bluuebunny/crossref_metadata_2025 huggingface dataset:
Adaptability of Blueberry Species to Various Soil Types: I. Growth and Initial Fruiting
Authors: Korcak R.F.
Published: August 2022

Bulk A horizon samples of 4 soils, with or without the addition of peatmoss, and 5 blueberry crosses were used in a study of the adaptability of blueberries to upland soil conditions under 3 fertilization regimes and trickle irrigation in outdoor pots. Blueberry progenies ranged from essentially pure highbush (Vaccinium corymbosum L.) to interspecific hybrids containing varying amounts of evergreen (V. darrowi Camp), lowbush (V. augustifolium Aiton), black highbush (V. atrococcum Heller), and rabbiteye (V. ashei Reade) blueberry germplasm. Blueberry growth, as measured by plant volume, initially was greatest on Manor clay loam, a Piedmont soil high in clay (30%), but by the 2nd growing season, growth was superior on Berryland soil. Various fertilizer sources affected small differences in growth. Generally those progenies that contained less highbush (V. corymbosum) parentage produced more vigorous growth. Depth of rooting and estimated root distribution were affected significantly by soil, but the addition of peatmoss had no consistent effect. Berryland sand and Manor loam soils, which represent extremes in clay content, both produced the deepest root systems. Fruiting and fruit characteristic data from the 2nd growing season indicated a significant effect of peatmoss on the Pope and Galestown soils, which resulted in lowered total fruit acidity. The Berryland soil produced fruit with the lowest total acidity. Blueberry plant growth over the first 2 seasons indicates that soil type can have pronounced effects on plant growth and rooting. These growth differences were due to soil characteristics other than particle size distribution, with fertilizer source having minimal effects on growth.
A Comparison of the Effects of ABA and an Antitranspirant on Chilling Injury of Coleus, Cucumbers, and Dieffenbachia
Authors: Semeniuk Peter , Moline H.E. , Abbott J.A.
Published: August 2022

Coleus blumei Benth ‘Buckley Supreme’, Cucumis sativus L. ‘Victory’, and Dieffenbachia picta Schott ‘Rudolph Roehrs’ plants were exposed to 5°C for 48 and 72 hr following pretreatment with abscisic acid (ABA) or an antitranspirant (ENVY). Foliar injury of untreated leaves occurred after 48 hr of exposure at 5°. Application of 200 mg.liter−1 ABA as a foliar spray provided protection against chilling symptoms in coleus and cucumber, but foliar application of ENVY had no protective effect. Dieffenbachia was not protected by either ABA or ENVY. Measurements of refreshed delayed light emission (RDLE) from excited chlorophyll molecules in intact leaves confirmed that ABA protected chilled cucumber chloroplasts; however, there was no difference between ABA-treated and untreated chilled dieffenbachia. Chemical names used: [S-(Z,E)]-5-(l-hydroxy-2,6,6-trimethyl-4-oxo-2-cyclohexen-l-yl)-3-methyl-2,4-pentadienoic acid [abscisic acid (ABA)].
Factors Affecting Storage and Germination of Chysalidocarpus lutescens Seeds
Authors: Broschat Timothy K. , Donselman Henry
Published: August 2022

A series of experiments evaluated the effects of seed maturity, seed cleaning, gibberellic acid (GA3) or water presoaking, temperature, and planting depth on the percentage and speed of germination of Chrysalidocarpus lutescens H. Wendl. seed. Effects of temperature, cleaning, and storage container on the viability of stored C. lutescens seed were determined in another set of experiments. Germination was rapid and consistent when yellow to fully ripe seed was exposed to temperatures between 30° and 35°C. Cleaning seed is not essential if planting is done immediately. Presoaking seeds in 1000 ppm GA3 for 48 hr slightly accelerated germination speed, but caused excessive elongation of the resulting seedlings and was therefore not recommended. The best method for long-term storage of C. lutescens seed was to clean yellow to fully ripe seed, air-dry at 80% to 90% RH, treat with a seed protectant fungicide, and store at 23° in tightly sealed polyethylene containers. Optimum planting depth was dependent on the drying potential of the germination site.
Effect of Growth Retardants on Root Formation and Polyamine Content in Apple Seedlings
Authors: Wang S.Y. , Faust M.
Published: August 2022

Growth retardants [ancymidol (0.1-1.0 mg·liter−1), chlormequat (0.5-500 mg·liter−1), and paclobutrazol (0.1-1.0 mg·liter−1)] reduced shoot extension, promoted root initiation, and increased root weight in apple seedlings (Malus domestica Borkh ‘York Imperial’). The induction of root formation and increase in root weight were accompanied by a considerable increase in polyamine levels. Daminozide (0.1-250.0 mg·liter−1) and dikegulac (0.25-500 mg·liter−1) also inhibited apple seedling growth; however, these compounds did not promote rooting. Chemical names used: α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidinemethanol (ancymidol); 2-chloro-N,N,N-trimethylethanaminium chloride (chlormequat chloride); butanedioic acid mono(2,2-dimethylhydrazide) (daminozide); 2,3:4,6-bis-O-(l-methylethylidene)-α-L-xylo-2-hexulofuranosonic acid (dikegulac); β-(4-chlorophenyl)methyl]-α-(l,l-dimethylethyl)-lH-1,2,4-triazole-l-ethanol (paclobutrazol).
Respiratory Characterization of Germinated Tomato Seeds Stored in Gels at Low Temperatures
Authors: Beers Eric P. , Pill Wallace G.
Published: August 2022

