Pine Bark Media Research Articles

Adsorption of copper ions from aqueous solution using surface modified pine bark media

Adsorption of copper ions from aqueous solution using surface modified pine bark media

An irrigation control system with a web-based interface for the management of Eucalyptus planting stock in a nursery

Efficient nursery irrigation is a key factor for the production of high-quality forestry planting stock. Conventional timer-based irrigation systems used by most forestry nurseries have some drawbacks that, if not properly managed, can lead to over-irrigation and water wastage, leaching of nutrients and contribute to increased incidences of pests and/or diseases. A practical method to accurately measure media water content and control irrigation more carefully could prevent some of these issues. To evaluate the potential use of an automated irrigation system, commercially available Decagon EC-5 dielectric soil water content sensors were laboratory-calibrated against the gravimetric method using coir/pine bark/vermiculite, coir/perlite and pine bark media to measure water content of nursery seedling containers. Using Eucalyptus dunnii seedlings raised in polystyrene seedling containers to test the irrigation system, a datalogger was programmed to control irrigation for low (0.22–0.26 m3 m−3), medium (0.26–0.32 m3 m−3) and high (0.32–0.41 m3 m−3) watering treatments. The measurements were displayed in near real-time using a web-based system, which allowed for system checking and from which data could be downloaded. The Decagon EC-5 sensors were successfully calibrated for all media (R2 > 0.97) and provided a better estimation of media water content than the manufacturer-supplied calibration equation better-suited for soils. The automated irrigation system effectively maintained the specified media water content for E. dunnii seedlings. The high watering treatment seedlings had the highest growth rates, although this treatment also had increased leaching of nutrients. By contrast, the low watering treatment seedlings showed the lowest growth rates, although these seedlings seemed to be more robust and tolerant of water stress. This study showed that the automated irrigation system, based on measurements of the media water content, can be successfully used in scheduling irrigation for Eucalyptus seedlings, leading to potential water savings.

Suitability of Fly Ash Vermicompost as a Component of Pine Bark Growing Media: Effects on Media Physicochemical Properties and Ornamental Marigold (Tagetes spp.) Growth and Flowering

ABSTRACTThis study evaluated the possibility of mixing fly ash vermicompost (FA) with pine bark (PB) compost to produce a horticultural growing medium for ornamental plants using ornamental marigolds (Tagetes spp.) as the test crop. Fly ash vermicompost was mixed with pine bark compost at 0, 25, 50, 75, and 100% and marigold seeds were sown with or without fertilizer in the resultant media to test their suitability as seedling growing media. FA substitution up to 50% significantly improved water-holding capacity, total porosity, and air-filled porosity. It also raised pH from 4.52 to a maximum of 8.33 when incorporated up to 75%. Incorporation of FA up to 75% resulted in significantly high germination percentages above 90% compared to only 22.5% for the 100% PB medium. However, after 4 weeks of growth, seedlings in the 25 and 50% FA substituted media had higher plant height and leaf area. The 25% FA treatment resulted in significantly higher number of flowers and buds compared to the 50 and 75%. For effective marigold seedling germination and growth, a 50% FA:50% PB growing medium is recommended while for maturity and flower production, the 25% FA:75% PB combination is preferred.

A Comparative Evaluation of the Physical and Chemical Characteristics of Composted Tea Tree (Melaleuca alternifoliaL.) with Pine Bark Growing Media in Tobacco (Nicotiana tabucumL.) Seedling Production

The search for suitable organic growing media substitutes for pine bark based media combinations has been prompted by concerns over high costs and lack of availability to smallholder farmers coupled with increasing demand for soilless media in Zimbabwe. A trial was conducted for 12 weeks to investigate the suitability of tea tree compost-based substrates for tobacco seedling production as a substitute of the traditional pine bark growing media. The use of composted tea tree growing media in float trays significantly (p<0.05) increases the bulk density of the media by 23–59% when compared with pine bark media. The cation exchange capacity of the native pine bark growing media was 14 to 95% lower than that for the composted tea tree media. The use of the composted tea as media for tobacco seedling nursery reduced seed germination by 10–37%, seedling stem height by 4–34%, and seedling stem girth by 6–175%. While the nutrient holding and supplying potential of the growing media in seedling production is important for normal seedling growth, its effect on seedling growth vigor is less important than that exerted by the presence of suitable physical conditions in the media.

