Effects of organic matter and controlled-release fertilizer on nutrient retention during intermittentmist propagation

Semi-hardwood cuttings of Ligustrum japonicum Thunb. and Juniperus conferta Parl. were propagated in sand or sand : peat (1 : 1 v/v) and top-dressed with osmocote controlled-release fertilizers at various rates. Soluble salts, NO^?₃, P and K leaching through media was greater in sand, especially with osmocote 14-14-14. Loss of P and K in both media was not as rapid as the loss of NO^?₃. The pH of leachate from sand : peat was significantly less than that from sand. The 18-6-12 osmocote provided steady nutrient release in both media.     

Distribution of Ilex and Juniperus roots in three container-media

Ilex crenata Thunb. cultivar ‘Green Luster’ and Juniperus horizontalis Moench. cultivar ‘Plumosa’ were grown in 3 container-media for 13 months. The container-media were dissected by 2 horizontal cuts to yield 3 depth zones, 3 equal concentric areas were outlined on the lower surface of each depth zone and root distribution determined. A greater number of Ilex roots were in the 2 inside concentric areas of the bottom two-thirds of the peat:perlite medium than in the same divisions of soil:peat:sand and pine bark:sand media. Juniperus roots were more evenly distributed through the depth zones of pine bark: sand than soil:peat:sand or peat:perlite media.     

Callus and axillary-bud culture of Vitis vinifera ‘Sylvaner Riesling’

Healthy growth of serially subcultured callus of the grape Vitis vinifera cultivar ‘Sylvaner’ was obtained by incubation at 30° C in continuous light in a defined culture medium containing 2% w/v sucrose, 1.0 mg l^?1 1-naphthaleneacetic acid (NAA) and 0.2 mg l^?1 kinetin (K). Organogenesis was not induced in this callus by alteration in the absolute or relative levels of NAA and K.Continued shoot initiation was obtained by culture of axillary buds in a medium containing 10^?5 M Benzyladenine (BA). Plantlets could be generated from these shoot buds by transfer to media containing 10^?7 M BA or lacking a cytokinin.     

Nitrogen and calcium nutrition of Petunia × hybrida ‘Coral Sea’

The effects of N and Ca nutrition on plant growth and shoot elemental content of Petunia × hybrida Hort. Vilm. - Andr. ‘Coral Sea’ were evaluated. Nitrogen and Ca were applied separately or in combination in three experiments: (1) N at 0, 100, 200 or 400 mg l^?1; (2) Ca at 0, 75, 150 or 300 mg l^?1; (3) N at 0 or 100 mg l^?1 and Ca at 0 or 150 mg l^?1 combined factorially. Shoot and root dry weights, branch length and flower number were highest when plants received 100 mg l^?1 N. Plants treated with 150 mg l^?1 Ca had the highest shoot and root dry weights. Branch length was maximal at 300 mg l^?1 Ca.Nitrogen and Ca interacted to increase shoot dry weights, branch number and length, leaf area and flower number. Increasing N concentrations increased N and decreased P, Mn and Zn shoot contents. Calcium content of shoots increased while N, P and Mg decreased in response to increasing applications of Ca to petunia plants. Minimal N and Ca tissue concentrations for optimal P. × hybrida growth were 3.3 and 0.67%, respectively.     

Plantlet regeneration from root callus of different Prunus species

Caulogenesis was obtained in vitro on the calli of Prunus sp., P. dawyckensis, P. canescens and hybrid P. incisa x serrula. These calli were formed on the roots of plantlets derived from meristem culture on a medium containing 6-benzylaminopurine (BAP) (10^?3 g/l) and gibberellic acid (GA₃) (10^?4 g/l). The first buds appeared after a month. After transfer of the calli on the same medium, the caulogenesis continued. The degree of regenation varied according to the species.     