Germinated seeds of ‘Heinz 1350 VF’ tomato (Lycopersicon esculentum Mill.) were subjected to short-term (through 5 days) low temperature (0° or 5°C) storage suspended in 2 fluid-drilling gels (Natrosol 250 HHR or Laponite 445). Following storage, a greenhouse emergence assay and respiratory characterization via double inhibitor titrations (0.4/mM KCN and 10.0/mM salicylhydroxamic acid) were conducted. After 3-day storage in Natrosol or moist cheesecloth, emergence was about 90% but had decreased to <60% following 3-day storage in Laponite. With 5-day storage in Natrosol, 0° drastically reduced seedling vigor relative to that at 5°. Total O2 consumption by all stored germinated seeds was less than that of unstored germinated seeds. Consumption of O2 via both the cytochrome and alternative respiratory pathways was not affected differentially by storage temperature or gel. The maximum inducible rate of oxygen consumption via the alternative pathway decreased during storage in Natrosol at 0° or Laponite at 5° relative to that of unstored seeds or seeds stored in Natrosol at 5°.
Cold Temperature Tolerance of Wild Tomato Species
Authors: Wolf S. , Yakir D. , Stevens M.A. , Rudich J.
Published: August 2022

Accessions of several wild tomato species [Lycopersicon hirsutum H. and B. (LA 1363 and LA 1777), L. chilense Dun. (LA 1969 and LA 1971), and Solanum lycopersicoides Dun. (LA 1964)] were examined for cold tolerance and compared to the fast germination of L. esculentum Mill. PI 341988 and to the normal germination of ‘UC82B’. The wild accessions were collected above 3000 m and presumed to be cold-tolerant because of natural habitat. A number of characteristics, including germination, emergence, chlorophyll fluorescence, electrolyte leakage, and plastochron index were used to evaluate chilling resistance. PI 341988 germinated faster than the other genotypes at temperatures above 10°C, but germination of this accession virtually ceased below 10°. The high-altitude accessions continued to germinate, albeit at a reduced rate, below 10°. Growth rates at 12°/6° (day/night) were compared to growth at 24°/18° and were found to be greater in the high-altitude accessions than ‘UC82B’ The reduction in chlorophyll fluorescence when leaf disks were exposed to 1° was less in the high-altitude accessions than in ‘UC82B’, indicating less effect of this temperature on photosynthesis in the wild species. Electrolyte leakage was greater in ‘UC82B’ and LA1777 (L. hirsutum) than high-altitude accessions of L. chilense and S. lycopersicoides, but evidence is presented that this method is not reliable in screening for cold tolerance. Crosses were made between ‘UC82B’ and the wild species, and segregating populations were screened using the methods mentioned above. In each population, there were plants that showed cold resistance similar to the wild parent, suggesting the possibility of developing cold-tolerant cultivars.
Pollen Yield from Olive Tree cvs. Manzanillo and Swan Hill in Closed Urban Environments
Authors: O’Rourke Mary Kay , Buchmann Stephen L.
Published: August 2022

Airborne pollen concentrations (grains/m3) within and near trees of 2 cultivars of Olea europaea L. were studied during the 30-day pollination period at 2 urban sites in Tucson, Ariz. ‘Manzanillo’, the dominant horticultural cultivar, was compared to the fruitless ‘Swan Hill’. Air sampling using a Burkard trap was undertaken from 2 Apr. until 1 May 1985; during this period, 95% of the 1985 Olea pollen was airborne. Peak atmospheric Olea pollen concentrations at both sites occurred on 14 Apr. 1985. Pollen concentrations around the ‘Manzanillo’ site ranged from 7 grains/m3 to 6196 grains/m3 per day. At the ‘Swan Hill’ site, daily totals were an order of magnitude less, from 5 to 309 grains/m3 per day. Hourly pollen concentrations for the ‘Manzanillo’ site on the peak day varied from 1000 to 18,133 grains/m3 per hr. Hourly values at the ‘Swan Hill’ site on the peak day varied from 7 to 896 grains/m3 per hr. Both sites exhibited rapidly increasing pollen concentrations at sunrise with a sharp increase for the ‘Manzanillo’ site between 1100 to 1300 hr. Both cultivars produced about 85,000 pollen grains per anther. An unknown anatomical or physiological factor in ‘Swan Hill’ inhibits stomial rupture, resulting in 85% inhibition of anther dehiscence and pollen-shedding.
Relationship of Harvest Date, Storage Conditions, and Fruit Characteristics to Bruise Susceptibility of Apple
Authors: Klein Joshua D.
Published: August 2022

Susceptibility of apples (Malus domestica Borkh. ‘Gala’ and ‘Granny Smith’) to impact damage increased from early to late harvest time and decreased during storage at 1°C. Impact damage was quantified as bruise depth, diameter, volume, or weight. Bruise weight calculated as a percentage of fruit weight was the least variable measurement of bruising that was also proportional to height to impact of the fruit. Although a range of 22 New Zealand-grown apple cultivars differed in susceptibility to bruising, the variation was not correlated with fruit density, fruit firmness, or polyphenol content and polyphenoloxidase (PPO) activity in epidermal and cortical fruit tissues.
Effects of Seed Coating and Osmotic Priming on the Germination of Lettuce Seeds
Authors: Valdes Veronica M. , Bradford Kent J.
Published: August 2022

Lettuce (Lactuca sativa L. ‘Empire’) seeds (achenes) were primed in aerated solutions of polyethylene glycol 8000 (−1.56 MPa) for 24 hr at 18°C and dried to 6% water content. Control (untreated) and primed seeds then were commercially coated in a clay-based material (Royal Sluis Splitkote). Priming prevented the occurrence of thermodormancy in seeds imbibed at temperatures between 32° and 37° and accelerated the rate of germination at all temperatures tested. Coating delayed germination slightly and reduced the maximum germination temperature of control seeds. Primed seeds exhibited thermodormancy when tested immediately after coating, but they soon regained their capacity for high-temperature germination. When tested after 5 months of storage at 5°, primed seeds germinated at temperatures up to 37° regardless of coating. Osmotically primed seeds retained the capacity for germination at high temperature after seed coating and storage, providing an effective means of improving stand establishment of direct-seeded lettuce in hot weather.
Inheritance of Ripening Uniformity and Relationship to Crop Load in Blueberry Progenies
Authors: Luby J.J. , Finn C.E.
Published: August 2022

