Taylor & Francis
Journal of Horticultural Science
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Manipulation of flowering in cineraria. IV. Devernalization
Yeh D.M., Atherton J.G., Craigon J.
Taylor & Francis
Journal of Horticultural Science, 1997, цитирований: 2, doi.org, Abstract
SummaryEffects of post-vernalization temperatures on leaf number below the flower, and the percentage of plants flowering, were studied in cineraria cvs Cindy Blue and Cindy Dark Red. Leaf number below the flower decreased with increase in the duration of vernalization at 6°C from one to four weeks. In plants vernalized for one or two weeks, subsequent temperatures of 20 or 25°C significantly increased leaf number by ca. 4–7 below the flower when compared with 10 to 15°C. Exposure of vernalized plants to high temperatures of 27 or 30°C resulted in more leaves being initiated below the flowers in plants chilled for two weeks and completely abolished the vernalization effect in plants that had been chilled for one week. Post-vernalization temperatures had no effect on flowering in plants that had been chilled for four weeks. Ninety two to 100% of plants showed a vernalization response after treatments at 6°C for one or two weeks provided that vernalization was followed by two weeks at 10 or 15°C. A reductio...
Manipulation of flowering in cineraria. II. Juvenility
Yeh D.M., Atherton J.G.
Taylor & Francis
Journal of Horticultural Science, 1997, цитирований: 6, doi.org, Abstract
SummaryCompetence to perceive florally inductive stimuli was examined in cineraria cvs Cindy Blue and Cindy Dark Red. Juvenility was observed in imbibed, but not germinated, seeds and persisted until the initiation of a critical number of leaves which defined transition to the senisitive, competent form at 6–7 leaves initiated in cv. Cindy Blue and 7–8 leaves initiated in cv. Cindy Dark Red. During this juvenile phase, plants were incompetent to perceive either chilling at 3°C and 6°C as a vernalization stimulus or short days as a photoperiodic stimulus. After phase transition, the level of competence was not affected by plant age or size. Chilling imbibed seeds at 4°C for four weeks reduced the leaf number below the flower in both cultivars. The competent stage for vernalization during germination appeared between radicle emergence and cotyledon unfolding. The seed vernalization effect was only apparent when plants from chilled germinated seeds were grown subsequently at a non-vernalizing temperature (ca...
Manipulation of flowering in cineraria. III. Cardinal temperatures and thermal times for vernalization
Yeh D.M., Atherton J.G., Craigon J.
Taylor & Francis
Journal of Horticultural Science, 1997, цитирований: 6, doi.org, Abstract
SummaryEffects of temperatures and durations of temperature treatments on flower induction were studied in cineraria cv. Cindy Blue grown in controlled environments. The earliest flower induction, recorded as the fewest leaves below the flower, was observed as 16–17 leaves initiated in non-juvenile plants that had been chilled at 5–7°C for 3–5 weeks as compared with 30–33 in plants grown throughout at 24°C. Plants demonstrated a true quantitative vernalization response in that flowering was delayed but not prevented by higher temperatures and further leaves were initiated below the flower after chilling had ended. The rate of progress to flower induction, measured as the reciprocal of leaf number below the flower, was shown to relate linearly to temperature. This enabled the base, optimum and maximum temperatures for vernalization to be derived respectively as –0.3, 5.9 and 15.8°C, where the base temperature corresponded to the rate at which the unvernalized plants would progress to flower induction. Rate...
The nitrogen requirement of vegetables: Comparisons of yield response models and recommendation systems
Goodlass G., Rahn C., Shepherd M.A., Chalmers A.G., Seeney F.M.
Taylor & Francis
Journal of Horticultural Science, 1997, цитирований: 14, doi.org, Abstract
Data from 26 experiments covering eight vegetable species, were examined to determine the best model to describe the yield response of vegetables to nitrogen (N) fertilizer. Although no single mode...
Bud-grafting success inAcer platanoides‘Crimson King‘ related to root growth
Howard B.H., Oakley W.
