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1.
《Scientia Horticulturae》1986,28(3):209-217
The effects on yield and radial fruit cracking of 2 media (soil in beds and soil-less medium in bags) and 2 drip-irrigation frequencies (once and 4 times daily) were determined for 4 greenhouse tomato (Lycopersicum esculentum L. Mill.) cultivars. For plants grown in soil-less medium, 2 tensiometer-controlled, drip-irrigation scheduling methods were compared. ‘Michigan’—‘Ohio’ hybrid fruit cracked significantly more than the 3 remaining cultivars, but did not differ in production of total and No. 1 fruit. The amount and severity of fruit cracking was least from the soil-less, bag-cultured plants. Total mean fruit weight was greatest from soil-grown plants. Although no differences in cracking occurred in the fruit from soil-less, bag-cultured plants, those whose irrigation was based on soil-less medium tensiometer readings produced lower total mean fruit weight than those whose irrigation was based on soil tensiometer readings. Number and weight of defective fruit was lowest from plants grown in soil-less medium and whose irrigation was based on soil tensiometer readings, and greatest from soil-grown plants. Fruit cracking was reduced by increasing the irrigation frequency from 1 to 4 times daily.  相似文献   

2.
Lychee (Litchi chinensis Sonn.) can be successfully propagated by several methods. The methods vary with respect to the uniformity and size of the new plants, the quality of the root system produced, time to bear, multiplication rate, destruction of parent tree, cost, labour requirements and the need for special techniques and equipment. Seedlings appear suitable for selection of new cultivars (and rootstocks), cuttings for rapid multiplication of new cultivars, marcottage and stooling for commercial multiplication of established cultivars and grafting for top-working new cultivars onto mature trees and/or onto improved rootstocks. Information is required on the comparative field performance of lychee propagated by these different techniques.  相似文献   

3.
During 1981, a large scale field experiment was set up with selected Begonia × tuberhybrida ‘Multiflora’ cultivars to compare the development of plantlets obtained by the classic propagation method to plantlets derived from tissue culture. The yield of tubers indicated that with tissue-culture-derived plants, a commercial tuber can be produced within one growing season. Plant quality and size are significantly increased compared with those from the classic vegetative propagation method of virus-infected cuttings.  相似文献   

4.
Lonicera caerulea L. var. emphyllocalyx (Maxim.) Nakai is a berry crop cultivated in cold regions. So far, commercial cultivars have been mainly introduced from selection of wild plants. Therefore, fruit traits and other agricultural characteristics have been limited. In this study, interspecific crosses between L. caerulea var. emphyllocalyx and Lonicera gracilipes var. glabra Miquel were examined to increase genetic variability of L. caerulea var. emphyllocalyx. Seedlings were obtained from reciprocal crosses between L. caerulea var. emphyllocalyx and L. gracilipes var. glabra. The hybrid nature of seedlings was confirmed with random amplified polymorphic DNA analysis. Viable green plants were obtained efficiently from L. gracilipes var. glabra × L. caerulea var. emphyllocalyx. In contrast, all plants produced from L. caerulea var. emphyllocalyx × L. gracilipes var. glabra were albino. These albino plants were very weak and only survived in culture condition. The chlorophyll deficiency was unilaterally observed, suggesting the occurrence of nuclear–cytoplasmic incompatibility. Viable F1 hybrids obtained from L. gracilipes var. glabra × L. caerulea var. emphyllocalyx are amphidiploid (2n = 4x = 36) as showing same to both parents. The hybrid plants are expected to increase the variability of fruit traits, and may have heat tolerance from L. gracilipes var. glabra.  相似文献   

