Coconut Coir Dust Research Articles

Semiconductor carbon composite from coir dust and sepiolite

Advantage of the water adsorption capacity of sepiolite at high relative humidity and that of activated carbon [7], being also used as adsorbent for NH 3 and H 2 S [8]. Here we report the preparation of a carbon composite by the carbonization of pellets containing coconut coir dust [9] as carbon source and sepiolite as a binder. It is known that carbonaceous materials present good electronic conductivity in addition to high surface areas [10,11], thus being ideal candidates for use as electrodes in systems such as sensors, energy storage and generation devices [12]. Monoliths are required for some of these applications, such as electrodes for supercapacitors, as specifically discussed by Rojo and co-workers [13,14], so here we propose a possibility of obtaining carbon monoliths from coconut coir with semiconducting properties.

EFFECT OF MULCHES AND COVER CROPS ON WATER STATUS AND GAS EXCHANGE OF COCONUT (Cocos nucifera L.) PALMS IN GRAVELLY SOILS

Two field experiments were conducted in gravelly soils (Andigama series) inSri Lanka to investigate the effect of different mulches and cover crops,utilized to conserve soil moisture, on water status, gas exchange andrelated soil parameters of coconut palms {Cocos nucifera L. var typica).The results revealed that mulching only the manure circle was not effectivein improving the palm water status, gas exchange and soil water statusduring dry periods in Andigama soil series (gravelly soils). The mulchestested were coconut husks, coir dust, straw, black polythene and driedcoconut fronds. The palms were equally sensitive to soil water depletionand responded to the water deficit by increasing the stomatal resistanceirrespective of the mulch treatment. When the manure circle was mulchedwith dried coconut fronds, and the rest of the land was also mulched with afive cm thick layer of coir dust, the palms showed an improved gasexchange ability than palms growing in bare land or with cover crops duringthe dry period.

ECONOMICS OF SOIL MOISTURE CONSERVATION IN COCONUT LANDS USING COCONUT HUSKS AND COIR DUST

Economic feasibility of soil moisture conservation in coconut production usingcoconut husks and coir dust was examined in this study. The preliminary data for thestudy were collected from two trials conducted by the CRI along with several othersecondary information. The results of the analysis' revealed that calculated Benefit-Costratios and Net Present Values are financially and economically acceptable under all thescenarios addressed in this study. Three different interest rates, such as 10%, 15%, 18%and two.effective time periods (viz. six and nine years) were used for the analysis.Based on the estimated economic parameters, it is concluded that the efforts on moistureconservation using coconut husks and coir dust in lateritic gravel and sandy soils areeconomically viable propositions. As the initial cost of investment is substantial, othermeans to overcome the problems of financial constraints in investment may be lookedinto.

EFFECTS OF APPLICATION OF COCONUT HUSK AND COIR DUST ON THE YIELD OF COCONUT

In recent years much attention has been focussed on the importance of moisture conservationpractices in coconut lands, particularly in drier parts of the Coconut triangle. Experiments wereconducted in mature coconut plantations, to study the effect of various methods of application ofcoconut husk and coir dust, in lateritic and sandly soils, on the yield of palms.The results revealed that the use of both husks and coir dust was beneficial to coconutproduction. This was partly attributed to their ability ot retain moisture in the soil and regenerationof more roots per unit area. In terms of copra yield per palm coir dust appeared to be more effectivethan husk in lateritic soil. Of the different placement methods, husk in pits caused significantimprovent in nut and copra yield per palm, while coir dust placed in trenches had the least effect.Furthermore, placing husk or coir dust in pits between two palms appeared to be more effectiveand economical than in circular trenches round each palm. Based on these results, use of coir dustin pits is recommended as an effective alternative to husk pits, for moisture conservation and inreducing the adverse effects on the palm during the dry period.