Pinus patula and pine hybrid hedge productivity in South Africa: a comparison between two vegetative propagation systems exposed to natural infection by Fusarium circinatum

In response to the Fusarium circinatum pine pathogen threat in southern Africa, research has been conducted on the development of F. circinatum-tolerant P. patula and P. patula hybrids. The objective of this study was to investigate the propagation potential of these taxa in two vegetative propagation systems, hydroponic sand beds and polythene bags with composted pine bark growing medium. Significant differences (p < 0.001) in mortality associated with F. circinatum were observed between the P. patula × P. tecunumanii (LE) hybrid (6%) and P. patula (19–23%). No significant differences in mortality associated with F. circinatum were observed within P. patula × P. tecunumanii (LE) families, which ranged from zero to 15%. Significant mortality differences (p < 0.001) were observed between P. patula families, which ranged from 8% to 44%. The number of rooted cuttings produced, per hedge established, over the four-year period was significantly better (p < 0.001) in the P. patula × P. tecunumanii (LE) hybrid (52) than in P. patula (29–33). Significant differences (p < 0.001) were also observed in the number of rooted cuttings produced per family, with P. patula × P. tecunumanii (LE) families ranging from 35 to 70 cuttings per hedge plant established and P. patula families between 20 and 42 cuttings. Over the four-year duration of the trial all taxa showed increased productivity in hedges grown in a hydroponic sand bed system, which received more consistent fertilisation and yielded an average of 55 rooted cuttings per hedge, over those grown in polythene bags with composted pine bark medium, which yielded 41 cuttings on average. This study demonstrated that the P. patula × P. tecunumanii (LE) hybrid is a feasible substitute for P. patula in both vegetative propagation systems, as it not only shows improved survival, through increased F. circinatum tolerance, but also improved productivity.

Foliar Blight of Annual Vinca (Catharanthus roseus) Caused by Phytophthora tropicalis in Virginia.

Annual vinca (Catharanthus roseus), also known as Madagascar periwinkle, has been cultivated as a major color crop for landscape and as an herbal medicine. This plant performs well in dry, warm locations with full sun or partial shade. Two-month-old diseased plants (cv. First Kiss Blueberry) with blighted leaves and stems were received from a local nursery in Suffolk, VA in May 2009. The disease began with dark, greenish black lesions on young leaves. Lesions gradually became tan or brown and leaves wilted and curled and finally turned necrotic. Brown, sunken lesions beginning at the branching points were typical symptoms on blighted stems and shoots. Blighted areas and spots were approximately 30 to 90 mm long and 20 to 40 mm wide on leaves and 40 mm long on stems. A Phytophthora species previously unknown to attack this plant was consistently isolated from diseased leaves and stems, and resultant isolates were grown on PARP-V8 agar. These isolates produced papillate sporangia on umbellate sympodium. Sporangia were mostly ellipsoid with a length/breadth ratio of >1.8 and tapered base; they were caducous with a long pedicel (usually >50 μm). These isolates also produced chlamydospores that averaged 31 μm in diameter. The isolates were identified as Phytophthora tropicalis by morphology. The identity was confirmed by DNA fingerprinting (1) and sequence analysis of ribosomal DNA internal transcribed spacers (GenBank Accession No. GQ478707). For pathogenicity studies, a zoospore suspension of 1,100 spores per milliliter was sprayed onto the foliage of 50-day-old healthy plants of the same cultivar grown in pine bark medium in six 10-cm-diameter plastic containers with a hand mister in the evening until runoff. Control plants were sprayed with tap water. Plants were placed in a tray containing a small amount of water and enclosed in plastic tents overnight to facilitate infection. The tents were removed the following morning, and plants were kept in a greenhouse under natural light and watered as needed. Within 4 days, all six inoculated plants developed foliar symptoms similar to what was observed on the diseased plant samples from the production nursery. The pathogen was reisolated from infected leaves and stems and its identity was confirmed by colony PCR-single-strand conformation polymorphism (3). The pathogenicity test was repeated once with the same results. Phytophthora aerial blight is a common destructive disease of annual vinca, which is usually caused by P. nicotianae. To our knowledge, this is the first report of foliar blight caused by P. tropicalis on annual vinca in Virginia. According to the head grower who submitted the disease samples, this new disease caused 10% crop loss of annual vinca this past spring. P. tropicalis was previously reported to attack ornamental shrubs, including Pieris japonica and Rhododendron catawbiense (2). This study indicates that P. tropicalis could be a potential threat to herbaceous annual crops as well.

