bluuebunny/crossref_metadata_2025 huggingface dataset:
Abscisic Acid Identification and its Quantitation in Leaves of Juglans Seedlings during Waterlogging1
Authors: Shaybany B. , Martin G. C.
Published: August 2022

A rapid method was developed for extraction and purification of free abscisic acid (ABA) from leaves of waterlogged seedlings of Juglans. There were significant increases (6-15 fold) in leaf ABA contents of treated plants reaching maximum levels after the first 12 to 18 hours of waterlogging. With the exception of J. nigra, the leaves of which were desiccated at 24 hr after treatment, ABA content rapidly declined to original levels by 30 hours after waterlogging. Changes in ABA concentration in walnut is likely a secondary expression to the stress induced by waterlogging.
Influence of Soil and Cultivar on Mineral Composition of Avocado Leaves in Florida1
Authors: Young T. W. , Koo R. C. J.
Published: August 2022

Leaves were collected in 1974 and 1975 from mature ‘Tonnage’, ‘Lula’, ‘Taylor’, and ‘Booth 8’ avocado trees (Persea americana Mill.) on sand, muck, and calcareous rock soils and analyzed for N, P, K, Ca, Mg, Mn, Cu, Zn, and Fe. Significant differences in levels of all 9 elements in ‘Tonnage’ leaves occurred among the 3 soil types. Crop size, fertilization, soil pH, soil Ca level, and exchange capacity of the soil appeared to be important factors in the variations. Differences in concentration of N and P were not significant among the 4 cultivars but were significant for the other elements.
Breeding for Multiple Root Rot Resistance in Snap Beans1
Authors: Dickson M. H. , Boettger M. A.
Published: August 2022

Inheritance of resistance to Pythium, Fusarium, and Rhizoctonia in snap beans, Phaseolus vulgaris L., was studied for three populations involving a common resistant parent (Cornell 2114-12) and 3 different susceptible parents. Pythium resistance was strongly associated with colored seed but resistance was found in some white seeded segregants and was widely influenced by degree of susceptibility of white seeded parents. In contrast to the widely accepted theory that colored seed and resistance to Rhizoctonia are tightly linked, Rhizoctonia resistance seemed to be independent of seed color. Heritability for Rhizoctonia resistance was 0.75 and 0.65 for broad and 0.32 and 0.29 for narrow sense heritability. Resistance to all three diseases was independent and quantitatively inherited. Correlations for resistance to Pythium and Fusarium in F4 with F3 selections (r = 0.557**) were in line with heritability expectations. In the Rhizoctonia selections, generation to generation correlation was high (r = 90**) among those with the best resistance but only moderate among those with moderate resistance. In view of the low narrow sense heritability, selection for resistance in later rather than earlier generations should be more effective.
Carbohydrate and Nitrogen Levels in Pistachio Branches as Related to Shoot Extension and Yield1
Authors: Crane Julian C. , Al-Shalan I.
Published: August 2022

The pistachio (Pistacia vera L.), characteristically a biennial bearer, produces its most extensive shoot growth in years of heavy crop production. Whereas levels of total sugars in bark and wood of bearing and nonbearing branches were similar throughout the year, starch levels tended generally to be higher in nonbearing than in bearing branches. Consequently, nonbearing branches one year gave rise to heavy crops the next and, beacuse of greater quantities of reserve foods, also produced extensive shoot growth. Bearing branches of that same year, .however, produced few or no nuts the next and, because of lesser quantities of reserve foods, produced markedly less shoot growth. No relationship between total nitrogen level and shoot growth or fruiting was evident.
Influence of Shade and Fertilizer on Light Compensation Point of Ficus benjamina L.1
Authors: Collard R. C. , Joiner J. N. , Conover C. A. , McConnell D. B.
Published: August 2022

Light and fertilizer significantly affected light compensation point (LCP) in Ficus benjamina in a 3 × 4 factorial experiment with 0%, 30%, 55% and 80% light exclusion and of 784, 1568 and 2352 kg N+K/ha/year. Increasing shade levels decreased LCP and at each shade level increasing fertilizer rates increased LCP. Fertilizer was less effective than shade in altering LCP. The highest LCP at 0% shade and 784 kg N+K/ha/year was nearly 3 times higher than the lowest LCP at 80% shade and 784 kg N+K/ha/year. Increasing shade and fertilizer levels increased chlorophyll content, plant size and visible quality.
Mid-summer Applications of Ethephon and Daminozide on Apples. II. Effect on ‘Delicious’1
Authors: Greene D. W. , Lord W. J. , Bramlage W. J.
Published: August 2022

Sprays of (2-chloroethyl)phosphonic acid (ethephon) applied to ‘Delicious’ apple trees (Malus domestica Borkh.) in July at concentrations of 500 to 1000 ppm shortly after the completion of June drop hastened the respiratory climacteric, and increased soluble solids, watercore and preharvest drop. These effects were diminished when 1000 ppm succinic acid-2,2-dimethyhydrazide (daminozide) was included with ethephon. All concentrations of ethephon increased flesh firmness. Two periods of fruit abscission occurred following ethephon application at high concentrations: shortly after application and immediately prior to harvest. After cold storage, fruit which had received 500 or 1000 ppm ethephon had less scald but a greater incidence of brown core. High ethephon concentrations increased bloom the following spring but had no influence on fruit set.
Ozone and Botrytis spp. Interaction in Onion Leaf Dieback: Field Studies1
Authors: Wukasch R. T. , Hofstra G.
Published: August 2022

