Peat-perlite Medium Research Articles

The effects of the combination of mycorrhizae, vermicompost and humic acid applications on ornamental sunflower growth parameters

This study aimed to investigate the effect of the combination of mycorrhizal fungi, vermicompost, and humic acid application on ornamental sunflower growth. The study employed ornamental sunflower (Helianthus annuus L. cv. ‘Sunsantion’) as the plant material. Seedlings, acquired from a local ornamental production company at the four-true-leaf stage, were planted in plastic pots (2 L) containing peat perlite medium (1:1 v/v). The research incorporated three distinct doses of humic acid (10, 20, and 30 ml/L) and vermicompost (10, 20, and 30 ml/L). Humic acid (HA) and vermicompost (VC) were applied by soil drenching with 200 ml solution per pot. After one week, the seedlings were transferred into the pots. In all Mycorrhizae applications, 2 g/pot mycorrhizae inoculated during seedling transferred into the pots. Additionally, 20 ml of humic acid (HA20/M2) and vermicompost (VC20/M2) were combined with mycorrhiza application and applied to the plants. No application was made to the control group. Relative growth rate (RGR) was calculated from harvested samples of individuals from the same application group at 15 and 30 days after plants were transferred into the pots. The highest RGR obtained from HA20/M2 and vermicompost VC20/M2 treatments was 3.55 and 3.48, respectively. Additionally, the highest values of flower diameter (11.71 cm), stem length (41.13 cm), stem diameter (8.46 cm), and flower longevity (10.4 days) were observed in VC20/M2 treatment.

Influence of Volumetric Water Content in a Peat-Perlite Medium on Mother Plant Growth and Daughter Plant Occurrence during ‘Seolhyang’ Strawberry Propagatio

Influence of Volumetric Water Content in a Peat-Perlite Medium on Mother Plant Growth and Daughter Plant Occurrence during ‘Seolhyang’ Strawberry Propagatio

Seed Germination and Seedling Growth of Tomato and Lettuce as Affected by Vermicompost Water Extracts (Teas)

Greenhouse experiments were conducted to evaluate the effects of different concentrations of vermicompost water extracts (teas) and seed soaking duration on germination of tomato (Solanum lycopersicum) and lettuce (Lactuca sativa) seeds. In the first experiment, tomato and lettuce seeds were soaked in vermicompost teas prepared from chicken manure-based vermicomposts for 9 hours. The concentrations of the extracts used were 10%, 5%, 3%, 1% (1:10, 1:20, 1:33, and 1:100 vermicompost-to-water ratio by volume), and 0% (water control). Seeds were sown in peat–perlite medium, and seedlings were harvested after 4 weeks. Soaking seeds in vermicompost teas significantly (P < 0.0001) increased germination percentage and seedling growth of tomato and lettuce compared with control. The response to concentrations of the vermicompost tea was generally linear. In another experiment, tea produced from food waste-based vermicompost was used. Tomato seeds were soaked in 20%, 10%, 5%, 1%, and 0% teas after 24 hours of soaking and sown into a sphagnum moss-based medium. Plant responses were linear and quadratic for germination and growth, respectively, with 1% vermicompost tea increasing germination, whereas 5% vermicompost tea significantly promoted growth. A third experiment was done to evaluate the interaction of a range of vermicompost tea concentrations (20%, 10%, 5%, 1%, and 0%) and length of soaking (24, 12, 8, 4, 1 hours, and 0: no soaking) on the germination of tomato seeds. There was a significant interaction (P < 0.001) between the concentration of vermicompost teas and lengths of soaking. Soaking duration generally had a significantly positive and linear effect on germination of tomato seeds across the concentrations of vermicompost tea. Germination rates of tomato seeds were significantly greater after 8, 12, and 24 hours of soaking. However, within each soaking duration, concentrations of vermicompost teas had variable effects on seed germination. The presence of N-indole-3-acetic acid (IAA), cytokinin, gibberellins, and humic acids in the teas could have been responsible for the faster germination of tomato seeds when soaked at lower concentrations and longer soaking times.

