Root formation,bud growth and survival of ornamental shrubs propagated by cuttings on different planting dates

Summary

Semi-hardwood cuttings of Cornus alba ‘Sibirica’, Deutzia ‘Mont Rose’, Forsythia × intermedia ‘Lynwood’, Ligustrum vulgare ‘Liga’, Philadelphus × virginalis, Potentilla fruticosa ‘Goldfinger’, and Spiraea × vanhouttei were planted on seven dates from July to October in two years and at three locations to investigate the effect of planting date on root formation, axillary bud growth, and plant survival. Cuttings were planted directly in the field and covered with polyethylene. Generally, root formation, bud growth, and plant survival were similar both years and at the three locations. All species except Deutzia had relatively constant rooting percentages at planting dates until mid August. For all species rooting percentages declined from mid August to October. Except for Deutzia, plant survival the following spring was constant or decreasing with planting date. For all species except Potentilla axillary bud growth and survival of cuttings planted in late September or October tended to increase while rooting percentages continued to decrease. In all species there was a close relationship between axillary bud growth and survival. Results revealed that many roots per cutting accelerated axillary bud growth.     

Interaction of source-plant age and shoot ringing on rooting of cashew (Anacardium occidentale L.) cuttings

Summary

IBA-treated cuttings rooted only when prepared fom bark-ringed shoots. The response to ringing declined with increasing age of the tree. However, on marcotting, the ringed shoots of four year old trees showed more and earlier rooting.     

Partitioning sources of rooting potential in plum hardwood cuttings

SUMMARY

Rooting of leafless winter hardwood cuttings of the plum rootstock Prunus insititia ‘Pixy’ increased as the location from which the shoots were taken from within specially grown stockplants decreased in height above ground, associated with a parallel reduction in shoot thickness. However, the actual height of the least-ready-rooting crown cuttings had no effect on rooting, suggesting that relative rather than absolute position is important. Rooting was unaffected by bark-ringing and trunk incision distal to the shoot position, suggesting that such treatments did not interfere with a basipetally translocated root promotor which might have accounted for improved rooting of cuttings in the lower parts of the hedge. The rooting of crown cuttings above a bark ring was reduced considerably compared with that of cuttings from normal bushes, and this was associated with increased thickness of shoots distal to the ring. Delaying pruning in spring until after growth had started resulted in thinner crown shoots compared with those from plants pruned normally while dormant, and the rooting of these thinner crown shoots was much higher than that of the normal crown cuttings. It was shown by covariance analysis that shoot thickness accounted for part of the rooting response but could not account for the total effect due to shoot position within the bush, ringing, or time of pruning. Competence to root appears to develop independently in individual shoots, modified by a shoot thickness factor which favours the subordinate shoots induced in the shoot hierarchy of severely pruned hedges.     

Progress towards clonal propagation of Camellia japonica cv. Alba Plena by tissue culture techniques

Summary

Optimal rooting conditions have been determined for shoot cultures of Camellia japonica cv. Alba Plena derived from a 50 year old tree: dipping the base of shoots in 1 g l^?l solution for 15 min, followed by 12 days’ darkness, induced 87% rooting in shoots cultured with Woody Plant Medium (WPM) macronutrients. Halving the auxin concentration or exposure time considerably reduced this rate, and root formation was severely inhibited if an initial dark period for the entire shoot was not used. The type of support (agar or paper bridges) did not significantly affect the rooting percentage or number of roots per rooted shoot, but liquid media induced greater root elongation. No significant differences were observed between the use of WPM and a modified Heller’s medium as regards the rooting percentages achieved, but the number of roots formed was considerably greater with WPM, as was the survival rate after transfer to soil (70% for transfer as against 35% with the modified Heller’s medium). Best survival rates were achieved when shoots were transferred to the acclimatization soil 12 days after auxin treatment, i.e. immediately after the dark period.     