Mass multiplication of Pogostemon cablin (Blanco) Benth genotypes and increase of essential oil and patchoulol yield

Patchouli ( Pogostemon cablin) is an aromatic species indigenous to Asia that has been cultivated in many parts of the world for the extraction of essential oils from its leaves. The objective of this study is to develop protocols for plant regeneration and acclimatization from three genotypes of patchouli. For the plant regeneration experiment, a completely randomized factorial design, employing the growth regulators kinetin and indole acetic acid (IAA), was used. The acclimatization used different mixtures of coconut coir dust and vermiculite supplemented with NPK fertilizer and limestone. Direct regeneration of plants was observed for MS medium supplemented with low concentrations (0.5–2.0 mg L −1) of kinetin and IAA alone or in combination for all of the studied genotypes. For genotypes POG014 and POG021, there were 175 and 154 shoots, respectively, obtained per explant with the use of 1.0 mg L −1 kinetin and 0.5 mg L −1 IAA. For genotype POG002, there were 41 shoots obtained per explant in a medium supplemented with 1.0 mg L −1 kinetin. The acclimatization of micropropagated plantlets of all three genotypes showed the best results with the vermiculite substrate plus MS medium salts. Essential oil content and the percentage of patchoulol were higher in plants derived from micropropagation in the three genotypes studied.

Amelioration of salt stress by irrigation management in pepper plants grown in coconut coir dust

A long-term greenhouse experiment was conducted to study the effects of irrigation frequency and salinity on pepper fruit yield and quality in crops growing in coconut coir. Two salinity levels (4 mM NaCl, 2.6 dS m-1 and 24 mM NaCl, 4.6 dS m-1) were combined with four irrigation treatments (one irrigation event every two days (0.5), one irrigation event per day (1), four irrigation events per day (4), and eight irrigation events per day (8)) in a 2 × 4 factorial combination. The effect on fruit quality was evaluated at the early and late harvest seasons, corresponding with two different periods of fruit production (May and July). We found that above-ground total biomass and marketable fruit yield decreased in the salinized treatments. When salinized (24 mM NaCl) nutrient solution (NS) was applied, increasing the number of irrigation events to eight per day resulted in a decrease in the incidence of blossom-end rot and a corresponding increase in the marketable fruit yield. When control (4 mM NaCl) NS was applied, one irrigation event per day yielded as much marketable fruit as was produced with the highest irrigation frequency, and therefore increased water use efficiency, expressed as marketable fruit weight per L of NS applied. When NS containing 24 mM NaCl was used, there was an increase of Cl- but not Na+ in the leaf tissue, with this increase reaching its maximum in the treatment involving eight irrigation events per day. Salinity decreased the Ca2+ concentration of the fruit only in the early harvest season of production. However, increasing irrigation frequency consistently resulted in higher Ca2+ concentration in the fruit. The effects of salinity on the morphological and organoleptic properties of the fruit were more pronounced in the late harvest season.

Agronomical Response and Water Use Efficiency of Sweet Pepper Plants Grown in Different Greenhouse Substrates

An experiment was carried out to assess the influence of three types of substrate on the growth and yield of sweet pepper (Capsicum annuum L.). Plants were grown during three cycles (2005, 2006, and 2007) in coconut coir dust (CC), urea formaldehyde foam (UF), and rice hull (RH) amended with polyacrylamide gel (water absorber). Growth parameters, dry weight (DW) of vegetative and generative parts, intercepted radiation, water uptake, total fruit yield, and quality parameters were analyzed. Plant height, total leaf fresh weight, and stem diameter were higher in CC and lower for the RH substrate, which also showed lower yields and fruit quality. Accumulated dry matter was modeled according to water uptake and substrate using a linear function. Upper and lower limits in water use efficiency, between 2.5 and 5.7 g DW/L, are linked to the irrigation strategies and crop seasons. Light use efficiency (LUE) under different conditions was also determined to predict plant dry matter and a unique value was obtained for the three substrates (LUE = 0.91 g/MJ). Three different irrigation strategies were proposed for each substrate as a function of intercepted radiation and defining an α coefficient (expressed in mm/m2/MJ) that coupled crop and climate components. These crop characterization and prediction tools could help to optimize plant growth and yield for environmentally friendly substrates.