Efeito de casca de camarão, hidrolisado de peixe e quitosana no controle da murcha de Fusarium oxysporum f.sp. chrysanthemi em crisântemo

The incorporation of shrimp peelings and fish hydrolyzate into a pine-bark container medium and an aerial spray of chitosan were investigated for the control of Fusarium wilt of chrysanthemum. Disease severity was evaluated by means of a six-category scale (0 - healthy plant to 5 - dead plant) at 8, 12, 15 and 20 weeks after planting in experiments with shrimp peelings and fish hydrolyzate, and after 18 weeks in the chitosan experiment. The total microbial activity of the container media was evaluated (by fluorescein diacetate hydrolysis), physicochemical attributes of the media were assessed, and plant growth components were measured. Incorporation of shrimp peelings into the pine-bark medium at 4% (v/v) suppressed wilt, but at 5% the plants exhibited symptoms of phytotoxicity and died. The suppression of Fusarium wilt was possibly due to physicochemical and biological changes in container medium induced by the shrimp peel. Given that the concentration which was phytotoxic was only slightly higher than the concentration which suppressed wilt and promoted plant growth, caution is needed in any use of shrimp peelings for wilt control. The fish hydrolyzate increased wilt severity as the concentration was increased. No consistent effects were found of chitosan applied to the aerial parts of the plant.

GRAFTING PAPAYAS (CARICA PAPAYA L.)

Papaya is one of the few fruit crops still propagated by seed. Vegetative propagation by leafy cuttings has been practiced successfully in South Africa for over 40 years, because Papaya ringspot virus has not been a problem. Grafting has been done in various places but problems have arisen locally with bacterial infection of the scions. Several approaches were made to try to help overcome the problem viz. (i) application of soluble silicon to the parent stock and rootstock plants, (ii) spraying scions and rootstocks with Eco-77 ® , a suspension of Trichoderma spores, or a Bacillus broth culture, at the time of grafting, (iii) surface sterilization of rootstock and scion with (a) 5 or 10% household bleach (containing 3.5% sodium hypochlorite) or (b) 10% hydrogen peroxide. Parent stock plants have been repeatedly cut back to ensure the production of many thinner (10-20 mm diameter) side shoots suitable for use as scions. Seedling rootstocks were grown in a composted pine bark medium in plastic bags in a greenhouse. Results showed that household bleach was the significantly best method of surface sterilization. Success rate was 81%, after 15 weeks, when side grafted onto well fertilized and vigorous rootstocks. The biological treatments were not beneficial.