A suspected interaction between ozone injury and Botrytis spp. infection on onions (Allium cepa L.) was investigated in the field by reducing one or both causal agents by chemical antioxidants and/or fungicides. ‘Autumn Spice’ and ‘Rocket’ onions received 4 sprays of the fungicide anilazine and/or one of the following chemicals with antioxidant properties: fenarimol, ancymidol, chlormequat, piperonyl butoxide, metiram, chlorthalonil, or DuPont DPX-4891. Ozone levels exceeded 4 hourly averages of 8 pphm on at least 7 occasions during July, ozone injury was routinely observed in the field, and Botrytis was frequently isolated from lesions on onion leaves. Single and combination treatments of all fungicides and antioxidants generally reduced leaf necrosis and the Botrytis incidence. Fungicide-antioxidant combination treatments were superior to either fungicide or antioxidants alone in reducing Botrytis infection. Yields of ‘Autumn Spice’ were increased by most treatments while ‘Rocket’ onion yields were generally decreased. DPX-4891, the only antioxidant which was nonfungitoxic to Botrytis in vitro, was frequently superior to fungicides in preventing Botrytis lesions and was also the most effective in reducing ozone injury. These results support the hypothesis that onions injured by ozone are more susceptible to Botrytis infection.
Water Relations and Physiological Activity of Potatoes1
Authors: Ackerson R. C. , Krieg D. R. , Miller T. D. , Stevens R. G.
Published: August 2022

The effects of water stress on internal water potential components and specific physiological processes were investigated in field grown potatoes (Solanum tuberosum L. cv. Viking). Leaf water potential (ψleaf) as estimated by the pressure chamber, was not directly related to soil water potential (ψsoil) until a specific minimum ψsoil was attained. Subsequently ψleaf did not increase in response to increases in ψsoil. Water stress affected physiological processes such as stomatal resistance, photosynthesis and enzyme activity. A decline in ψleaf was apparently responsible for increased stomatal resistance and decreases in photosynthetic rates. The activities of ribulose diphosphate carboxylase and phosphoenolpyruvate carboxylase decreased as ψleaf declined. The relationship between water stress and physiological processes and the inability of ψleaf to respond to increases in ψsoil after a maximum stress may partially explain the extreme sensitivity of potatoes to even mild water stress.
Uptake and Metabolism of 15N-labeled Potassium Nitrate by French Prune (Prunus domestica L.) Leaves and the Effects of Two Surfactants1
Authors: Weinbaum Steven A. , Neumann Peter M.
Published: August 2022

15N-labeled potassium nitrate was applied in a foliar spray to French prune/Marianna 2624 trees (Prunus domestica L.), and the nitrogen absorbed by the leaves was quantified. Nitrogen derived from a single foliar spray averaged 3% of total leaf nitrogen. L77, a non-ionic organosilicone surfactant which lowers surface tensions of aqueous solutions sufficiently for stomatal penetration, significantly enhanced the rate of NO3 absorption and increased incorporation of foliar-derived nitrogen into alcohol insoluble macromolecules. This enhancement was not apparent when labeled NO3 was applied with Regulaid, a carbohydrate-based non-ionic surfactant. About 25% of the foliar-derived N was apparently transported from leaves within 3 days when the stomatal penetrant was employed. No transport was evident in the absence of the penetrant.
Influence of Subsoil Acidity on Tomato Yield and Fruit Size1
Authors: Doss B. D. , Evans C. E. , Turner J. L.
Published: August 2022

‘Tropic’ and ‘Walter’ tomatoes (Lycopersicon esculentum, Mill.) were grown in central Alabama on a Lucedale fine sandy loam soil (Rhodic Paleudult) with uniform 0- to 15-cm surface soil pH of about 6.0 and subsoil pH ranging from 4.4 to 6.2. Depth and amount of soil water extraction and plant heights increased as subsoil pH increased. Marketable tomato yields were influenced by subsoil pH, with maximum yields occurring at pH 5.6 to 5.8. Marketable yields ranged from 10,400 to 55,500 kg/ha for ‘Tropic’ and from 14,000 to 39,400 kg/ha for ‘Walter’. Yield of large size fruit of ‘Tropic’ was greater above pH 5.0 than below pH 5.0. Fruit size distribution for ‘Walter’ was not affected by subsoil pH.
Effects of Fruiting on Scorch, Premature Defoliation, and Nutrient Status of ‘Chickasaw’ Pecan Leaves1
Authors: Sparks Darrell
Published: August 2022

The effect of retaining fruit on the induction of scorch, defoliation, and nutrient status of pecan [Carya illinoensis (Wang) K. Koch] leaves was compared with the effect of fruit removal. Fruit retention induced leaf scorch and defoliation. Fruiting suppressed N, P, and Zn accumulation in leaves and resulted in a net loss of K from leaves. Potassium loss from leaves was associated with a high K content in the shuck. The data suggest that heavy fruiting in pecans can induce a K stress which in severe cases results in leaf scorch and defoliation.
Effect of Fruiting on Carbohydrate and Mineral Composition of Stems and Leaves of French Prunes1
Authors: Ryugo Kay , Nii N. , Iwata M. , Carlson R. M.
Published: August 2022

Leaves and stems from bearing and non-bearing branches of French prune (Prunus domestica L. cv. Agen) were collected periodically during the growing season and analyzed for their carbohydrate and mineral contents. The non-bearing shoots contained more starch than the bearing ones during the period when the fruits were growing rapidly and accumulating soluble solids. The % dry matter and alcohol insoluble substances (AIS) were also higher in the former than those of the latter. Analysis of fruits revealed that sorbitol was the predominant carbohydrate, followed by sucrose and reducing sugars during the ripening period. These findings indicate that when internal competition for carbohydrates becomes limited, the stem cells assimilate constituents, presumably cell wall substances, other than reserve food. Leaf analysis also reflected the diminished competition in that the dry matter, sugar and starch contents were consistently higher in leaves from non-bearing limbs than those collected from bearing ones on a unit area basis. No difference was detectable in mineral contents of leaves and stems collected from de-fruited and bearing limbs.
Breaking Bud Rest on Detached Apple Shoots: Effects of Wounding and Ethylene1
Authors: Paiva Edilson , Robitaille Henry A.
Published: August 2022