Biochemical properties of compost tea associated with compost quality and effects on pak choi growth

This study investigated the links between variability in compost quality, the biochemical characteristics of their extracts (compost tea) and plant growth indicator through a series of experiments. Five different commercially produced composts were selected for quality evaluation. They were: (i) chicken manure-based thermophilic compost (ii) green waste thermophilic compost (iii) food waste vermicompost; (iv) chicken manure-based vermicompost (aged); and (v) chicken manure-based vermicompost (fresh). Compost teas were prepared from each compost using aerated extraction method with compost to water ratio of 1:10 (v:v), and were applied weekly for four weeks to pak choi (Brassica rapa cv Bonsai, Chinensis group) grown in a peat-perlite medium. The results demonstrated that compost quality generally impacted: (i) nutrient extraction efficiency (ii) microbial activity (iii) phytohormones and (iv) total nutrient content of the extracts. These differences in extract quality similarly impacted growth and mineral nutrient status of pak choi. Applications of compost tea increased growth and mineral nutrient content of pak choi. The responses were greater with aged chicken manure-based vermicompost tea, chicken manure-based thermophilic compost tea, and food waste vermicompost tea. The positive influence on plant growth was largely associated with mineral N and gibberellin (GA4) present in the teas. In vitro cultivation of pak choi with GA4 concentrations similar to those measured in the teas confirmed a direct positive effect of GA4 on growth. These findings suggest that either vermicompost or thermophilic compost can be used for the production of compost tea but the tea quality and its effect on plant may be predicted based on compost quality.

Cotton gin trash compost in the substrate reduces the daminozide spray dose needed to produce compact potted chrysanthemum

Research was conducted to evaluate cotton gin trash compost (CGC) as a peat substitute in the growth medium of compact potted chrysanthemum, and its possible interaction with the plant growth retardant butanedioic acid mono-(2,2- dimethylhydrazide) (daminozide) applied to control plant size. Rooted terminal cuttings of Dendranthema grandiflora Tzvelev. var. Yoko Ono were potted in an 1 peat: 1 perlite (by volume) medium or in an 1 CGC: 1 peat: 2 perlite (by volume) medium and their foliage was sprayed three times with an aqueous solution of 0, 2000, 2500, 3000 or 3500mgl−1 daminozide. The replacement of half of the peat amount in the growth medium with CGC had a restrictive effect on shoot elongation, retarding mainly the internodal length, effect similar to that induced by daminozide. Plants grown in the CGC medium and not treated with daminozide had similar shoot lengths as plants in the peat-perlite medium sprayed with 2000 or 2500mgl−1 daminozide. The combination of CGC with the lowest daminozide concentration used (2000mgl−1) induced shoot growth retardation similar to that induced by the highest concentrations (3000–3500mgl−1) of daminozide in the peat-perlite medium. Leaf size was reduced by CGC as by the higher doses of daminozide, while flower head size was not affected. Both, daminozide and CGC, induced an acceleration of flowering, but the final flower head number was not affected. CGC decreased shoot, flower head and peduncle dry weights and increased root dry weight. At planting day, CGC medium had higher pH, EC, bulk density and total solids and lower total porosity and EAW (easily available water) compared to peat-perlite medium; it also held less water in saturation and drained faster. At the end of the experiment the two media had similar pH and EC values. Substitution of 50% peat with CGC in the commonly used medium for potted chrysanthemum commercial cultivation resulted in a reduction of at least 33% of the dose of daminozide necessary to meet the needs of the market for compact plants, with multiple economic and environmental benefits.

Effects of Vermicompost Tea (Aqueous Extract) on Pak Choi Yield, Quality, and on Soil Biological Properties

This study investigated the effects of vermicompost tea (aqueous extract) on yield and chemical quality of pak choi (Brassica rapa cv Bonsai, Chinensis group) grown in three media (two soils and a peat-perlite medium) under two fertilizer regimes (compost and synthetic fertilizer). The impacts of tea application on the chemical and biological properties of the growth media were also investigated. Vermicompost teas were prepared using various extraction methods (non-aerated, aerated, aerated with additives) with 1:10 (v:v) chicken manure-based vermicompost to water dilution and applied weekly at the rate of 200 mL plant−1 for 4 weeks. Application of vermicompost tea increased plant production, total carotenoids and total glucosinolates in plant tissue. This effect was most prominent under compost fertilization. Total phenolic was lower in vermicompost tea treated plants compared to those treated with only mineral nutrient solution and the water control. Vermicompost tea improved mineral nutrient status of plants and media, and enhanced the biological activity of the media. Variability in yield and chemical quality of plants across treatments was explained largely by variability in tissue N uptake and dry matter accumulation. Dehydrogenase activity and soil respiration of vermicompost tea-treated growth media were approximately 50% higher than untreated media. This study confirmed that vermicompost tea can positively influence plant yield and quality and increase soil biological activity in multiple soil types.