Taylor & Francis
Journal of Horticultural Science, 1997, цитирований: 0, doi.org, Abstract
SummarySummer bud-grafting (budding) of the red-leaved scion ‘Crimson King’ onto Acer platanoides rootstocks is unreliable. Typically, the rootstock produces copious callus from the incision in the stem, but the scion bud-chip fails to survive and complete the union. Percentage bud-take was consistently low when rootstocks were grown and budded in 2 litre containers (e.g. 33%), moderately high, but below commercially acceptable levels, when grown in a light sandy loam soil in the field (e.g. 77%), and often very high when grown in deep sand beds (e.g. 100%). The growth of larger structural roots was in the order pot < field soil < sand beds, and confining the roots of field-grown rootstocks in porous mesh bags reduced bud-take from 79 to 13% averaged over three sites. Increasing shoot growth by growing rootstocks in a polythene house did not improve bud-take, but increasing the pot size from 2.0 to 7.5 litres did so. Extensive root growth appears to be one of a number of factors determining bud-take, whic...
Sweet cherry rootstock studies: Comparisons ofPrunus cerasusL. andPrunushybrid clones as rootstocks for Van, Merton Glory and Merpet scions
Webster A.D., Lucas A.
Taylor & Francis
Journal of Horticultural Science, 1997, цитирований: 3, doi.org, Abstract
SummarySixteen Prunus species and hybrid clones were tested as potential dwarfing rootstocks for the sweet cherry scion cvs Van, Merton Glory and/or Merpet. The trials were grown without irrigation on light loam soils at Horticulture Research International, East Mailing, UK. Although several of the rootstocks produced fully dwarfed trees, only one, a clone of P. mugus, showed good nursery budtake and tree longevity. Trees on another dwarfing rootstock, Gisela 1 (Gi.172/9), grew very poorly on this site and several of the trees died before the completion of the experiment. Trees on Gi.202/2 and MxM 39 both showed poor graft compatibility. Although not fully dwarfing, several other rootstocks tested showed great promise by inducing excellent yield precocity and productivity. Amongst the most promising rootstocks were Weiroot 10, Gi.195/4 and Gisela 6 (Gi.148/1).
Effects of humidity on the growth and flowering of cut-flower chrysanthemums (Dendranthema grandifloraTzvelev)
Hand D.W., Langton F.A., Hannah M.A., Cockshull K.E.
Taylor & Francis
Journal of Horticultural Science, 1996, цитирований: 6, doi.org, Abstract
SummaryFour discrete and continuous humidity treatments (0.1, 0.4, 0.7 and 1.1 kPa vapour pressure deficit) were applied to plants of three chrysanthemum cultivars (Snowdon, Pink Gin and Snapper) growing in daylit, controlled environment cabinets in autumn and spring experiments to determine effects on growth and flowering. There was some reduction in total leaf area and leaf dry weight in the highest humidity treatment but, overall, effects on stem and leaf growth were slight. Effects of high humidity on flowering were more marked, with estimated maximum delays of 4–5 d in flower development and reductions in flower dry weight at harvest. Visual appearance was not impaired in any of the treatments. It was concluded that the chrysanthemum is relatively insensitive to humidity within the range tested and that it is unlikely that this environmental variable is of major consequence in commercial growing during the winter period.
Salinity effects on the xylem vessels in tomato fruit among cultivars with different susceptibilities to blossom-end rot
Belda R.M., Fenlon J.S., Ho L.C.
Taylor & Francis
Journal of Horticultural Science, 1996, цитирований: 17, doi.org, Abstract
SummaryThe number and size of xylem vessels in the vascular bundles at the proximal and distal positions of both pericarp and placental tissues of tomato fruit were measured in three cultivars with different susceptibilities to blossom-end rot grown at two salinity levels. While the total number of vascular bundles in the pericarp is greater than in the placenta, the average bundle size in the distal pericarp is larger than that in the distal placenta. Salinity reduced the total bundle area in the distal tissue more in the susceptible cultivars, i.e. Calypso and Spectra than in the less susceptible cultivar, Counter. Both the number and size of xylem vessels in the bundles of proximal placenta tissue were greater than in the proximal pericarp; while the reverse was true in the distal tissue. Salinity reduced the total xylem area in the bundle of the distal tissue significantly, particularly in ‘Spectra’. Thus, the total xylem area in the distal layer was reduced more by salinity in the placenta of the sus...