5.
Strawberry (Fragaria × ananassa Duch.) is rich source of dietary antioxidants, minerals and nutrients. Dietary antioxidants have been known as beneficial for enhancing the fitness, preventing certain diseases and even mitigating the effects of ageing. The objectives of the present study were to determine variability and inheritance of antioxidants, to identify antioxidant rich and productive genotypes, and to suggest suitable breeding approaches. The genotypes, namely Ofra, Chandler, Festival and Camarosa showed higher concentrations of dietary antioxidants and therefore could be useful in future breeding. Results indicate that the effect of the genotypes on antioxidant contents is stronger than that of the environment. The high heritability (>80%) and low genetic advance as percentage of mean (<40%) for ascorbic acid and β-carotene contents could be improved by heterosis breeding. However, selection and hybridization would be effective tools to enhance the phenols and anthocyanin content, and yield potential as these traits showed high heritability (>80%) and high genetic advance as percentage of mean (>40%). Positive direct effect on fruit yield was highest for phenol content (0.609) which is also fairly close to its correlation coefficient (0.765) indicating that a direct selection based on phenol content would be most effective and that the phenol content could be used as a reliable biochemical marker to identify the productive genotypes having higher amounts of dietary antioxidants. The information could also be used for developing antioxidant rich cultivars, i.e. ‘Breeding Strawberry for High Antioxidants’.  相似文献   

6.
A randomized block split-plot experiment was established at Burgershall Research Station, eastern Transvaal to compare three cultivars (Williams, Dwarf Cavendish and Grand Nain) and three types of planting material (conventional 2 kg pared suckers, 200 and 500 mm high, tissue cultured plants rooted in bags). In the first crop cycle (P), tissue culture (TC) plants were up to 300 mm taller than conventional suckers (CON) at flowering. Over all three cultivars, TC plants yielded 56 t ha-1 annum“1 which was 20.4% higher than CON plants, due to larger bunches and a shorter cycle to harvest. Cvs Williams and Grand Nain yielded similarly at 54 t ha-1 annum-1 which was 9% more than ‘Dwarf Cavendish’ over all planting materials. There were 30 (1.76%) distinct somaclonal variants in the plantation of 1,700 plants. In the second crop cycle (Rl), there was a significant carry-over effect with TC plants, as shown by the increased vigour and size of the first ratoon followers selected on TC mother plants. Such TC followers outyielded CON followers by 18.6% in the second cycle, almost matching the first cycle. In the third crop cycle (R2) there was no difference in plant size between TC and CON, although a yield increase of 9.6% in favour of TC was obtained, indicating a reduced carry-over effect of TC by the third cycle. After three cycles, the average annual yield increase with TC was 19.4% for ‘Dwarf Cavendish’, 15% for ‘Williams’ and 13% for ‘Grand Nain’.  相似文献   

7.
In 2003, highbush blueberry (Vaccinium corymbosum) cultivars ‘Brigitta Blue’ and ‘Nelson’ were treated with a foliar boron-containing, ascofol spray (Wuxal®). After blossoming, the plants were sprayed three times with 0.5% ascofol solution. Control plants were sprayed with tap water. Fruit harvest of each cultivar was on July 19 and 30, respectively. Leaf samples were taken on June 4 and August 7. The boron content of fruits and leaves was analyzed along with fruit yield and single berry weight. The potential absorption rate of applied boron (boron increase in leaves and fruits) was calculated. Foliarly applied boron was readily taken up by the leaves of both cultivars and translocated to the fruits. A potential boron absorption rate of 2.4% was calculated for ‘Nelson’. Foliar application of boron did not increase fruit yield in either cultivar. However, ‘Nelson’ showed a slight increase of berry weight in the second harvest, associated with the boron treatments.  相似文献   

8.
Sweet potato (Ipomoea batatas Lam.) root sections were obtained from the cultivars ‘Centennial’, ‘Redmar’ and ‘Jewel’ with a No. 6 cork borer. These sections were cut into 2–3-mm discs and explanted on to modified Murashige and Skoog (MS) medium consisting of MS high mineral salts, myo-inositol (100 mg l?1), Staba vitamins, 6-benzyl-aminopurine (2.0 mg l?1), naphthaleneacetic acid (0.1 mg l?1), sucrose (30 g l?1) and agar (10 g l?1). Root discs from internal regions of the tuberous roots gave rise to calli and meristematic bud-like centers (MBLC's). A small percentage of ‘Centennial’ MBLC's burst open to reveal plantlets which grew and rooted well on the medium. Some of the ‘Jewel’ MBLC's contained only roots, while those of ‘Redmar’ did not differentiate. MBLC-formation occurred most often on discs taken from fresh (unstored) roots of ‘Centennial’. Petiole sections taken from in vitro-cultured plants of all 3 cultivars developed plants quite readily on the medium. Shoots of all 3 cultivars grew rapidly, to yield whole rooted plants which could easily be moved to soil and grown in the greenhouse and field.  相似文献   