Differentiation of the dynamic variables affecting rooting ability in juvenile and mature cuttings of cherry (Prunus avium)

Summary

The rooting potential of four types or origins of Prunus avium cuttings from the same mature trees (over 20 years-old) was compared using a mist propagation bed during early Summer (June). The cuttings originated from juvenile sucker shoots of the current and previous year, and mature crown shoots (current year’s lateral ‘long-shoots’ and multi-year terminal ‘short shoots’). The morphological differences in inter-node length, stem diameter and leaf area between the four cutting types were highly significant (P = 0.05), leading to large differences in cutting volume and, so it is argued, to assimilate reserves. Juvenile cuttings rooted well (65% and 77% rooting for hardwood and softwood shoots, respectively), while mature cuttings rooted poorly (4% and 7% for mature hardwood and softwood cuttings, respectively). Leaf abscission was significantly more frequent in mature hardwood cuttings (16 – 78%) than in the other cutting types (1.6 – 9%) at the end of the propagation period. Leaf loss resulted from two processes: abscission and leaf rotting. Physiologically (i.e., in carbon assimilation, leaf transpiration and stomatal conductance), the four cutting types were not significantly different early in the post-severance period (day-4); but, by day-22, stomatal conductance was lowest in mature hardwood cuttings that still had leaves. At this time, the most physiologically-active unrooted cuttings were from juvenile hardwood and mature softwood shoots. The extent of physiological and morphological variability between cutting types and their probable impact on processes affecting rooting ability is complex and highly interactive. Consequently, it is not possible to explain the causes of the variation in rooting ability between juvenile and mature cuttings, although this study suggests that the constraints to rooting are likely to reflect physiological differences between the different cutting types. It is concluded that, to resolve the debate about factors that affect the rooting ability of juvenile and mature cuttings (i.e., ontogenetic vs. physiological ageing), there is a need to achieve morphological and physiological comparability in the tissues.     

Rooting of Castanea sativa Mill,shoots: Effect of Agrobacterium rhizogenes T-DNA genes

Two Agrobacterium strains, Agrobacterium tumefaciens-ORF11 and Agrobacterium rhizogenes wild type 1855, were inoculated at the base of shoots of Castanea sativa Mill, in an attempt to improve the rooting (number and quality) of the shoots, or, later, of the cuttings. The inoculum was administered in June or in July, with or without a growth regulator mixture (indolebutyric acid, polyvinylpyrolidone, a naphthol and certain vitamins), and with or without basal etiolation. A rhizogenes 1855 was always ineffective (except for callus production); but when/1. tumefaciens-ORF\l was inoculated in June and in combination with growth regulator and etiolation, rapid and viable rhizogenesis was induced on the shoots within a month. If these rooted shoots were then air layered for four months (until October) a good root system developed that allowed the plantlets to be potted immediately (rather than in the following March after four months in a mist propagation bed, as would otherwise be the case) with high survival after potting. With this method, the clonal propagation of adult chestnut trees becomes a practical possibility.     

Poststorage quality and rooting ability of Epipremnum pinnatum cuttings after treatment with ethylene action inhibitors

Summary

The influence of the ethylene action inhibitors STS and 1-MCP on poststorage performance and subsequent rooting of cuttings was investigated in Epipremnum pinnatum. Unfavourable storage conditions resulted in decreasing poststorage quality of single-eye cuttings, expressed as leaf drop and yellowing. 1-MCP and STS prohibited leaf drop and yellowing in E. pinnatum. STS pretreatment decreased rooting ability significantly, measured as percentage of rooted cuttings, number of roots, total root length and dry weight. STS caused severe injuries to the cuttings, which were worse if the cuttings were stored rather than propagated immediately. There was no significant difference in rooting between 1-MCP treated cuttings and untreated control in either stored or unstored cuttings. The influence of ethylene action inhibitors on rooting and a possible use of 1-MCP for practical use to increase poststorage performance in cuttings are discussed.     