Timed Release of Flurprimidol from a Granular Formulation in Mulches and Sand

Flurprimidol is a plant growth regulator that can be applied as a granular formulation. Understanding flurprimidol release from a granular formulation and movement in various mediums will impact how it is used. Dissipation of flurprimidol from a granular formulation and movement through organic media and sand were evaluated in a greenhouse and laboratory experiment. Experimental variables included media type, depth, and irrigation event. Dissipation isotherms were determined by applying nonlinear regression. Mobility was evaluated using columns filled with media, which was surface-spiked with the granular formulation and then irrigated once daily for 22 consecutive days. Leachate was collected and analyzed by high-performance liquid chromatography–mass spectroscopy. Half-life (DT50), defined as time to 50% reduction, varied among sand, media, and media depth. Flurprimidol dissipation was rapid through sand with DT50 of 6 days. DT50 increased with increasing media depth from 5 to 10 cm for pine bark plus sand, 18 and 35 days, and hardwood bark plus sand, 77 and 173 days, respectively. Maximum flurprimidol leaching was a cumulative 71% of applied amounts over 22 irrigation events through the sand. Hardwood and pine bark media allowed less than 25% of flurprimidol to escape through the column. Data for all media indicated that flurprimidol was mobile through the substrates but exhibited hysteresis with pine bark and hard wood bark media. An initial pulse of flurprimidol will release slowly from this formulation over time. These results indicate that flurprimidol will dissipate from a granular formulation over time and that it will have movement through sand soil and pine bark and hardwood bark media to reach the roots of growing plants.

Effects of Fertilizer Rate on Growth and Fruiting of Containerized Southern Highbush Blueberry

The effects of fertilizer rate and composition on growth and fruiting of ‘Misty’ and ‘Star’ southern highbush blueberry were evaluated in a containerized production system using pine bark medium. Two fertilizer analyses (12N–1.8P–46.6K and 12N–5.2P–9.9K) and three fertilizer rates were used. Plant growth and fruiting were unaffected by fertilizer analysis. Growth and fruit yield of ‘Star’ increased linearly with increasing fertilizer rate. For ‘Misty’, plant growth and yield were reduced at the highest fertilizer rate as a result of a high incidence of blueberry stem blight associated with that treatment. Flower bud density was highest for the ‘Misty’ plants receiving the high fertilizer rate and this may have resulted in excessive fruit set leading to stress-induced blueberry stem blight. Optimum fertilizer rates for young southern highbush blueberry plants grown in containerized pine bark systems appear to be cultivar-specific and similar to fertilizer requirements in soil culture.

Effects of urea formaldehyde foam soil amendment on growth and response to transient water deficit stress of potted Flindersia schottiana saplings

Hydrocell™is a urea formaldehyde resin foam (UFRF) product used as a soil amendment. It is proposed to improve the physicochemical properties ( viz. water relations and aeration) of the plant root zone. Flindersia schottiana is a tree species used in the ornamental horticulture industry. This study investigated the potential of Hydrocell™ [0–50% (v/v) incorporation rates] to promote growth of F. schottiana saplings during containerized nursery production in composted pine bark medium. The growth response of the potted saplings to transient water stress was also assessed. In addition, growth of F. schottiana saplings potted into three different soil types (sand, loam, clay) was assessed in the presence and absence of 30% (v/v) Hydrocell™. Under well-watered conditions in composted pine bark, Hydrocell™ treatments enhanced sapling leaflet numbers, with 30% (v/v) being the most beneficial treatment. However, no consistent significant differential effects of incorporation rate on either plant height or stem diameter were recorded. Extended time to wilting upon withholding irrigation was achieved, with the optimum Hydrocell™ rate being 10% (v/v). Among the three soil types compared, use of 30% (v/v) Hydrocell™ resulted in improved growth of potted F. schottiana saplings in the sand and loam soils, but not in the clay soil. These findings suggest that the UFRF, Hydrocell™, holds limited promise as a soil amendment for trees in the nursery phase. Optimum incorporation rates (v/v) would need to be determined for individual media types, specific irrigation regimes and individual taxa.