Leaching of applied phosphorus in container media

Pre-plant P as superphosphate (8.7% P) at the rate of 1.5 kg m^?3 was added to two root media in 16.5-cm azalea-type pots. Saturated media were periodically leached to 15% excess. Media type had a definite influence on P leached. Over one third of the total applied P was leached from a peat moss:vermiculite (PV) (1:1, v:v) mix after 9 weeks compared to less than 5% leached from a sand:soil:peat moss (SSP) (1:1:1, v:v:v) mix in a simulated plant watering scheme. Approximately the same amount of P was leached at any given watering in the PV (4.2%), whereas 2.6% of that applied was lost after an initial watering at 1 h and only 0.04% after an initial watering at 9 weeks in the SSP mix. This difference was related to differences in P fixation by the various root media components.P adsorption isotherms were conducted on 7 root media components or mixtures of components, including the 2 above-mentioned mixes, to determine the quantity of P adsorbed to give 0.2 ppm in the soil solution. The resulting plot of P adsorbed versus P in solution confirmed that the greater leaching loss of P in the soil-less mix was due to a lower P adsorption capacity. Maximum P adsorption capacity in the soilless media was reached with the addition of 262 g P m^?3. The adsorption capacities of soil, sand and SSP were not reached at the highest rate of P addition (524 g P m^?3. The higher P buffering capacity of these materials necessitates greater P addition to achieve 0.2 ppm soluble P, considered optimum for most plants, but ensures that the level of soluble P will be maintained for a longer period.     

Effects of nitrogen and phosphorus on root and shoot growth of Cotoneaster divaricata Rehd. & Wils.

Root and shoot growth rates of Cotoneaster divaricata were determined using a growing system of polyvinyl chloride pipe cylinders in which longitudinal sections could be removed for periodic root observations. Plants were fertilized with nitrogen (N), phosphorus (P), and potassium (K). N, as NH₄NO₃, was applied weekly at levels of 0, 250 or 500 mg/l and P, as H₃PO₄, was incorporated in the medium at levels of 0, 5 or 50 mg/l. K, as KCl, was maintained in the medium at a 150 mg/l level by soil tests conducted weekly. Shoot growth was increased after N application. However, no difference was observed between N levels. P increased shoot growth only at the highest N level applied. Although root growth was not increased by either N or P, high N levels inhibited root growth, whereas P stimulated root growth. No correlation (r = 0.19) was observed between shoot and root growth.     

Effect of nitrogen form and radiation on growth and mineral concentration of two Brassica species

Three greenhouse experiments were carried out to determine the growth, yield, nitrate, total N and S concentration in shoots, and water uptake of hydroponically grown Brassica rapa L. subsp. nipposinica var. chinoleifera and Brassica juncea L. In each experiment, daily photosynthetically active radiation (PAR) level was 5.0 mol m⁻² (low), 6.8 mol m⁻² (medium) or 9.0 mol m⁻² (high). Plants were supplied with nutrient solutions having equal N concentrations of 11 mM in different forms: 100% NH₄, 50% NH₄ + 50% NO₃, and 100% NO₃. Nitrogen supplied as 100% NH₄ reduced fresh and dry shoot biomass, leaf area, and leaf number in both Brassica species, especially at low and medium PAR levels. In both Brassica species, S concentrations were highest, while nitrate concentrations were lowest in leaves of plants grown at N supplied as 100% NH₄. No differences in leaf nitrate concentrations were observed between 50% NH₄ + 50% NO₃ and 100% NO₃ treatments. Low and high PAR levels increased the nitrate concentrations and decreased the N/S ratio in leaves of both crops compared to medium PAR level. Fresh shoot biomass was maximized in Brassica rapa when PAR level was above the medium value and nitrate was supplied in the nutrient solution as NO₃ or as a mixture of 50% NO₃ and 50% NH₄. The highest fresh shoot biomass of Brassica juncea was observed in all nutrient solution treatments at high PAR level.     