9.
The genetic diversity of 15 carob (Ceratonia siliqua L.) cultivars located in an experimental field from Algarve (Portugal) was evaluated over 7 years using 12 fruit and seed phenotypic characters, in order to characterize carob cultivars. The values of morphological traits obtained by cultivar were compared with those from other countries of the Mediterranean basin. Statistically significant differences were found between cultivars for all characters which were examined, what indicates a high genetic diversity. The relationship among these characters was analyzed by principal component analysis (PCA) resulting in the separation of these cultivars classed in four groups (clusters I–IV) and in four ungrouped cultivars. A three dimension of the model was found to be significant and explained 74.5% of the total variation, in which the first component accounting for 34.6% of the total variation is dominated by fruit characters, while the second component is dominated by seed characters. Cultivars plotted on the left-lower quadrant on the space determined by principal components 1 and 2 are characterized by fruits with high seed yield more appropriated for industrial rentability. The correlation analyses established by cultivar provided a specific understanding about the way how fruit and seed characteristics correlate within each cultivar. This approach can be useful for the development of a breeding programme, aiming to increase the seed yield, seed thickness, individual and total seed weight by fruit, characteristics that are determinant to improve the industrial exploitation of carob.  相似文献   

10.
Summary

Tomato (Lycopersicon esculentum L. Mill) cultivars Early Urbana and Red Clode were grown in the field at adverse temperatures (stress regimes) until they set fruit in two growing seasons (Autumn and Spring) during 1999 and 2000 in Ahwaz (Southern Iran). To test the effectiveness of auxins in enhancing fruit set, racemes of tomato were sprayed during early fruit set with 25, 50 and 100 mg l–1 4-chlorophenoxy acetic acid (4-CPA) and indole-3-butyric acid (IBA) followed by two additional applications at three intervals. The control plants were treated with deionized water. At harvest, racemes from autumn and spring plantings that were treated with 4-CPA had more large fruits than the control racemes. In both growing seasons, neither cultivar showed a significant difference in fruit set in plants treated with IBA, compared with controls. The ratio of fruit/flower in all racemes treated with 4-CPA increased significantly compared with the other treatments. However, auxin treatments did not significantly affect the number of flowers per raceme. Plants treated with 4-CPA produced the highest yield of marketable fruit. The greatest increase in total yield and parthenocarpic fruit occurred with 4-CPA treatments. Also, there was little difference between concentrations of 4-CPA on fruit set in both cultivars. It may be concluded that the response of fruit setting in tomato to either low or high temperatures regimes was auxin dependent and that 4-CPA was more effective than IBA.  相似文献   

11.
《Scientia Horticulturae》2002,95(3):261-268
Selection of suitable production locations in Australia and New Zealand for production of myoga (Zingiber mioga Roscoe) has been limited by lack of information on climatic influences on flowering. This study focused on photoperiod as potential production sites within Australia differ considerably in daylength due to the geographical range. The two cultivars available in Australia (Inferior and Superior) were examined in this trial due to previously observed differences in vegetative and reproductive development.Plants grown under long-day conditions (16 h) and short-day conditions (8 h) with a night break produced flower buds, while those under short-day conditions (8 h) did not. The failure of plants under short-day conditions to produce flower buds was due to abortion of developing floral primordia rather than a failure to initiate inflorescences. It was concluded that for flower development in myoga a qualitative long-day requirement must be satisfied, but that flower initiation was day-neutral.Short-day conditions resulted in abortion of flower primordia, premature senescence of foliage and reduced foliage dry weight in both cultivars. Early senescence and low flower bud yield of the Inferior cultivar, but not the Superior cultivar have been observed in crop evaluation trials in Southern Australia and New Zealand. Differences in critical photoperiod between the two cultivars may explain this observation and therefore photoperiodic requirements may be an important consideration in site and planting date selection for different cultivars.  相似文献   

12.
Abstract

Influence of initial transplant size on yield components was investigated using two strawberry cultivars over a three-year period. Plants were sorted into three groups according to crown size each fall before transplanting.