Asexual Propagation of Grapevine Transmits Pierce’s Disease Pathogen (Xylella fastidiosa) to Rooted Cuttings

An objective of this study was to investigate rooting success of grape cuttings propagated from vines symptomatic of Pierce’s disease. Additional objectives were to assess if rooted cuttings could survive and produce viable plants, and determine if Xylella fastidiosa (causal agent of Pierce’s disease) could be found in rooted cuttings. In Jan. 2008, cuttings were taken from symptomatic and asymptomatic ‘Merlot’ and ‘Cabernet Sauvignon’ grapevines growing in the Hill Country and Gulf Coast regions of Texas. Six weeks after cuttings were propagated, each cutting was uprooted and evaluated for rooting and infection parameters. Cuttings were then planted in containers and held in the greenhouse to evaluate survivability. To confirm the presence of X. fastidiosa, propagated cuttings were tested by real-time polymerase chain reaction. Data indicate several rooted cuttings tested positive for X. fastidiosa and appeared viable and healthy. Therefore, vines infected with X. fastidiosa have the ability to produce asexually propagated cuttings, and potentially contaminate non-infected vineyards.     

Effects of basal temperature on the rooting of hardy hybrid Rhododendrons

The effects of 3 basal temperatures; 15°, 20° and 25°C, on rooting of the hardy hybrid Rhododendron cultivars ‘Pink Pearl’, ‘Mrs. R.S. Holford’ and ‘Fastuosum Flore Pleno’ have been studied.A temperature of 15°C gave least rotting in all 3 cultivars and therefore more cuttings survived to root. Rotting increased and rooting decreased with increasing temperature.In cuttings without evident rotting, 25°C gave better rooting than 15°C, indicating that with improved control of disease, propagation at the higher temperature may be beneficial.The ease of rooting in unrotted cuttings was similar in R. ‘Fastuosum Flore Pleno’ and R. ‘Pink Pearl’ but lower in R. ‘Mrs. R.S. Holford’. Rotting was greatest in R. ‘Mrs. R.S. Holford’ and least in R. ‘Fastuosum Flore Pleno’.     

Influence of rootstock on orchard productivity and fruit quality in peach cv. ‘Redhaven’

Summary

We have evaluated the influence of four different peach rootstocks (Prunus pumila,‘GF 655/2’ ,‘Missour’ and ‘GF 677’ as a standard) planted in medium-heavy to heavy soil on phenological events (flowering and harvest date), growth, yield, fruit quality and mortality of peach (P. persica L.) scions of cv. ‘Redhaven’. At the end of flowering, there were no significant differences between the different rootstocks in the years 1999, 2000, 2003 and 2004. In 2001, trees grafted on P. pumila reached the end of flowering 2 d before trees grafted on the other rootstocks. ‘Redhaven’ fruits ripened on the same day on trees grafted on the different rootstocks. The differences were only between years. The results showed that significantly less vigorous trees, according to their trunk cross-sectional area (TCSA) and canopy volume, with the lowest yield, were observed on P. pumila rootstock. The rootstock P. pumila had a significant negative influence on fruit dimensions and mortality was 50%. Trees grafted on ‘GF 655/2’ rootstock produced significantly lower yields than those grafted on ‘GF 677’ or ‘Missour’ rootstocks. Only the ‘GF 655/2’ rootstock had root suckers. Trees grafted on ‘GF 677’ rootstock were significantly more vigorous than on the other rootstocks, and produced the highest yield with good fruit quality. The final canopy volumes of peach trees grafted on the different rootstocks were very different. The most vigorous trees were those grafted on ‘GF 677’ rootstock, where the final tree volume was 12.8 m³. Trees grafted on P. pumila and ‘GF 655/2’ had significantly lower TCSA values than on the other rootstocks.     

Stock plant shading and rooting of dahlia cuttings

The effect of shading dahlia mother plants on rootability of cuttings was studied with three cultivars: ‘Choot Hashani’, ‘Orpheo’ and ‘Lavender Perfection’. Reducing natural light intensity by approximately 50% increased rooting percentage of ‘Orpheo’ cuttings, but did not affect rooting of the harder cuttings of ‘Lavender Perfection’. Shading stock plants during midday hours only caused internode elongation in ‘Orpheo’, but did not increase rooting. In ‘Choot Hashani’ the same shading treatment promoted rooting. Shading only the base of the cutting when still on the mother plant greatly promoted rooting percentage and mean number of roots per cutting. The reason for the variability in the response to shading is discussed and it is concluded that the shading effect is limited to the root initiation region. It is assumed that shading improves rooting by promoting the herbaceous character of the rooting region. Shading did not affect rooting of cuttings which remained woody in spite of shade.     