Efficient Propagation Technique of Euphorbia ×lomi Thai Hybrids

A simple and efficient in vivo propagation protocol of two cultivars of Euphorbia ×lomi Rauh is described. Mother plants of ‘Nguen Muang’ and ‘Porn Ying Yai’ were soilless grown in 1 coconut coir dust:1 perlite (by volume) and 2 sphagnum peat:1 perlite (by volume) to produce cuttings. Plants cultured in peat-based substrate showed thicker stems (36.0 versus 30.5 mm, respectively), higher production of cuttings (10.4 versus 5.6 per plant), higher water absorption (265.7 versus 153.5 mL/plant/d), and higher content of nutrients in the root zone as compared with those cultivated in coir dust mixture. Cuttings harvested from 1-year-old mother plants of both cultivars were treated with 4000 ppm of α-naphthalene acetic acid (NAA) powder and inserted into bottom-heated benches filled with different substrates [perlite, 1 perlite:1 coir dust (by volume), coir dust] for rooting. Cuttings in pure perlite evidenced higher rooting percentage (86.2%) and longer roots (6.2 cm) than those in other media. Application of NAA resulted in higher rooting capacity (78.8 versus 68.3%, respectively) and higher amount of roots per cutting (13.4 versus 10.2) than treatment without auxin. Rooted cuttings grown in 1 peat:1 perlite medium (by volume) produced higher marketable potted plants than in 2 peat:1 perlite medium.

EL POLVO DE COCO COMO SUSTRATO ALTERNATIVO PARA LA OBTENCIÓN DE PLANTAS ORNAMENTALES PARA TRASPLANTE

The present experiment was carried out to evaluate the feasibility of using coconut coir dust as a growing medium for the germination and initial development of six ornamental plant species, and to determine the possibility to substitute Peat Moss. The species selected for the study were: Dianthus chinensis (Dianthus), Gazania rigens (Gazania), Tagetes erecta (Marigold), Viola wittrockiana (Pansy), Antirrhinum majus (Snapdragon), and Petunia x hybrida (Petunia). Seeds of the six species were germinated in coir dust, Peat Moss or Peat Lite. Previous seeding, the pH of coir dust was adjusted to 6.2 and it was amended with dolomitic limestone and KNO3 as nutrient charge. Afterwards, coir dust or Peat Moss was mixed with perlite and vermiculite at a 70:20:10 proportion (v/v), respectively. A randomized block design with three replications was selected to evaluate the effect of the growing media on plant height, shoot and root dry mass, germination rate and marketable ranking of plants. Shoot height of plants grown in coir dust was decreased significantly in gazania (21 %), snapdragons (30 %), and petunia (13 %), as well as shoot dry mass of snapdragons (24 %) and root dry mass of dianthus (22 %). Nonetheless, coir dust did not affect plug quality since the percent of marketable plugs and germination rate were comparable in coir dust and Peat Moss. It is concluded that coconut coir dust can be used as a growing medium in ornamental plug production and can substitute Peat Moss.

Wetting agent effect on physical properties of new and reused rockwool and coconut coir waste