Fruits were harvested once a week over a ten-week period each year. There were marked differences between ‘Chandler’ and ‘Camarosa’ cultivars. Transplants of the ‘Chandler’ cultivar with larger crown diameters produced significantly greater early and total marketable yield than transplants with smaller crown diameters. Regression analysis of yield components against initial crown diameter revealed a positive relationship between total fruit numbers produced per plant and initial crown size for both cultivars. Total weight of marketable fruit produced per plant was positively associated with initial crown diameter of transplants. Relationships between initial crown diameter and early yield components were not as consistent among the two cultivars tested. Early yield components of ‘Chandler’ were all correlated to initial crown diameter of transplants. The size of the transplant did not influence early yield components of ‘Camarosa’ except for fruit size. There was a significant relationship between the postharvest dry weight of plants and initial crown diameter of transplants.  相似文献   

13.
The importance of root size system has long been recognized as crucial to cope with drought conditions. This investigation was conducted to: (i) evaluate the variability in root size system of hot pepper at maturity; (ii) estimate the effect of root size system on yield under drought conditions; and (iii) effect of water stress on xylem vessel development and total xylem cross-sectional area in roots of hot pepper cultivars. Twelve diverse hot pepper cultivars were grown in wooden boxes with two different water treatments, normal and in 50% water application as water deficit condition. Mean primary root length (PRL) showed a significant positive correlation with final fruit yield at normal as well as stressed condition. Total dry mass of fruit was reduced by 34.7% in drought treatments (DI) compared to full watered treatment (FI). At harvest, water-stressed plants had 21% lower root dry weight mass but higher root:shoot ratio other than FI. PRL, lateral root density, total xylem area per root cross-section showed a significant positive relationship with fruit yield. Also, lateral root density was higher in cultivars with higher xylem density, particularly in tolerant cultivars. Lateral root density (r = 0.847, P < 0.001) and total xylem cross-sectional area in root (r = 0.926, P < 0.001) were tightly related with total biomass production. The importance of root traits contributing to withstand drought in hot pepper is discussed.  相似文献   

14.
Eleven cultivars of Chrysanthemum × grandiflorum (Ramat.) Kitam.: ‘Richmond’ and its 10 radiomutants, representing the Lady group, were propagated in vitro with shoot tips and leaves as explants. The aim of this study was to investigate if the explant type used for micropropagation affects the genotype and phenotype of chrysanthemums. Plants grown from shoot tips and adventitious buds formed on leaves were rooted in vitro, acclimatized and cultivated in glasshouse up to full-flowering. The colour and shape of inflorescences of plants obtained from two different explant types were compared within the cultivars. All plants derived from shoot-tip explants showed the inflorescence colour and shape typical for the cultivars. Inflorescence colour of plants derived from adventitious buds were true-to-type in four cultivars: ‘Richmond’, ‘Lady Amber’, ‘Lady White’ and ‘Lady Yellow’. All plants of ‘Lady Apricot’ (originally: golden beet) and ‘Lady Salmon’ (salmon) propagated from adventitious buds technique showed altered inflorescence colour (respectively: purple gold; pink and white). ‘Lady Bronze’ (originally: reddish brown), ‘Lady Orange’ (orange brown) and ‘Lady Rosy’ (purple gold) propagated with adventitious buds had both typical and changed inflorescence colours (respectively: yellow; yellow and red; reddish pink). ‘Lady Vitroflora’ showed altered number of ligulate florets grown into tubes in inflorescence when propagated with shoot tips and leaves as explants. Those changes might be an effect of either chimeral structure or somaclonal variation of the plants investigated. The variation appears only if non-meristematical explants were used. The adventitious buds technique might be useful in chrysanthemum breeding as a source of a new variability.  相似文献   