Bell Pepper Fruit Yield and Quality as Influenced by Solar Radiation-based Irrigation and Container Media in a Passively Ventilated Greenhouse

Frequent fertigation of soilless-grown bell pepper (Capsicum annuum L.) can increase fruit production, but development of fruit disorders may offset the increase in yield of first-quality (blemish-free) fruit in greenhouses with minimal environmental control. Fruit yield and quality were studied as affected by water volumes and nutrient concentration levels, delivered with irrigation events initiated after determined cumulative solar radiation levels, in ‘HA3378’ bell pepper from October to May in north–central Florida. Irrigation events occurred after solar radiation integral levels (SRI; ±SD) 1.7 ± 0.42, 3.7 ± 0.42, 5.7 ± 0.42, 7.7 ± 0.42, and 9.7 ± 0.42 kW·min−1·m−2, which led to mean number of daily irrigation events of 61 ± 31, 26 ± 12, 17 ± 8, 12 ± 5, and 10 ± 4 respectively. In peat mix, perlite, and pine bark media, volume per irrigation event and concentration levels of the nutrient solution were, in the first experiment, 74 mL standard (74-s), and in a second concurrent experiment, 74 mL half-standard (74-½s) or 3) 37 mL standard (37-s). In both studies, combined marketable fruit yields of first quality and second quality (minor cracking patterns and yellow spots) increased linearly with decreasing SRI (increased events per day). First-quality fruit weight with 74-s was unaffected by media and, in a quadratic response to SRI, reached 5.4 kg·m−2 at 5.7 kW·min−1·m−2. First-quality weight with 74-½s and 37-s did not differ. Weight was unaffected by SRI in peat mix and perlite, and a quadratic response was recorded in pine bark, with yields of ≤3.6 kg·m−2. Fruit cracking incidence decreased with increased SRI, and was generally greater in pine bark. Incidence of yellow spots doubled with 74-½s compared with 37-s, and decreased linearly with increased SRI; the disorder was minor with 74-s. Compared with 37-s, 74-½s decreased fruit with blossom-end rot by 14%, increased marketable fruit weight by 10% in media with the lowest water-holding capacity (perlite, pine bark), and increased nutrient use efficiency. With any media used, the SRI set point of 5.7 kW·min−1·m−2 (daily mean of 17 irrigation events) and 74 mL, at standard nutrient concentration levels, appeared to produce greater blemish-free fruit yield than delivering 37 mL/event or half-concentrated 74 mL/event within the range of SRI means of 1.7 to 9.7 kW·min−1·m−2 (61–10 irrigation events/day). Disorder-tolerant pepper cultivars, better temperature control, and August plantings are additional suggestions for irrigation management to increase first-quality fruit yield.

Water and nutrient retention by Aquasoil® and Stockosorb® polymers

Water retention and hydration rate of Aquasoil and Stockosorb polymers, the effects of these polymers on the water, ammonium and nitrate retention of a pine bark growth medium and the response of the polymers to fertilizer solutions were investigated. Aquasoil retained 129 g of distilled water g−1 of polymer, whereas Stockosorb retained 216 g−1 of polymer. Both polymers reached their maximum capacity in about one hour. The polymers when combined with 1 or 2 g 500 g−1 of pine bark, improved the water retention capacity of the growth medium. However, longer time was required in the growth medium for the polymers to reach maximum capacity than in the distilled water. All polymer-amended pine bark media retained more ammonium, compared to non-amended media. The 2 g polymer treatment retained greater amounts of NO3 than the lower rates. Retention of water by the Aquasoil® and Stockosorb® polymers was reduced to 88% and 86% of capacity compared to distilled water, whereas fertilizer solution reduced water retention to 53% and 42% of capacity. Soaking in distilled or tap water improved water retention of the polymers over fertilizer solutions.