Buds of ‘Golden Delicious’ apple (Malus domestica Borkh.) were in deep rest between October 25 and December 20, 1976, although the uppermost bud on decapitated (apical and basal cuts) shoot segments developed at all sampling dates. Increases in rate of development of the uppermost bud, as well as in % break of lower buds after completion of deep rest, were both linear with time. Increases in % budbreak with time occurred in a basipetal direction, suggesting a gradient of increasingly deep rest from shoot apex to base. Development of the uppermost bud on decapitated shoots during deep rest was a result of the apical cut, and was not influenced by the original position of that bud on the intact shoot. The bud above the basal cut developed only on shoots with the terminal bud intact (basal cut only). Notching above a second bud on decapitated shoots did cause that bud to develop in addition to the uppermost bud. Results are discussed on the basis of a 2 stage rest model, rest gradient and apical dominance. There was no evidence for a role of ethylene in wounding or dinitro-orthocresol-stimulated budbreak. In addition, neither ethylene-releasing chemicals nor silver or cobalt had any influence on budbreak when applied to shoots at 2 dates during the rest period.
Growth and Nutrient Interrelationships in Snap Beans as Affected by Several Sources of Potassium and Magnesium1
Authors: Palaniyandi Ravindran , Smith Cyril B.
Published: August 2022

Snap beans (Phaseolus vulgaris L. cv. Bush Blue Lake 283) were grown in 2 greenhouse experiments in soil with 8 fertilizer treatments with a basic NP treatment to which various sources of K and Mg were added. The NP treatment substantially increased vine weight and leaf concentrations and total plant content of N, P, Ca, Mg, Mn and Na. In NPK treatments, regardless of K source, substantial increases in the leaf K and decreases in leaf P and particularly Mg concentrations were shown while only potassium chloride enhanced Mn leaf concentrations. In NPMg treatments, regardless of Mg source, leaf Mg increased but no reduction in K concentration occurred. Adding both K and Mg to the NP treatment did not affect the Mg leaf concentration. Treatments caused a redistribution of elements in plant parts.
Response of Sweet Cherry Leaf Tissue to Hydrogen Fluoride Fumigation at Different Nitrogen Levels1
Authors: Facteau T. J. , Wang S. Y. , Rowe K. E.
Published: August 2022

Foliar uptake of fluoride (F) resulting from hydrogen fluoride (HF) fumigations was linear with dose (concentration F in μg/m3 × duration of exposure in hours) at F concentrations lower than 17.5 μg/m3. Above this level, duration of exposure was the only important factor and uptake was non-linear with time. Higher leaf N levels resulted in greater F uptake. Production of CO2 was increased more by high F concentration for short periods than by low concentration for longer periods where leaf N was optimal or supraoptimal. Amino nitrogen (AN) levels increased more at low F concentration for longer periods than high concentration for shorter periods. The response patterns were similar at optimal and supraoptimal leaf N. Protein nitrogen (PN) decreased with increasing In HF dose at optimal and very low leaf N levels. Changes in PN and AN were significantly correlated in leaf tissue with optimal, but not in tissues with deficient or supraoptimal N.
Interaction of Moisture Potential and Activated Carbon on Lettuce Seed Germination1
Authors: Sharples G. C.
Published: August 2022

Activated carbon stimulated seed germination of lettuce (Lactuca sativa L.) in soil and vermiculite. Stimulation was strongly dependent upon the moisture potential. Germinating seeds were shown to excrete an inhibitor into the micro-environment which cannot diffuse away rapidly at moisture potentials near the soil field capacity or at analogous potentials in vermiculite. Increasing the moisture potential or adding activated carbon caused rapid removal of inhibitor from the seed micro-environment.
Translocation of 14C in ‘Stuart’ Pecan in the Spring following Assimilation of 14CO2 during the Previous Growing Season1
Authors: Lockwood David W. , Sparks Darrell
Published: August 2022

Leaves on selected branches of 3-year-old ‘Stuart’ pecan (Carya illinoensis (Wang) K. Koch) trees were treated weekly with 14CO2 for one growing season. Carbon-14 distribution within the tree during dormancy and its mobilization the following season were followed by autoradiography and liquid scintillation counting. During dormancy, 14C distribution was predominantly on the treated side of the tree. Tissues that developed during the season of treatment were heavily labelled. Carbon-14 mobilization was evident at bud break. Translocation was primarily to new growth, i.e., to leaves, shoots, pistillate and staminate inflorescences, and new roots. First-formed leaves, veins, and primary growth were more heavily labelled than later leaves, interveinal tissue, or secondary growth. Tissues from treated branches were labelled more intensely than those from untreated branches. Storage substrates decreased as shoots developed.
Effect of Nine Controlled-release Fertilizers on Chrysanthemum Growth and Foliar Analysis1
Authors: Sharma Govind C. , Patel Ashwin J.
Published: August 2022