15.
Cuttings from 2 cultivars of Cornus alba propagated in late September produced more and longer roots in long days (LD) than in natural days (ND). The effects of photoperiod on rooting were much less when cuttings were propagated in mid-August. LD during propagation in mid-August delayed the onset of leaf senescence and bud dormancy so that heavier and taller plants were obtained. Bud dormancy did not develop if the plants were grown under LD throughout the winter. Such treatment produced very tall plants and resulted in a greater proportion of their dry matter being distributed to the stems.Short-day (SD) treatment hastened bud dormancy development followed eventually by leaf senescence. Returning the plants to LD after more than 3 months of SD-treatment did not overcome the bud dormancy regardless of whether the plants still had leaves.It is recommended that if material of Cornus alba is propagated in August, the natural photoperiod should be extended during propagation so as to improve plant growth.  相似文献   

16.
Plants of six strawberry cultivars were raised under controlled conditions and tested for flowering and yield potential. Short days (SD) at intermediate temperatures for 4 weeks in August induced profuse flowering in subsequent long days (LD) in all cultivars except the late-flowering ‘Malwina’. LD conditions induced flowering only in ‘Nobel’, which has an everbearing parent. ‘Nobel’ and ‘Saga’ exhibited broad temperature adaptation for SD floral induction, which was generally reduced or suppressed at 9 and 27°C. After autumn planting, all cultivars flowered most abundantly in plants raised in SD and intermediate temperatures. Flowering was earliest in ‘Nobel’ and ‘Rumba’. Plants that did not reach floral commitment after 4 weeks in SD continued and completed induction under subsequent natural SD conditions after planting in the field, demonstrating the capability of fractional induction. Berry yield varied in parallel with flowering in the field and was always higher in plants raised under SD conditions. The traditional cultivars ‘Florence’ and ‘Sonata’ out-yielded the more recent cultivars. Some cultivars lost more than two thirds of their initiated flowers during the winter with obvious consequences for their yields. With proper raising management, acceptable yields were obtained after autumn planting even in a cool Nordic climate.  相似文献   

17.
The effects of partial root-zone drying (PRD), as compared to deficit irrigation (DI) and full irrigation (FI), on strawberry (cv. Honeoye) berry yield, yield components and irrigation water use efficiency (WUEI) were investigated in a field lysimeter under an automatic rain-out shelter. The irrigation treatments were imposed from the beginning of flowering to the end of fruit maturity. In FI the whole root zone was irrigated every second day to field capacity viz. volumetric soil water content (θ) of 20%; while in DI and PRD 60% water of FI was irrigated to either the whole or one-half of the root system, respectively, at each irrigation event. In PRD, irrigation was shifted from one side to the other side of the plants when θ of the drying side had decreased to 8–11%. Compared to FI plants, leaf water potential was significantly lower in DI and PRD plants in 3 out of 10 measurement occasions, while stomatal conductance was similar among the three treatments. Leaf area, fresh berry yield (FY), individual berry fresh weight, berry water content, and berry dry weight (DW) were significantly lower in DI and PRD plants than those of FI plants; whereas the total number of berry per plant was similar among treatments. Compared with FI, the DI and PRD treatments saved 40% of irrigation water, and this led to a 28 and 50% increase of WUEI based on berry FY and DW, respectively, for both DI and PRD. Conclusively, under the conditions of this study PRD had no advantage compared to DI in terms of berry yield and WUEI. DI and PRD similarly decreased berry yield and yield components and thus cannot be recommended under similar conditions.  相似文献   