The Fate of Bifenthrin and Fipronil in Pine Bark Nursery Media

Bifenthrin and fipronil are important pesticides used in the nursery industry for the control of imported fire ants. Our research measured the influence of irrigation frequency and time on the degradation of bifenthrin and fipronil in pine bark nursery medium. Pine bark media leachates were collected over a 180-d period. Levels of bifenthrin, fipronil, and metabolites of fipronil (MB 46513, MB 45950, MB 46136) were measured using gas chromatography and mass spectrophotometery. Bifenthrin leachate concentrations decreased from 60 ppb on day 1 to ≈1 ppb after 120 d. Fipronil leachate concentrations decreased from 40 ppb on day one to a low of 15 ppb after 120 d. In contrast, metabolites MB 45950 and MB 46136 gradually increased over the 180-d period. Metabolite MB 46513 was not detected during the experiment. Pine bark medium leachate concentrations of bifenthrin and fipronil were greater than previously reported levels in pure water. We theorize that organic compounds present in pine bark may have increased the solubility of these chemicals.

EFFECTS OF SELECTED SOIL FUNGICIDES ON NITRIFICATION AND GROWTH OF PRIVET IN A PINE BARK MEDIUM

Nitrification inhibitors were evaluated for their capacity to retard oxidation of ammonium in a pine bark medium. Nitrapyrin, captan, etridiazole, and metalaxyl were added to a pine bark medium in amounts ranging from none to 133% of manufacturers' or research-based recommendations. Inhibition of nitrification was assessed by measurements of appearance of nitrate and disappearance of ammonium at 4-wk intervals for 12 wk. The effects of these chemicals on the growth and nitrogen (N) composition of privet (Ligustrum ibolium L.) in containers of pine bark mix were assessed. Based on retention of ammonium and suppression of nitrate accumulation, etridiazole and nitrapyrin were effective inhibitors, whereas captan and metalaxyl were not. Etridiazole was more effective than nitrapyrin, and the efficacy of etridiazole increased as amount of application increased. The efficacy lasted for about 4 wk with nitrapyrin or etridiazole. With the amounts of fertilization and inhibitors used, growth or total N concentration of privet was not affected by the inhibitors.

322 In Vitro Propagation of the Ornamental Bromeliad, Tillandsia eizii

Many bromeliad species indigenous to the rain forests of Central and South America are threatened because of over-collection and habitat destruction. Studies were conducted to develop propagation protocols for Tillandsia eizii, a rare ornamental bromeliad of ceremonial significance to the Highland Maya communities in Chiapas, Mexico. We anticipate using in vitro propagation for the conservation of this species with the potential of utilizing bromeliads as an alternative and sustainable forest resource. Protocols were developed for the sterilization and germination of axenic seed. Seedling growth in vitro was assessed and outplanting studies were conducted. Media were evaluated to promote adventitious bud production in experiments using the plant growth regulators naphthaleneacetic acid and benzylaminopurine. Pulse time and duration, as well as the stage of seed development, had a marked effect on bud production. The effects of various potting media on plant growth and survival were assessed. A pure pine bark medium elicited over 95 percent survival. Plants exhibited a “tank-like” morphology characteristic of plants in the wild.

336 A Comparison of Virus-free Versus Infected Sweetpotato Transplants for Cutting Propagation

Production of disease-free sweetpotato [Ipomoea batatas (L.) Lam.] transplants is of major importance to certified and foundation seed programs and producers. Sweetpotato roots are traditionally planted and cuttings are harvested from propagation beds. The objective of this study was to investigate the efficiency of producing cuttings in nursery containers. Virus-tested and virus-infected `Beauregard' sweetpotato transplants were harvested from planting beds for the purpose of producing cuttings for transplants. Cuttings were established in 3.7-L plastic nursery containers filled with 100% pine bark amended with either low, medium, or high rates of Osmocote 14-14-14 and dolomitic lime. Resulting transplants produced a greater number of cuttings and greater plant biomass with higher fertilizer rates. Increasing fertilizer rates also had a positive effect on cutting production and biomass. Dry weight and stem growth were similar for both virus-infected and virus-tested transplants following first and second harvests. Producing foundation cuttings in nursery containers filled with a pine bark medium proved to be an efficient method of increasing virus-tested sweetpotato cuttings.