Water transport through the roots of ornamental shrub cuttings

Summary

The use of leafy cuttings to propagate ornamental shrubs such as Corylus maxima cv. Purpurea is often hampered by “weaning” problems. These arise when the rooted cuttings are removed from the supportive environment designed to promote rooting and are transferred to a more natural, but relatively stressful, environment. The shrivelling of leaves which ensues points to some failure of normal plant water relations, which may be caused either by excessive water loss from the leaves, or an inadequate water supply from the roots, or a combination of these factors. To understand this problem more fully, the root hydraulic conductance of C. maxima cv. Purpurea cuttings was investigated, and compared with that of Weigela florida cv. Variegata, a shrub which does not exhibit weaning problems. The root hydraulic conductance for both species increased with the size of the root system, and root fresh weight was shown to provide a useful basis for relative measurements of root conductance. On this basis, cuttings of W. florida exhibited a higher root hydraulic conductance than comparable C. maxima cuttings (1.5 × 10^?4 and 9.7 × 10^?5 g s^?1 MPa^?1 g_root^?1 respectively), but the difference was not sufficiently large to account for the differences in weaning of these two species. It is suggested that the adventitious root system of C. maxima is functioning normally, but that it cannot supply enough water to balance uncontrolled water loss from the leaves.     

Effect of indolebutyric acid and sampling-dates on the rooting of four Tilia taxa

Softwood and semi-hardwood cuttings of 4 Tilia taxa were taken at different times and treated with high concentrations of IBA. Rooting-response varied with taxa and sampling-date. Rooting in Tilia americana L. cuttings was maximum when taken on 19 May and 1 June. Cuttings of Tilia cordata Mill. did not differ significantly in rootability when taken on 19 May, 22 June or 13 July, but rooting was significantly less with 3 August cuttings. Tilia × euchlora Koch cuttings did not root. All Tilla × euchlora Koch ‘Redmond’ cuttings taken on 19 May or 22 June rooted. A 5-second basal dip of IBA significantly stimulated rooting, especially in the range of 20 000–35 000 mg 1^?1.     

Rooting potential in plum hardwood cuttings: II. Relationships between shoot variables and rooting in cuttings from different sources

There was a positive correlation between shoot length and the proximal diameter of the prepared cutting in stockplant sources of Prunus insititia ‘Pixy’ that had different rooting potential. The precise relationship depended on source, with shoots from a severely pruned micropropagated source, and those developing from the trunks of various stock- plants, usually being thinner for any given length than normal distal cuttings from pruned and non-pruned conventional source stockplants. To a large extent rooting percentage, root numbers and root length increased between sources as the overall ratio of proximal stem diameter to shoot length decreased. Cuttings from the relatively thick, short shoots of the unpruned source were among the poorest rooting, while those from the relatively thin, long shoots from the trunk, and from the micropropagated source, rooted best. This between-source effect reflected the fact that within the less ready rooting sources there was also a negative correlation between the proximal diameter of the cutting and its rooting ability. This relationship was lost progressively as the rooting potential of sources increased, thus giving no opportunity for a trend to occur in the trunk-derived cuttings from the micropropagated source where virtually all cuttings rooted.     