Iron Assimilation and Carbon Metabolism in ‘Concord’ Grapevines Grown at Different pHs

‘Concord’ grapevines (Vitis labruscana Bailey) are susceptible to lime-induced chlorosis, which decreases growth and productivity. In two separate experiments, we grew own-rooted vines in a peat–perlite medium adjusted to different pHs with CaCO3 to characterize how lime-induced Fe deficiency affects root and leaf ferric chelate reductase (FCR) and key enzymes and metabolites involved with glycolysis and the tricarboxylic acid (TCA) cycle in leaves. In addition, we measured the pH of the xylem sap as well as Fe, citrate, and malate concentrations. For both experiments, foliar levels of total Fe, active Fe (extracted in 0.1N HCl), and chlorophyll decreased as lime rate increased. An increase in root-medium pH from 5.8 to 7.5 resulted in a 10-fold increase in root FCR activity, whereas leaf FCR activity decreased 10-fold. An increase in root-medium pH did not raise xylem sap pH but decreased Fe and citrate to some extent. Xylem malate was highest at pH 6.6 and decreased both above and below this pH. Foliar data were evaluated in relation to active Fe content, because it is a better indicator of Fe nutritional status. Lower active Fe decreased midday CO2 assimilation and PSII quantum efficiency as well as night respiration. As active Fe decreased, aconitase activity decreased linearly, whereas the activity of glucose-6-phosphate dehydrogenase, NAD(P)-isocitrate dehydrogenase, NAD(P)-malic enzyme, malate dehydrogenase, phosphoenolpyruvate (PEP) carboxylase, PEP phosphatase, and pyruvate kinase increased curvilinearly. Glucose-6-phosphate, fructose-6-phosphate, and 3-phosphoglycerate content decreased curvilinearly as active Fe decreased. Malate content increased as active Fe increased to 1.0 mg·m−2 and then decreased above this level. Citrate increased linearly as active Fe decreased and was an order of magnitude lower than malate content. Our results suggest that leaf FCR activity may limit Fe assimilation to a greater extent than root FCR activity. The decreased leaf aconitase activity under Fe deficiency is the most likely cause of the increase in citrate levels. Greater activity of the other glycolytic and TCA enzymes under Fe deficiency may help to funnel carbon into the mitochondria and enhance NAD(P) reduction. Citrate levels (and the citrate:malate ratios) in the xylem exudate and leaf were much lower when compared with other species and may be linked to Fe inefficiency of ‘Concord’.

Capillary Mats Alter the Water Content in Medium during Mist Propagation of Dendranthema

A capillary mat-mist system was developed to provide near constant media water contents at differing quantities of mist. Media water contents were reduced by increasing the capillary mat height above a constant water table maintained at bench level. Increased tensions from 0 to 10 cm above the water table reduced water content in Oasis, rockwool, and peat-perlite by 35.4%, 27.6%, and 17.4%, respectively. There was no difference in water content for each medium when the mist quantity ranged between 600 and 1800 mL·m-2·h-1, except when the capillary mat was at 9 cm above the water table and mist volume was 300 mL·m-2·h-1. Chrysanthemum cuttings rooted best when water content was highest regardless of media. Using the peat-perlite medium, water content had the greatest impact on rooting when the mist volume was low (600 mL·m-2·h-1). Relative water content of cuttings was lowest during the first 5 days of sticking and both reduced media water content and mist quantity resulted in the lowest internal water status for the cuttings.

Phosphate and Potassium Retention and Release during Chrysanthemum Production from Precharged Materials: I. Alumina