The effect of temperature and photoperiod on the rate of flower initiation and the onset of dormancy in the strawberry (FragariaxananassaDuch.)
Le Mière P., Hadley P., Darby J., Battey N.H.
Taylor & Francis
Journal of Horticultural Science, 1996, цитирований: 21, doi.org, Abstract
SummaryThe effects of temperature and photoperiod on flower and inflorescence initiation during the autumn were investigated in the strawberry cv. Elsanta. The variation in starch under these environmental conditions was also recorded, to test whether this might provide a useful indicator of the onset of imposed and/or true dormancy. Photoperiod had no effect on the rate of flower initiation or final flower number in the primary, secondary or tertiary inflorescences. Temperature had little effect on the final flower number in the primary inflorescence. However, the rate of flower initiation increased linearly with increasing temperature in the secondary (r2 = 0.98) and tertiary inflorescences (r2 = 0.97), to an optimum of 18.6°C in the secondary and 19.9°C in the tertiary inflorescence, and declined at temperatures above these. The quantity of starch in the roots increased during the autumn, and the rate of increase was negatively correlated with temperature. This indicates that root starch concentration ...
Prevention of hot-water treatment damage in narcissus bulbs by pre-warming
Hanks G.R.
Taylor & Francis
Journal of Horticultural Science, 1995, цитирований: 2, doi.org, Abstract
SummaryHot-water treatment (HWT) used to control stem nematode in narcissus bulbs can lead to yield loss through damage to flower, leaf and root initials. Warm storage of bulbs, usually at 30°C, reduces this damage. The effects of two pre-warming treatments (18°C for two weeks or 30°C for one week before HWT) were investigated in bulbs hot-water treated at a range of dates (from early-July to late-September). Experiment 1 was conducted on bulbs of cv. Carlton lifted on three dates. In the year after HWT, flower numbers were much reduced when HWT was applied after mid-August following storage at ambient temperatures, or after late-August following storage at 30°C, but numbers were only slightly reduced even with late-September HWT when given after 18°C storage. Pre-warming was somewhat more effective after early lifting. Late HWT reduced yields of bulbs harvested after two years' growth, but 18°C treatment largely prevented these losses. In Experiment 2, the beneficial effects of 18°C treatment were confir...
The effects of storage atmosphere on the keeping quality of ‘Idared’ apples
Stow J.
Taylor & Francis
Journal of Horticultural Science, 1995, цитирований: 3, doi.org, Abstract
SummaryThe response of ‘Idared’ apples to storage in atmospheres containing less carbon dioxide than the recommended 8% was investigated after it was found that core flush could develop in 8% CO2 + 13% O2 at 3.5°C. Storage in
The effects of temperature on the flower size of pansy (Viola x wittrockianaGams.)
Pearson S., Parker A., Adams S.R., Hadley P., May D.R.
Taylor & Francis
Journal of Horticultural Science, 1995, цитирований: 14, doi.org, Abstract
SummaryThe effects of temperature on the flower size of pansy were investigated in two experiments under both glasshouse and controlled environment conditions. Under glasshouse conditions, flower size (mm2) decreased linearly with increasing temperature between 9 and 31°C (r2 = 0.72). A transfer experiment showed that the decrease in flower size was proportional to the magnitude of the increase in temperature and to the duration of exposure. Thus, prolonged exposures to higher temperatures led to progressively smaller flowers. Temperature prior to visible bud stage had little effect on final flower size, but all subsequent stages were equally sensitive to increased temperatures. Thus, a period of high temperature had the same affect regardless of the stage of floral development. A proportion of the reduction in final flower size to temperature could be attributed to changes in the duration of flower development with temperature. A model was developed which showed that final flower size could be accurately...