Single application of 9 controlled-release fertilizers applied prior to planting and liquid fertilization applied at each watering were evaluated on pot chrysanthemum, Chrysanthemum morifolium Ramat cv. Sunny Mandalay. Three rates (20, 40 and 60 g N/35 liter of mix) were applied of the following controlled-release fertilizers (N−P−K): Sulfur-coated urea (36−0−0 as SCU-A and SCU-B), Osmocote (14−6.1 − 11.6) and 18−2.6−9.8) Mag AmP (7−17.5−5.0 as fine and coarse), Precise (8−4.8−4.1 and 12−2.6−5.0) and Agriform (14−1.7−5.0). Liquid fertilization applied 200 ppm N, P2O5 and K2O with each watering. Generally 60 g N/35 liter resulted in higher quality plants than did the lower rates, effect of Osmocote (14−6.1−11.6) on plant dry weight, visual rating and plant spread was not significantly different from liquid fertilizer. Precise (8−4.8−4.1), Osmocote (18− 2.6−9.8) and coarse MagAmP produced marketable plants of slightly lower quality than those obtained with liquid feed. Problems observed were primarily those of nutrient balance: very low P (SCU) and high P content (MagAmP); P-induced Mn deficiency (MagAmP); some lower leaf burn with initial high N release (Precise) and injury probably caused by ammonium and high rates of urea formaldehyde-based fertilizer (Agriform). The low initial release of N to support vegetative growth was also an important limitation with Agriform and other fertilizers.
The Effect of Ultrahighfrequency Electromagnetic Energy on Adenosine Triphosphatase Activity in Germinating Weed Seeds1
Authors: Hooper Gary R. , Rice Robert P. , Flegler Stanley L. , Putnam Alan R.
Published: August 2022

UHF Electromagnetic energy (2450 MHz) is lethal at dosages from 100-200 J/cm2 to seeds of several weed species. Seeds were exposed to uniform energies by placing them in a quartz tube and inserting the tube in a waveguide. Seeds of barnyard grass, (Echinochlea crusgalli (L.) Beauv.), large crabgrass (Digitaria sauginalis (L.) and common purslane (Portulaca oleracea L.) showed no visible external damage when viewed in the scanning electron microscope at up to 5,000 × after treatment. No discernible internal damage was visible when tissues were immediately fixed and viewed by transmission electron microscopy after receiving minimum lethal dosages of UHF energy. At higher UHF dosages, membrane breakage and loss of integrity of organelles was observed. ATPase activity in treated seeds was monitored by transmission electron microscopy as an indicator of possible UHF destruction of enzymes. ATPase activity of tissues was absent after minimal or higher dosages of microwaves. Cells receiving minimal UHF treatment otherwise appeared normal. Toxicity from microwaves may occur as a result of selective heating of cells which results in partial protein denaturization and inactivation of key enzymes.
Effects of Evaporative Cooling for Bloom Delay on ‘Bartlett’ and ‘Bosc’ Pear Tree Performance1
Authors: Collins M. D. , Lombard P. B. , Wolfe J. W.
Published: August 2022

Two mist systems, one in a mature orchard and the other in a young hedgerow, delayed bloom 15 days for ‘Bartlett’ and 8 days for ‘Bosc’ pear (Pyrus communis L.), while a low pressure sprinkler system delayed bloom for 14 days for ‘Bartlett’ and 8 days for ‘Bosc’ in 1976. Bloom delay generally increased fruit set and seed content of the fruit. Return bloom was greatly reduced in the mature orchard ‘Bartlett’ mist and ‘Bosc’ sprinkler plots in 1976 and, in turn, cropping was reduced the following year on these plots. Yield during treatment years was generally lower in the delayed areas. Fruit growth rates were accelerated in the bloom-delayed trees, but total fruit volume was less than the non-delayed fruit. Leaf nitrogen levels were reduced in all bud delayed treatments. Pear psylla oviposition was delayed in the mist system. Fire blight, caused by Erwinia amylovora (Burr.) Winslow et al., absent in 1975, was found in the misted ‘Bosc’ and in the sprinkled plots of both cultivars in 1976.
Relation of Nitrogen and Phosphorus Fertilization to Fruiting and Petiole Composition of ‘Solo’ Papaya1
Authors: Awada M. , Long C.
Published: August 2022

N and P fertilizers in factorial combinations were applied to flowering and bearing papaya (Carica papaya L.) grown on aa lava soil. An increase in N fertilization increased the number of harvested fruit and yield of marketable fruit and culls but decreased fruit size. P fertilization increased the number of harvested fruit and yield of culls but did not affect yield of marketable fruit. N fertilization increased petiole concentrations of N, Mg, S, Fe, Mn, Zn, and Cu and decreased those of K and B. P fertilization increased petiole concentrations of P, N, and Mn, and decreased those of Ca, S, and Cu. Petiole N concentrations associated with maximum yield of marketable fruits were determined under low P (41 kg P/ha) and the combined medium (186 kg P/ha) and high P (723 kg P/ha) plots.
Estimates of Heritabilities and Variance Components in Pickling Cucumber1
Authors: Smith O. S. , Lower R. L. , Moll R. H.
Published: August 2022

Variance component estimates were obtained in a North Carolina Design I experiment for several traits in pickling cucumber (Cucumis sativus L.) for a simulated once-over mechanical harvest. The reference population was random-mating and derived from 18 inbred lines obtained from several U.S. breeding programs. Environments sampled were the spring and fall of a single year. Data indicated most of the genetic variance was additive for all traits except fruit color. Evidence for relatively large genotype by environment interaction variances were found for number of fruit, length to diameter (L/D) ratio, and fruit firmness. Heritabilities, based on full-sib families grown in 2 replications in each of 2 seasons, for dollar value and number of fruit, were .19 and .17 respectively. Genotypic and phenotypic correlations for number of fruit and dollar value were high indicating selection for increased number of fruit would be effective in increasing crop value.
Soil-plant Water Relations in a New York Vineyard: Resistances to Water Movement1
Authors: Liu W. T. , Wenkert W. , Allen L. H. , Lemon E. R.
Published: August 2022

