, a period when fruit growth was rapid. N, P and K accumulated in leaves-plus-petioles, stems and fruit whereas Ca and Mg were abundant in leaves-plus-petioles but was quite low in fruit tissue. By 98 days after transplanting, the plants had absorbed the following amounts of nutrients in kg/ha: 118 N, 15 P, 123 K, 41 Ca, and 32 Mg. Total dry matter was 4758 kg/ha at the same time. Leaf efficiency as measured by mean net assimilation rate was high during fruit set and growth but declined after commercial harvest. A relatively low leaf area index and a correspondingly high mean net assimilation rate suggested that increased plant populations would result in increased efficiency. There were 114,500 marketable fruits/ha picked during 2 harvests which weighed 13.4 MT.
Effect of Promalin on the Physical Characteristics of ‘Delicious’ Apples Grown in Two Geographic Locations1
Authors: Miller Stephen S.
Published: August 2022

A commercial formulation of N-(phenylmethyl) lH-purin-6-amine plus gibberellin A4A7 (Promalin) was applied to ‘Delicious’ apples (Malus domestica, Borkh.) from 1975 to 1978 in 2 geographic locations at rates of 12.5 to 50 ppm. Promalin at 25 ppm increased fruit weight, length/diameter ratio (L/D), and percent “typey” fruit at both a cool mountain location and at a lower warm elevation. The effect on “typiness” in the warm growing area did not appear to be of commercial significance, but the increase in fruit weight did appear significant under these conditions. Response varied with strain. Addition of a spray adjuvant, Triton CS-7, at the lower elevation, did not improve response. Rates of 12.5 or 25 ppm applied at petal fall of the “king” blossom appeared to be equally effective under high temperature conditions conducive to oblate fruits.
Interactions of Ethylene, Temperature, Light, and CO2 on Leaf and Stipule Abscission and Chlorosis in Philodendron scandens subsp. oxycardium1
Authors: Marousky F. J. , Harbaugh B. K.
Published: August 2022

Plants of Philodendron scandens subsp. oxycardium (Schott) Bunt. were exposed to ethylene-air mixtures at various temperatures and levels of light and CO2. Plants held in ethylene (2.5 to 10μl/liter air) abscised leaves and stipules, developed chlorotic foliage, and grew poorly. As the levels and duration of exposure to ethylene increased, the rate of leaf abscission increased. Plants exposed to 5μl ethylene/liter air at 23.5°C for 3 days in light abscised more than 50% of their leaves, whereas plants similarly handled but held in darkness lost 20%. At a given level of ethylene, the lower the temperature the fewer the number of leaves abscised. Plants held at 27° at 10 μl/liter air had total leaf abscission. Plants held in ethylene with 5% CO2 or with lanolin-coated leaves abscised fewer leaves than plants without added CO2 or non-coated leaves.
Phytotoxicity of Ethylene Dibromide to Cherry and Banana Fruit1
Authors: Wade N. L. , Rigney C. J.
Published: August 2022

Fruit of cherry (Prunus avium L.) and banana (Musa sp.,) AAA Group, Cavendish sub-group cv. Williams Hybrid, when fumigated with ethylene dibromide (EDB) and held at 20°C were injured visibly by treatment concentrations of 32 g/m3 or more. EDB (4 g/m3) stimulated the rates of both ethylene (C2H4) evolution and respiration in cherries, while higher concentrations up to 32 g/m3 caused proportionately greater increases in the rates of gas exchange. Cherries stored at 1° after fumigation with 32 g/m3 EDB did not display the increases in gas exchange which were observed at 20°, but during a 7 day storage period severe Symptoms of phytotoxicity developed. The increases in gas exchange are, therefore, effects and not causes of EDB injury. The Stimulation of C2H4 production in cherries by EDB was reduced by pretreatment with Co2+, indicating that EDB affects the methionine pathway of ethylene synthesis. In bananas treated with 4 g/m3 EDB and held at 20°, the respiration rate increased but C2H4 evolution and electrolyte leakage from slices of pulp tissue were unaffected. When the EDB concentration was raised to 32 g/m3, respiration and C2H4 evolution rates and electrolyte leakage increased.
Nucleic Acids in Developing Fruits and Other Tissues of Shamouti Orange (Citrus sinensis (L.) Osbeck)1,2,3
Authors: Goren R.
Published: August 2022

A procedure for the extraction and fractionation of nucleic acids from citrus tissues was developed. Typical elution profiles of nucleic acids extracted from leaves, root tips, flowers, and fruits at different stages of development showed the well-known peaks of s-RNA, DNA, lr-RNA, and hr-RNA. In flowers and, especially, in young fruits the additional X-RNA peak was also present following the hr-RNA peak. The level of nucleic acids decreased markedly in the young fruit on the dry matter basis during the first 3 months of growth, mostly due to decrease in hr-RNA. During maturation the RNA fractions in the albedo decreased, while it increased in the flavedo due to increase in hr-RNA content. The fast growth of the young fruit apparently is accompanied by intensive metabolization or turnover of nucleic acids, rather than by dilution.
Influence of Transplanting Time in Nursery Production1,2
Authors: Harris Richard W. , Davis William B. , Stice Norman W. , Long Dwight
Published: August 2022

Root pruning and care during the first two nursery transplantings of 4 tree species significantly increased the percentage of plants with good root systems. The 4 species were Eucalyptus sideroxylon A. Cunn., red iron bark; Pinus radiata D. Don., Monterey pine; Pistacia chinensis Bunge., Chinese pistache; and Quercus ilex L., holly oak. The percentage of trees with good root systems decreased the longer seedlings stayed in the seed flat and in peat pot liners, particularly those not root pruned. In all but one case, the earlier plants were moved from the seed flat into peat pots and on into into gallon cans, the more the plants grew in caliper and height.

Plants root pruned during the early moves were larger than those not root pruned. However, root pruning at the later moves resulted in smaller plants than those moved earlier or than those moved at the same time but not root pruned. The combination of lengths of time in the seed flat and in the peat pot (time in the greenhouse) which resulted in the best combination of quality root systems and large plants was only 1/2 to 2/3 the time now common nursery practice (90-120 days).