The intervals, in days, between 10%, 50%, and 90% ripened fruit, as well as crop load, were estimated over 2 years in progenies from a partial diallel cross among 17 blueberry (Vaccinium corymbosum L., V. angustifolium Ait., and V. corymbosum × V. angustifolium hybrids) parents. General combining ability (GCA) mean squares were highly significant for all ripening intervals and for crop load, while specific combining ability mean squares were nonsignificant, indicating a large proportion of additive genetic variance. Narrow-sense heritability estimates were about 0.50 for the three ripening intervals (10–50%, 50–90%, and 10–90%). Several parents had large positive GCA effects, indicating their contribution to a long ripening interval. Most progenies with large crop loads required >15 days between 10% and 90% ripened fruit. Despite the consistently positive relationship between ripening interval length and crop load, variation among families and the potential for within-family segregation suggest the possibility of obtaining genotypes with high yield potential and improved uniform ripening.
Nitrogen Recovery in Single- and Multiple-harvested Direct-seeded Broccoli Trials
Authors: Kowalenko C.G. , Hall J.W.
Published: August 2022

Broccoli (Brassica olerica L. var. italica) and corn (Zea mays L.) N-treated adjacent plots had essentially the same initial Ν content. Extractable inorganic Ν to a depth of 60 cm (N at 28 to 48 kg·ha-1) was considerably less than the Ν taken up into the total above-ground parts of the crop (N at 118 to 157 kg·ha-1); thus, both crops depended on mineralization of soil Ν for their growth. Although broccoli and corn had the same total demand for Ν as shown by total uptake, only broccoli responded to Ν application. Since corn required Ν over a longer period of time (116 days) than broccoli (90 days), the net mineralization rate of soil Ν [0.8 to 1.0 kg·ha-1 (per day)] matched approximately the average Ν uptake rate over the whole season [1.1 to 1.2 kg·ha-1 (per day)] in the corn trial. Net Ν mineralization rate [-0.1 to 1.4 kg·ha-1 (per day)] tended to be less than the average Ν uptake rate by broccoli (1.3 to 3.1 kg·ha-1 (per day)], resulting in the response to Ν applied. Slightly more downward movement of inorganic Ν occurred in the 1982 than in the 1979 broccoli trial. This coincided with slightly higher precipitation in 1982 particularly late in the growing season. By using path coefficient analyses, it was found that several plant variables were consistently correlated with horticultural yield, but the nature of the relationship was not consistent from year to year, suggesting that slightly different mechanisms contributed to the yield effect each year but that the net result was similar.
The Effect of Raised Beds, Population Densities, and Planting Date on the Incidence of Bacterial Soft Rot in Chinese Cabbage
Authors: Fritz V.A. , Honma S.
Published: August 2022

Raised bed culture and different population densities were studied to determine their effect on bacterial soft rot (Erwinia carotovora ssp. carotovora) during summer production of Chinese cabbage (Brassica campestris L. Group pekinensis). Seeds were sown on different dates to determine the relationship between head formation and the occurrence of soft rot. Tropical (heat-tolerant) cultivars were evaluated for summer production potential in raised-bed and flat-culture systems. Raised beds were, in some instances, beneficial in reducing the incidence and progression of soft rot. Phyllosphere air temperatures on raised beds were slightly lower than on flat culture; however, the effect on reducing soft rot incidence is unclear. Plants grown at 30-cm within-row spacing produced fewer marketable heads than plants at 46, 61, or 76 cm. Plants from seed sown after mid June had a significantly higher incidence of soft rot when compared to earlier planting dates.
Early Season Yield Responses of Selected Strawberry Cultivars to Photoperiod and Chilling in a Florida Winter Production System
Authors: Durner Edward F. , Poling E. Barclay , Albregts Earl A.
Published: August 2022

‘Douglas’, ‘Tufts’, and ‘Pajaro’ strawberry (Fragaria × ananassa Duch.) plants were sampled for 3 consecutive years (1982–1984), and ‘Chandler’ plants were sampled for one year (1984) from September through October from a North Carolina nursery. Plants were subjected to short days (12-hr photoperiod) at day/night temperatures of 15.5°/4.4°C in 1982–1983 and to short days (9-hr photoperiod) and long days (9-hr photoperiod with a 3-hr night interruption) with or without chilling [15.5°/4.4° (day/night) or 22.0718.0° (day/night), respectively] in 1984 for 0, 1, 6, or 12 days in the NCSU phytotron. After treatment, plants were shipped to Florida for planting in the winter planting system for evaluation of early season yield (1 Dec. -15 Jan.). Optimum digging dates for all cultivars were observed to be a photoperiod response. Chilling enhanced early yield for ‘Douglas’ and ‘Pajaro’ when plants were dug prior to or at the optimum date. Plants dug later than the optimum date had much lower yields, even with substantial chilling. In ‘Chandler’, slight chilling (<125 hr from 1 Sept. until digging date) suppressed early yield, while increased chilling (>125 hr) enhanced early yield when plants were dug at or prior to the optimum date. Chilling decreased early yield in ‘Tufts’ regardless of digging date. Significant yield increases were only obtained with chilling much greater than that which naturally occurs in North Carolina.
Screening of Peach and Other Prunus Species for Resistance to Ring Nematode in the Greenhouse
Authors: Okie W.R. , Nyczepir A.P. , Reilly C.C.
Published: August 2022