An improved surface disinfection method for shoot expiants fromIrisrhizomes infected with bacterial soft rot (Erwinia carotovorasubsp,carotovora)
Berger F., Waites W.M., Leifert C.
Taylor & Francis
Journal of Horticultural Science, 1994, цитирований: 5, doi.org, Abstract
SummaryThe standard method (protocol 1) for disinfecting shoot expiants used for initiation of plant tissue cultures failed when Iris rhizomes were infected with bacterial soft rot (Erwinia carotovora subsp, carotovora), Two new disinfection protocols were therefore developed, They involved keeping stock plants without irrigation for two months prior to excision of expiants; alcohol disinfection of the expiants prior to excision from the rhizome; dipping of the expiant in alcohol immediately after excision; soaking in 1 % (v/v) sodium hypochlorite (protocol 2) or saturated calcium hypochlorite (protocol 3); and soaking in mercuric chloride, With protocols 2 and 3 up to 90% and 62% respectively of expiants taken from infected Iris rhizomes showing soft-rot symptoms remained free of detectable microorganisms in vitro.
Wood and tree age as factors influencing the ability of apple flowers to set fruit
Robbie F.A., Atkinson C.J.
Taylor & Francis
Journal of Horticultural Science, 1994, цитирований: 16, doi.org, Abstract
SUMMARYThe different fruit setting ability of flowers borne on different aged wood and trees of 'Cox's Orange Pippin'apple was examined. Developmental and physiological changes of flower buds were examined from bud burst to full bloom and related to their ability to set fruit. The capacity of apple flowers on young wood to set fruit was considerably less than that on older wood and although fewer fruits were retained until final set, it was the lack of initial set that limited cropping. There were gross morphological differences between flowers on different aged wood. Flower clusters on young wood typically had smaller leaf areas and mean flower weights as well as fewer flowers than those on older wood. The reduction in flower cluster size did not appear to be the obvious result of competition between reproductive and vegetative growth for mineral nutrients. Female fertility, effective pollination period, and the microscopical anatomy of flowers were also examined. Flowers on both young wood and trees sho...
Cantharid beetle feeding damage toRubusplants in eastern Scotland
Gordon S.C., Woodford J.A.
Taylor & Francis
Journal of Horticultural Science, 1994, цитирований: 2, doi.org, Abstract
SUMMARYIn May 1991 the stems of expanding fruiting laterals of red raspberry (Rubus idaeus) in plantations inTayside, easternScotland were extensively chewed by adults of Cantharis obscura L. (Coleoptera: Cantharidae). This appears to be the firstrecord of damage to plants by this group of insects in the UK. In choice tests, the adultbeetles damaged excised fruitinglaterals of both cultivated black raspberry (R. occidentalis) cv. Cumberland, and red raspberry cv. Glen Prosen, but did little damage to other closely related Rubus species and hybrids, including wild bramble (R. fruticosus agg.) and wild red raspberry (R. idaeus var. vulgatus).
The influence of autumn temperature on flowering time and cropping ofPyrus communiscv. Conference
Atkinson C.J., Taylor L.
Taylor & Francis
Journal of Horticultural Science, 1994, цитирований: 15, doi.org, Abstract
The influence of autumn temperatures on flowering and cropping date was examined for Pyrus communis cv. Conference. Warming potted trees in both October and November delayed bud development and the date of blossoming, relative to unheated control and field-grown trees. The later the warming treatment was applied in the autumn, the more the flowering date was delayed. The delay in flowering date is suggested to be due to an increase in bud dormancy in response to a reduction in winter chilling. Mean fruit yields and fruit number per tree were greater in trees warmed during October compared with unheated control trees, but declined with heating in November. Some evidence is presented which suggests that flower number per cluster may decline with warming. Both the initial and final set increased with warming. Fruit set was also likely to have been influenced by treatment differences in fruit number per tree. The results of this work are discussed in relation to attempts to provide a physiological understandi...