Effects of light,macronutrients, and sucrose on germination and development of the endangered fern Adiantum reniforme var. sinense (Adiantaceae)

Effects of light, macronutrients strength of Murashige and Skoog (MS) (1962), and sucrose in the culture medium on spore germination and gametophyte development of the endangered fern Adiantum reniforme var. sinense were investigated. The presence of light was found to be essential for both spore germination and gametophyte growth. Moreover, a medium consisting of 1/4 MS with 15 g/l sucrose was optimal for spore germination and early gametophyte development; whereas, MS medium with 30 g/l sucrose was optimal for further gametophyte development. Increasing amounts of sucrose (45–60 g/l) in the medium delayed gametophyte growth and development. Additionally, sporophyte formation and early growth of gametophytes in a medium consisting of clay and peat (v/v = 1:2) was higher than those in a medium consisting of pure river sand. These findings indicated that requirements for nutrients for spore germination and early gametophyte development of A. reniforme var. sinese were relatively low, but these increased with further gametophyte development, formation and growth of sporophytes.     

Propagating palms in vitro with special emphasis on the date palm (Phoenix dactylifera L.)

Tissue-culture methods are described for the vegetative propagation of several palm species either through shoot tip culture or plantlet differentiation via embryogenic callus. The influence of explant size, medium composition and physical environment required for the establishment of palm shoot tips in vitro was determined. Date palm (Phoenix dactylifera L.) seedling shoot tips of various sizes were cultured in either liquid or agar modified Murashige and Skoog (MS) medium containing 0.0–1.0 mg 1^?1 α-naphthaleneacetic acid (NAA) and 0.0–15.0 mg 1^?1 benzyladenine or N⁶-(Δ²-isopentenyl) adenine (2iP) in order to enhance shoot growth and induce axillary budding. Satisfactory date palm shoot tip growth and proliferation was obtained from explants that were 3 mm in length, consisting of the apical meristem region and 2–5 adjacent leaf primordia. Optimum shoot tip development and axillary budding was obtained by initially establishing explants on an agar medium for 2 weeks, then transferring to a liquid medium. Shoot tips from several palm species were cultured on MS media containing 100 mg 1^?1 2,4-dichlorophenoxyacetic acid (2,4-D), 3 mg 1^?1 2iP and 3 g 1^?1 activated charcoal, or on MS medium containing 1 mg 1^?1 NAA and charcoal, to determine their morphogenetic responses in vitro. Shoot tips of Metroxylon sp., Phoenix canariensis Hort. ex. Chabaud., P. dactylifera ‘Khalasa’, ‘Thoory’ and ‘Zahidi’, and P. roebelenii O'Brien planted on medium with 2,4-D and 2iP initiated callus, asexual embryos and free-living plantlets after 4–8 months in culture. Shoot tips from Erythea edulis S. Wats., P. canariensis, P. dactylifera ‘Khalasa’, Thoory' and ‘Zahidi’, Washingtonia filifera Wendl. and W. robusta Wendl. cultured on medium containing NAA developed into plantlets with well-developed leaves and adventitious roots within 2–6 months from the time of planting. In some cases, cultured date palm shoot tips gave rise to axillary buds.     

Effects of controlled-release fertilizer on root and shoot growth of Cotoneaster divaricata Rehd. & Wils.

Semi-hardwood cuttings of Cotoneaster divaricata grown in 926 cm³-containers were top-dressed with controlled-release Osmocote (18.0 N-2.6 P-10.0 K) at levels of 0, 2, 3 or 6 g/l of container. Optimum shoot and root growth was obtained at 2 g/l. Applications of controlled-release fertilizer significantly increased foliar N and P concentration, but not foliar K. The most desirable shoot-to-root ratio occurred at 2 g/l.     

The effect of quantum flux density and net photosynthetic rate on morphology and time to flower of hybrid geraniums

Three cultivars of 63-day-old hybrid geraniums (Pelargonium × hortorum Bailey) were grown under high (800–1200 mE m^?2 s^?1), medium (300–600 mE m^?2 s^?1) or low (100–160 mE m^?2 s^?1) quantum flux densities. Plants grown under low light and 25% greater total leaf area but 25% lower dry weight than plants grown under medium or high levels, regardless of cultivar. Time to flower in all cultivars was negatively correlated with quantum flux density, and specific leaf weight and leaf thickness were positively correlated to net photosynthetic rate. ‘Sprinter Scarlet’ and ‘Sooner Red’ had similar correlation coefficients (r) for most relationships, but r values for ‘Ringo’ were generally not as strong. Quantum flux density appears to affect both organogenesis and maturation of the flower.     