Seedlings or rooted cuttings of 35 lines of peach [Prunus persica (L.) Batsch] and other Prunus spp. were screened for resistance or tolerance to the ring nematode Criconemella xenoplax (Raski) Luc & Raski (Cx). Host reaction to Cx was evaluated by comparing root and shoot growth of infested plants with that of uninfested checks. Reaction of Cx to the host was reflected in nematode density per gram root dry weight (NPGR). Effects of Cx on root growth were not always correlated with increases in Cx per 100 cm3 of soil or in NPGR. Prunus japonica Thunb. and P. tomentosa Thunb. showed no Cx-related growth reduction and had lower Cx densities than most other lines. ‘Lovell’ peach had a smaller root system and fewer Cx per pot than ‘Nemaguard’ peach, but differences in NPGR were not significant. With high inoculum levels, significant differences in NPGR between lines, and in growth parameters within lines, could be detected after 6 months.
Growth of Citrus Rootstock (Carrizo Citrange) Seedlings During and After Long-term CO2 Enrichment
Authors: Koch Karen E. , Allen L. Hartwell , Jones Pierce , Avigne Wayne T.
Published: August 2022

Carrizo citrange seedlings [Citrus sinensis (L.) Osbeck × Poncirus trifoliata (L.) Raf.] were grown in field enclosures for 17 weeks during 1984 at 330, 660, or 990 µl·liter-1 CO2 and then transferred to ambient air for 10 weeks to examine growth during and after these treatments. Immediately after the CO2 treatment period, plants grown at the highest CO2 level had accumulated about 120% more total dry matter than those at 330 µl·liter-1 CO2, compared to a mean increase of 67% at 660 µl·liter-1. Shoot length, leaf area, and leaf number were also increased 71%, 55%, and 39%, respectively, at 990 µl·liter-1 CO2 and somewhat less at 660 µl·liter-1. Percentage gains from CO2 enrichment decreased during the posttreatment period, but absolute differences were maintained or increased for at least 10 more weeks. During the treatment period, dry matter partitioning among leaves, stems, and roots did not vary with CO2 level, but root growth after transplanting and transfer to ambient air occurred at the expense of shoot growth in plants that had been grown at ambient CO2 levels. Plant growth, in terms of dry weight, shoot length, leaf area, and leaf number, was advanced 1.0 to 3.5 weeks after 17 weeks at elevated CO2 levels, and fresh weight per centimeter of stem length was about 1 month ahead. This last parameter can be used as an approximate indicator of readiness for scion budding, suggesting that CO2 enrichment could represent a considerable value to the citrus nursery industry. Data are also consistent with the hypothesis that a greater response to elevated CO2 is likely to occur where a high sink demand and/or low levels of leaf starch are maintained. Both such demand and low leaf starch occur in citrus seedlings, which have a pronounced juvenility period and capacity for continuous flush-type growth.
Hydroponic Tomato Yield Affected by Chlormequat Chloride, Seeding Time, and Transplant Maturity
Authors: Adler Paul R. , Wilcox Gerald E.
Published: August 2022

The addition of chlormequat chloride to tomato (Lycopersicon esculentum Mill.) transplants decreased fruit yield, number, and size. Flowering was accelerated both by chlormequat chloride and by transplanting at a more advanced stage of development. By transplanting a more mature plant without chlormequat chloride, yield was increased over the first 3 weeks of harvest. Although it is difficult to manage a “leggy” transplant, typical of flowering hydroponic tomato transplants grown under low light levels and close spacing, increased yield was sufficient to justify this management practice. Chemical name used: 2-chloro-N,N,N-trimethylethanaminium chloride (chlormequat chloride).
Effect of Fertilizer, Paclobutrazol, and Chlormequat on Strawberry
Authors: McArthur D.A.J. , Eaton G.W.
Published: August 2022

In a greenhouse study with strawberry (Fragaria × ananassa Duchesne), foliar sprays of paclobutrazol (PP333) at 10, 46, 215, or 1000 ppm and chlormequat chloride (CCC) at 215 or 1000 ppm decreased runnering, but PP333 was most effective. PP333 inhibited runnering more for ‘Totem’ than ‘Shuksan’, with the reverse true for CCC. Biweekly fertilization with 20N-4.3P-8.3K at 180 mg/pot increased leaf area and runnering relative to 45 mg/pot. PP333 at equal rates produced larger decreases in leaf area than CCC. Both high fertilizer and PP333 in a rate-dependent manner delayed leaf senescence and berry ripening. CCC increased yield in ‘Shuksan’ only, and while berry fresh weight was increased by PP333, no increase in yield occurred, as it was offset with a decreased number of berries that ripened over the period of our study. PP333 decreased pollen germination. Soil residues of PP333 were evident 11 weeks after application. Chemical names used: β-[(4-chlorophenyl)methyl]-α-(1,1-dimethylethyl)-1H- - 1,2,4-triazole-1-ethanol (paclobutrazol); 2-chloro-N, N, N-trimethylethanaminium chloride (chlormequat chloride).
Growth of Zoysiagrass from Vegetative Plugs in Response to Fertilizers
Authors: Fry J.D. , Dernoeden P.H.
Published: August 2022

Little research has been conducted to determine the influence of fertilizer sources and rates on zoysiagrass (Zoysia japonica Steud.) establishment. Our objectives were to determine the influence of slow-release N sources, water-soluble N from urea, and N, P, and K combinations on rate of zoysiagrass establishment. Prior to field planting of zoysiagrass plugs, N rates of 98, 196, and 392 kg·ha-1 from ureaformaldehyde (UF, 38N-0P-0K), isobutylidine diurea (IBDU, 31N-0P-0K, and a composted sewage sludge (1.0N-0.9P-0.2K) were incorporated into a soil with existing high P (193 kg·ha-1) and intermediate K levels (86 kg·ha-1). In a separate study nitrogen from urea (46N-0P-0K, 195 kg·ha-1), P from treble superphosphate (0N-19P-0K, 126 kg·ha-1) and K from muriate of potash (0N-0P-32K, 103 kg·ha-1) also were incorporated before planting. Five months after planting, none of the slow-release N sources or N-P-K combinations had enhanced coverage of the zoysiagrass. No additional fertilizer was applied in the 2nd year. Although statistically significant differences were found among treatments by the end of the 2nd growing season, the actual increases in zoysiagrass coverage provided by the fertilizers were no greater than 5% more than the unfertilized zoysiagrass. In a 3rd study, N (49 kg·ha-1) from urea, applied as a topdressing either once, four, or seven times annually, resulted in a negative linear [coverage = 63.8 − 0.02 (kg N/ha per year), r2 = 0.57] response in zoysiagrass coverage the initial year, but not in the 2nd year. Nitrogen from urea (49 kg·ha-1) applied bimonthly or monthly the 2nd year had a greater beneficial effect on zoysiagrass growth than topdressing or preplant incorporation of N the initial year.
Effects of Temperature on the Deep Supercooling Characteristics of Dormant and Deacclimating Sweet Cherry Flower Buds
Authors: Andrews Preston K. , Proebsting Edward L.
Published: August 2022