Effects of some biotic and abiotic factors on symptom expression of lettuce big-vein virus in lettuce (Lactuca sativa)
Walsh J.A.
Taylor & Francis
Journal of Horticultural Science, 1994, цитирований: 14, doi.org, Abstract
SummaryA nutrient film technique (NFT) system was developed to infect lettuce plants with an isolate of Olpidium brassicae carrying lettuce big-vein virus (LBVV) and to examine the effect of some biotic and abiotic factors on symptom expression of the virus. The NFT system had the advantage of removing any effects due to variation in moisture and allowed continuous and natural infection of test plants. The developmental stage of lettuce plants (5 true leaves) and duration of exposure to inoculum (4 wk) in the NFT system that induced most severe symptoms were determined. Within the temperature range previously reported to favour symptom expression of LBVV (14–18°C), significant differences in symptom severity were detected. Despite previous reports that low temperatures favour symptom expression, the most severe symptoms were induced in the shortest time at 18°C. Compared with diurnal temperature regimes of 10°C night and 18°C day, plants kept at constant 18°C developed more severe symptoms more rapidly. S...
The effect of explant density, temperature and light on rhizome growthin vitroofAlstroemeria
Bond S., Alderson P.G.
Taylor & Francis
Journal of Horticultural Science, 1993, цитирований: 1, doi.org, Abstract
The effects of number of rhizome explants per culture jar and of ranges of temperature, irradiance and daylength on explant growth, were assessed for Alstroemeria in vitro. Increasing explant number from one to five per culture jar produced no significant differences in the number of aerial shoots per explant, whereas an explant number of six produced a significant decrease (P = 0.01). Increases of temperature, in the range 8 to 18°C significantly increased the number of lateral rhizomes and aerial shoots per explant. Root number was unaffected by temperature. Decreases in irradiance from 20 W m-2 to 5 W m'2, and increases in daylength from 8 to 20 h, produced no significant changes in the number of lateral rhizomes, aerial shoots or roots per explant. For good multiplication the requirements for the culture environment were a temperature of 15°C, an irradiance of 5 W m~2 with a daylength of 8 h.
Salinity effects on the network of vascular bundles during tomato fruit development
Belda R.M., Ho L.C.
Taylor & Francis
Journal of Horticultural Science, 1993, цитирований: 32, doi.org, Abstract
The development and distribution of the conducting tissue of tomato fruit in relation to salinity was studied by recording the number of vascular bundles in different layers of the fruit tissues at...
Some responses of cucumber, grown in beds of peat, to N, K and Mg
Adams P., Graves C.J., Winsor G.W.
Taylor & Francis
Journal of Horticultural Science, 1992, цитирований: 3, doi.org, Abstract
Two levels of N and four levels of K, applied to beds of sphagnum peat before planting (Experiment A), were tested in factorial combination with three concentrations of N (50, 175 and 300 mg 1-1) and two of K (50 and 250 mg T1) in the liquid feed. In three cucumber crops grown, Mg was supplied or omitted before planting as a split plot factor (96 subplots). In two further crops (Experiment B), grown in fresh peat, six concentrations of N (20-320 mg 1-1) were tested in the liquid feed, all other nutrient levels being constant. In Experiment A, the early yield was reduced by low and high levels of N. The main effect of N on the final yield was not significant, but maximum yield was achieved with 175-300 mg 1-1 N in the liquid feed where the peat received a small amount of ureaformaldehyde (15 g m“2) and Mg fertilizer. The N x Mg interaction became increasingly marked with successive crops; the loss in yield due to Mg deficiency (
Effect of (2RS, 3RS)-paclobutrazol on endogenous indole-3-acetic acid in shoot apices of pear cv. Doyenne du Comice
Browning G., Singh Z., Kuden A., Blake P.