Influence of medium-nitrogen level on growth periodicity of Ilex crenata Thunb. ‘Helleri’

Ilex crenata Thunb. ‘Helleri’ plants were grown in sand culture and supplied daily with nutrient solutions of 10, 40, 70 or 100 mg l^?1 nitrogen (N). Plant growth at all rates of N was characterized by an initial period of simultaneous shoot and root dry weight accumulation, followed by shoot elongation, root growth cessation, and major accumulations of N and dry weight. Plants grown at the greater N rates accumulated more N and exhibited a higher shoot-to-root ratio as a result of greater shoot than root growth. Plants grown at the higher N applications initiated extension growth before plants grown at lower N levels.     

Root development of Thuja plicata in peat-substitute rooting media

In this study we investigated the potential usefulness of different substrates produced from gorse (Ulex europaeus L.) for propagating cuttings of Thuja plicata ‘Atrovirens’. The gorse was composted by different methods, to produce four types of compost. These composts were then used as such (100% compost) or in mixes with coarse sand and pine bark compost (25% compost, 25% coarse sand and 50% pine bark compost, v/v/v) to prepare eight different substrates. The substrates were compared in cutting propagation trials carried out in a greenhouse, with a standard rooting medium consisting of 25% Sphagnum peat moss, 25% coarse sand and 50% pine bark compost (v/v/v). Cuttings were taken from a garden hedge in March 2003, and comprised shoots of the previous year's growth. The bases of the cuttings were treated with a 0.4% solution of IBA rooting hormone, then inserted into cells filled with the corresponding substrate and placed on a propagation bench. Rooting percentage and visual rooting score were determined in July. The quality of roots was evaluated, as total root length and number of root tips, in July, September and November 2003, by use of a Delta-T Scan system. The rooting success of the cuttings ranged from 75% to 90%, except when the substrate comprised the pure composted gorse, obtained after the shorter period in an enclosed composting system with addition of fertilizer and reuse of leachates. Most of the cuttings in this substrate died and only 4% of the cuttings rooted successfully. Physicochemical characteristics of this rooting medium included very high electrical conductivity, low C/N ratio and high water retention. Addition of coarse sand and pine bark compost to the composted gorse significantly increased the rooting success. The root quality variables differed depending on the substrate considered and date of harvest. The results showed that substrates made from gorse compost are of potential use as a peat substitute for propagating cuttings of T. plicata ‘Atrovirens’. The physicochemical properties of the composted gorse should be determined before its use to establish whether it can be used pure as a substrate for rooting or whether it should be mixed with other substances.     

Effect of vesicular—arbuscular mycorrhizae on growth of Chrysanthemum morifolium Ramat

Benefits of inoculation with the mycorrhizal fungus Glomus fasciculatus (Thaxter) Gerd. Trappe, on growth of Chrysanthemum morifolium ‘Circus’ were determined for varied conditions of N fertilization (375, 1500 or 3000 kg N/ha/year) and irradiance (6 or 800 μE m^?2s^?1) during lighting long-day treatments. High N fertilization combined with high level of irradiance produced the most mycorrhizal infection. Mycorrhizal infection generally increased C. morifolium height, especially with continuation of long-day lighting to 8 weeks. Mycorrhizae also improved flower, stem and root dry weight for most treatments, particularly the 1500 or 3000 kg N/ha/year fertilization rate and 4- or 8-week long-day light treatments. Although mycorrhizal inoculation increased C. morifolium growth most under extended long-day treatments, only the 2-week duration night lighting resulted in commercially acceptable plant size.     

Nutrient shift in Parthenocissus tricuspidata seedling in response to soil water stress

A climate-controlled greenhouse experiment was conducted to determine the influence of soil water stress on the nutrient status of a climbing plant, Parthenocissus tricuspidata (Sieb.et Zucc) Planch. The results showed that water stress constrained N uptake more than P and K uptake in P. tricuspidata. Soil water supply significantly affected N efficiency ratio, but had no effect on P and K efficiency ratios. P. tricuspidata had low K concentration (<10 mg g⁻¹) in all its plant tissues, which allowed the plant to limit its stomatal opening and reduce its water loss. The study revealed that P. tricuspidata is able to adjust biomass distribution, nutrient uptake and nutrient use efficiency in response to soil water stress and that nutrient management for this plant under water stress should focus on N more than on P and K.     