Seasonal changes in the temperature of the median low-temperature exotherm (LTE50) of dormant sweet cherry (Prunus avium L. cv. Bing) flower buds were significantly correlated with the preceding minimum air temperature in the orchard and the water content of the flower primordia. When buds were exposed to temperatures just below the high temperature exotherms, water migrated from the primordia to the bud scales. Under these conditions, the LTE50 decreased almost 5°C during the first day, but only 1°/day thereafter. The minimum LTE50 was near −32° after the buds were frozen for 10 days. Thawing buds at 0° or above increased the LTE50 about 1°/hr, to −20° to −21°. The LTE50 did not increase above these temperatures until the buds were exposed to 20° for 1-2 days following the completion of rest. During deacclimation, both the LTE50 and temperature range of the low temperature exotherms (LTEs) increased. These changes were accompanied by fluctuations in the capacity of the flower buds to exhibit deep supercooling, expressed as the fraction of an LTE produced per flower primordium (LTE/primordium). Even on days when the LTE/primordium was low, the temperature required to injure 50% of the flower primordia was similar to the LTE50.
Flurprimidol: Plant Response, Translocation, and Metabolism
Authors: Sterrett J. P. , Tworkoski T. J.
Published: August 2022

Flurprimidol was injected into several species to evaluate effects on growth. Height growth was inhibited 85% in bean (Phaseolus vulgaris L. ‘Black Valentine’) and 90% in California privet (Ligustrium ovalifolium Hassk.) by the lowest flurprimidol doses (125 and 625 μg/plant, respectively). Shoot growth was further suppressed as doses increased. Gibberellic acid reversed the inhibitory effect of flurprimidol on privet. In June, height growth of field-grown yellow-poplar (Liriodendron tulipifera L.) and American sycamore (Platanus occidentalis L.) was uniformly reduced 35% by all flurprimidol doses. By late July, height growth increment decreased linearly as flurprimidol increased from 5 to 40 mg/tree. Thirty-five days after injection of 2.5 mg 14C-labeled flurprimidol in 1-year-old apple (Malus domestica Borkh.), 10% had moved into the new shoots, 1.5% into the scion phloem, and 80% remained near the injection site. A high percentage of the 14C activity was unmetabolized flurprimidol; 95% of the 14C activity in the xylem, 86% in the phloem, and 75% in the shoot. Although it is not highly mobile, flurprimidol effectively inhibits shoot growth, apparently inhibiting gibberellin synthesis. Chemical names used: α-(1-methylethyl)-α-[4-(trifluoro-methoxy)phenyl]-5-pyrimidinemethanol (flurprimidol).
Effects of Physical and Environmental Factors on the Release Kinetics of Ethylene from (2-Chloroethyl)phosphonic Acid and (2-Chloroethyl)-methylbis(phenylmethoxy)silane
Authors: Beaudry R. M. , Kays S. J.
Published: August 2022

Several environmental and physical factors affect the kinetics of ethylene release from (2-chloroethyDphosphonic acid and (2-chloroethyl)methylbis(phenylmethoxy)silane. Target surface chemistry exerted a strong influence on the evolution of ethylene from both compounds. Ethylene release from (2-chloroethyl)methylbis(phenylmethoxy) silane was slowed by glass and hydrophobic substances such as wax, surfactants in the spray solution, and high concentrations of the parent molecule, but not by epicuticular waxes on leaves. Ethylene evolution from (2-chloroethyl)phosphonic acid was inhibited by glass and high levels of epicuticular waxes. The rate of ethylene release from both compounds was positively correlated with temperature; however, ethylene released from (2-chloroethyl)methylbis(phenylmethoxy)silane was much less affected by temperature increases. Increases in light intensity promoted the initial release of ethylene from (2-chloroethyl)methylbis(phenylmethoxy)silane, but decreased long-term yield. Light intensity had no effect on the breakdown of (2-chloroethyl)phosphonic acid.
Genetic Diversity of North American Strawberry Cultivars
Authors: Sjulin Thomas M. , Dale Adam
Published: August 2022

Pedigrees of 134 North American strawberry (Fragaria × ananassa Duch.) cultivars introduced since 1960 were used to calculate 1) the genetic contribution of founding clones to these cultivars; 2) genetic relatedness among these cultivars; and 3) inbreeding coefficients of these cultivars. Fifty-three founding clones accounted for the pedigrees of these cultivars, with a mean genetic contribution ranging from <0.1% to 11%. Cultivars were clustered according to the genetic contribution into groups strongly related to geographic region of origin. Cultivars developed in California plus those derived in large part from California germplasm were a distinct cluster. The remaining cultivars divided strongly into two geographical divisions, with cultivars of a western or northern origin primarily in the first division, and cultivars of a southern or eastern origin primarily in the 2nd division. Cluster groups within each division also were related to the region of origin of cultivars. Cultivars also were clustered on the basis of Wright’s coefficient of relationship, a measure of genetic relatedness. Cluster groups from this analysis were strongly related to region of origin of cultivars, and were similar in content to groups based on genetic contributions. Inbreeding coefficients ranged from 0.0 to 0.875, but were <0.5 for all cultivars developed from cross-fertilization. Inbreeding coefficients were related partly to region of origin of the cultivars, but this relationship was probably an indirect result of unequal numbers of generations of controlled hybridization from common ancestors. For example, cultivars developed in California, which resulted from more generations of hybridization, generally had higher inbreeding coefficients. Strategies are suggested for maintaining and increasing genetic diversity of North American breeding populations.
Root Morphological Characteristics of Field-grown Cowpeas
Authors: Kahn Brian A. , Stoffella Peter J.
Published: August 2022