Mist propagation of peach and almond × peach hybrids

Several factors contributing to the successful rooting of stem cuttings of four peach clones and one almond × peach hybrid under intermittent mist were tested. With the almond × peach cross, leaf-bud cuttings were also tested.Severe cutting back of adult peach mother trees in winter favoured rooting of the cuttings, but less severe cutting back induced maximum roots per cutting.For short periods vermiculite was found to be a suitable medium. Sand alone or mixed with vermiculite or gravel gave poor results. Gravel alone or mixed with vermiculite was intermediate. For growing the rooted cuttings for a longer period, a mixture of perlite and peat was very suitable.A period of illumination of 3 h starting at midnight with incandescent light improved rooting of peach cuttings in August and October, but not in June.With cuttings obtained from old fruit-bearing peach trees highest rooting rates were obtained in July, but best root development occurred when rooting was carried out in October. In July rooting rate of basal cuttings was much higher than that of terminal ones. Success with leaf-bud cuttings (including a small branch piece) obtained from young mother trees of the almond × peach hybrid was only achieved at the end of May or in June.Dipping the base of peach cuttings in water before rooting was of advantage with one cultivar rooted in September, but of no advantage with another cultivar rooted in June.When the base of stem cuttings was dipped for a prolonged period in IBA solutions of various concentrations, highest rooting rates were obtained with 25–50 ppm IBA for peaches and with 200 ppm for the almond × peach hybrid. The addition of Phygon XL to this solution was of some advantage for peach cuttings. The concentration inducing maximum root development was higher than that required for maximum rooting and callusing. The optimal IBA concentration for rooting of almond × peach leaf-bud cuttings was 100 ppm.Penetration of the IBA into the leaf-bud cuttings reached a maximum 45 min a after floating them on a 100 ppm solution.Transplanting cuttings which had been rooted under mist was somewhat difficult; however, high rates of survival were obtained with cuttings planted in September which had developed a good root system.     

Rooting of Berberis and Ligustrum cuttings from stock plants grown at selected light intensities

Plants of Berberis thunbergii DC., B. thunbergii DC, ‘Atropurpurea’, Ligustrum obtusifolium Seibold and Zucc. var. regelianum (Koehne) Rehd., and L. × vicaryi Beckett were grown at 37, 53, 70 and 100% full sunlight to determine rootability of cuttings. Rooting hormone levels of 0, 0.1, 0.3 and 0.8% IBA in talc were applied to the cuttings, and % rooting, root length, and fresh and dry weights were recorded. Optimum rooting of cuttings of Berberis resulted when stock plants were grown at 70% light, with 37% light being the next most successful. Optimum rooting of cuttings of Ligustrum obtusifolium var. regelianum resulted when stock plants were grown at 37% light. Rooting of Ligustrum × vicaryi did not respond to light intensity. An interaction between rooting-hormone and light intensity was noted for root length of Ligustrum species.     

Cloning of Ceylon olive (Elaeocarpus serratus L.) using conventional methods

Ceylon olive (Elaeocarpus serratus L.; family Elaeocarpaceae) is an under-utilised edible fruit tree that is sparsely distributed in the southern peninsula of the Indian sub-continent. Fresh and ripened fruit are edible and are used to prepare value-added products such as squash, jams and pickles. Methods to produce clonal E. serratus plants using softwood cuttings, air-layers, and grafts were investigated. Softwood cuttings were collected during the wet summer season (June–August) and showed 96.7% rooting success following 2.5 mM indole-3-butyric acid (IBA) treatment for 3 h. Hardwood cuttings collected during the wet summer season and subjected to IBA treatment failed to root. The duration of the auxin treatment significantly influenced the rooting percentage of softwood cuttings. Seasonal variations in the rooting response of softwood cuttings was also noted. The wet summer (June–August) was the best season for rooting softwood cuttings. Air-layers of hardwood branches, prepared during the wet summer season by pre-treating with 7.5 mM IBA resulted in 87.1% rooting. The spliced grafting technique could be applied also to elite Ceylon olive clones, with 70% and 50% survival rates of softwood and hardwood grafts, respectively. Ceylon olive could therefore be cloned by adopting these methods. Propagation based on softwood cuttings would facilitate moderate-scale cloning of this valuable, elite germplasm.     