Leaf water potentials did not limit stomatal opening of Vitis labruscana Bailey cv. Concord during the summers of 1972 and 1973 in a New York vineyard. Midday leaf-water potentials ranged from −8 to −16 bars and were closely related to individual leaf irradiance. The diurnal variation of leaf, stem, and fruit cluster water potentials on a typical clear day were about 5, 11, and 6 bars, respectively. Water potential gradients at midday across the root, shoot, and petiole-leaf systems averaged about 10, 1 and 3 bars, respectively. The gradient across the root consistently increased throughout the day relative to plant transpiration rate. Minimum stomatal resistance on days after cold nights (less than 10°C) was 2.7 ± 1.1 s cm-1, while the mean resistance on all other days was 1.0 ± 0.5 s cm-1. Cool night temperatures inhibited stomatal opening and closing independently of leaf water potential.
Hardcore in Some Sweet Potato Cultivars and Lines1
Authors: Hammett H. L. , Albritton R. C. , Withers F. T.
Published: August 2022

Twenty-one cultivars and/or breeding lines of sweet potato (Ipomoea batatas Lam) were exposed to 1°C for 48 hours followed by 48 hours at 25° and evaluated for hardcore during each of 2 seasons at the Mississippi Agricultural and Forestry Experiment Station. Hardcore was 50% more severe in 1976 than in 1975. One breeding line, ‘M3-309’, exhibited no injury symptoms either season; 60% of ‘M2-325’ roots and 15% of the ‘Centennial’ roots were injured. Other cultivars and breeding lines showed intermediate injury. Hardcore susceptibility was not correlated with dry matter content.
Effect of Peach Seedling Rootstocks and Orchard Sites on Cold Hardiness and Survival of Peach1
Authors: Yadava U. L. , Doud S. L.
Published: August 2022

Two-year-old ‘Redhaven’ peach (Prunus persica (L.) Batsch) trees on 7 different peach seedling rootstocks growing on short-life and on non-short-life sites were examined for cold hardiness of trunks using trunk cambial browning (TCB), and cold hardiness of twigs using tests for electrolytic conductivity (EC), triphenyl tetrazolium chloride (TTC), and ninhydrin-reactive compounds (NRC). It was found that Lovell, Halford, and NA 8 rootstocks invariably imparted more cold hardiness to ‘Redhaven’ budded onto them than other rootstocks tested, whereas maximum cold injury was sustained by trees on NRL 4 rootstock. Tree mortality was higher and cold injury was more severe on the short-life site than on the non-short-life site.
Effect of Preplanting Irrigations on Distribution of Soil Nitrate Nitrogen and Total Soluble Salts in Lettuce Beds1
Authors: Pew W. D. , Gardner B. R.
Published: August 2022

A preplant N application and the 2 irrigation methods most commonly used in Arizona to germinate commercially grown lettuce (Lactuca sativa L.) were studied in relation to the movement of soil NO3-N and total soluble salts (TSS) in lettuce beds. The intermittent pattern of irrigation resulted in highest levels of TSS at all sampling depths two weeks after the germination and emergence of the lettuce. Total soluble salts and NO3-N concentrations were increased by irrigation and were greatest in the surface 5 cm and center of the bed. Nitrogen application increased the amount of NO3-N found in the lettuce beds. Neither irrigation nor N treatment caused any accumulation of NO3-N in the area of the beds where the lettuce seedlings usually grow. The distribution patterns indicate that preplant N applications would be ineffective in meeting the early N needs of the plants.
A Laboratory Assay for Resistance to the Tobacco Hornworm in Lycopersicon and Solanum spp.1
Authors: Kennedy G. G. , Henderson W. R.
Published: August 2022

A laboratory procedure for assaying Lycopersicon spp. for resistance to the tobacco hornworm Manduca sexta (L.) is described. Results from this procedure, which employed excised foliage from greenhouse grown plants and first instar hornworm larvae from a colony maintained in the laboratory on artificial diet, were similar to those obtained with intact plants, with field collected hornworm larvae, and with field grown resistant plants. The Lycopersicon hirsutum f. glabratum accessions PI 134417 and LA 407 were highly resistant to M. sexta. Resistance was manifest as a significant reduction in larval survival and in weight gained by survivors over a 72 hour period. The interplant variation in larval weight gains within accessions was highly significant, suggesting that most of the accessions tested were segregating for resistance to M. sexta.
Effect of pH on Foliar Absorption of Phosphorus Compounds by Chrysanthemum1
Authors: Reed David W. , Tukey H. B.
Published: August 2022

Solution pH differentially affected the foliar absorption of phosphorus compounds by Chrysanthemum morifolium Ramat cv. Giant #4 Indianapolis White. All phosphates were absorbed readily at pH 2, which was accompanied by necrosis of the treated area of the leaf. Maximum absorption occurred with Na phosphate at pH 3-6, K phosphate at pH 7-10, and NH4 phosphate at all pH values (3-10), whereas Ca phosphate was not readily absorbed. The results could be explained by pH dictating the phosphate form present in solution; solubility, moisture retention, and crystallization on the leaf surface of the predominant phosphate salt were the factors determining the degree of absorption.
Effects of a Pre-storage High CO2 Treatment on British Columbia and Washington State ‘Golden Delicious’ Apples1
Authors: Lau Oi Lim , Looney Norman E.
Published: August 2022