Field experiments were conducted in 1984 at Bixby, Okla. and Fort Pierce, Fla. to examine root morphological components of cowpeas (Vigna unguiculata Walp.). Six or seven cultivars were sampled individually at anthesis and again at harvest (when most pods were dry) to assess differences in root morphology. Root masses were partitioned into adventitious, basal, lateral, and tap components. On average, adventitious roots accounted for <10% of the total root mass of plants at both locations. Basal roots averaged about 21% and 37% of the total root mass in Oklahoma and Florida, respectively. The majority of the root mass occurred in the taproot and its associated laterals at both locations. Lateral roots averaged about 24% of the total root mass at both locations. Taproots averaged about 31% of the total root mass in Florida but accounted for 49% at harvest in Oklahoma. Cultivars differed in root morphological characteristics and in total root dry weight at both growth stages in both locations. Seed yield was not correlated strongly with any of the root-related variables.
Effects of Water Stress on Pollen of Phaseolus vulgaris L.
Authors: Shen Xiu Ying , Webster Barbara D.
Published: August 2022

In the article “Effects of Water Stress on Pollen of Phaseolus vulgaris L.”, by Xiu Ying Shen and Barbara D. Webster (J. Amer. Soc. Hort. Sci. 111:807–810, September 1986), on p. 808, the last sentence before Results and Discussion should read: “The term microspore refers to the uninucleate structures released from tetrads after meiosis. The term pollen grain refers to the above structures after mitosis of the microspore nucleus and formation of the vegetative (tube) and generative cells.”
Calcium and Ethephon Effects on Tabasco Pepper Leaf and Fruit Retention and Fruit Color Development
Authors: Conrad R.S. , Sundstrom F.J.
Published: August 2022

All possible combinations of ethephon at 0, 5000, 10,000, and 15,000 ppm, and calcium as Ca(OH)2 at concentrations of 0, 0.01, 0.1, and 1 m were applied to Tabasco pepper (Capsicum frutescens L.). In the greenhouse, as ethephon rates increased, leaf retention percentages decreased. Over all ethephon rates, as Ca(OH)2 concentration increased, Tabasco leaf retention percentages increased. Ethephon-induced fruit abscission was greatest in less-mature fruit. Overall fruit retention percentages were greatest when ethephon was applied with either 0.1 or 1 m Ca(OH)2. In the field, when ethephon was applied without Ca(OH)2, leaf and fruit abscission was so great that data could not be recorded. When ethephon was applied with 0.1 m Ca(OH)2, percentages of orange and red fruit on the plant increased with an increase in ethephon rate. Chemical name used: (2-choloroethyI)phosphonic acid (ethephon).
Osmotic Priming of Tomato Seeds: Effects on Germination, Field Emergence, Seedling Growth, and Fruit Yield
Authors: Alvarado Ana Daniela , Bradford Kent J. , Hewitt John D.
Published: August 2022

Osmotic priming of seed was evaluated as a means of improving stand establishment, early seedling growth, and yield of processing tomatoes (Lycopersicon esculentum Mill. cvs. UC204 and 6203). Seeds were primed in aerated solutions of 3% KNO3 (w/v) or of polyethylene glycol 8000 (PEG) of equivalent osmotic potential (-1.25 MPa; 314 g-kg−1 of water) at 20°C for 7 days, rinsed, and dried in forced air at 30°. Under laboratory conditions, seeds primed in either osmoticum germinated more rapidly than untreated seeds at 20° and 30°. At 10°, the PEG treatment was of little benefit for either variety, while the KN03 treatment still reduced the time to 50% germination to 60% to 80% of the control value. Priming did not affect the final germination percentage. Seedling emergence in the field was evaluated in March and April planting dates. In both trials, seedlings from primed seeds emerged earlier and more uniformly than seedlings from untreated seeds. Seedlings from primed seeds maintained greater mean plant dry weights, leaf areas, and ground cover percentages than untreated seedlings throughout the preflowering period. This advantage was due entirely to early emergence rather than to an increased relative growth rate. The early growth advantage from seed priming did not improve earliness of maturity, total yield, or soluble solids content of fruit.
Phosphorus Requirements of Wine Grapes: Extractable Phosphate of Leaves Indicates Phosphorus Status
Authors: Skinner P.W. , Matthews M.A. , Carlson R.M.
Published: August 2022

Although premium wine grapes (Vitis vinifera L.) are planted in soils of low P availability, there is little knowledge of P requirements and of the appropriate methods of P analysis in grapevines. Therefore, acetic acid extractable P was investigated as a method for determining grapevine P status. Analysis of absorption spectra established that absorbance peaks at 710 or 882 nm of the phosphomolybdate complex formed in acetic acid extracts of grapevine tissues can be used for analysis of P status. Acetic acid-extractable P was independent of sample size and extraction time and was linearly related (r2 = 0.96) to total P in four premium wine grape varieties. Lamina indicated whole plant P status better than petioles, since extractable P accumulated more in lamina than in petioles. Total and extractable P of basal lamina decreased significantly after anthesis, which diminished the differences between P-sufficient and P-deficient vines. Therefore, the best time to assess vine P status using leaves is at anthesis. When P fertilizer was applied, lamina-extractable P was positively correlated with berry weight, yield, and pruning weight in Chenin blanc vines growing under P-deficient conditions. The results indicate that acetic acid extractable P in lamina sampled at anthesis is a sensitive measure of grapevine P status.
High Temperature Effects on Growth and Floral Development of Chrysanthemum
Authors: Whealy C.A. , Nell T.A. , Barrett J.E. , Larson R.A.
Published: August 2022