Branching, Growth, and Flowering Responses of Perovskia atriplicifolia to Florel, Sumagic, and B-Nine

Russian sage (Perovskia atriplicifolia) grown in a pine bark medium in 1-gal containers were sheared to a height of 15 cm on 20 June 1997. One day later the plants were treated with foliar sprays of Florel (ethephon) at 0, 500, or 1000 ppm. One week later, sprays of B-Nine (daminozide, 5000 ppm) or Sumagic (uniconazole, 15 ppm) were applied to some of the plants previously treated with Florel, or previously nontreated. Three weeks after initial treatments, the Florel (500 and 1000 ppm) and the Sumagic treatments, applied individually, reduced plant height by 26%. The B-Nine treatment reduced height by 18%. Combination treatments (Florel followed by Sumagic or Florel followed by B-Nine) provided additional height control Florel at 500 or 1000 ppm significantly increased branching of Perovskia. Additional treatments with B-Nine or Sumagic had little effect on this response. Florel delayed flowering by ≈7 to 10 days.

Assessment of Biologically Converted Swine Waste as a Fertilizer Source in Container Production

Swine waste (SW), the by-product of North Carolina's booming hog industry, is one of the state's most underutilized resources. Currently, SW is used to grow coastal bermuda hay, a “disposal” crop with little to no economic value. Use of SW by commercial growers as fertilizer would reduce the need to dispose of SW and could reduce the overall input of nutrients into the environment. Our objectives were to determine: plant growth characteristics of SW, the effects of SW on leachable forms of nitrogen, and the physical effects of SW in a pine bark media. To avoid pathogens, we used SW (BionSoil™) that had been biologically digested as part of a proprietary SW treatment process (Bion Technologies, Inc.). Liners of `Rose Madness' petunia, `Skogholm' cotoneaster, `Girard's Red' azalea, and `Wilson's Yellow' daylily were planted in 3.8-L plastic pots that contained one of the following (by volume): 10% SW:90% pine bark, 20% SW:80% pine bark, 30% SW:70% pine bark, or pine bark (control) amended with 3.6 kg of 23-4-8 controlled release fertilizer (CLF), 3.6 kg dolomitic limestone, and 330 g micronutrient fertilizer per m3. Shoot dry weights were determined for all species at harvest. Root dry weights were obtained for cotoneaster and daylily. Leachate nitrogen and pH was determined periodically throughout the 22-week study. By the 14th week, nitrogen and potassium deficiencies were identified on plants growing in SW-amended media. Those treatments were subsequently topdressed with a corrective application of 9 g of 23N–4P–8K CRF. Generally, SW can produce plants similar to short-term CRF without the need for supplemental micronutrients or lime Root biomass was greater in SW media than in the control. A mid-season application of a N–P–K fertilizer may be necessary.

Effects of salinity and alkalinity on pansy and impatiens in three different growing media

The quality of irrigation water used for greenhouse crop production can strongly influence plant growth. However, the effect on plant growth is probably a combination of water quality and the type of growing media used. To determine the effect of saline and alkaline irrigation water on plant growth and nutrition, pansy and impatiens were grown in peat, peat:pine bark, and pine bark media under standard greenhouse conditions. Salinity treatments of 0, 100 and OmgL‐1 NaCl: CaCl2 and alkalinity treatments of 0, 100, 200, 300, and 400 mg L‐1 NaHCO3 were applied at every irrigation. Salinity levels at 100 mg L‐1 and greater caused necrosis of leaf edges, upward curling of leaves, and reduced flower number for pansy. Treatment symptoms for impatiens were reduced growth, general chlorosis, and reduced flower number. These treatment symptoms increased in severity for plants grown in pine bark. Alkalinity levels at 200 mg L‐1 and greater caused decreased flower number, necrosis of leaf edges, and downward cupping of leaves of pansy. Treatments symptoms of impatiens were general chlorosis, water‐soaked appearance of leaves and leaf abscission. Elemental concentrations of sodium (Na+), chloride (Cl), calcium (Ca++), magnesium (Mg++), and potassium (K+) varied in media solution and tissue with symptom and treatment.