Soilless root media have little capacity to retain PO4 or K, and this contributes to leaching of these nutrients during greenhouse crop production. The objective of this research was to evaluate the suitability of precharged alumina as a sole source of PO4 and K during greenhouse production of potted chrysanthemum [Dendranthema ×grandiflora Kitam. (syn. Chrysanthemum ×morifolium Ramat.)]. Phosphate and K adsorption and desorption curves were created at 25 °C for two particle sizes (0.5 to 0.9 and 1.8 to 3.2 mm) of alumina (Al2O3; acid-washed and unwashed), and a medium of 7 peat: 3 perlite (v/v) using solutions of KH2 PO4 (P at 0 to 20,000 mg.L-1). Based on these curves, 1.8 to 3.2 mm, unwashed alumina was selected for use in the studies. Precharged alumina was tested in two greenhouse studies at 10% and 30% (v/v) of a peat-perlite medium used to produce `Sunny Mandalay' chrysanthemum. Phosphate, K, and pH were determined on unaltered root medium solutions collected throughout the 10-week cropping cycle, and foliar analyses were conducted on tissue collected at the middle and end of the cycle. Potassium release was adequate to meet chrysanthemum demand for 4 weeks, but inadequate for the remainder of the production cycle. Precharged alumina retained and released PO4 at sustained concentrations (P at <2 mg·L-1) over the course of a 10-week cropping cycle. Growth of plants receiving PO4 from precharged alumina was not significantly different from the controls receiving liquid fertilizer (P at 46.5 mg·L-1) at each watering when precharged alumina comprised 30% of the medium, and only slightly less when precharged alumina comprised 10% of the medium. A phosphorus budget showed that while 36% (103 mg) of the applied PO4-P was lost in the leachate of the controls, only 0.1% (2 mg) was lost from plants produced with alumina-P. This research demonstrates that in a soilless medium with physical properties similar to standard commercial mixes, low but adequate PO4 concentrations can be achieved and sustained using current production practices.

Effect of low pH and aluminium on growth of pinus sylvestris L. Seedlings mycorrhizal with Suillus luteus (L.ex Fr.) S.F. gray

Mycorrhizal syntheses of pine seedlings were conducted with the strain of Suillus luteus No 14 characterized by high tolerance to Al 3+ ions. The experiment was performed as a semi-sterile culture in peat-perlite medium with Al 3+ ion concentration of 4.0 mM. Three mycorrhizal morphotypes were distinguished on the pine roots: single, dichotomously branched and coralloid. The coralloid mycorrhizas were rare on plants treated with Al. Mycorrhizal plants. However mycorrhizas from seedlings treated with Al revealed a thinner mantle and a lack of the Hartig net as compared with the untreated control. There was no growth reduction of tested seedlings by the Al 3+ concentration used. Mycorrhiza formation with the selected S. luteus strain caused lower Al 3+ translocation to the upper part of the tested seedlings compared with the nonmycorrhizal control. It may be concluded that Al 3+ ion concentrations that appear in the moderately polluted fine-root layers of forest soil may in certain condition negatively influence mycorrhiza formation of young Scots pine trees.

Effect of Various NaCl Levels on the Growth, Chlorophyll, Proline and Mineral Compositions of Tomato (Lycopersicon esculentum L.) Grown on Peat-Perlite Medium with Nutrient Solution

The effect of increasing levels of NaCl (0, 50, 75 and 100 mM) on the fresh and dry weight, chlorophyll, proline and mineral constituents of tomato (Lycopersicon esculentum L.) grown on peat-perlite medium with nutrient solution under greenhouse conditions was investigated. According to experimental results, fresh and dry weight of the plants were decreased by NaCl treatments. Sodium and Cl content of the plants were increased, while K and total-N contents were decreased by NaCl treatments. Chlorophyll and proline content of the plants were increased by NaCl applied to the nutrient solution.

872 PB 226 ENHANCED ROOT AND SHOOT GROWTH OF CHRYSANTHEMUM CUTTINGS PROPAGATED IN MEDIA INOCULATED WITH TRICHODERMA HARZIANUM

Trichoderma harzianum is a well-documented biocontrol agent that has been shown to enhance rooting of chrysanthemum `White Marble'. The objective of this research was to determine if T. harzianum would enhance rooting of hard-to-root chrysanthemum cuttings. Two hard-to-root cultivars (`Dark Bronze Charm' and `Golden Bounty') and two easy-to-root cultivars (`Davis' and `White Marble') were propagated in a 1:1 peat-perlite medium amended with T. harzianum at a rate of 0, 5, or 25g/kg medium. Measurements were taken 7, 14, and 21 days after insertion of the cuttings into the medium. Interactions occurred between rate of amendment and day of measurement for some variables measured. However, overall there was increased root fresh and dry weight of all cultivars when T. harzionum rates were 5 or 25 g/kg medium. Increased root fresh and dry weight occurred on days 14 and 21 for most cultivars. Root fresh and dry weight increased with increasing rate of amendment on day 14 but there was no difference between the 5 and 25 g/kg rates on day 21. Shoot fresh weight was increased with 5 or 25 g/kg each measurement day for all cultivar except `White Marble' and shoot length was increased with 25g/kg for all cultivars.