Thirty-two lots of ‘Golden Delicious’ apples (Malus domestica Borkh.) from 22 British Columbia (B.C.) orchards varied in their susceptibility to injury from a 10-day 14 or 18% CO2 treatment preceding controlled atmosphere storage. In general, the incidence of injury was much higher than in 25 lots of Washington State ‘Golden Delicious’ treated similarly in a commercial storage. A small improvement in firmness was observed in the B.C. fruit. Within the 32 B.C. lots, susceptibility to CO2 injury was not related to fruit skin color, size, soluble solids or acidity, the N, K, Mg, Ca, Zn, Fe or B content of the leaves, or N, K, Mn, Mg, Ca or Zn content of the fruits. However, Washington ‘Golden Delicious’ were less green, were lower in N, Mn and Zn and higher in K, Mg and soluble solids than B.C. fruit which may provide a clue to their resistance to CO2 injury.
Early Root Growth of Carrots in Organic Soil1
Authors: White J. M. , Strandberg J. O.
Published: August 2022

Early root growth of carrots (Daucus carota L.) was studied in specially constructed pots containing organic soil under controlled environments at 16°, 20°, 24°, and 28°C. Carrot tops produced greater amounts of bio-mass on a fresh or dry weight basis than did roots, whereas taproots demonstrated faster rates of linear growth than did the tops throughout the 24-day sampling period at all temperatures. The optimum range of temperatures for carrot root growth was 20-24°C. Taproots reached the potential length for market-acceptable storage roots (15.2 cm) between 12 and 16 days after planting at 20°, 24°, and 28°C and after 20 days at 16°C. Average taproot lengths after 24 days at 16°, 20°, 24°, and 28°C were 23.6, 38.5, 35.6, and 16.7 cm, respectively. Secondary roots had developed by the 8th day and tertiary roots by the 20th day. Tertiary roots were confined to the upper 5 cm of the root system at this early date.
Effect of Ozone on Growth and Assimilate Partitioning in Parsley1
Authors: Oshima R. J. , Bennett J. P. , Braegelmann P. K.
Published: August 2022

Parsley (Petroselinum crispum (Mill.) Nym. cv. Banquet) incurred leaf injury, reduced growth, and altered assimilate partitioning after exposures to 20 pphm ozone. Total plant dry weight and root dry weight were decreased 23% and 43% respectively, with little effect on leaves. The relative growth rate of fumigated plants was reduced after the initial ozone exposure but leveled off at a steady state above that of the control plants when plant dry weights reached about 4.5 g. Ozone appeared to have its greatest effect on growth during initial exposures.
Response of Onions Grown for Transplants to Soil Fumigation1
Authors: Jaworski C. A. , McCarter S. M. , Johnson A. W. , Williamson R. E.
Published: August 2022

Six general-purpose fumigants applied by different methods were evaluated for control of the fungal-nematode complex on onion (Allium cepa L.) for transplant production. Most soil treatments improved plant vigor, size, uniformity, and yield, and these positive responses were correlated with reduced populations of soil-borne fungi and nematodes. Growth response and control of pathogens varied with the fumigant used and the method of application. Populations of Pythium spp. and Fusarium spp. were reduced with methyl bromide, methyl bromide-chloropicrin mixture, chloropicrin, DD-MENCS (Vorlex), metham (748 liters/ha, drenched) and Bunema (drenched). Metham (748 liters/ha, drenched or drenched and incorporated) controlled Rhizoctonia solani Kuehn. Complete control of root-knot nematodes was obtained with methyl bromide and methyl bromide-chloropicrin mixture and nearly complete control with chloropicrin and DD-MENCS.
Rootstock and Seasonal Influences on Carbohydrate Levels and Cold Hardiness of ‘Redhaven’ Peach1
Authors: Layne R. E. C. , Ward G. M.
Published: August 2022

Flower buds and apical shoots of ‘Redhaven’ peach (Prunus persica (L.) Batsch) were shown to be slightly more cold hardy in the autumn and winter when propagated on seedlings of Siberian C than on those of Harrow Blood. Apical shoots consistently had higher levels of total carbohydrates, reducing sugars, and other carbohydrate fractions on Siberian C than on Harrow Blood seedlings from winter to spring. The cold hardiness of flower buds was closely correlated with the hardiness of apical shoots. In addition, both flower bud and shoot hardiness were closely correlated with total sugars, sucrose, and reducing sugars in the shoots from autumn to spring. However, hardiness of flower buds and apical shoots was not correlated with total carbohydrates or starch. The TI50, a new method of expressing the hardiness of apical shoots was an objective index of cold hardiness and somewhat analogous to the T50 method for expressing hardiness of flower buds.
Cuticle Development and Surface Morphology of Olive Leaves with Reference to Penetration of Foliar-applied Chemicals1
Authors: Leon J. M. , Bukovac M. J.
Published: August 2022

Surface morphology and development of the cuticle of olive (Olea europaea L, cv. Manzanillo) leaves were studied in relation to some factors (wetting, retention) that influence absorption of foliar-applied substances. Cuticle deposition occurred at a uniform rate during leaf development, then ceased at full expansion. The total weight of the cuticular membrane per unit surface area remained constant during leaf expansion. The weight of the cuticular membrane of the adaxial epidermis was about 1.4 mg/cm2 and in μg/cm2 the principal constituents were: epicuticular wax, 243; cutin, 886; cuticular wax, 272. The thickness of the cuticle was greater on the adaxial (11.5 μm) than on the abaxial surface (4.5 μm), and both surfaces were covered with large (130 μm diameter) peltate trichomes, their number being greater on the abaxial surface (143/mm2 vs. 18/mm2). Stomata were present only on the abaxial surface (470/mm2). The large number of trichomes contributed significantly to the effective surface area of the leaf, which was about 3 times greater for the abaxial than for the adaxial surface. No epicuticular wax fine-structure was observed. Both surfaces were difficult to wet. The advancing contact angle formed by distilled water was 106° for the adaxial and 125° for the abaxial surface. Retention as indexed by dipping leaves in distilled water was 0.34 μl/cm2. When sprayed, maximum retention was 31.3 and 36.9 μl/cm2 by the adaxial and abaxial surfaces, respectively.
Influence of Plot Size and Seeding Rate in Field Screening Studies for Cucumber Resistance to Cucumber Beetles1
Authors: Quisumbing Alberto R. , Lower Richard L.
Published: August 2022