Taylor & Francis
Journal of Horticultural Science, 1992, цитирований: 2, doi.org, Abstract
The possibility that the stimulation of pear flower initiation by (2RS, 3RS)-paclobutrazol (PP333) might be caused by changes in shoot apex IAA as apical activity is slowed, affecting apical dominance, was studied. Applied directly to the shoot tip, 30 mg 1-1 of PP333 inhibited growth of cv. Doyenne du Comice as effectively as 100, 300 or 1000 mg P1. Retardation of shoot growth by these concentrations did not reduce IAA production by the shoot apex, as measured by gas chromatography-mass spectrometry (GC-MS). On the contrary, at 100, and to a lesser extent 300 mg 1-1 the chemical induced a large, but transient increase in IAA within two days after treatment. Full mass spectral evidence for the presence of native IAA in the pear shoot apex was obtained.
The susceptibility of modern tomato cultivars to blossom- end rot in relation to salinity
Adams P., Ho L.C.
Taylor & Francis
Journal of Horticultural Science, 1992, цитирований: 78, doi.org, Abstract
Three cultivars, Counter, Calypso and Spectra, were grown in NFT at a range of salinities (electrical conductivities of 5,10 and 15 mS cm-1) in two successive crops during the year. The incidence o...
Water relations and cropping of apple cultivars on a dwarfing rootstock in response to imposed drought
Higgs K.H., Jones H.G.
Taylor & Francis
Journal of Horticultural Science, 1991, цитирований: 18, doi.org, Abstract
SummaryWater relations of 15 scion cultivars of apple (Malus x domestica Borkh.) were compared when grafted on a very drawfing rootstock (M.27). Three of these were studied in detail. Drought was imposed by using under-tree polythene tents to reduce the amount of water reaching the root zone. Some cultivar differences in tree water relations were observed, e.g. ‘James Grieve’ consistently had the highest leaf conductances and the lowest leaf water potentials. Drought decreased growth much more than it decreased fruit yield. The use of family trees (two scions on one rootstock) for increasing the efficiency of scion comparisons was shown to improve the precision of comparisons. Various methods of estimating the water status of the crop were compared, including direct soil moisture measurement with a neutron probe, measurement of leaf water potential on exposed scion leaves, covered scion leaves or leaves on suckers, and estimates of the root surface water potential.
Carbohydrates and their effects on growth and establishment ofTiliaandBetula: I. Seasonal changes in soluble and insoluble carbohydrates
Abod S.A., Webster A.D.
Taylor & Francis
Journal of Horticultural Science, 1991, цитирований: 12, doi.org, Abstract
SummaryChanges in starch, sugar and total carbohydrate concentrations were monitored in roots, stems and leaves of newly transplanted Tilia and Betula plants throughout one growing season. Sucrose, glucose and fructose were present with small amounts of sorbitol. Concentrations of starch and sugar and the total carbohydrate content of the roots of both species declined between planting and early June, the result of reduced concentrations within primary roots, and the death of fine roots. It is suggested that this decline in root carbohydrate is partly explained by translocation to the above-ground organs to support budburst and early leaf growth. New roots and increases in the total root carbohydrate were measured much sooner after transplanting Betula than Tilia. By early July total carbohydrate in the roots of both species had increased considerably, a change attributable to increased starch concentrations in primary roots; fine roots, in contrast, contained least carbohydrate at this time. Most rapid g...
The role of spur and bourse leaves of three apple cultivars on fruit set and growth and calcium content
Proctor J.T., Palmer J.W.
Taylor & Francis
Journal of Horticultural Science, 1991, цитирований: 21, doi.org, Abstract
SummaryIndividual flowering spurs on mature wood of ‘Cox’s Orange Pippin’, ‘Golden Delicious’ and ‘Crispin’ apple trees were modified by removing the spur leaves, the bourse shoot, or both, at full bloom and two, four and eight weeks afterwards. Leaf removal reduced fruit set, yield (as fruit number and not size), fruit calcium level at harvest, and return bloom. Defoliation had its greatest effect on fruit calcium level when done early in the season and plots of this against treatment time suggested a curvilinear relationship. Return bloom was dependent on the presence of the bourse shoots on the spur but not on spur leaves. Return bloom of all three cultivars declined with the number of fruitlets per spur four weeks after full bloom.
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