18.
《Scientia Horticulturae》2001,88(3):191-202
Two fennel (Foeniculum vulgare Mill.) varieties, Dolce and Azoricum, were field grown for swollen base (SB) production to select the most productive variety and the most suitable source of N fertilizers in fields supplemented with cattle manure, calcium superphosphate and potassium sulfate. Plants were then grown either with or without one of the synthetic N fertilizers, ammonium sulfate (AS), ammonium nitrate (AN) or urea applied at a rate of 170 kg N ha−1.Plants of var. Dolce were heavier in fresh weight and produced swollen bases (SBs) of 25% higher marketability percentage, 143% yield increase and 50% more oil content as compared to Azoricum. The increased SB yield and quality in var. Dolce were due to its lower bolting tendency as compared to var. Azoricum. Among all measured parameters, bolting tendency and SB oil content proved to be variety-dependent since both parameters showed no responses to N fertilizer source.When N was applied as a synthetic source, SB yield and quality were markedly reduced with about a 36% increase in SB nitrate content as compared to the control. The lowest SB yield and quality were obtained when AN or urea was used. Although AS produced a comparable yield to that of the control, the physical quality of the harvested SBs was adversely affected. The major compound in SB essential oil, trans-anethole, increased only with AN source in var. Dolce but fluctuated in var. Azoricum. The second most common compound, para-anis-aldehyde in var. Dolce or limonene in var. Azoricum, however, was markedly reduced with the application of any synthetic N source.It is suggested, therefore, that var. Dolce is more recommended for SB production than var. Azoricum. Fertilizing with synthetic N sources during plant growth and development is not advised when the soil has already been supplemented with organic nitrogen as not only are SB yield, quality and flavor reduced but also its safety for human consumption.  相似文献   

19.
Managed turf areas are both a source and a sink for greenhouse gases (GHGs). Management practices, including turfgrass selection and mowing, influence the amount of carbon (C) and nitrogen (N) stored in the soil, as well as the associated GHG emissions. The objective of this research was to determine the net C and N balance (i.e. the amount of C and N stored less the amount emitted) of managed turfgrass systems with different grasses (species and cultivars) and management practices (mowing frequency and grass clippings management). Data explicitly quantified in this experiment include annual mowing requirements and accompanying GHG emissions, annual dry matter yield, soil C and N accumulation, and GHG flux of tall fescue (Schedonorus arundinaceus) and Kentucky bluegrass (Poa pratensis) cultivars with varying growth rates. Leaf, verdure, and root tissue C and N were also determined, along with the corresponding biomass. Estimations of emissions from fertilization, irrigation, and pesticide applications were also included in the net balance calculations.All of the turfgrasses and management practices in this experiment resulted in a system-wide net C sink, though the magnitude of the sink varied by turfgrass selection and management strategy. In general, higher-yielding grasses and management practices increased soil C but also increased mowing requirements and thus emissions. Returning grass clippings was found to increase yield, soil and leaf tissue N, and soil C, but it also marginally increased mowing requirements. The results of this experiment support the assertion that managed turfgrass areas can act as a net C sink to help curb the increasing atmospheric GHG concentrations. The C sequestration potential of managed turfgrass is another of the numerous functional benefits of urban grasslands.  相似文献   

20.
Summary

Stem yield and quality of roses for cut flower production were evaluated. The plants were grown in two planting systems as an alternative to the traditional ``vase-shaped'' system. In the trellised system, two cultivars of Rosa hybrida (cvs Gabrielle and Kardinal) were planted in a commercial glasshouse in 3.m sections of bed. Within-row spacing was varied to give 6–16 plants m–2. After a three-month establishment phase the basal shoots were bent to an angle of 308 above horizontal and restrained with a trellis wire. Flowering shoots sprouting from axillary buds along a basal shoot were harvested at their lowest node, minimizing branching. Compared with ``vase-shaped'' rose plants at the same density, trellised roses produced 24% more basal shoots, 46% more flowering shoots (cv. Gabrielle) and approximately 46% less blind shoots per plant over five months. Phenotypic variation was greater in cv. Gabrielle than in cv. Kardinal in response to within-row spacing, as indicated by the number of basal shoots formed. Within-row spacing, over the range explored, did not affect the number of flowering shoots per basal shoot. Trellising rose plants increased stem yield and quality, but production over the long-term requires further investigation. The single shoot planting system contained a mixed population of single-stemmed rose plants of Rosa hybrida (cvs Gabrielle and Gerdo). It was grown in a field over a range of within-row spacings to give 20–105 plants m–2. Over three harvests, increasing the number of plants by 10 plants m–2 reduced the proportion of flowering shoots by 4.4%. Expressed on a unit area basis, a five-fold increase in plants m–2 produced a three-fold increase in stem production.  相似文献   

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