Wettability of growing medium in horticulture is an important practical factor of this industry. With a proper choice and a right application, wetting agent in the nutrient solution would improve wettability and some other physical properties of growing media. The aim of this study was to evaluate the effects on some physical properties of new and reused rockwool and coconut coir dust substrates with different doses of wetting agent (2, 10, 20, 100, 200, 1000, 2000, 10,000 and 20,000 mg L −1) applied to the nutrient solution and their effects measured by using bioassays. The wetting agent was ether poly-ethylene-glycol nonil-phenol with 20% (w/v) as an active ingredient of a non-ionic surfactant. Bioassay results showed differences among species. For this, the method can be suggested as a good tool to be utilized through fertigation in soilless crops; however, other studies should be proposed for each species in particular. Except to the 2 mg L −1 wetting agent content in reused coir waste, the total water-holding capacity increased with the wetting agent. With 2 mg L −1 wetting agent content there was an important and significant increase the easily available water (over 600%) in both substrates (including the reused ones), while higher doses show no significant differences. The effect of adjuvants added through fertigation is directly dependant on the substrate type evaluated. The substrate reutilized after one crop, reduces the air capacity and increases the easily available water and total water-holding capacity. 2 mg L −1 is the wetting agent concentration more adequate in coir waste and rockwool.

Cultivo in vitro de embriões zigóticos e aclimatação de plântulas de coqueiro-anão

O objetivo deste trabalho foi ajustar os protocolos de cultivo in vitro de embriões zigóticos e de aclimatação de plântulas de coqueiro-anão-verde do Brasil de Jiqui (Cocos nucifera L.). Os embriões zigóticos maduros, colocados assepticamente em meio de cultura líquido Y3 suplementado com 27,8 mg L-1 de Fe2SO4.7H2O e 60 g L-1 de sacarose, apresentaram maior germinação e formação de plântulas normais. As plântulas transferidas para meio indutor de enraizamento Y3, gelificado e suplementado com 1 mg L-1 de ANA, 0,5 mg L-1 de BAP e 2,5 g L-1 de carvão ativado, apresentaram incremento do desenvolvimento radicular e da parte aérea. Na fase de aclimatação, o substrato composto por areia lavada e pó de casca de coco seco, na proporção de 1:1, proporcionou maior sobrevivência das plântulas (58,33%), maior crescimento da parte aérea (39,08 cm) e maior número de folhas (6,33). Os protocolos estabelecidos para o cultivo in vitro de embriões zigóticos e a aclimatação de coqueiro-anão-verde de Jiqui podem ser utilizados no intercâmbio e conservação de germoplasma.

Kinetic and calorimetric study of the adsorption of dyes on mesoporous activated carbon prepared from coconut coir dust

Mesoporous activated carbon has been prepared from coconut coir dust as support for adsorption of some model dye molecules from aqueous solutions. The methylene blue (MB) and remazol yellow (RY) molecules were chosen for study of the adsorption capacity of cationic and anionic dyes onto prepared activated carbon. The adsorption kinetics was studied with the Lagergren first- and pseudo-second-order kinetic models as well as the intraparticle diffusion model. The results for both dyes suggested a multimechanism sorption process. The adsorption mechanisms in the systems dyes/AC follow pseudo-second-order kinetics with a significant contribution of intraparticle diffusion. The samples simultaneously present acidic and basic sites able to act as anchoring sites for basic and acidic dyes, respectively. Calorimetric studies reveal that dyes/AC interaction forces are correlated with the pH of the solution, which can be related to the charge distribution on the AC surface. These AC samples also exhibited very short equilibrium times for the adsorption of both dyes, which is an economically favorable requisite for the activated carbon described in this work, in addition to the local abundance of the raw material.

Rice Straw Compost and Water Deficit Affect Yield, Quality and Water Use Efficiency (WUE) of Tomatoes Grown in Different Media