Pinched plants of Chrysanthemum morifolium Ramat. ‘Orange Bowl’ and ‘Surf’ grown in a chamber maintained at 22° day/18°C night were transferred to 30° day/26° night at the beginning of week 1, 3, 5, or 7 after start of photoinduction period (15-hr nyctoperiod). Plants remained at high temperatures for 2, 4, 6, 8, or 10 weeks and then were returned to the 22°/18° chamber. Exposure to high temperatures during the first 4 weeks of short days increased the number of nodes, leaf area, stem length, and dry weight of leaves and stems. Rate of floret initiation and perianth differentiation decreased when exposed to high temperatures during the first 4 weeks of short days in ‘Orange Bowl’ but not in ‘Surf’. ‘Orange Bowl’ exposed to high temperatures for 10 weeks from the start of short days flowered 12 days later than plants grown at lower temperatures and formed bracteate buds. Flowering of ‘Orange Bowl’ grown at 22718° during the first 4 weeks of short days, then transferred to high temperatures, was not substantially delayed and flowers developed normally. Flowering was delayed 3 days when ‘Surf’ was exposed to high temperatures for 8 weeks from the start of short days. Exposure to high temperatures did not cause bracteate bud formation in ‘Surf’. With both cultivars, increasing the duration of high temperature exposure increased the time to flowering.
Hydathode Anatomy and Adaxial Water Loss in Micropropagated ‘Silvan’ Blackberry
Authors: Donnelly D.J. , Skelton F.E. , Nelles J.E.
Published: August 2022

Foliar anatomical comparisons were made between in vitro-grown plantlets and greenhouse-grown plants of ‘Silvan’ blackberry (Rubus sp.) using scanning and light microscopy. Each apex and marginal serration of in vitro- and greenhouse-grown leaves had a terminal hydathode region composed of a scattered, primarily adaxial, group of sunken water pores. Water pores and stomata of plantlet leaves were open, while greenhouse-grown plant leaves had closed water pores and stomata or comparatively small apertures. Internally, the hydathodes of both cultured plantlets and greenhouse-grown plants were delimited by a bundle sheath that flanked the vascular tissues and extended to the epidermis. Between the vascular tissues and the epidermis were loosely arranged epithem cells. The hydathodes of plantlet leaves were simpler than those of greenhouse-grown plants, with fewer water pores and reduced epithem. Water loss from detached leaves of plantlets occurred through both leaf surfaces, although more water was lost from the abaxial surface. In contrast, foliar water loss from severed leaf blades of greenhouse-grown plants was primarily abaxial.
Weight Loss in Sweet Potatoes During Curing and Storage: Contribution of Transpiration and Respiration
Authors: Picha David H.
Published: August 2022

In the article “Weight Loss in Sweet Potatoes During Curing and Storage: Contribution of Transpiration and Respiration”, by David H. Picha (J. Amer. Soc. Hort. Sci. 111:889–892, November 1986), Figs. 1 and 2 were reversed. The correct figures and captions are printed below.
Stomatal Resistance and Water Potential of Calceolaria Grown Under Two Different Heating Systems
Authors: Panter Karen Kampman , Hanan Joe J.
Published: August 2022

Calceolaria × herbeohybrida cv. Multiflora Mix was sown on five dates in the 1984 and 1985 winter seasons and grown in greenhouses heated with forced hot-air or infrared heating systems. Neither stomatal resistance nor water potential was significantly different between plants grown in the two heating systems.
Development of Ornamental Crops Under Split Night Temperatures
Authors: Shanks James B.
Published: August 2022

Trials over five consecutive winter seasons with ornamental crops growing in the greenhouse at split night and constant night temperatures (SNTs and CNTs) showed that a 5-hr period of 17°C minimum temperature during the dark period accelerated development over a CNT minimum of 12° to 13°. Maintaining 17° from 1700-2100 HR accelerated development over a 9° to 12° minimum CNT more than later periods of a 17° minimum with Euphorbia, Hydrangea, Kalanchoe, and Lilium. Continuation of 17° until 0100 or 0200 hr before a 9° to 12° minimum CNT was adequate for flower formation in Chrysanthemum. SNTs improved the bract : stem size ratio in Euphorbia and cyme size in Hydrangea relative to a 17° minimum CNT. Begonia × hiemalis, Begonia semperflorens, Brassaia, Coleus, Fuchsia, and Impatiens showed favorable growth responses or the potential for energy savings through the use of SNTs.
Firmness of Tomato Fruit Tissues According to Cultivar and Ripeness
Authors: Hall C.B.
Published: August 2022

The firmness of tissues of a transverse equatorial slice of fruits of ‘Flora-Dade’, ‘Walter’, ‘MH-1’, and ‘Homestead 24’ tomatoes (Lycopersicon esculentum Mill.) was determined at different stages of ripeness by use of an Instron Food Testing System. The outer, radial, and inner pericarp tissues of ‘Flora-Dade’ and ‘MH-1’ were firmer than those of ‘Walter’ when ripened 6, 8, or 10 days at 20°C after incipient color formation. ‘Walter’ tissues were intermediate in firmness between ‘MH-1’ and ‘Flora-Dade’ at the mature green stage, but had softened much more than either at the incipient color stage. Most of the softening of the tissues of the three cultivars had occurred by 4 days after incipient color. The placental tissue of ‘Homestead 24’ fruit was much firmer than that of ‘Walter’ and ‘Flora-Dade’ over a period of 7 to 19 days after incipient color stage, although the outer pericarp tissue was much softer than that of the latter two.
Isozyme Variation Among California Almond Cultivars: I. Inheritance
Authors: Hauagge R. , Kester D.E. , Asay R.A.
Published: August 2022