Plot size (number of hills) and seeding rate (SR) were evaluated for their effect on susceptibility of cucumber, Cucumis sativus L., seedlings screened for resistance to the striped and spotted cucumber beetles, Acalymma vittatum (Fabricius) and Diabrotica undecimpunctata howardi Barber, respectively. Susceptibility estimates were highest with single-hill plots in 1971 but there was no difference between 2 and 3 hills per plot in 1972. Plot sizes were significantly different only in degree of cotyledon damage. Six replicates appear satisfactory for field studies. SR may or may not influence susceptibility. Combined 1973-1974 data indicate that 15 seeds per hill may be practical for field studies.
Texture Modification of ‘Van’ Sweet Cherries by Postharvest Calcium Treatments1
Authors: Lidster P. D. , Porritt S. W. , Tung M. A.
Published: August 2022

Calcium (Ca) moved rapidly into sweet cherry fruit (Prunus avium L.) flesh and reached a maximum in 7 days after a postharvest calcium chloride (CaCl2) dip. Flesh Ca content was increased by increasing the CaCl2 or thickener concentration or by prolonged immersion time in the dipping solution. After 21 days of 0°C storage, texture attributes of fruit firmness and bioyield were positively correlated with fresh Ca levels.
Flower Production of Freesia hybrida Seedlings under Night Interruption Lighting and Short Day Influence1
Authors: Gilbertson-Ferriss Terry L. , Wilkins H. F.
Published: August 2022

Flowering dates of freesias (Freesia hybrida Bailey) sown at monthly intervals varied according to monthly temperature fluctuations over a 2-year period. Seeds germinated from April to June reached anthesis from December to March. April through June seeding dates were acceptable for obtaining optimal flower production and quality in Minnesota, but these plants were slower to flower than those seeded from July through November. Night interruptions by incandescent light hastened flowering, but flower quality was poorer than from plants grown under natural days. Short days and night interruptions using BCJ-Ruby incandescent lamps had no influence on flowering date.
Quality of Sweet Corn Stored in Controlled Atmospheres or under Low Pressure1
Authors: Spalding Donald H. , Davis Paul L. , Reeder William F.
Published: August 2022

Tobelle’ sweet corn (Zea mays var. saccharata (Sturtev.) Bailey) stored for 3 weeks at 1.7°C and 98100% relative humidity in controlled atmospheres (2 or 21% 02 with 0, 15, or 25% CO2) or at low atmospheric pressure (50 mm Hg) did not differ significantly in appearance or flavor. Sucrose content of stored corn remained higher in 2% O2 at normal or low atmospheric pressure (76 mm Hg) than in other atmospheres. Ethanol content increased during storage, except in 21% O2 without added CO2, and was highest in corn stored in atmospheres containing 25% CO2. The high sucrose content of ‘Florida Sweet’ even after 3-weeks-storage suggests that for maintenance of high market quality, breeding cultivars that retain quality in combination with prompt precooling offers more chance of success than modified atmospheres.
Postharvest Characteristics of Poinsettias as Influenced by Handling and Storage Procedures1
Authors: Staby George L. , Thompson J. F. , Kofranek A. M.
Published: August 2022

Sleeved poinsettia plants (Euphorbia pulcherrima, Willd. cvs. Annette Hegg Supreme and Annette Hegg Dark Red) stored best at 10°C. Lower temperatures (2-7°C) induced chilling damages as manifested mainly by bract blueing. Higher temperatures (up to 16°) resulted in increased leaf petiole epinasty and bract drooping. The bract blueing and leaf petiole epinasty disorders became worse as storage duration increased from 2 to 10 days, while bract drooping decreased during this same period. Plants sleeved and stored in paper were generally of higher quality upon removal than those sleeved and stored in plastic. Under relatively static conditions (15m/minute air speed), poinsettias froze at about −4°. Sleeving poinsettias delayed low-temperature damage. The injury of sleeved poinsettias was related to temperature, air speed, and exposure time which can be estimated by: time to injury (minutes) = 3.94 × chill factor (°C) + 61.9.
Promotion of Inflorescence Development by Growth Substance Treatments to Tomato Plants Grown in Insufficient Light Conditions1
Authors: Kinet J. M. , Hurdebise D. , Parmentier A. , Stainier R.
Published: August 2022

The development of the inflorescence of tomato (Lycopersicon esculentum Mill.) plants grown in adverse light conditions was stimulated by exogenous applications of benzyladenine (BA) and gibberellin (GA) directly on the inflorescence. These two compounds had sequential effect in regulating the development of the inflorescence, the action of BA being exerted first and that of GA only subsequent to BA action. In combination with BA, GA4+7 was more effective than GA3 in promoting the development of the inflorescence. Determinations of carbohydrate contents in the inflorescences showed that during the treatment period with the growth substances, the soluble sugars and starch levels increased temporarily. Studies on the partitioning of the dry matter between the different plant portions suggested that the growth substances modified the distribution pattern of the assimilates within the plant; the inflorescence being favored at the expense of the young leaves above.
Influence of Potting Media, Temperature, and Concentration of Ancymidol on Growth of Chrysanthemum morifolium Ramat.1
Authors: Bonaminio Vincent P. , Larson Roy A.
Published: August 2022