ABSTRACT The investigations on the utilization of rice straw compost aimed to evaluate its effect as an additive at 30% (v/v) under two stress cycles with two growing media, soilless media (coconut coir dust and peat 3:2) and greenhouse soil (top soil, sand and peat 2:1:2) on yield, quality components and water use efficiency (WUE) of tomato grown under a protected environment. The addition of rice straw compost at 30% (v/v), significantly (p < 0.05) increased plant dry biomass, fruit diameter, yield and WUE in both media, whereas the water deficit significantly (p < 0.05) decreased these parameters in most of the treatments. Soilless media amended with rice straw compost resulted in the greatest water use efficiency. The application of rice straw compost, however, had the opposite effect on total organic matter in the two media. The total organic matter significantly (p < 0.05) increased in the greenhouse soil, while it significantly (p < 0.05) decreased in the soilless media. Days to 100% wilt were significantly positively correlated (R2= 0.90) with the total organic carbon of the media so that increases in total organic matter resulted in decreases in the number of days to 100% wilt of plant. Thus, whenever the total organic matter increased, decreases in the loss of media moisture content occurred. Utilization of rice straw compost, as an additive for growing media at 30%, significantly increased total yield and WUE by up to 70% and 34% for soilless and greenhouse soil, respectively.

INFLUENCE OF DIFFERENT SUBSTRATES AND NUTRIENT SOLUTIONS ON THE YIELDS AND THE INCIDENCE OF ABIOTIC DISORDERS OF BROCCOLI

INFLUENCE OF DIFFERENT SUBSTRATES AND NUTRIENT SOLUTIONS ON THE YIELDS AND THE INCIDENCE OF ABIOTIC DISORDERS OF BROCCOLI

YIELD, WATER USE AND NUTRIENT UPTAKE OF A TOMATO CROP GROWN ON COCONUT COIR DUST

YIELD, WATER USE AND NUTRIENT UPTAKE OF A TOMATO CROP GROWN ON COCONUT COIR DUST

Terrestrische ökotoxikologische Testmethoden für die Tropen

Goal, Scope, and BackgroundSoil organisms play a crucial role in the terrestrial ecosystem. Plant Protection Products (PPPs) are known to affect soil organisms and might have negative impacts on soil functions influenced by these organisms. Little research has been done to day on the impact of PPs on tropical ecosystems. Therefore, in this study it was investigated whether fate and effects of pesticides differ between tropical and temperate regions and whether data generated under temperate conditions can be used for the Environmental Risk Assessment (ERA) in tropical regions.MethodsIn the first part of this study, the effects of two fungicides (Benomyl and Carbendazim) and one insecticide (lambda-Cyhalothrin) on soil invertebrates (i.e. earthworms and arthropods) were evaluated in laboratory tests modified for tropical conditions (temperature, soil, test species). Besides using some native species, the tests were done mainly with two (temperate and tropical) strains of earthworms (Eisenia fetida) and the peregrine isopod speciesPorcellionides pruinosus as standard test species. The chemicals were spiked in two natural and two artificial soils. A tropical artificial soil (TAS), containing a tropical fern product (Xaxim) or coconut coir dust as organic matter, was developed in this study.Results and ConclusionsThe results from the laboratory tests showed that all three test chemicals differed from those gained under temperate conditions. In the case of the fungicides the toxicity was lower but in the case of the insecticide higher under tropical than under temperate conditions. The native tropical earthwormPontoscolex corethrurus reacted more sensitively against Carbendazim in comparison to the standard test speciesEisenia fetida.Recommendation and PerspectiveDetails of the environmental risk assessment of the three model chemicals based on the results of the laboratory described here (and including the results of higher tier tests (semi-field and field tests)) will be described in Part 2 of this series

Influence of Particle Size on Physical and Chemical Properties of Coconut Coir Dust as Container Medium

The influence of particle size (diameter between <0.125 mm and >2 mm) on the physical, physico-chemical and chemical properties of a coconut coir dust from Mexico was studied. Particle size significantly affected the physical properties, especially the air–water relationships. Air content increased and water-holding capacity (total and readily available) decreased with increasing particle diameter. The easily-available water content did not reveal a clear pattern of variation, showing the largest value in the fraction 0.125–0.25 mm. Particle size equivalent to 0.5 mm brought about an important and highly significant change in the physical properties studied. Coconut coir dust particle size also affected the physico-chemical and chemical characteristics, but to a lesser degree. Both the electrical conductivity and the available macro- and micro-element concentrations were significantly higher in the smaller size ranges, the largest values being obtained in the finest particle size fraction (<0.125 mm).