Effects of soil fertility on growth,nutrient concentration and mycorrhizal development of Liriodendron tulipifera seedlings inoculated with the vesicular-arbuscular fungus, Glomus fasciculatus

Seedlings were grown in 3.28-liter containers under greenhouse conditions and were inoculated with the vesicular-arbuscular mycorrhizal fungus, Glomus fasciculatus (Thaxter) Gerdemann and Trappe. Inoculated and non-inoculated seedlings were treated with 0, 2 or 4 g l^?1 nitrogen (N) as 19-6-12 controlled-release fertilizer. Mycorrhizal development increased growth of seedlings infected by G. fasciculatus at both 2 and 4 g l^?1 N. Without supplemental fertilizer, there was no growth increase of mycorrhizally infected seedlings.     

Effect of temperature and irradiance on vegetative and generative development in Pelargonium × hortorum ‘Radio’

Vegetatively propagated plants of Pelargonium × hortorum ‘Radio’ were grown at 8 combinations of irradiance and temperature levels; 4 or 22 W m^?2 combined with 12, 15, 18 or 21°C. Increase in leaf number, leaf area, shoot and number of inflorescences per plant were all greater at 22 W m^?2 than at 4 W m^?2. At 22 W m^?2, increase in temperature affected leaf number, leaf area and shoot number, but not inflorescence number. However, at 4 W m^?2, number of inflorescences — but not leaf or shoot number — was affected by temperature. When effects of temperature differences were observed, the highest temperature resulted in the greatest number of leaves and shoots and the largest leaf area, but the lowest number of inflorescences per plant. The results indicate that photosynthesis or energy metabolism is of importance to floral initiation in Pelargonium × hortorum.     

Some responses of cucumber,grown in beds of peat,to N,K and Mg

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 (<31%) increased with the amount of N applied. K deficiency reduced the yield by up to 66%, and very high levels of K also tended to decrease the yield. The K x Mg interaction became more marked with time and the loss in yield due to Mg deficiency (<23%) increased with the amount of K applied. Leaves from N, K and Mg deficient plants contained <2.5% N, <1.0% K and <0.28% Mg respectively. In Experiment B, where N was supplied only in the liquid feed, the highest yield was obtained at 220 mg 1^-1. The relation between yield and the total amount of N supplied in the feed was defined by a quadratic regression.     

Nitrogen-enriched ground kenaf (Hibiscus cannabinus L.) stem core as a component of soilless growth media

Summary

Four experiments showed that stem core (xylem of kenaf (Hibiscus cannabinus L.) in combination with sphagnum peat moss and fertilizer nutrients was a satisfactory growth medium for plants of ‘Toy Boy’ tomato (Lycopersicon esculentum Mill.). Greater shoot growth was achieved in media containing 20 to 35% kenaf by volume than 50%, and with fine kenaf (2–4 mm diameter) than coarser grades. In the absence of weekly solution fertilization, N-enrichment of the kenaf was necessary to support greater shoot growth than occurred in commercial growth media. Soaking the kenaf in solutions of increasing nitrogen (N) concentration (0 to 15,000 mg N l^?1) increased shoot growth, but urea ammonium nitrate (UAN, 30N–0P–OK) generally resulted in greater shoot growth than 20N–4.4P–16.6K at the same N concentration. The soaking time for kenaf in UAN was considerably less than in the complete fertilizer to produce similar shoot dry weights. Only a small portion of the kenaf in the growth media required pre-plant N enrichment provided the N concentration of the soak solution was increased in ‘ proportion to the volume reduction. Increasing the N concentration of weekly solution fertilization (20N–4.4P–16.6K) from 0 to 500 mg N l^?1 increased shoot growth irrespective of the N concentration of the kenaf soak solution. In media receiving 0 or 100 mg N l^?1 weekly solution fertilization, shoot growth increased with increasing N concentration of the kenaf soak solution.