Production of clonal plantlets of tropical pine in tissue culture via axillary shoot activation

A method for the production of multiple clonal plantlets of Pinuscaribaea var. hondurensis Morlet, P. oocarpa Schiede, and P. tecunumanii Equiluz and Perry (P. patula Schiede and Deppe ssp. tecunumanii (Equiluz and Perry) Styles) from juvenile sources is described. The procedure is based on the spontaneous production of axillary shoots following shoot elongation. Much interclonal variation exists with respect to expiant multiplication. The addition of activated charcoal (0.1%) stimulates shoot elongation, especially in recalcitrant clones of P. caribaea. Axillary bud initiation may be stimulated by 6-benzylaminopurine, but levels above 1 μM can result in failure of induced buds to form shoots. Rooting occurs at about 50% in nonsterile peat–perlite medium without auxin pretreatment. Rooted plantlets can be readily hardened and will grow normally in the glasshouse.

Rock Phosphate as a Source of Phosphorus for Vesicular-arbuscular Mycorrhizal Development and Growth of Citrus in a Soilless Medium

Abstract Vesicular-arbuscular mycorrhizal (VAM) development of Glomus intraradices Schenck & Smith and growth response of Carrizo citrange [Poncirus trifoliata (L.) Raf. × Citrus sinensis (L.) Osbeck] and sour orange (C. aurantium L.) seedlings were examined in peat-perlite medium fertilized with 4 levels of superphosphate (SP) and rock phosphate (RP). Loss of P from SP-amended medium was exponential, whereas release of P was linear from RP-amended medium. With SP, root colonization by G. intraradices and growth response of both citrus rootstocks were reduced compared to RP-amended medium. VAM colonization and growth response were less with SP-amended medium than RP, probably because of the initially high available P from SP which inhibited VAM development, and because P later declined to levels insufficient to support maximum growth. When RP was used as a controlled-release source of P, VAM colonization was comparable to that observed in mineral soils. Growth of VAM plants exceeded that of uninoculated plants fertilized with increased levels of soluble P because of P-induced Cu deficiency in absence of VAM. An additional advantage of RP was long-term availability of P, compared to SP which leached within weeks after application to peat-perlite. No further P fertilization may be necessary if RP and VAM inoculum are incorporated into soilless media before planting, whereas repeated application of soluble P would be required for slow-growing woody plants like citrus.

Effects of Container Media and Backfill Composition on the Establishment of Container-grown Plants in the Landscape1

Abstract The addition of peat-perlite to backfill soil increased the initial root movement through the backfill of transplanted holly (Ilex crenata Thunb. cv. Green Luster) grown in a peat-perlite medium. Backfill composition had no effect on the initial movement of roots of plants grown in a soil-peat-sand or pine bark-sand medium.

Chemical Weed Control in Container-grown Nursery Stock1

Abstract Broad-spectrum herbicides severly injured container-grown (Cotoneaster divaricata, Rehd. & Wils. and Euonymus fortunei, (Turcz.) Hand-Mazz. cv. Coloratus, because of rapid leaching into the root zone as a result of the porous peat-perlite medium. Injury was eliminated when activated carbon at 0.75 kg/m3 was mixed into the medium. Weed control was achieved by applying a 2.5 cm layer of the medium containing herbicide (but not activated carbon). The most effective herbicides were dichlobenil (0.44 g/m2), dichlobenil (0.44 g/m2) plus trifluralin (0.22 g/m2), or simazine (0.44 g/m2).

The Influence of Nitrogen and Potassium Nutrition on Vine and Root Development of the ‘Allgold’ Sweetpotato at Early Stage of Storage Root Enlargement1

Abstract Plants of the ‘Allgold’ sweetpotato were grown for 60 days with 3 levels of N and K in a peat-perlite medium to determine the influence of these nutrients on plant development early in the stage of root enlargement. Dry vine and fresh root weights were highly correlated, with high N and medium K resulting in the largest vine and root weights. The numbers of roots were influenced more by K than by N, but the size of roots was influenced more by N than by K. The addition of N without K was responsible for long roots, and the addition of K reduced root length at all N levels.