Effect of Soilless Potting Media and Water Management on Development of Fungus Gnats (Diptera: Sciaridae) and Plant Growth

Coconut coir dust is being marketed as a soilless medium substitute for sphagnum peat moss that inhibits fungus gnat (Bradysia sp.) development. However, little information is available on the effects of coconut coir dust on Bradysia sp. In a laboratory study we examined the effect of substituting coconut coir dust for peat moss, with or without a food source, on the development of fungus gnats. An average of less than one adult emerged when 20 fungus gnat eggs were provided with pure or sterilized peat moss or coconut coir. A significantly higher number of adults (11.5-13) emerged when a food source of 1 g of yeast was added to either soilless potting medium type. The adults required up to 10 fewer days to emerge when food was provided, compared to sterilized and pure media, except for the pure peat moss. In a greenhouse study examining the effects of coir and peat at different textures and different moisture levels on fungus gnat survival, there were significant differences at the different levels of moisture. There was a higher population of larvae in the coarse medium containing peat. In the coir-based media, the fine-textured medium had the highest population level of fungus gnats. There were no significant effects on fungus gnat populations among the different levels of moisture within a medium type. However, there was a tendency for lower populations in the most moist and the driest media and the highest survival in the media that were maintained at 52.5% moisture. Plant growth was best in the media with the lowest number of fungus gnats (coarse coconut coir dust-based and fine and medium peat-based media). These results suggest that it is possible to select growing media that minimize fungus gnat populations, while optimizing plant growth. However, contrary to claims made by growing media producers, coconut coir dust does not necessarily inhibit fungus gnat development.

Enhancing root systems of waiting-bed strawberry plants grown on substrates

SummaryTo find techniques to improve root system development of waiting-bed strawberry plants ‘Camarosa’ grown in substrates, the influence of two substrates (peat and coconut coir dust), or plants from three waiting-beds at different altitudes, and of root treatments with different plant growth regulators (naphthalenacetic acid at 25, 50 and 75 mg g–1; indolebutyric acid at 10, 20 and 30 mg g–1; l-triacontanol at 0.02, 0.04 and 0.06 mg g–1) by dipping runners prior to planting, were studied in two experiments in the 1997–98 and 1998–99 seasons. In both years, plants from high elevation beds (HE) produced the greatest root development, and plants from medium elevation beds (ME) produced more new roots than those from low elevation beds (LE). Root development of plants grown in peat was greater than those grown in coconut coir dust in the first experiment and only on the first measuring dates (one month after planting). This difference was particularly high in plants from high or medium elevation nurseries, when the degree of root development was greater. No differences between substrates were observed in the second experiment. Treatments with the different growth regulators tested, at any of the concentrations used, did not improve root development on average for the other factors.

Physico-chemical and chemical properties of some coconut coir dusts for use as a peat substitute for containerised ornamental plants

Selected physico-chemical and chemical characteristics of 13 coconut coir dust (mesocarp pithy tissue plus short-length fibres) samples from Asia, America and Africa were evaluated as peat alternatives. All properties studied differed significantly between and within sources, and from the control Sphagnum peat. pH of coir dust was slightly acidic, whereas salinity varied dramatically between 39 and 597 mS m −1 in the saturated media extract. The cation exchange capacity and carbon/nitrogen (C/N) ratio ranged from 31.7 to 95.4 cmol c kg −1 and from 75 to 186, respectively. Most carbon was found as lignin and cellulose. The concentrations of available nitrogen, calcium, magnesium and micro-elements were low, while those of phosphorus and potassium were remarkably high (0.28–2.81 mol m −3 and 2.97–52.66 mol m −3 for P and K, respectively). Saline ion concentrations, especially chloride and sodium, were also high.