Stockplant factors affecting root initiation in cuttings of Triplochiton scleroxylon K. Schum., an indigenous hardwood of west africa

The ability of auxin-treated T. scleroxylon cuttings to root was affected by the prior management of potted stockplants. In undecapitated single-stem stockplants more cuttings from upper rather than lower mainstem nodes rooted; a difference paralleled by leaf water potential immediately after severance, although there was also a positive relationship with internode length. The rooting percentage of mainstem cuttings from unpruned stockplants ranged from 15% to 43% whereas that of cuttings from the lateral shoots of pruned stockplants ranged from 40% to 83%. Considerably more cuttings rooted from stockplants which were severely pruned than from those where decapitation removed only the top node; there seemed to be an inverse relationship with the number of shoots per plant and the carbohydrate: nitrogen ratio. However, in tall pruned stock- plants, more cuttings from lower lateral (basal) than from upper (apical) shoots rooted, although the differences between cuttings from basal and apical lateral shoots were less when the stockplants’ mainstems were orientated at 45° or kept horizontal, instead of vertically. Adding NPK 16 weeks before harvesting cuttings from 10-node vertical stockplants increased the rooting ability of cuttings from basal shoots without affecting the rooting of those from apical shoots. More lateral shoot cuttings rooted when two, instead of one or four lateral shoots were allowed to develop per stockplant, this being associated with less cutting mortality than occurred in pruned stockplants. In stock- plants with two shoots, cuttings from basal lateral shoots rooted better than those from apical shoots, although without competition from basal shoots. The rooting of apical shoots was enhanced by application of a complete fertilizer. The presence of basal shoots reduced the rooting ability of apical shoots even with the fertilizer application. Many of the effects of lateral branch position on rooting may be related to light intensity, for greater rooting percentages occurred among cuttings from lower, more shaded, than from upper less shaded branches. This positional effect was eliminated when branches were uniformly illuminated.     

Rooting stem cuttings of Chinese chestnut

Rooting of Chinese chestnut (Castanea mollissima Blume.) stem cuttings following treatment with indole-3-butyric acid (IBA) was investigated. Tip and basal cutting from vigorous epicormic shoots and terminal shoots with 2–3 cm of the previous year's wood were taken from mature regions of trees approximately 40 years of age. Cuttings were dipped for 5 s in an aqueous solution of either 3 or 6 g l^?1 IBA. Rooting occurred only in the basal softwood cuttings. Average rooting of 33.5, 5.0 and 1.6% for ‘AU-Leader’, ‘AU-Homestead’ and ‘AU-Cropper’, respectively, was obtained using the 3 g l^?1 IBA solution, and 35.0, 6.7 and 3.3%, respectively, using the 6 g l^?1 IBA solution.     

Nährstoffaufnahme von Obstbäumen im 1. und 2. Standjahr

The nutrient uptake of fruit trees in the first and second year of cultivation was analyzed. The following fruit species and fruit varieties were examined: sour cherry (‘Schattenmorelle, Rheinland’, Hüttners Hochzucht 170?×?53, one year old tree), pear (‘Conference’, Quince A, two year old tree), apple on M 9 inoculated with the varieties ‘Pinova’ (two year old tree with one year old crown, two year old tree), ‘Elstar’ (one year old tree, two year old tree with one year old crown, two year old tree), ‘Jonagold’ (one year old tree, two year old tree with one year old crown, two year old tree) und Süßkirsche (‘Regina’, Gisela 5, two year old tree).

1. There was low nutrient uptake in the first and second year of cultivation.
2. In the second year of cultivation the nutrient uptake of all fruit species was clearly higher than in the first year of cultivation.
3. In average of the proved fruit varieties the nutrient uptake in the first year of cultivation was: 8?kg N/ha, 2?kg P/ha, 6?kg K/ha, 1?kg Mg/ha and 9?kg Ca/ha.
4. In average of the proved fruit varieties the nutrient uptake in the second year of cultivation was: 3?kg P/ha, 9?kg K/ha, 3?kg Mg/ha and 26?kg Ca/ha.
5. Especially in the first year of cultivation the trees of the stone fruits showed a higher nutrient uptake per tree than the trees of the pome fruits. But related to the nutrient uptake per hectar this difference reversed or became infinitely small.
6. The nutrient uptake of both the three apple varieties and the different plant materials showed only low differences.