Horizontal starch gel electrophoresis was used to study the inheritance of some isozyme variants in almond seedling and almond-peach hybrid populations. In almond, aspartate aminotransferase (AAT), glucose phosphate isomerase (GPI), and leucine aminopeptidase (LAP) have two zones of activity, one of which is monomorphic in each case. The polymorphic loci, AAT-1 and GPI-2 each had two alleles and behaved as dimers in the electrophoretic analysis. LAP-1 behaved like a monomeric enzyme with two functional alleles, in addition to an hypothesized null allele. PGM behaved like a monomeric enzyme specified by two polymorphic loci, Pgm-1 and Pgm-2. Pgm-1 displayed two alleles, while Pgm-2 apparently had three, although one gave aberrant segregation ratios. Acid phosphatase (AcP), glyceraldehyde-phosphatase dehydrogenase (GAP), and 6-phosphogluconate dehydrogenase (6-PGD) isozymes showed two zones of activity in the almond cultivars assayed and produced no allelic variation. In peach, AAT-1 and GPI-2 had the same Rf values as almond and segregated in typical Mendelian ratios in F1 and F2 almond × peach populations. The alleles for LAP-1 and LAP-2 not only had different mobilities in almond and peach but were tightly linked to each other within each species. Thus, four-banded patterns were produced in the F1, which segregated in the F2 to peach, almond, and hybrid phenotypes with a reduced number of recombinants.
Comparison of Two Onion Irrigation Scheduling Programs
Authors: Kruse E. Gordon , Ells James E. , McSay Ann E.
Published: August 2022

Two onion (Allium cepa L.) irrigation scheduling procedures were compared in field studies over a 3-year period. The McSay–Moore model uses volume of distilled water evaporated from calibrated Bellani atmometers as a basis for predicting irrigation. This model tells when to irrigate, but not how much to apply. The ARS/USDA model uses energy and aerodynamic equations to make estimates of evaporation rates from meteorological data. This model not only predicts when to irrigate, but also the amount to apply. Given the conditions for these experiments, onion yields and water use efficiencies were greater with the ARS/USDA than with the McSay–Moore model.
Hydathode Structure of Micropropagated Plantlets and Greenhouse-grown ‘Totem’ Strawberry Plants
Authors: Donnelly D.J. , Skelton F.E.
Published: August 2022

Leaves of in vitro-grown plantlets and greenhouse-grown plants of ‘Totem’ strawberry (Fragaria × ananassa Duch.) were compared using scanning and light microscopy. Each apex and marginal serration of in vitro- and greenhouse-grown leaves had a terminal hydathode region. The leaf teeth were composed of an acuminate-mucronate tip, obscured in greenhouse-grown plants by an abaxial cluster of thick-walled unicellular trichomes, and a subterminal, adaxial group of sunken water pores. Water pores and stomata of plantlet leaves were open, whereas greenhouse-grown plant leaves had closed water pores and stomata or comparatively small apertures. Internally, the hydathodes of greenhouse-grown plants and cultured plantlets were delimited by a bundle sheath that extended below the vascular tissues, approaching the adaxial epidermis on each side of the zone of water pores. Between the epidermis and the vascular tissues were loosely arranged epithem cells. The hydathodes of plantlet leaves were smaller than greenhouse-grown plants, with fewer water pores and reduced epithem.
Use of Ancymidol Bulb Dips to Control Stem Elongation of Easter Lilies Grown in a Pine Bark Medium
Authors: Larson R.A. , Thorne C.B. , Milks R.R. , Isenberg Y.M. , Brisson L.D.
Published: August 2022

Experiments were conducted on the Easter lily cultivars (Lilium longiflorum thunb.) Ace and Nellie White over a 4-year period to compare ancymidol bulb dips to media drenches and foliar spray applications. Several bulb dip concentrations and durations were used. ‘Ace’ plants responded more than ‘Nellie White’ plants to bulb dips, primarily because of more natural vigorous growth of ‘Ace’ plants. A 1-hr dip at 33 ppm gave adequate height control, but flowering was delayed. Reliance on bulb dips to achieve optimum height control may be questionable because ancymidol must be applied before one is certain excessive height will be a problem. Chemical name used: α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidinemethanol (ancymidol).
Effects of Sequential Low-oxygen and Standard Controlled Atmosphere Storage Regimens on Apple Quality
Authors: Lidster P.D. , Lougheed E.C. , McRae K.B.
Published: August 2022

Storing ‘McIntosh’ apples (Malus domestica Borkh.) initially in 1.0% or 1.5% CO2 plus 1.0% O2 at 3°C (LO) was more effective in retarding firmness loss than initial storage in 4.5% or 5.0% CO2 plus 3.0% O2 at 3° (SCA), indicating that early exposure to LO suppressed the subsequent rate of softening in SCA. ‘McIntosh’ firmness retention, determined 1 day after storage and after 7 days at 20°, decreased with fruit maturity for all LO and SCA storage regimens, but mature fruit tended to soften more rapidly in SCA after being exposed initially to LO. Initial storage in SCA for >75 days with subsequent storage in LO (in 1984) did not result in firmer apples than those stored continuously in SCA. The initial exposure period in LO needed to induce retention of apple firmness depended on cultivar and temperature. For ‘McIntosh’, ‘Spartan’, and ‘Golden Delicious’ cultivars, respectively, maximum post-storage fruit firmness was reached after 7.5, 4.5, and 1.5 months of initial exposure to LO at 0° and after 4.5, 3.0, and 3.0 months at 3°. Poststorage evolution of CO2 and C2H4 and the severity of senescent disorders generally decreased with continuing storage in LO, but the incidence of low-O2 injury increased. Poststorage ethanol evolution increased with exposure to 1.0% O2 in ‘McIntosh’ apples stored at 0°, and ‘Spartan’ apples held at either 0° or 3°. Chemical name used: butanedioic acid mono(2,2-dimethylhydrazide) (daminozide).