Influence of temperature, media and concentration of ancymidol (α-cyclopropyl-α-[p-methoxyphenyl]-5-pyrimidine-methanol) on the growth and flowering of selected cultivars of Chrysanthemum morifolium were studied. As day/night temperature increased or decreased from 22/18°C length of time required for the plants to come into flower increased. Stem elongation and leaf area decreased while fresh weight increased as temperatures decreased from 30/26° to 18/14°. Ancymidol applied at a concentration of 0.25 mg/pot of aqueous drench was sufficient to control height of plants grown in most media except pine bark humus. Incorporation of river sand, greenhouse soil or Ca(OH)2 into pine bark humus increased ancymidol's effectiveness. Increasing growth regulator concentration also resulted in adequate height control for plants grown in pine bark humus.
Carbohydrate Fractions of American Holly, Ilex opaca Ait. Leaves as Affected by Tissue Preparation, Leaf Maturation and Time of Day1
Authors: Balge R. C. , Dunham C. W. , Liebhardt W. C. , Svec L. V.
Published: August 2022

Leaf samples of Ilex opaca ‘Miss Helen’ were collected over a 2-month period and analyzed on a mg/g basis for total nonstructural carbohydrates (TNSC), individual ethanol soluble sugars (IESS), total ethanol soluble sugars (TESS) and apparent storage carbohydrates (ASC). Samples were preserved for analysis by 4 methods: 1) liquid nitrogen killed freeze-dried (NFD); 2) liquid nitrogen killed oven-dried (NOD); 3) oven-dried (OD) and 4) ambient air-dried (AD). The samples showed significant decreases in TNSC between the NFD and NOD, NOD and OD and OD and AD methods; a significant decrease in TESS with the NOD and OD methods and a further significant decrease in TESS with the AD method. A significant increase in ASC was noted with the AD method. Gas liquid chromatographic analysis of the IESS revealed a significant decrease in D-fructose and D-galactose with the AD method, a significant decrease in α-D and β-D glucose with the OD method and an additional decrease in both sugars with the AD method. Sucrose was undetectable with the NOD method, and was significantly decreased with the OD and AD methods. TNSC, TESS and ASC all decreased significantly with leaf maturation and expansion. Time of day of sampling showed no significant differences in any carbohydrate fraction.
Effect of Daminozide and Ethephon on Yield and Quality of Erect Blackberries1
Authors: Morris J. R. , Cawthon D. L. , Nelson G. S. , Cooper P. E.
Published: August 2022

Succinic acid-2,2-dimethylhydrazide (daminozide) applied to ‘Raven’ blackberries at 4000 ppm and to ‘Raven’ and ‘Brazos’ at 2000 ppm between full bloom and first color development and at 2000 ppm in a multiple application applied at full bloom, 2 weeks, and 3 weeks after full bloom resulted in reduced berry size and yield with no beneficial effects on fruit quality. (2-Chloroethyl) phosphonic acid (ethephon) applied to the same cultivare at 1000 ppm 4 days prior to the first harvest increased the amount of fruit mechanically harvested on the first harvest. Ethephon treatment improved color but resulted in mechanically harvested fruit having lower soluble solids and acidity.
The Role of Ancymidol in Clerodendrum Flower Initiation and Development1
Authors: Koranski David S. , Struckmeyer B. Esther , Beck G. E.
Published: August 2022

Clerodendrum thomsoniae Balf. plants untreated and treated with a 0.3 mg drench of ancymidol (a-cyclopropyl-a-(4-methoxyphenyl)-5-pyrimidmemethanol) flowered under a 12 hr photoperiod and were mostly vegetative under a 15 hr photoperiod. Initiation of flower parts was 8 days earlier in ancymidol treated than untreated plants. Although ancymidol hastened the initiation of flower parts, untreated plants flowered at nearly the same time as treated ones. The shoot apex remained vegetative and axillary buds flowered in treated and some untreated plants. In untreated plants, flower induction in the axillaries was apparent at 12 days and only sepal and petal primorida were present at 16 days after the initiation of the experiment when the plants were 9 cm tall. In treated plants, induction was apparent 4 days after treatment; flower development was accelerated; and at 16 days all flower parts were differentiating.
Effect of pH on Foliar Absorption of Rubidium Compounds by Chrysanthemum1
Authors: Reed David W. , Tukey H. B.
Published: August 2022

Foliar absorption of RbCl, RbNO3 and Rb2SO4 by Chrysanthemum morifolium Ramat. cv. Giant No. 4 Indianapolis White was greatest at pH 2, at which there was considerable leaf damage, but changed little at pH 3-10. Absorption of RbCl was greater than RbNO3 or Rb2SO4 regardless of pH. Absorption of Rb and phosphate as Rb phosphate was minimal at pH 3-6, but was greatly increased at pH 7-10. These results may be explained by the degree of drying and crystallization of the applied compounds on the leaf surface.
Vegetative Growth and Flowering of Pot Chrysanthemums in Response to Supplemental HPS Radiation and Split-night Temperatures
Authors: Hicklenton P. R. , McRae K. B.
Published: August 2022

Chrysanthemum X morifolium Ramat. cvs. Yellow Paragon and Copper Ann, when grown as pot plants, produced more flowering stem breaks and greater flower weight in crops planted in January and February (spring) than in those grown under similar greenhouse conditions in October and November (fall). Spring crops also showed longer vegetative dry weight, shorter stem breaks, and earlier flower development. Supplemental high-pressure sodium (HPS) irradiation resulted in a larger increase in flower weight and number of flowering breaks in the fall than in the spring. Flower development was hastened by HPS irradiation only in the fall. Split-night temperatures did not delay flowering and resulted in a relatively small reduction in flower weight and number of flowering breaks in the spring. Unacceptable delays and degradation of flower quality occurred with this treatment in the fall and HPS was only partly successful in restoring acceptable quality and time to harvest.